move png support to separate file

git-svn-id: svn://svn.icculus.org/quake3/trunk@1253 edf5b092-35ff-0310-97b2-ce42778d08ea

3 files changed, 2468 insertions, 2447 deletions

diff --git a/code/renderer/tr_image.c b/code/renderer/tr_image.c
index 37b91c2..5812228 100644
--- a/code/renderer/tr_image.c
+++ b/code/renderer/tr_image.c
@@ -33,13 +33,11 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #define JPEG_INTERNALS
 #include "../jpeg-6/jpeglib.h"
 
-#include "../qcommon/puff.h"
-
+#include "tr_image_png.h"
 
 static void LoadBMP( const char *name, byte **pic, int *width, int *height );
 static void LoadTGA( const char *name, byte **pic, int *width, int *height );
 static void LoadJPG( const char *name, byte **pic, int *width, int *height );
-static void LoadPNG( const char *name, byte **pic, int *width, int *height );
 
 static byte			 s_intensitytable[256];
 static unsigned char s_gammatable[256];
@@ -1931,2450 +1929,6 @@ int SaveJPGToBuffer( byte *buffer, int quality,
 
 //===================================================================
 
-/*
-=================
-PNG LOADING
-=================
-*/
-
-/*
- *  Quake 3 image format : RGBA
- */
-
-#define Q3IMAGE_BYTESPERPIXEL (4)
-
-/*
- *  PNG specifications
- */
-
-/*
- *  The first 8 Bytes of every PNG-File are a fixed signature
- *  to identify the file as a PNG.
- */
-
-#define PNG_Signature "\x89\x50\x4E\x47\xD\xA\x1A\xA"
-#define PNG_Signature_Size (8)
-
-/*
- *  After the signature diverse chunks follow.
- *  A chunk consists of a header and if Length
- *  is bigger than 0 a body and a CRC of the body follow.
- */
-
-struct PNG_ChunkHeader
-{
-    uint32_t Length;
-    uint32_t Type;
-};
-
-#define PNG_ChunkHeader_Size (8)
-
-typedef uint32_t PNG_ChunkCRC;
-
-#define PNG_ChunkCRC_Size (4)
-
-/*
- *  We use the following ChunkTypes.
- *  All others are ignored.
- */
-
-#define MAKE_CHUNKTYPE(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | ((d)))
-
-#define PNG_ChunkType_IHDR MAKE_CHUNKTYPE('I', 'H', 'D', 'R')
-#define PNG_ChunkType_PLTE MAKE_CHUNKTYPE('P', 'L', 'T', 'E')
-#define PNG_ChunkType_IDAT MAKE_CHUNKTYPE('I', 'D', 'A', 'T')
-#define PNG_ChunkType_IEND MAKE_CHUNKTYPE('I', 'E', 'N', 'D')
-#define PNG_ChunkType_tRNS MAKE_CHUNKTYPE('t', 'R', 'N', 'S')
-
-/*
- *  Per specification the first chunk after the signature SHALL be IHDR.
- */
-
-struct PNG_Chunk_IHDR
-{
-    uint32_t Width;
-    uint32_t Height;
-    uint8_t  BitDepth;
-    uint8_t  ColourType;
-    uint8_t  CompressionMethod;
-    uint8_t  FilterMethod;
-    uint8_t  InterlaceMethod;
-};
-
-#define PNG_Chunk_IHDR_Size (13)
-
-/*
- *  ColourTypes
- */
-
-#define PNG_ColourType_Grey      (0)
-#define PNG_ColourType_True      (2)
-#define PNG_ColourType_Indexed   (3)
-#define PNG_ColourType_GreyAlpha (4)
-#define PNG_ColourType_TrueAlpha (6)
-
-/*
- *  number of colour components
- *
- *  Grey      : 1 grey
- *  True      : 1 R, 1 G, 1 B
- *  Indexed   : 1 index
- *  GreyAlpha : 1 grey, 1 alpha
- *  TrueAlpha : 1 R, 1 G, 1 B, 1 alpha
- */
-
-#define PNG_NumColourComponents_Grey      (1)
-#define PNG_NumColourComponents_True      (3)
-#define PNG_NumColourComponents_Indexed   (1)
-#define PNG_NumColourComponents_GreyAlpha (2)
-#define PNG_NumColourComponents_TrueAlpha (4)
-
-/*
- *  For the different ColourTypes
- *  different BitDepths are specified.
- */
-
-#define PNG_BitDepth_1  ( 1)
-#define PNG_BitDepth_2  ( 2)
-#define PNG_BitDepth_4  ( 4)
-#define PNG_BitDepth_8  ( 8)
-#define PNG_BitDepth_16 (16)
-
-/*
- *  Only one valid CompressionMethod is standardized.
- */
-
-#define PNG_CompressionMethod_0 (0)
-
-/*
- *  Only one valid FilterMethod is currently standardized.
- */
-
-#define PNG_FilterMethod_0 (0)
-
-/*
- *  This FilterMethod defines 5 FilterTypes
- */
-
-#define PNG_FilterType_None    (0)
-#define PNG_FilterType_Sub     (1)
-#define PNG_FilterType_Up      (2)
-#define PNG_FilterType_Average (3)
-#define PNG_FilterType_Paeth   (4)
-
-/*
- *  Two InterlaceMethods are standardized :
- *  0 - NonInterlaced
- *  1 - Interlaced
- */
-
-#define PNG_InterlaceMethod_NonInterlaced (0)
-#define PNG_InterlaceMethod_Interlaced    (1)
-
-/*
- *  The Adam7 interlace method uses 7 passes.
- */
-
-#define PNG_Adam7_NumPasses (7)
-
-/*
- *  The compressed data starts with a header ...
- */
-
-struct PNG_ZlibHeader
-{
-    uint8_t CompressionMethod;
-    uint8_t Flags;
-};
-
-#define PNG_ZlibHeader_Size (2)
-
-/*
- *  ... and is followed by a check value
- */
-
-#define PNG_ZlibCheckValue_Size (4)
-
-/*
- *  Some support functions for buffered files follow.
- */
-
-/*
- *  buffered file representation
- */
-
-struct BufferedFile
-{
-    byte *Buffer;
-    int   Length;
-    byte *Ptr;
-    int   BytesLeft;
-};
-
-/*
- *  Read a file into a buffer.
- */
-
-static struct BufferedFile *ReadBufferedFile(const char *name)
-{
-    struct BufferedFile *BF;
-
-    /*
-     *  input verification
-     */
-
-    if(!name)
-    {
-        return(NULL);
-    }
-
-    /*
-     *  Allocate control struct.
-     */
-
-    BF = ri.Malloc(sizeof(struct BufferedFile));
-    if(!BF)
-    {
-        return(NULL);
-    }
-
-    /*
-     *  Initialize the structs components.
-     */
-
-    BF->Length    = 0;
-    BF->Buffer    = NULL;
-    BF->Ptr       = NULL;
-    BF->BytesLeft = 0;
-
-    /*
-     *  Read the file.
-     */
-
-    BF->Length = ri.FS_ReadFile((char *) name, (void **) &BF->Buffer);
-
-    /*
-     *  Did we get it? Is it big enough?
-     */
-
-    if(!(BF->Buffer && (BF->Length > 0)))
-    {
-        ri.Free(BF);
-
-        return(NULL);
-    }
-
-    /*
-     *  Set the pointers and counters.
-     */
-
-    BF->Ptr       = BF->Buffer;
-    BF->BytesLeft = BF->Length;
-
-    return(BF);
-}
-
-/*
- *  Close a buffered file.
- */
-
-static void CloseBufferedFile(struct BufferedFile *BF)
-{
-    if(BF)
-    {
-        if(BF->Buffer)
-        {
-            ri.FS_FreeFile(BF->Buffer);
-        }
- 
-        ri.Free(BF);
-    }
-}
-
-/*
- *  Get a pointer to the requested bytes.
- */
-
-static void *BufferedFileRead(struct BufferedFile *BF, int Length)
-{
-    void *RetVal;
-
-    /*
-     *  input verification
-     */
-
-    if(!(BF && Length))
-    {
-        return(NULL);
-    }
- 
-    /*
-     *  not enough bytes left
-     */
-
-    if(Length > BF->BytesLeft)
-    {
-        return(NULL);
-    }
-
-    /*
-     *  the pointer to the requested data
-     */
-
-    RetVal = BF->Ptr;
- 
-    /*
-     *  Raise the pointer and counter.
-     */
-
-    BF->Ptr       += Length;
-    BF->BytesLeft -= Length;
-
-    return(RetVal);
-}
-
-/*
- *  Rewind the buffer.
- */
-
-static qboolean BufferedFileRewind(struct BufferedFile *BF, int Offset)
-{
-    int BytesRead; 
-
-    /*
-     *  input verification
-     */
-
-    if(!BF)
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  special trick to rewind to the beginning of the buffer
-     */
-
-    if(Offset == -1)
-    {
-        BF->Ptr       = BF->Buffer;
-        BF->BytesLeft = BF->Length;
-  
-        return(qtrue);
-    }
-
-    /*
-     *  How many bytes do we have already read?
-     */
-
-    BytesRead = BF->Ptr - BF->Buffer;
-
-    /*
-     *  We can only rewind to the beginning of the BufferedFile.
-     */
-
-    if(Offset > BytesRead)
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  lower the pointer and counter.
-     */
-
-    BF->Ptr       -= Offset;
-    BF->BytesLeft += Offset;
-
-    return(qtrue);
-}
-
-/*
- *  Skip some bytes.
- */
-
-static qboolean BufferedFileSkip(struct BufferedFile *BF, int Offset)
-{
-    /*
-     *  input verification
-     */
-
-    if(!BF)
-    {
-        return(qfalse);
-    }
- 
-    /*
-     *  We can only skip to the end of the BufferedFile.
-     */
-
-    if(Offset > BF->BytesLeft)
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  lower the pointer and counter.
-     */
-
-    BF->Ptr       += Offset;
-    BF->BytesLeft -= Offset;
-
-    return(qtrue);
-}
-
-/*
- *  Find a chunk
- */
-
-static qboolean FindChunk(struct BufferedFile *BF, uint32_t ChunkType)
-{
-    struct PNG_ChunkHeader *CH;
-
-    uint32_t Length;
-    uint32_t Type;
-
-    /*
-     *  input verification
-     */
-
-    if(!BF)
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  cycle trough the chunks
-     */
-
-    while(qtrue)
-    {
-        /*
-         *  Read the chunk-header.
-         */
-
-        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
-        if(!CH)
-        {
-            return(qfalse);
-        }
-
-        /*
-         *  Do not swap the original types
-         *  they might be needed later.
-         */
-
-        Length = BigLong(CH->Length);
-        Type   = BigLong(CH->Type);
-  
-        /*
-         *  We found it!
-         */
-
-        if(Type == ChunkType)
-        {
-            /*
-             *  Rewind to the start of the chunk.
-             */
-	     
-            BufferedFileRewind(BF, PNG_ChunkHeader_Size);
-  
-            break;
-        }
-        else
-        {
-            /*
-             *  Skip the rest of the chunk.
-             */
-
-            if(Length)
-            {
-                if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
-                {
-                    return(qfalse);
-                }  
-            }
-        }
-    }
-
-    return(qtrue);
-}
-
-/*
- *  Decompress all IDATs
- */
-
-static uint32_t DecompressIDATs(struct BufferedFile *BF, uint8_t **Buffer)
-{
-    uint8_t  *DecompressedData;
-    uint32_t  DecompressedDataLength;
-
-    uint8_t  *CompressedData;
-    uint8_t  *CompressedDataPtr;
-    uint32_t  CompressedDataLength;
-
-    struct PNG_ChunkHeader *CH;
-
-    uint32_t Length;
-    uint32_t Type;
-
-    int BytesToRewind;
-
-    int32_t   puffResult;
-    uint8_t  *puffDest;
-    uint32_t  puffDestLen;
-    uint8_t  *puffSrc;
-    uint32_t  puffSrcLen;
-
-    /*
-     *  input verification
-     */
-
-    if(!(BF && Buffer))
-    {
-        return(-1);
-    }
-
-    /*
-     *  some zeroing
-     */
-
-    DecompressedData = NULL;
-    DecompressedDataLength = 0;
-    *Buffer = DecompressedData;
-
-    CompressedData = NULL;
-    CompressedDataLength = 0;
-
-    BytesToRewind = 0;
-
-    /*
-     *  Find the first IDAT chunk.
-     */
-
-    if(!FindChunk(BF, PNG_ChunkType_IDAT))
-    {
-        return(-1);
-    }
-
-    /*
-     *  Count the size of the uncompressed data
-     */
-
-    while(qtrue)
-    {
-        /*
-         *  Read chunk header
-         */
-
-        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
-        if(!CH)
-        {
-            /*
-             *  Rewind to the start of this adventure
-             *  and return unsuccessfull
-             */
-
-            BufferedFileRewind(BF, BytesToRewind);
-
-            return(-1);
-        }
-
-        /*
-         *  Length and Type of chunk
-         */
-
-        Length = BigLong(CH->Length);
-        Type   = BigLong(CH->Type);
-
-        /*
-         *  We have reached the end of the IDAT chunks
-         */
-
-        if(!(Type == PNG_ChunkType_IDAT))
-        {
-            BufferedFileRewind(BF, PNG_ChunkHeader_Size); 
-  
-            break;
-        }
-
-        /*
-         *  Add chunk header to count.
-         */
-
-        BytesToRewind += PNG_ChunkHeader_Size;
-
-        /*
-         *  Skip to next chunk
-         */
-
-        if(Length)
-        {
-            if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
-            {
-                BufferedFileRewind(BF, BytesToRewind);
-
-                return(-1);
-            }
-
-            BytesToRewind += Length + PNG_ChunkCRC_Size;
-            CompressedDataLength += Length;
-        } 
-    }
-
-    BufferedFileRewind(BF, BytesToRewind);
-
-    CompressedData = ri.Malloc(CompressedDataLength);
-    if(!CompressedData)
-    {
-        return(-1);
-    }
- 
-    CompressedDataPtr = CompressedData;
-
-    /*
-     *  Collect the compressed Data
-     */
-
-    while(qtrue)
-    {
-        /*
-         *  Read chunk header
-         */
-
-        CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
-        if(!CH)
-        {
-            ri.Free(CompressedData); 
-  
-            return(-1);
-        }
-
-        /*
-         *  Length and Type of chunk
-         */
-
-        Length = BigLong(CH->Length);
-        Type   = BigLong(CH->Type);
-
-        /*
-         *  We have reached the end of the IDAT chunks
-         */
-
-        if(!(Type == PNG_ChunkType_IDAT))
-        {
-            BufferedFileRewind(BF, PNG_ChunkHeader_Size); 
-  
-            break;
-        }
-
-        /*
-         *  Copy the Data
-         */
-
-        if(Length)
-        {
-            uint8_t *OrigCompressedData;
-   
-            OrigCompressedData = BufferedFileRead(BF, Length);
-            if(!OrigCompressedData)
-            {
-                ri.Free(CompressedData); 
-  
-                return(-1);
-            }
-
-            if(!BufferedFileSkip(BF, PNG_ChunkCRC_Size))
-            {
-                ri.Free(CompressedData); 
-
-                return(-1);
-            }
-  
-            memcpy(CompressedDataPtr, OrigCompressedData, Length);
-            CompressedDataPtr += Length;
-        } 
-    }
-
-    /*
-     *  Let puff() calculate the decompressed data length.
-     */
-
-    puffDest    = NULL;
-    puffDestLen = 0;
- 
-    /*
-     *  The zlib header and checkvalue don't belong to the compressed data.
-     */
-
-    puffSrc    = CompressedData + PNG_ZlibHeader_Size;
-    puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
-
-    /*
-     *  first puff() to calculate the size of the uncompressed data
-     */
-
-    puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
-    if(!((puffResult == 0) && (puffDestLen > 0)))
-    {
-        ri.Free(CompressedData);
- 
-        return(-1);
-    }
-
-    /*
-     *  Allocate the buffer for the uncompressed data.
-     */
-
-    DecompressedData = ri.Malloc(puffDestLen);
-    if(!DecompressedData)
-    {
-        ri.Free(CompressedData);
- 
-        return(-1);
-    }
-
-    /*
-     *  Set the input again in case something was changed by the last puff() .
-     */
-
-    puffDest   = DecompressedData;
-    puffSrc    = CompressedData + PNG_ZlibHeader_Size;
-    puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
- 
-    /*
-     *  decompression puff()
-     */
-
-    puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
-
-    /*
-     *  The compressed data is not needed anymore.
-     */
-
-    ri.Free(CompressedData);
-
-    /*
-     *  Check if the last puff() was successfull.
-     */
-
-    if(!((puffResult == 0) && (puffDestLen > 0)))
-    {
-        ri.Free(DecompressedData);
- 
-        return(-1);
-    }
-
-    /*
-     *  Set the output of this function.
-     */
-
-    DecompressedDataLength = puffDestLen;
-    *Buffer = DecompressedData;
-
-    return(DecompressedDataLength);
-}
-
-/*
- *  the Paeth predictor
- */
-
-static uint8_t PredictPaeth(uint8_t a, uint8_t b, uint8_t c)
-{
-    /*
-     *  a == Left
-     *  b == Up
-     *  c == UpLeft
-     */
-
-    uint8_t Pr;
-    int p;
-    int pa, pb, pc;
-
-    Pr = 0;
-
-    p  = ((int) a) + ((int) b) - ((int) c);
-    pa = abs(p - ((int) a));
-    pb = abs(p - ((int) b));
-    pc = abs(p - ((int) c));
-
-    if((pa <= pb) && (pa <= pc))
-    {
-        Pr = a;
-    }
-    else if(pb <= pc)
-    {
-        Pr = b;
-    }
-    else
-    {
-        Pr = c;
-    }
-
-    return(Pr);
-
-}
-
-/*
- *  Reverse the filters.
- */
-
-static qboolean UnfilterImage(uint8_t  *DecompressedData, 
-                              uint32_t  ImageHeight,
-		              uint32_t  BytesPerScanline, 
-		              uint32_t  BytesPerPixel)
-{
-    uint8_t   *DecompPtr;
-    uint8_t   FilterType;
-    uint8_t  *PixelLeft, *PixelUp, *PixelUpLeft;
-    uint32_t  w, h, p;
-
-    /*
-     *  some zeros for the filters
-     */
-
-    uint8_t Zeros[8] = {0, 0, 0, 0, 0, 0, 0, 0};
-
-    /*
-     *  input verification
-     *
-     *  ImageHeight and BytesPerScanline are not checked,
-     *  because these can be zero in some interlace passes.
-     */
-
-    if(!(DecompressedData && BytesPerPixel))
-    {
-	return(qfalse);
-    }
-
-
-    /*
-     *  Set the pointer to the start of the decompressed Data.
-     */
-
-    DecompPtr = DecompressedData;
-
-    /*
-     *  Un-filtering is done in place.
-     */
-
-    /*
-     *  Go trough all scanlines.
-     */
-
-    for(h = 0; h < ImageHeight; h++)
-    {
-        /*
-         *  Every scanline starts with a FilterType byte.
-         */
-
-        FilterType = *DecompPtr;
-        DecompPtr++;
-
-        /*
-         *  Left pixel of the first byte in a scanline is zero.
-         */
-
-        PixelLeft = Zeros;
-
-        /*
-         *  Set PixelUp to previous line only if we are on the second line or above.
-         *
-         *  Plus one byte for the FilterType
-         */
-
-        if(h > 0)
-        {
-            PixelUp = DecompPtr - (BytesPerScanline + 1);
-        }
-        else
-        {
-            PixelUp = Zeros;
-        }
-
-        /*
-         * The pixel left to the first pixel of the previous scanline is zero too.
-         */
-
-        PixelUpLeft = Zeros;
-
-        /*
-         *  Cycle trough all pixels of the scanline.
-         */
-
-        for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
-        {
-            /*
-             *  Cycle trough the bytes of the pixel.
-             */
-
-            for(p = 0; p < BytesPerPixel; p++)
-            {
-                switch(FilterType)
-                { 
-                    case PNG_FilterType_None :
-                    {
-                        /*
-                         *  The byte is unfiltered.
-                         */
-
-                        break;
-                    }
-
-                    case PNG_FilterType_Sub :
-                    {
-                        DecompPtr[p] += PixelLeft[p];
-
-                        break;
-                    }
-
-		    case PNG_FilterType_Up :
-                    {
-                        DecompPtr[p] += PixelUp[p];
-
-                        break;
-                    }
-
-                    case PNG_FilterType_Average :
-                    {
-                        DecompPtr[p] += ((uint8_t) ((((uint16_t) PixelLeft[p]) + ((uint16_t) PixelUp[p])) / 2));
-
-                        break;
-                    }
-
-                    case PNG_FilterType_Paeth :
-                    {
-                        DecompPtr[p] += PredictPaeth(PixelLeft[p], PixelUp[p], PixelUpLeft[p]);
-
-                        break;
-                    }
-
-                    default :
-                    {
-                        return(qfalse);
-                    }
-                }
-            }
-   
-            PixelLeft = DecompPtr;
-
-            /*
-             *  We only have a upleft pixel if we are on the second line or above.
-             */
-
-            if(h > 0)
-            {
-                PixelUpLeft = DecompPtr - (BytesPerScanline + 1);
-            }
-
-	    /*
-             *  Skip to the next pixel.
-             */
-
-            DecompPtr += BytesPerPixel;
-	 
-            /*
-             *  We only have a previous line if we are on the second line and above.
-             */
-
-            if(h > 0)
-            {
-                PixelUp = DecompPtr - (BytesPerScanline + 1);
-            }
-        }
-    }
-
- return(qtrue);
-}
-
-/*
- *  Convert a raw input pixel to Quake 3 RGA format.
- */
-
-static qboolean ConvertPixel(struct PNG_Chunk_IHDR *IHDR,
-			     byte                  *OutPtr,
-			     uint8_t               *DecompPtr,
-                             qboolean               HasTransparentColour,
-                             uint8_t               *TransparentColour,
-                             uint8_t               *OutPal)
-{
-    /*
-     *  input verification
-     */
-    
-    if(!(IHDR && OutPtr && DecompPtr && TransparentColour && OutPal))
-    {
-     return(qfalse);
-    }
-
-    switch(IHDR->ColourType)
-    {
-        case PNG_ColourType_Grey :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_1 :
-                case PNG_BitDepth_2 :
-                case PNG_BitDepth_4 :
-                {
-    		    uint8_t Step;
-                    uint8_t GreyValue;
-
-                    Step = 0xFF / ((1 << IHDR->BitDepth) - 1);
-
-                    GreyValue = DecompPtr[0] * Step;
-  
-                    OutPtr[0] = GreyValue;
-                    OutPtr[1] = GreyValue;
-                    OutPtr[2] = GreyValue;
-                    OutPtr[3] = 0xFF;
-
-                    /*
-                     *  Grey supports full transparency for one specified colour
-                     */
-
-                    if(HasTransparentColour)
-                    {
-                        if(TransparentColour[1] == DecompPtr[0])
-                        {
-                            OutPtr[3] = 0x00;
-                        }
-                    }
-	
-
-                    break;
-                }
-      
-                case PNG_BitDepth_8 :
-                case PNG_BitDepth_16 :
-                {
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[0];
-                    OutPtr[2] = DecompPtr[0];
-                    OutPtr[3] = 0xFF;
-      
-                    /*
-                     *  Grey supports full transparency for one specified colour
-                     */
-
-                    if(HasTransparentColour)
-                    {
-                        if(IHDR->BitDepth == PNG_BitDepth_8)
-                        {
-                            if(TransparentColour[1] == DecompPtr[0])
-                            {
-                                OutPtr[3] = 0x00;
-                            }
-                        }
-                        else
-                        {
-                            if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]))
-                            {
-                                OutPtr[3] = 0x00;
-                            }
-                        }
-                    }
-
-                    break;
-                }
-      
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-    
-            break;
-        }
-
-        case PNG_ColourType_True :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                {
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[1];
-                    OutPtr[2] = DecompPtr[2];
-                    OutPtr[3] = 0xFF;
-      
-                    /*
-                     *  True supports full transparency for one specified colour
-                     */
-
-                    if(HasTransparentColour)
-                    {
-                        if((TransparentColour[1] == DecompPtr[0]) &&
-                           (TransparentColour[3] == DecompPtr[1]) &&
-                           (TransparentColour[5] == DecompPtr[3]))
-                        {
-                            OutPtr[3] = 0x00;
-                        }
-                    }
-
-                    break;
-                }
-      
-                case PNG_BitDepth_16 :
-                {
-                    /*
-                     *  We use only the upper byte.
-                     */
-
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[2];
-                    OutPtr[2] = DecompPtr[4];
-                    OutPtr[3] = 0xFF;
-      
-                    /*
-                     *  True supports full transparency for one specified colour
-                     */
-
-                    if(HasTransparentColour)
-                    {
-                        if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]) &&
-                           (TransparentColour[2] == DecompPtr[2]) && (TransparentColour[3] == DecompPtr[3]) &&
-                           (TransparentColour[4] == DecompPtr[4]) && (TransparentColour[5] == DecompPtr[5]))
-                        {
-                            OutPtr[3] = 0x00;
-                        }
-                    }
-
-                    break;
-                }
-
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-
-            break;
-        }
-
-        case PNG_ColourType_Indexed :
-        {
-            OutPtr[0] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 0];
-            OutPtr[1] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 1];
-            OutPtr[2] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 2];
-            OutPtr[3] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 3];
-	
-            break;
-        }
-
-        case PNG_ColourType_GreyAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                {
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[0];
-                    OutPtr[2] = DecompPtr[0];
-                    OutPtr[3] = DecompPtr[1];
-      
-                    break;
-                }
-  
-                case PNG_BitDepth_16 :
-                {
-                    /*
-                     *  We use only the upper byte.
-                     */
-
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[0];
-                    OutPtr[2] = DecompPtr[0];
-                    OutPtr[3] = DecompPtr[2];
-      
-                    break;
-                }
-
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-
-            break;
-        }
-
-        case PNG_ColourType_TrueAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                {
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[1];
-                    OutPtr[2] = DecompPtr[2];
-                    OutPtr[3] = DecompPtr[3];
-      
-                    break;
-                }
-      
-                case PNG_BitDepth_16 :
-                {
-                    /*
-                     *  We use only the upper byte.
-                     */
-
-                    OutPtr[0] = DecompPtr[0];
-                    OutPtr[1] = DecompPtr[2];
-                    OutPtr[2] = DecompPtr[4];
-                    OutPtr[3] = DecompPtr[6];
-      
-                    break;
-                }
-
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-
-            break;
-        }
-
-        default :
-        {
-            return(qfalse);
-        }
-    }
-
-    return(qtrue);
-}
-
-
-/*
- *  Decode a non-interlaced image.
- */
-
-static qboolean DecodeImageNonInterlaced(struct PNG_Chunk_IHDR *IHDR,
-                                         byte                  *OutBuffer, 
-                                         uint8_t               *DecompressedData,
-                                         uint32_t               DecompressedDataLength,
-                                         qboolean               HasTransparentColour,
-                                         uint8_t               *TransparentColour,
-                                         uint8_t               *OutPal)
-{
-    uint32_t IHDR_Width;
-    uint32_t IHDR_Height;
-    uint32_t BytesPerScanline, BytesPerPixel, PixelsPerByte;
-    uint32_t  w, h, p;
-    byte *OutPtr;
-    uint8_t *DecompPtr;
-
-    /*
-     *  input verification
-     */
-
-    if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
-    {
-	return(qfalse);
-    }
-
-    /*
-     *  byte swapping
-     */
-     
-    IHDR_Width  = BigLong(IHDR->Width);
-    IHDR_Height = BigLong(IHDR->Height);
-
-    /*
-     *  information for un-filtering
-     */
-
-    switch(IHDR->ColourType)
-    {
-        case PNG_ColourType_Grey :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_1 :
-                case PNG_BitDepth_2 :
-                case PNG_BitDepth_4 :
-                {
-                    BytesPerPixel    = 1;
-                    PixelsPerByte    = 8 / IHDR->BitDepth;
-
-                    break;
-                }
-
-                case PNG_BitDepth_8  :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-  
-        case PNG_ColourType_True :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8  :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-     
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_Indexed :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_1 :
-                case PNG_BitDepth_2 :
-                case PNG_BitDepth_4 :
-                {
-                    BytesPerPixel    = 1;
-                    PixelsPerByte    = 8 / IHDR->BitDepth;
-
-                    break;
-                }
-
-                case PNG_BitDepth_8 :
-                {
-                    BytesPerPixel    = PNG_NumColourComponents_Indexed;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-         
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_GreyAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-     
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_TrueAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-    
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-
-            break;
-        }
-
-        default :
-        {
-            return(qfalse);
-        }
-    }
-
-    /*
-     *  Calculate the size of one scanline
-     */
-
-    BytesPerScanline = (IHDR_Width * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
-
-    /*
-     *  Check if we have enough data for the whole image.
-     */
-
-    if(!(DecompressedDataLength == ((BytesPerScanline + 1) * IHDR_Height)))
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  Unfilter the image.
-     */
-
-    if(!UnfilterImage(DecompressedData, IHDR_Height, BytesPerScanline, BytesPerPixel))
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  Set the working pointers to the beginning of the buffers.
-     */
-
-    OutPtr = OutBuffer;
-    DecompPtr = DecompressedData;
-
-    /*
-     *  Create the output image.
-     */
-
-    for(h = 0; h < IHDR_Height; h++)
-    {
-        /*
-         *  Count the pixels on the scanline for those multipixel bytes
-         */
-
-        uint32_t CurrPixel;
-  
-        /*
-         *  skip FilterType
-         */
-
-        DecompPtr++;
-
-        /*
-         *  Reset the pixel count.
-         */
-
-        CurrPixel = 0;
-
-        for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
-        {
-	    if(PixelsPerByte > 1)
-	    {
-                uint8_t  Mask;
-                uint32_t Shift;
-		uint8_t  SinglePixel;
-
-                for(p = 0; p < PixelsPerByte; p++)
-                {
-                    if(CurrPixel < IHDR_Width)
-                    {
-                        Mask  = (1 << IHDR->BitDepth) - 1;
-                        Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
-
-                        SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
-
-			if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
-			{
-			    return(qfalse);
-			}
-
-                        OutPtr += Q3IMAGE_BYTESPERPIXEL;
-                        CurrPixel++;
-                    }
-                }
-	    
-	    }
-	    else
-	    {
-		if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
-		{
-		    return(qfalse);
-		}
-  
-
-                OutPtr += Q3IMAGE_BYTESPERPIXEL;
-	    }
-
-            DecompPtr += BytesPerPixel;
-        }
-    }
-
-    return(qtrue);
-}
-
-/*
- *  Decode an interlaced image.
- */
-
-static qboolean DecodeImageInterlaced(struct PNG_Chunk_IHDR *IHDR,
-                                      byte                  *OutBuffer, 
-                                      uint8_t               *DecompressedData,
-                                      uint32_t               DecompressedDataLength,
-                                      qboolean               HasTransparentColour,
-                                      uint8_t               *TransparentColour,
-                                      uint8_t               *OutPal)
-{
-    uint32_t IHDR_Width;
-    uint32_t IHDR_Height;
-    uint32_t BytesPerScanline[PNG_Adam7_NumPasses], BytesPerPixel, PixelsPerByte;
-    uint32_t PassWidth[PNG_Adam7_NumPasses], PassHeight[PNG_Adam7_NumPasses];
-    uint32_t WSkip[PNG_Adam7_NumPasses], WOffset[PNG_Adam7_NumPasses], HSkip[PNG_Adam7_NumPasses], HOffset[PNG_Adam7_NumPasses];
-    uint32_t w, h, p, a;
-    byte *OutPtr;
-    uint8_t *DecompPtr;
-    uint32_t TargetLength;
-
-    /*
-     *  input verification
-     */
-
-    if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
-    {
-	return(qfalse);
-    }
-
-    /*
-     *  byte swapping
-     */
-
-    IHDR_Width  = BigLong(IHDR->Width);
-    IHDR_Height = BigLong(IHDR->Height);
-
-    /*
-     *  Skip and Offset for the passes.
-     */
-
-    WSkip[0]   = 8;
-    WOffset[0] = 0;
-    HSkip[0]   = 8;
-    HOffset[0] = 0;
-
-    WSkip[1]   = 8;
-    WOffset[1] = 4;
-    HSkip[1]   = 8;
-    HOffset[1] = 0;
-
-    WSkip[2]   = 4;
-    WOffset[2] = 0;
-    HSkip[2]   = 8;
-    HOffset[2] = 4;
-
-    WSkip[3]   = 4;
-    WOffset[3] = 2;
-    HSkip[3]   = 4;
-    HOffset[3] = 0;
-
-    WSkip[4]   = 2;
-    WOffset[4] = 0;
-    HSkip[4]   = 4;
-    HOffset[4] = 2;
-
-    WSkip[5]   = 2;
-    WOffset[5] = 1;
-    HSkip[5]   = 2;
-    HOffset[5] = 0;
-
-    WSkip[6]   = 1;
-    WOffset[6] = 0;
-    HSkip[6]   = 2;
-    HOffset[6] = 1;
-
-    /*
-     *  Calculate the sizes of the passes.
-     */
-
-    PassWidth[0]  = (IHDR_Width  + 7) / 8;
-    PassHeight[0] = (IHDR_Height + 7) / 8;
-
-    PassWidth[1]  = (IHDR_Width  + 3) / 8;
-    PassHeight[1] = (IHDR_Height + 7) / 8;
-
-    PassWidth[2]  = (IHDR_Width  + 3) / 4;
-    PassHeight[2] = (IHDR_Height + 3) / 8;
-
-    PassWidth[3]  = (IHDR_Width  + 1) / 4;
-    PassHeight[3] = (IHDR_Height + 3) / 4;
-
-    PassWidth[4]  = (IHDR_Width  + 1) / 2;
-    PassHeight[4] = (IHDR_Height + 1) / 4;
-
-    PassWidth[5]  = (IHDR_Width  + 0) / 2;
-    PassHeight[5] = (IHDR_Height + 1) / 2;
-
-    PassWidth[6]  = (IHDR_Width  + 0) / 1;
-    PassHeight[6] = (IHDR_Height + 0) / 2;
-
-    /*
-     *  information for un-filtering
-     */
-
-    switch(IHDR->ColourType)
-    {
-        case PNG_ColourType_Grey :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_1 :
-                case PNG_BitDepth_2 :
-                case PNG_BitDepth_4 :
-                {
-                    BytesPerPixel    = 1;
-                    PixelsPerByte    = 8 / IHDR->BitDepth;
-
-                    break;
-                }
-
-                case PNG_BitDepth_8  :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-  
-        case PNG_ColourType_True :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8  :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-     
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_Indexed :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_1 :
-                case PNG_BitDepth_2 :
-                case PNG_BitDepth_4 :
-                {
-                    BytesPerPixel    = 1;
-                    PixelsPerByte    = 8 / IHDR->BitDepth;
-
-                    break;
-                }
-
-                case PNG_BitDepth_8 :
-                {
-                    BytesPerPixel    = PNG_NumColourComponents_Indexed;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-         
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_GreyAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-     
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-  
-            break;
-        }
-
-        case PNG_ColourType_TrueAlpha :
-        {
-            switch(IHDR->BitDepth)
-            {
-                case PNG_BitDepth_8 :
-                case PNG_BitDepth_16 :
-                {
-                    BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
-                    PixelsPerByte    = 1;
-
-                    break;
-                }
-    
-                default :
-                {
-                    return(qfalse);
-                }
-            }
-
-            break;
-        }
-
-        default :
-        {
-            return(qfalse);
-        }
-    }
-
-    /*
-     *  Calculate the size of the scanlines per pass
-     */
-
-    for(a = 0; a < PNG_Adam7_NumPasses; a++)
-    {
-	BytesPerScanline[a] = (PassWidth[a] * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
-    }
-
-    /*
-     *  Calculate the size of all passes
-     */
-
-    TargetLength = 0;
-
-    for(a = 0; a < PNG_Adam7_NumPasses; a++)
-    {
-	TargetLength += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
-    }
-
-    /*
-     *  Check if we have enough data for the whole image.
-     */
-
-    if(!(DecompressedDataLength == TargetLength))
-    {
-        return(qfalse);
-    }
-
-    /*
-     *  Unfilter the image.
-     */
-
-    DecompPtr = DecompressedData;
-
-    for(a = 0; a < PNG_Adam7_NumPasses; a++)
-    {
-        if(!UnfilterImage(DecompPtr, PassHeight[a], BytesPerScanline[a], BytesPerPixel))
-        {
-            return(qfalse);
-        }
-	
-	DecompPtr += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
-    }
-
-    /*
-     *  Set the working pointers to the beginning of the buffers.
-     */
-
-    DecompPtr = DecompressedData;
-
-    /*
-     *  Create the output image.
-     */
-
-    for(a = 0; a < PNG_Adam7_NumPasses; a++)
-    {
-        for(h = 0; h < PassHeight[a]; h++)
-        {
-            /*
-             *  Count the pixels on the scanline for those multipixel bytes
-             */
-
-            uint32_t CurrPixel;
-
-            /*
-             *  skip FilterType
-             */
-
-            DecompPtr++;
-
-            /*
-             *  Reset the pixel count.
-             */
-
-            CurrPixel = 0;
-
-            for(w = 0; w < (BytesPerScanline[a] / BytesPerPixel); w++)
-            {
-        	if(PixelsPerByte > 1)
-	        {
-                    uint8_t  Mask;
-                    uint32_t Shift;
-		    uint8_t  SinglePixel;
-
-                    for(p = 0; p < PixelsPerByte; p++)
-                    {
-                        if(CurrPixel < PassWidth[a])
-                        {
-                            Mask  = (1 << IHDR->BitDepth) - 1;
-                            Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
-
-                            SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
-
-    			    OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((CurrPixel * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
-
-    			    if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
-			    {
-			        return(qfalse);
-			    }
-
-                            CurrPixel++;
-                        }
-                    }
-	    
-	        }
-    	        else
-	        {
-	    	    OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((w * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
-
-		    if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
-		    {
-		        return(qfalse);
-		    }
-	        }
-
-                DecompPtr += BytesPerPixel;
-            }
-        }
-    }
-
-    return(qtrue);
-}
-
-/*
- *  The PNG loader
- */
-
-static void LoadPNG(const char *name, byte **pic, int *width, int *height)
-{
-    struct BufferedFile *ThePNG;
-    byte *OutBuffer;
-    uint8_t *Signature;
-    struct PNG_ChunkHeader *CH;
-    uint32_t ChunkHeaderLength;
-    uint32_t ChunkHeaderType;
-    struct PNG_Chunk_IHDR *IHDR;
-    uint32_t IHDR_Width;
-    uint32_t IHDR_Height;
-    PNG_ChunkCRC *CRC;
-    uint8_t *InPal;
-    uint8_t *DecompressedData;
-    uint32_t DecompressedDataLength;
-    uint32_t i;
-
-    /*
-     *  palette with 256 RGBA entries
-     */
-
-    uint8_t OutPal[1024];
-
-    /*
-     *  transparent colour from the tRNS chunk
-     */
-
-    qboolean HasTransparentColour = qfalse;
-    uint8_t TransparentColour[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-
-    /*
-     *  input verification
-     */
-
-    if(!(name && pic))
-    {
-        return;
-    }
-
-    /*
-     *  Zero out return values.
-     */
-
-    *pic = NULL;
-
-    if(width)
-    {
-        *width = 0;
-    }
-
-    if(height)
-    {
-        *height = 0;
-    }
-
-    /*
-     *  Read the file.
-     */
-
-    ThePNG = ReadBufferedFile(name);
-    if(!ThePNG)
-    {
-        return;
-    }           
-
-    /*
-     *  Read the siganture of the file.
-     */
-
-    Signature = BufferedFileRead(ThePNG, PNG_Signature_Size);
-    if(!Signature)
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return;
-    }
- 
-    /*
-     *  Is it a PNG?
-     */
-
-    if(memcmp(Signature, PNG_Signature, PNG_Signature_Size))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Read the first chunk-header.
-     */
-
-    CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
-    if(!CH)
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  PNG multi-byte types are in Big Endian
-     */
-
-    ChunkHeaderLength = BigLong(CH->Length);
-    ChunkHeaderType   = BigLong(CH->Type);
-
-    /*
-     *  Check if the first chunk is an IHDR.
-     */
-
-    if(!((ChunkHeaderType == PNG_ChunkType_IHDR) && (ChunkHeaderLength == PNG_Chunk_IHDR_Size)))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Read the IHDR.
-     */ 
-
-    IHDR = BufferedFileRead(ThePNG, PNG_Chunk_IHDR_Size);
-    if(!IHDR)
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Read the CRC for IHDR
-     */
-
-    CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
-    if(!CRC)
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
- 
-    /*
-     *  Here we could check the CRC if we wanted to.
-     */
- 
-    /*
-     *  multi-byte type swapping
-     */
-
-    IHDR_Width  = BigLong(IHDR->Width);
-    IHDR_Height = BigLong(IHDR->Height);
- 
-    /*
-     *  Check if Width and Height are valid.
-     */
-
-    if(!((IHDR_Width > 0) && (IHDR_Height > 0)))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Do we need to check if the dimensions of the image are valid for Quake3?
-     */
-
-    /*
-     *  Check if CompressionMethod and FilterMethod are valid.
-     */
-
-    if(!((IHDR->CompressionMethod == PNG_CompressionMethod_0) && (IHDR->FilterMethod == PNG_FilterMethod_0)))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Check if InterlaceMethod is valid.
-     */
-
-    if(!((IHDR->InterlaceMethod == PNG_InterlaceMethod_NonInterlaced)  || (IHDR->InterlaceMethod == PNG_InterlaceMethod_Interlaced)))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return;
-    }
-
-    /*
-     *  Read palette for an indexed image.
-     */
-
-    if(IHDR->ColourType == PNG_ColourType_Indexed)
-    {
-        /*
-         *  We need the palette first.
-         */
-
-        if(!FindChunk(ThePNG, PNG_ChunkType_PLTE))
-        {
-            CloseBufferedFile(ThePNG);
-  
-            return;
-        }
-
-        /*
-         *  Read the chunk-header.
-         */
-
-        CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
-        if(!CH)
-        {
-            CloseBufferedFile(ThePNG);
-   
-            return; 
-        }
-
-        /*
-         *  PNG multi-byte types are in Big Endian
-         */
-
-        ChunkHeaderLength = BigLong(CH->Length);
-        ChunkHeaderType   = BigLong(CH->Type);
-  
-        /*
-         *  Check if the chunk is an PLTE.
-         */
-
-        if(!(ChunkHeaderType == PNG_ChunkType_PLTE))
-        {
-            CloseBufferedFile(ThePNG);
-   
-            return; 
-        }
-
-        /*
-         *  Check if Length is divisible by 3
-         */
-
-        if(ChunkHeaderLength % 3)
-        {
-            CloseBufferedFile(ThePNG);
-   
-            return;   
-        }
-
-        /*
-         *  Read the raw palette data
-         */
-
-        InPal = BufferedFileRead(ThePNG, ChunkHeaderLength);
-        if(!InPal)
-        {
-            CloseBufferedFile(ThePNG);
-   
-            return; 
-        }
-   
-        /*
-         *  Read the CRC for the palette
-         */
-
-        CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
-        if(!CRC)
-        {
-            CloseBufferedFile(ThePNG);
- 
-            return; 
-        }
-
-        /*
-         *  Set some default values.
-         */
-
-        for(i = 0; i < 256; i++)
-        {
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = 0x00;
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = 0x00;
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = 0x00;
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;  
-        }
-
-        /*
-         *  Convert to the Quake3 RGBA-format.
-         */
-
-        for(i = 0; i < (ChunkHeaderLength / 3); i++)
-        {
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = InPal[i*3+0];
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = InPal[i*3+1];
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = InPal[i*3+2];
-            OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
-        }
-    }
-
-    /*
-     *  transparency information is sometimes stored in an tRNS chunk
-     */
-
-    /*
-     *  Let's see if there is a tRNS chunk
-     */
-
-    if(FindChunk(ThePNG, PNG_ChunkType_tRNS))
-    {
-        uint8_t *Trans;
-
-        /*
-         *  Read the chunk-header.
-         */
-
-        CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
-        if(!CH)
-        {
-            CloseBufferedFile(ThePNG);
- 
-            return; 
-        }
-
-        /*
-         *  PNG multi-byte types are in Big Endian
-         */
-
-        ChunkHeaderLength = BigLong(CH->Length);
-        ChunkHeaderType   = BigLong(CH->Type);
-
-        /*
-         *  Check if the chunk is an tRNS.
-         */
-
-        if(!(ChunkHeaderType == PNG_ChunkType_tRNS))
-        {
-            CloseBufferedFile(ThePNG);
- 
-            return; 
-        }
-
-        /*
-         *  Read the transparency information.
-         */
-
-        Trans = BufferedFileRead(ThePNG, ChunkHeaderLength);
-        if(!Trans)
-        {
-            CloseBufferedFile(ThePNG);
- 
-            return;  
-        }
-
-        /*
-         *  Read the CRC.
-         */
-
-        CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
-        if(!CRC)
-        {
-            CloseBufferedFile(ThePNG);
-  
-            return; 
-        }
- 
-        /*
-         *  Only for Grey, True and Indexed ColourType should tRNS exist.
-         */
-
-        switch(IHDR->ColourType)
-        {
-            case PNG_ColourType_Grey :
-            {
-                if(!ChunkHeaderLength == 2)
-                {
-                    CloseBufferedFile(ThePNG);
-  
-                    return;    
-                }
-   
-                HasTransparentColour = qtrue;
-   
-		/*
-		 *  Grey can have one colour which is completely transparent.
-		 *  This colour is always stored in 16 bits.
-		 */
-
-                TransparentColour[0] = Trans[0];
-                TransparentColour[1] = Trans[1];
-   
-                break;
-            }
-   
-            case PNG_ColourType_True :
-            {
-                if(!ChunkHeaderLength == 6)
-                {
-                    CloseBufferedFile(ThePNG);
-  
-                    return;    
-                }
-   
-                HasTransparentColour = qtrue;
-
-		/*
-		 *  True can have one colour which is completely transparent.
-		 *  This colour is always stored in 16 bits.
-		 */
-
-                TransparentColour[0] = Trans[0];
-                TransparentColour[1] = Trans[1];
-                TransparentColour[2] = Trans[2];
-                TransparentColour[3] = Trans[3];
-                TransparentColour[4] = Trans[4];
-                TransparentColour[5] = Trans[5];
-   
-                break;
-            }
-   
-            case PNG_ColourType_Indexed :
-            {
-                /*
-		 *  Maximum of 256 one byte transparency entries.
-		 */
-		
-		if(ChunkHeaderLength > 256)
-                {
-                    CloseBufferedFile(ThePNG);
-  
-                    return;    
-                }
-
-                HasTransparentColour = qtrue;
-
-                /*
-                 *  alpha values for palette entries
-                 */
-
-                for(i = 0; i < ChunkHeaderLength; i++)
-                {
-                    OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = Trans[i];
-                }
-
-                break;
-            }
-  
-            /*
-             *  All other ColourTypes should not have tRNS chunks
-             */
-
-            default :
-            {
-                CloseBufferedFile(ThePNG);
-  
-                return;
-            }
-        } 
-    }
-
-    /*
-     *  Rewind to the start of the file.
-     */
-
-    if(!BufferedFileRewind(ThePNG, -1))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
- 
-    /*
-     *  Skip the signature
-     */
-
-    if(!BufferedFileSkip(ThePNG, PNG_Signature_Size))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return; 
-    }
-
-    /*
-     *  Decompress all IDAT chunks
-     */
-
-    DecompressedDataLength = DecompressIDATs(ThePNG, &DecompressedData);
-    if(!(DecompressedDataLength && DecompressedData))
-    {
-        CloseBufferedFile(ThePNG);
- 
-        return;
-    }
-
-    /*
-     *  Allocate output buffer.
-     */
-
-    OutBuffer = ri.Malloc(IHDR_Width * IHDR_Height * Q3IMAGE_BYTESPERPIXEL); 
-    if(!OutBuffer)
-    {
-        ri.Free(DecompressedData); 
-        CloseBufferedFile(ThePNG);
- 
-        return;  
-    }
-
-    /*
-     *  Interlaced and Non-interlaced images need to be handled differently.
-     */
-
-    switch(IHDR->InterlaceMethod)
-    {
-	case PNG_InterlaceMethod_NonInterlaced :
-	{
-	    if(!DecodeImageNonInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
-	    {
-		ri.Free(OutBuffer); 
-    		ri.Free(DecompressedData); 
-    		CloseBufferedFile(ThePNG);
-
-		return;
-	    }
-	
-	    break;
-	}
-	
-	case PNG_InterlaceMethod_Interlaced :
-	{
-	    if(!DecodeImageInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
-	    {
-		ri.Free(OutBuffer); 
-    		ri.Free(DecompressedData); 
-    		CloseBufferedFile(ThePNG);
-
-		return;
-	    }
-	
-	    break;
-	}
-    
-	default :
-	{
-	    ri.Free(OutBuffer); 
-    	    ri.Free(DecompressedData); 
-    	    CloseBufferedFile(ThePNG);
-
-	    return;
-	}
-    }
-
-    /*
-     *  update the pointer to the image data
-     */
-
-    *pic = OutBuffer;
- 
-    /*
-     *  Fill width and height.
-     */
-
-    if(width)
-    {
-        *width = IHDR_Width;
-    }
-
-    if(height)
-    {
-        *height = IHDR_Height;
-    }
-
-    /*
-     *  DecompressedData is not needed anymore.
-     */
-
-    ri.Free(DecompressedData); 
-
-    /*
-     *  We have all data, so close the file.
-     */
-
-    CloseBufferedFile(ThePNG);
-}
-
-//===================================================================
-
 typedef struct
 {
 	char *ext;
diff --git a/code/renderer/tr_image_png.c b/code/renderer/tr_image_png.c
new file mode 100644
index 0000000..30a8951
--- /dev/null
+++ b/code/renderer/tr_image_png.c
@@ -0,0 +1,2466 @@
+/*
+===========================================================================
+ioquake3 png decoder
+Copyright (C) 2007,2008 Joerg Dietrich
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+===========================================================================
+*/
+
+#include "tr_local.h"
+
+#include "../qcommon/puff.h"
+
+/*
+=================
+PNG LOADING
+=================
+*/
+
+/*
+ *  Quake 3 image format : RGBA
+ */
+
+#define Q3IMAGE_BYTESPERPIXEL (4)
+
+/*
+ *  PNG specifications
+ */
+
+/*
+ *  The first 8 Bytes of every PNG-File are a fixed signature
+ *  to identify the file as a PNG.
+ */
+
+#define PNG_Signature "\x89\x50\x4E\x47\xD\xA\x1A\xA"
+#define PNG_Signature_Size (8)
+
+/*
+ *  After the signature diverse chunks follow.
+ *  A chunk consists of a header and if Length
+ *  is bigger than 0 a body and a CRC of the body follow.
+ */
+
+struct PNG_ChunkHeader
+{
+	uint32_t Length;
+	uint32_t Type;
+};
+
+#define PNG_ChunkHeader_Size (8)
+
+typedef uint32_t PNG_ChunkCRC;
+
+#define PNG_ChunkCRC_Size (4)
+
+/*
+ *  We use the following ChunkTypes.
+ *  All others are ignored.
+ */
+
+#define MAKE_CHUNKTYPE(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | ((d)))
+
+#define PNG_ChunkType_IHDR MAKE_CHUNKTYPE('I', 'H', 'D', 'R')
+#define PNG_ChunkType_PLTE MAKE_CHUNKTYPE('P', 'L', 'T', 'E')
+#define PNG_ChunkType_IDAT MAKE_CHUNKTYPE('I', 'D', 'A', 'T')
+#define PNG_ChunkType_IEND MAKE_CHUNKTYPE('I', 'E', 'N', 'D')
+#define PNG_ChunkType_tRNS MAKE_CHUNKTYPE('t', 'R', 'N', 'S')
+
+/*
+ *  Per specification the first chunk after the signature SHALL be IHDR.
+ */
+
+struct PNG_Chunk_IHDR
+{
+	uint32_t Width;
+	uint32_t Height;
+	uint8_t  BitDepth;
+	uint8_t  ColourType;
+	uint8_t  CompressionMethod;
+	uint8_t  FilterMethod;
+	uint8_t  InterlaceMethod;
+};
+
+#define PNG_Chunk_IHDR_Size (13)
+
+/*
+ *  ColourTypes
+ */
+
+#define PNG_ColourType_Grey      (0)
+#define PNG_ColourType_True      (2)
+#define PNG_ColourType_Indexed   (3)
+#define PNG_ColourType_GreyAlpha (4)
+#define PNG_ColourType_TrueAlpha (6)
+
+/*
+ *  number of colour components
+ *
+ *  Grey      : 1 grey
+ *  True      : 1 R, 1 G, 1 B
+ *  Indexed   : 1 index
+ *  GreyAlpha : 1 grey, 1 alpha
+ *  TrueAlpha : 1 R, 1 G, 1 B, 1 alpha
+ */
+
+#define PNG_NumColourComponents_Grey      (1)
+#define PNG_NumColourComponents_True      (3)
+#define PNG_NumColourComponents_Indexed   (1)
+#define PNG_NumColourComponents_GreyAlpha (2)
+#define PNG_NumColourComponents_TrueAlpha (4)
+
+/*
+ *  For the different ColourTypes
+ *  different BitDepths are specified.
+ */
+
+#define PNG_BitDepth_1  ( 1)
+#define PNG_BitDepth_2  ( 2)
+#define PNG_BitDepth_4  ( 4)
+#define PNG_BitDepth_8  ( 8)
+#define PNG_BitDepth_16 (16)
+
+/*
+ *  Only one valid CompressionMethod is standardized.
+ */
+
+#define PNG_CompressionMethod_0 (0)
+
+/*
+ *  Only one valid FilterMethod is currently standardized.
+ */
+
+#define PNG_FilterMethod_0 (0)
+
+/*
+ *  This FilterMethod defines 5 FilterTypes
+ */
+
+#define PNG_FilterType_None    (0)
+#define PNG_FilterType_Sub     (1)
+#define PNG_FilterType_Up      (2)
+#define PNG_FilterType_Average (3)
+#define PNG_FilterType_Paeth   (4)
+
+/*
+ *  Two InterlaceMethods are standardized :
+ *  0 - NonInterlaced
+ *  1 - Interlaced
+ */
+
+#define PNG_InterlaceMethod_NonInterlaced (0)
+#define PNG_InterlaceMethod_Interlaced    (1)
+
+/*
+ *  The Adam7 interlace method uses 7 passes.
+ */
+
+#define PNG_Adam7_NumPasses (7)
+
+/*
+ *  The compressed data starts with a header ...
+ */
+
+struct PNG_ZlibHeader
+{
+	uint8_t CompressionMethod;
+	uint8_t Flags;
+};
+
+#define PNG_ZlibHeader_Size (2)
+
+/*
+ *  ... and is followed by a check value
+ */
+
+#define PNG_ZlibCheckValue_Size (4)
+
+/*
+ *  Some support functions for buffered files follow.
+ */
+
+/*
+ *  buffered file representation
+ */
+
+struct BufferedFile
+{
+	byte *Buffer;
+	int   Length;
+	byte *Ptr;
+	int   BytesLeft;
+};
+
+/*
+ *  Read a file into a buffer.
+ */
+
+static struct BufferedFile *ReadBufferedFile(const char *name)
+{
+	struct BufferedFile *BF;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!name)
+	{
+		return(NULL);
+	}
+
+	/*
+	 *  Allocate control struct.
+	 */
+
+	BF = ri.Malloc(sizeof(struct BufferedFile));
+	if(!BF)
+	{
+		return(NULL);
+	}
+
+	/*
+	 *  Initialize the structs components.
+	 */
+
+	BF->Length    = 0;
+	BF->Buffer    = NULL;
+	BF->Ptr       = NULL;
+	BF->BytesLeft = 0;
+
+	/*
+	 *  Read the file.
+	 */
+
+	BF->Length = ri.FS_ReadFile((char *) name, (void **) &BF->Buffer);
+
+	/*
+	 *  Did we get it? Is it big enough?
+	 */
+
+	if(!(BF->Buffer && (BF->Length > 0)))
+	{
+		ri.Free(BF);
+
+		return(NULL);
+	}
+
+	/*
+	 *  Set the pointers and counters.
+	 */
+
+	BF->Ptr       = BF->Buffer;
+	BF->BytesLeft = BF->Length;
+
+	return(BF);
+}
+
+/*
+ *  Close a buffered file.
+ */
+
+static void CloseBufferedFile(struct BufferedFile *BF)
+{
+	if(BF)
+	{
+		if(BF->Buffer)
+		{
+			ri.FS_FreeFile(BF->Buffer);
+		}
+
+		ri.Free(BF);
+	}
+}
+
+/*
+ *  Get a pointer to the requested bytes.
+ */
+
+static void *BufferedFileRead(struct BufferedFile *BF, int Length)
+{
+	void *RetVal;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!(BF && Length))
+	{
+		return(NULL);
+	}
+
+	/*
+	 *  not enough bytes left
+	 */
+
+	if(Length > BF->BytesLeft)
+	{
+		return(NULL);
+	}
+
+	/*
+	 *  the pointer to the requested data
+	 */
+
+	RetVal = BF->Ptr;
+
+	/*
+	 *  Raise the pointer and counter.
+	 */
+
+	BF->Ptr       += Length;
+	BF->BytesLeft -= Length;
+
+	return(RetVal);
+}
+
+/*
+ *  Rewind the buffer.
+ */
+
+static qboolean BufferedFileRewind(struct BufferedFile *BF, int Offset)
+{
+	int BytesRead; 
+
+	/*
+	 *  input verification
+	 */
+
+	if(!BF)
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  special trick to rewind to the beginning of the buffer
+	 */
+
+	if(Offset == -1)
+	{
+		BF->Ptr       = BF->Buffer;
+		BF->BytesLeft = BF->Length;
+
+		return(qtrue);
+	}
+
+	/*
+	 *  How many bytes do we have already read?
+	 */
+
+	BytesRead = BF->Ptr - BF->Buffer;
+
+	/*
+	 *  We can only rewind to the beginning of the BufferedFile.
+	 */
+
+	if(Offset > BytesRead)
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  lower the pointer and counter.
+	 */
+
+	BF->Ptr       -= Offset;
+	BF->BytesLeft += Offset;
+
+	return(qtrue);
+}
+
+/*
+ *  Skip some bytes.
+ */
+
+static qboolean BufferedFileSkip(struct BufferedFile *BF, int Offset)
+{
+	/*
+	 *  input verification
+	 */
+
+	if(!BF)
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  We can only skip to the end of the BufferedFile.
+	 */
+
+	if(Offset > BF->BytesLeft)
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  lower the pointer and counter.
+	 */
+
+	BF->Ptr       += Offset;
+	BF->BytesLeft -= Offset;
+
+	return(qtrue);
+}
+
+/*
+ *  Find a chunk
+ */
+
+static qboolean FindChunk(struct BufferedFile *BF, uint32_t ChunkType)
+{
+	struct PNG_ChunkHeader *CH;
+
+	uint32_t Length;
+	uint32_t Type;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!BF)
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  cycle trough the chunks
+	 */
+
+	while(qtrue)
+	{
+		/*
+		 *  Read the chunk-header.
+		 */
+
+		CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
+		if(!CH)
+		{
+			return(qfalse);
+		}
+
+		/*
+		 *  Do not swap the original types
+		 *  they might be needed later.
+		 */
+
+		Length = BigLong(CH->Length);
+		Type   = BigLong(CH->Type);
+
+		/*
+		 *  We found it!
+		 */
+
+		if(Type == ChunkType)
+		{
+			/*
+			 *  Rewind to the start of the chunk.
+			 */
+
+			BufferedFileRewind(BF, PNG_ChunkHeader_Size);
+
+			break;
+		}
+		else
+		{
+			/*
+			 *  Skip the rest of the chunk.
+			 */
+
+			if(Length)
+			{
+				if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
+				{
+					return(qfalse);
+				}  
+			}
+		}
+	}
+
+	return(qtrue);
+}
+
+/*
+ *  Decompress all IDATs
+ */
+
+static uint32_t DecompressIDATs(struct BufferedFile *BF, uint8_t **Buffer)
+{
+	uint8_t  *DecompressedData;
+	uint32_t  DecompressedDataLength;
+
+	uint8_t  *CompressedData;
+	uint8_t  *CompressedDataPtr;
+	uint32_t  CompressedDataLength;
+
+	struct PNG_ChunkHeader *CH;
+
+	uint32_t Length;
+	uint32_t Type;
+
+	int BytesToRewind;
+
+	int32_t   puffResult;
+	uint8_t  *puffDest;
+	uint32_t  puffDestLen;
+	uint8_t  *puffSrc;
+	uint32_t  puffSrcLen;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!(BF && Buffer))
+	{
+		return(-1);
+	}
+
+	/*
+	 *  some zeroing
+	 */
+
+	DecompressedData = NULL;
+	DecompressedDataLength = 0;
+	*Buffer = DecompressedData;
+
+	CompressedData = NULL;
+	CompressedDataLength = 0;
+
+	BytesToRewind = 0;
+
+	/*
+	 *  Find the first IDAT chunk.
+	 */
+
+	if(!FindChunk(BF, PNG_ChunkType_IDAT))
+	{
+		return(-1);
+	}
+
+	/*
+	 *  Count the size of the uncompressed data
+	 */
+
+	while(qtrue)
+	{
+		/*
+		 *  Read chunk header
+		 */
+
+		CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
+		if(!CH)
+		{
+			/*
+			 *  Rewind to the start of this adventure
+			 *  and return unsuccessfull
+			 */
+
+			BufferedFileRewind(BF, BytesToRewind);
+
+			return(-1);
+		}
+
+		/*
+		 *  Length and Type of chunk
+		 */
+
+		Length = BigLong(CH->Length);
+		Type   = BigLong(CH->Type);
+
+		/*
+		 *  We have reached the end of the IDAT chunks
+		 */
+
+		if(!(Type == PNG_ChunkType_IDAT))
+		{
+			BufferedFileRewind(BF, PNG_ChunkHeader_Size); 
+
+			break;
+		}
+
+		/*
+		 *  Add chunk header to count.
+		 */
+
+		BytesToRewind += PNG_ChunkHeader_Size;
+
+		/*
+		 *  Skip to next chunk
+		 */
+
+		if(Length)
+		{
+			if(!BufferedFileSkip(BF, Length + PNG_ChunkCRC_Size))
+			{
+				BufferedFileRewind(BF, BytesToRewind);
+
+				return(-1);
+			}
+
+			BytesToRewind += Length + PNG_ChunkCRC_Size;
+			CompressedDataLength += Length;
+		} 
+	}
+
+	BufferedFileRewind(BF, BytesToRewind);
+
+	CompressedData = ri.Malloc(CompressedDataLength);
+	if(!CompressedData)
+	{
+		return(-1);
+	}
+
+	CompressedDataPtr = CompressedData;
+
+	/*
+	 *  Collect the compressed Data
+	 */
+
+	while(qtrue)
+	{
+		/*
+		 *  Read chunk header
+		 */
+
+		CH = BufferedFileRead(BF, PNG_ChunkHeader_Size);
+		if(!CH)
+		{
+			ri.Free(CompressedData); 
+
+			return(-1);
+		}
+
+		/*
+		 *  Length and Type of chunk
+		 */
+
+		Length = BigLong(CH->Length);
+		Type   = BigLong(CH->Type);
+
+		/*
+		 *  We have reached the end of the IDAT chunks
+		 */
+
+		if(!(Type == PNG_ChunkType_IDAT))
+		{
+			BufferedFileRewind(BF, PNG_ChunkHeader_Size); 
+
+			break;
+		}
+
+		/*
+		 *  Copy the Data
+		 */
+
+		if(Length)
+		{
+			uint8_t *OrigCompressedData;
+
+			OrigCompressedData = BufferedFileRead(BF, Length);
+			if(!OrigCompressedData)
+			{
+				ri.Free(CompressedData); 
+
+				return(-1);
+			}
+
+			if(!BufferedFileSkip(BF, PNG_ChunkCRC_Size))
+			{
+				ri.Free(CompressedData); 
+
+				return(-1);
+			}
+
+			memcpy(CompressedDataPtr, OrigCompressedData, Length);
+			CompressedDataPtr += Length;
+		} 
+	}
+
+	/*
+	 *  Let puff() calculate the decompressed data length.
+	 */
+
+	puffDest    = NULL;
+	puffDestLen = 0;
+
+	/*
+	 *  The zlib header and checkvalue don't belong to the compressed data.
+	 */
+
+	puffSrc    = CompressedData + PNG_ZlibHeader_Size;
+	puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
+
+	/*
+	 *  first puff() to calculate the size of the uncompressed data
+	 */
+
+	puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
+	if(!((puffResult == 0) && (puffDestLen > 0)))
+	{
+		ri.Free(CompressedData);
+
+		return(-1);
+	}
+
+	/*
+	 *  Allocate the buffer for the uncompressed data.
+	 */
+
+	DecompressedData = ri.Malloc(puffDestLen);
+	if(!DecompressedData)
+	{
+		ri.Free(CompressedData);
+
+		return(-1);
+	}
+
+	/*
+	 *  Set the input again in case something was changed by the last puff() .
+	 */
+
+	puffDest   = DecompressedData;
+	puffSrc    = CompressedData + PNG_ZlibHeader_Size;
+	puffSrcLen = CompressedDataLength - PNG_ZlibHeader_Size - PNG_ZlibCheckValue_Size;
+
+	/*
+	 *  decompression puff()
+	 */
+
+	puffResult = puff(puffDest, &puffDestLen, puffSrc, &puffSrcLen);
+
+	/*
+	 *  The compressed data is not needed anymore.
+	 */
+
+	ri.Free(CompressedData);
+
+	/*
+	 *  Check if the last puff() was successfull.
+	 */
+
+	if(!((puffResult == 0) && (puffDestLen > 0)))
+	{
+		ri.Free(DecompressedData);
+
+		return(-1);
+	}
+
+	/*
+	 *  Set the output of this function.
+	 */
+
+	DecompressedDataLength = puffDestLen;
+	*Buffer = DecompressedData;
+
+	return(DecompressedDataLength);
+}
+
+/*
+ *  the Paeth predictor
+ */
+
+static uint8_t PredictPaeth(uint8_t a, uint8_t b, uint8_t c)
+{
+	/*
+	 *  a == Left
+	 *  b == Up
+	 *  c == UpLeft
+	 */
+
+	uint8_t Pr;
+	int p;
+	int pa, pb, pc;
+
+	Pr = 0;
+
+	p  = ((int) a) + ((int) b) - ((int) c);
+	pa = abs(p - ((int) a));
+	pb = abs(p - ((int) b));
+	pc = abs(p - ((int) c));
+
+	if((pa <= pb) && (pa <= pc))
+	{
+		Pr = a;
+	}
+	else if(pb <= pc)
+	{
+		Pr = b;
+	}
+	else
+	{
+		Pr = c;
+	}
+
+	return(Pr);
+
+}
+
+/*
+ *  Reverse the filters.
+ */
+
+static qboolean UnfilterImage(uint8_t  *DecompressedData, 
+		uint32_t  ImageHeight,
+		uint32_t  BytesPerScanline, 
+		uint32_t  BytesPerPixel)
+{
+	uint8_t   *DecompPtr;
+	uint8_t   FilterType;
+	uint8_t  *PixelLeft, *PixelUp, *PixelUpLeft;
+	uint32_t  w, h, p;
+
+	/*
+	 *  some zeros for the filters
+	 */
+
+	uint8_t Zeros[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+	/*
+	 *  input verification
+	 *
+	 *  ImageHeight and BytesPerScanline are not checked,
+	 *  because these can be zero in some interlace passes.
+	 */
+
+	if(!(DecompressedData && BytesPerPixel))
+	{
+		return(qfalse);
+	}
+
+
+	/*
+	 *  Set the pointer to the start of the decompressed Data.
+	 */
+
+	DecompPtr = DecompressedData;
+
+	/*
+	 *  Un-filtering is done in place.
+	 */
+
+	/*
+	 *  Go trough all scanlines.
+	 */
+
+	for(h = 0; h < ImageHeight; h++)
+	{
+		/*
+		 *  Every scanline starts with a FilterType byte.
+		 */
+
+		FilterType = *DecompPtr;
+		DecompPtr++;
+
+		/*
+		 *  Left pixel of the first byte in a scanline is zero.
+		 */
+
+		PixelLeft = Zeros;
+
+		/*
+		 *  Set PixelUp to previous line only if we are on the second line or above.
+		 *
+		 *  Plus one byte for the FilterType
+		 */
+
+		if(h > 0)
+		{
+			PixelUp = DecompPtr - (BytesPerScanline + 1);
+		}
+		else
+		{
+			PixelUp = Zeros;
+		}
+
+		/*
+		 * The pixel left to the first pixel of the previous scanline is zero too.
+		 */
+
+		PixelUpLeft = Zeros;
+
+		/*
+		 *  Cycle trough all pixels of the scanline.
+		 */
+
+		for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
+		{
+			/*
+			 *  Cycle trough the bytes of the pixel.
+			 */
+
+			for(p = 0; p < BytesPerPixel; p++)
+			{
+				switch(FilterType)
+				{ 
+					case PNG_FilterType_None :
+					{
+						/*
+						 *  The byte is unfiltered.
+						 */
+
+						break;
+					}
+
+					case PNG_FilterType_Sub :
+					{
+						DecompPtr[p] += PixelLeft[p];
+
+						break;
+					}
+
+					case PNG_FilterType_Up :
+					{
+						DecompPtr[p] += PixelUp[p];
+
+						break;
+					}
+
+					case PNG_FilterType_Average :
+					{
+						DecompPtr[p] += ((uint8_t) ((((uint16_t) PixelLeft[p]) + ((uint16_t) PixelUp[p])) / 2));
+
+						break;
+					}
+
+					case PNG_FilterType_Paeth :
+					{
+						DecompPtr[p] += PredictPaeth(PixelLeft[p], PixelUp[p], PixelUpLeft[p]);
+
+						break;
+					}
+
+					default :
+					{
+						return(qfalse);
+					}
+				}
+			}
+
+			PixelLeft = DecompPtr;
+
+			/*
+			 *  We only have a upleft pixel if we are on the second line or above.
+			 */
+
+			if(h > 0)
+			{
+				PixelUpLeft = DecompPtr - (BytesPerScanline + 1);
+			}
+
+			/*
+			 *  Skip to the next pixel.
+			 */
+
+			DecompPtr += BytesPerPixel;
+
+			/*
+			 *  We only have a previous line if we are on the second line and above.
+			 */
+
+			if(h > 0)
+			{
+				PixelUp = DecompPtr - (BytesPerScanline + 1);
+			}
+		}
+	}
+
+	return(qtrue);
+}
+
+/*
+ *  Convert a raw input pixel to Quake 3 RGA format.
+ */
+
+static qboolean ConvertPixel(struct PNG_Chunk_IHDR *IHDR,
+		byte                  *OutPtr,
+		uint8_t               *DecompPtr,
+		qboolean               HasTransparentColour,
+		uint8_t               *TransparentColour,
+		uint8_t               *OutPal)
+{
+	/*
+	 *  input verification
+	 */
+
+	if(!(IHDR && OutPtr && DecompPtr && TransparentColour && OutPal))
+	{
+		return(qfalse);
+	}
+
+	switch(IHDR->ColourType)
+	{
+		case PNG_ColourType_Grey :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_1 :
+				case PNG_BitDepth_2 :
+				case PNG_BitDepth_4 :
+				{
+					uint8_t Step;
+					uint8_t GreyValue;
+
+					Step = 0xFF / ((1 << IHDR->BitDepth) - 1);
+
+					GreyValue = DecompPtr[0] * Step;
+
+					OutPtr[0] = GreyValue;
+					OutPtr[1] = GreyValue;
+					OutPtr[2] = GreyValue;
+					OutPtr[3] = 0xFF;
+
+					/*
+					 *  Grey supports full transparency for one specified colour
+					 */
+
+					if(HasTransparentColour)
+					{
+						if(TransparentColour[1] == DecompPtr[0])
+						{
+							OutPtr[3] = 0x00;
+						}
+					}
+
+
+					break;
+				}
+
+				case PNG_BitDepth_8 :
+				case PNG_BitDepth_16 :
+				{
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[0];
+					OutPtr[2] = DecompPtr[0];
+					OutPtr[3] = 0xFF;
+
+					/*
+					 *  Grey supports full transparency for one specified colour
+					 */
+
+					if(HasTransparentColour)
+					{
+						if(IHDR->BitDepth == PNG_BitDepth_8)
+						{
+							if(TransparentColour[1] == DecompPtr[0])
+							{
+								OutPtr[3] = 0x00;
+							}
+						}
+						else
+						{
+							if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]))
+							{
+								OutPtr[3] = 0x00;
+							}
+						}
+					}
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_True :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				{
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[1];
+					OutPtr[2] = DecompPtr[2];
+					OutPtr[3] = 0xFF;
+
+					/*
+					 *  True supports full transparency for one specified colour
+					 */
+
+					if(HasTransparentColour)
+					{
+						if((TransparentColour[1] == DecompPtr[0]) &&
+								(TransparentColour[3] == DecompPtr[1]) &&
+								(TransparentColour[5] == DecompPtr[3]))
+						{
+							OutPtr[3] = 0x00;
+						}
+					}
+
+					break;
+				}
+
+				case PNG_BitDepth_16 :
+				{
+					/*
+					 *  We use only the upper byte.
+					 */
+
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[2];
+					OutPtr[2] = DecompPtr[4];
+					OutPtr[3] = 0xFF;
+
+					/*
+					 *  True supports full transparency for one specified colour
+					 */
+
+					if(HasTransparentColour)
+					{
+						if((TransparentColour[0] == DecompPtr[0]) && (TransparentColour[1] == DecompPtr[1]) &&
+								(TransparentColour[2] == DecompPtr[2]) && (TransparentColour[3] == DecompPtr[3]) &&
+								(TransparentColour[4] == DecompPtr[4]) && (TransparentColour[5] == DecompPtr[5]))
+						{
+							OutPtr[3] = 0x00;
+						}
+					}
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_Indexed :
+		{
+			OutPtr[0] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 0];
+			OutPtr[1] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 1];
+			OutPtr[2] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 2];
+			OutPtr[3] = OutPal[DecompPtr[0] * Q3IMAGE_BYTESPERPIXEL + 3];
+
+			break;
+		}
+
+		case PNG_ColourType_GreyAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				{
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[0];
+					OutPtr[2] = DecompPtr[0];
+					OutPtr[3] = DecompPtr[1];
+
+					break;
+				}
+
+				case PNG_BitDepth_16 :
+				{
+					/*
+					 *  We use only the upper byte.
+					 */
+
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[0];
+					OutPtr[2] = DecompPtr[0];
+					OutPtr[3] = DecompPtr[2];
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_TrueAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				{
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[1];
+					OutPtr[2] = DecompPtr[2];
+					OutPtr[3] = DecompPtr[3];
+
+					break;
+				}
+
+				case PNG_BitDepth_16 :
+				{
+					/*
+					 *  We use only the upper byte.
+					 */
+
+					OutPtr[0] = DecompPtr[0];
+					OutPtr[1] = DecompPtr[2];
+					OutPtr[2] = DecompPtr[4];
+					OutPtr[3] = DecompPtr[6];
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		default :
+		{
+			return(qfalse);
+		}
+	}
+
+	return(qtrue);
+}
+
+
+/*
+ *  Decode a non-interlaced image.
+ */
+
+static qboolean DecodeImageNonInterlaced(struct PNG_Chunk_IHDR *IHDR,
+		byte                  *OutBuffer, 
+		uint8_t               *DecompressedData,
+		uint32_t               DecompressedDataLength,
+		qboolean               HasTransparentColour,
+		uint8_t               *TransparentColour,
+		uint8_t               *OutPal)
+{
+	uint32_t IHDR_Width;
+	uint32_t IHDR_Height;
+	uint32_t BytesPerScanline, BytesPerPixel, PixelsPerByte;
+	uint32_t  w, h, p;
+	byte *OutPtr;
+	uint8_t *DecompPtr;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  byte swapping
+	 */
+
+	IHDR_Width  = BigLong(IHDR->Width);
+	IHDR_Height = BigLong(IHDR->Height);
+
+	/*
+	 *  information for un-filtering
+	 */
+
+	switch(IHDR->ColourType)
+	{
+		case PNG_ColourType_Grey :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_1 :
+				case PNG_BitDepth_2 :
+				case PNG_BitDepth_4 :
+				{
+					BytesPerPixel    = 1;
+					PixelsPerByte    = 8 / IHDR->BitDepth;
+
+					break;
+				}
+
+				case PNG_BitDepth_8  :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_True :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8  :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_Indexed :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_1 :
+				case PNG_BitDepth_2 :
+				case PNG_BitDepth_4 :
+				{
+					BytesPerPixel    = 1;
+					PixelsPerByte    = 8 / IHDR->BitDepth;
+
+					break;
+				}
+
+				case PNG_BitDepth_8 :
+				{
+					BytesPerPixel    = PNG_NumColourComponents_Indexed;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_GreyAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_TrueAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		default :
+		{
+			return(qfalse);
+		}
+	}
+
+	/*
+	 *  Calculate the size of one scanline
+	 */
+
+	BytesPerScanline = (IHDR_Width * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
+
+	/*
+	 *  Check if we have enough data for the whole image.
+	 */
+
+	if(!(DecompressedDataLength == ((BytesPerScanline + 1) * IHDR_Height)))
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  Unfilter the image.
+	 */
+
+	if(!UnfilterImage(DecompressedData, IHDR_Height, BytesPerScanline, BytesPerPixel))
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  Set the working pointers to the beginning of the buffers.
+	 */
+
+	OutPtr = OutBuffer;
+	DecompPtr = DecompressedData;
+
+	/*
+	 *  Create the output image.
+	 */
+
+	for(h = 0; h < IHDR_Height; h++)
+	{
+		/*
+		 *  Count the pixels on the scanline for those multipixel bytes
+		 */
+
+		uint32_t CurrPixel;
+
+		/*
+		 *  skip FilterType
+		 */
+
+		DecompPtr++;
+
+		/*
+		 *  Reset the pixel count.
+		 */
+
+		CurrPixel = 0;
+
+		for(w = 0; w < (BytesPerScanline / BytesPerPixel); w++)
+		{
+			if(PixelsPerByte > 1)
+			{
+				uint8_t  Mask;
+				uint32_t Shift;
+				uint8_t  SinglePixel;
+
+				for(p = 0; p < PixelsPerByte; p++)
+				{
+					if(CurrPixel < IHDR_Width)
+					{
+						Mask  = (1 << IHDR->BitDepth) - 1;
+						Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
+
+						SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
+
+						if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
+						{
+							return(qfalse);
+						}
+
+						OutPtr += Q3IMAGE_BYTESPERPIXEL;
+						CurrPixel++;
+					}
+				}
+
+			}
+			else
+			{
+				if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
+				{
+					return(qfalse);
+				}
+
+
+				OutPtr += Q3IMAGE_BYTESPERPIXEL;
+			}
+
+			DecompPtr += BytesPerPixel;
+		}
+	}
+
+	return(qtrue);
+}
+
+/*
+ *  Decode an interlaced image.
+ */
+
+static qboolean DecodeImageInterlaced(struct PNG_Chunk_IHDR *IHDR,
+		byte                  *OutBuffer, 
+		uint8_t               *DecompressedData,
+		uint32_t               DecompressedDataLength,
+		qboolean               HasTransparentColour,
+		uint8_t               *TransparentColour,
+		uint8_t               *OutPal)
+{
+	uint32_t IHDR_Width;
+	uint32_t IHDR_Height;
+	uint32_t BytesPerScanline[PNG_Adam7_NumPasses], BytesPerPixel, PixelsPerByte;
+	uint32_t PassWidth[PNG_Adam7_NumPasses], PassHeight[PNG_Adam7_NumPasses];
+	uint32_t WSkip[PNG_Adam7_NumPasses], WOffset[PNG_Adam7_NumPasses], HSkip[PNG_Adam7_NumPasses], HOffset[PNG_Adam7_NumPasses];
+	uint32_t w, h, p, a;
+	byte *OutPtr;
+	uint8_t *DecompPtr;
+	uint32_t TargetLength;
+
+	/*
+	 *  input verification
+	 */
+
+	if(!(IHDR && OutBuffer && DecompressedData && DecompressedDataLength && TransparentColour && OutPal))
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  byte swapping
+	 */
+
+	IHDR_Width  = BigLong(IHDR->Width);
+	IHDR_Height = BigLong(IHDR->Height);
+
+	/*
+	 *  Skip and Offset for the passes.
+	 */
+
+	WSkip[0]   = 8;
+	WOffset[0] = 0;
+	HSkip[0]   = 8;
+	HOffset[0] = 0;
+
+	WSkip[1]   = 8;
+	WOffset[1] = 4;
+	HSkip[1]   = 8;
+	HOffset[1] = 0;
+
+	WSkip[2]   = 4;
+	WOffset[2] = 0;
+	HSkip[2]   = 8;
+	HOffset[2] = 4;
+
+	WSkip[3]   = 4;
+	WOffset[3] = 2;
+	HSkip[3]   = 4;
+	HOffset[3] = 0;
+
+	WSkip[4]   = 2;
+	WOffset[4] = 0;
+	HSkip[4]   = 4;
+	HOffset[4] = 2;
+
+	WSkip[5]   = 2;
+	WOffset[5] = 1;
+	HSkip[5]   = 2;
+	HOffset[5] = 0;
+
+	WSkip[6]   = 1;
+	WOffset[6] = 0;
+	HSkip[6]   = 2;
+	HOffset[6] = 1;
+
+	/*
+	 *  Calculate the sizes of the passes.
+	 */
+
+	PassWidth[0]  = (IHDR_Width  + 7) / 8;
+	PassHeight[0] = (IHDR_Height + 7) / 8;
+
+	PassWidth[1]  = (IHDR_Width  + 3) / 8;
+	PassHeight[1] = (IHDR_Height + 7) / 8;
+
+	PassWidth[2]  = (IHDR_Width  + 3) / 4;
+	PassHeight[2] = (IHDR_Height + 3) / 8;
+
+	PassWidth[3]  = (IHDR_Width  + 1) / 4;
+	PassHeight[3] = (IHDR_Height + 3) / 4;
+
+	PassWidth[4]  = (IHDR_Width  + 1) / 2;
+	PassHeight[4] = (IHDR_Height + 1) / 4;
+
+	PassWidth[5]  = (IHDR_Width  + 0) / 2;
+	PassHeight[5] = (IHDR_Height + 1) / 2;
+
+	PassWidth[6]  = (IHDR_Width  + 0) / 1;
+	PassHeight[6] = (IHDR_Height + 0) / 2;
+
+	/*
+	 *  information for un-filtering
+	 */
+
+	switch(IHDR->ColourType)
+	{
+		case PNG_ColourType_Grey :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_1 :
+				case PNG_BitDepth_2 :
+				case PNG_BitDepth_4 :
+				{
+					BytesPerPixel    = 1;
+					PixelsPerByte    = 8 / IHDR->BitDepth;
+
+					break;
+				}
+
+				case PNG_BitDepth_8  :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_Grey;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_True :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8  :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_True;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_Indexed :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_1 :
+				case PNG_BitDepth_2 :
+				case PNG_BitDepth_4 :
+				{
+					BytesPerPixel    = 1;
+					PixelsPerByte    = 8 / IHDR->BitDepth;
+
+					break;
+				}
+
+				case PNG_BitDepth_8 :
+				{
+					BytesPerPixel    = PNG_NumColourComponents_Indexed;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_GreyAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_GreyAlpha;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		case PNG_ColourType_TrueAlpha :
+		{
+			switch(IHDR->BitDepth)
+			{
+				case PNG_BitDepth_8 :
+				case PNG_BitDepth_16 :
+				{
+					BytesPerPixel    = (IHDR->BitDepth / 8) * PNG_NumColourComponents_TrueAlpha;
+					PixelsPerByte    = 1;
+
+					break;
+				}
+
+				default :
+				{
+					return(qfalse);
+				}
+			}
+
+			break;
+		}
+
+		default :
+		{
+			return(qfalse);
+		}
+	}
+
+	/*
+	 *  Calculate the size of the scanlines per pass
+	 */
+
+	for(a = 0; a < PNG_Adam7_NumPasses; a++)
+	{
+		BytesPerScanline[a] = (PassWidth[a] * BytesPerPixel + (PixelsPerByte - 1)) / PixelsPerByte;
+	}
+
+	/*
+	 *  Calculate the size of all passes
+	 */
+
+	TargetLength = 0;
+
+	for(a = 0; a < PNG_Adam7_NumPasses; a++)
+	{
+		TargetLength += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
+	}
+
+	/*
+	 *  Check if we have enough data for the whole image.
+	 */
+
+	if(!(DecompressedDataLength == TargetLength))
+	{
+		return(qfalse);
+	}
+
+	/*
+	 *  Unfilter the image.
+	 */
+
+	DecompPtr = DecompressedData;
+
+	for(a = 0; a < PNG_Adam7_NumPasses; a++)
+	{
+		if(!UnfilterImage(DecompPtr, PassHeight[a], BytesPerScanline[a], BytesPerPixel))
+		{
+			return(qfalse);
+		}
+
+		DecompPtr += ((BytesPerScanline[a] + (BytesPerScanline[a] ? 1 : 0)) * PassHeight[a]);
+	}
+
+	/*
+	 *  Set the working pointers to the beginning of the buffers.
+	 */
+
+	DecompPtr = DecompressedData;
+
+	/*
+	 *  Create the output image.
+	 */
+
+	for(a = 0; a < PNG_Adam7_NumPasses; a++)
+	{
+		for(h = 0; h < PassHeight[a]; h++)
+		{
+			/*
+			 *  Count the pixels on the scanline for those multipixel bytes
+			 */
+
+			uint32_t CurrPixel;
+
+			/*
+			 *  skip FilterType
+			 */
+
+			DecompPtr++;
+
+			/*
+			 *  Reset the pixel count.
+			 */
+
+			CurrPixel = 0;
+
+			for(w = 0; w < (BytesPerScanline[a] / BytesPerPixel); w++)
+			{
+				if(PixelsPerByte > 1)
+				{
+					uint8_t  Mask;
+					uint32_t Shift;
+					uint8_t  SinglePixel;
+
+					for(p = 0; p < PixelsPerByte; p++)
+					{
+						if(CurrPixel < PassWidth[a])
+						{
+							Mask  = (1 << IHDR->BitDepth) - 1;
+							Shift = (PixelsPerByte - 1 - p) * IHDR->BitDepth;
+
+							SinglePixel = ((DecompPtr[0] & (Mask << Shift)) >> Shift);
+
+							OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((CurrPixel * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
+
+							if(!ConvertPixel(IHDR, OutPtr, &SinglePixel, HasTransparentColour, TransparentColour, OutPal))
+							{
+								return(qfalse);
+							}
+
+							CurrPixel++;
+						}
+					}
+
+				}
+				else
+				{
+					OutPtr = OutBuffer + (((((h * HSkip[a]) + HOffset[a]) * IHDR_Width) + ((w * WSkip[a]) + WOffset[a])) * Q3IMAGE_BYTESPERPIXEL);
+
+					if(!ConvertPixel(IHDR, OutPtr, DecompPtr, HasTransparentColour, TransparentColour, OutPal))
+					{
+						return(qfalse);
+					}
+				}
+
+				DecompPtr += BytesPerPixel;
+			}
+		}
+	}
+
+	return(qtrue);
+}
+
+/*
+ *  The PNG loader
+ */
+
+void LoadPNG(const char *name, byte **pic, int *width, int *height)
+{
+	struct BufferedFile *ThePNG;
+	byte *OutBuffer;
+	uint8_t *Signature;
+	struct PNG_ChunkHeader *CH;
+	uint32_t ChunkHeaderLength;
+	uint32_t ChunkHeaderType;
+	struct PNG_Chunk_IHDR *IHDR;
+	uint32_t IHDR_Width;
+	uint32_t IHDR_Height;
+	PNG_ChunkCRC *CRC;
+	uint8_t *InPal;
+	uint8_t *DecompressedData;
+	uint32_t DecompressedDataLength;
+	uint32_t i;
+
+	/*
+	 *  palette with 256 RGBA entries
+	 */
+
+	uint8_t OutPal[1024];
+
+	/*
+	 *  transparent colour from the tRNS chunk
+	 */
+
+	qboolean HasTransparentColour = qfalse;
+	uint8_t TransparentColour[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+
+	/*
+	 *  input verification
+	 */
+
+	if(!(name && pic))
+	{
+		return;
+	}
+
+	/*
+	 *  Zero out return values.
+	 */
+
+	*pic = NULL;
+
+	if(width)
+	{
+		*width = 0;
+	}
+
+	if(height)
+	{
+		*height = 0;
+	}
+
+	/*
+	 *  Read the file.
+	 */
+
+	ThePNG = ReadBufferedFile(name);
+	if(!ThePNG)
+	{
+		return;
+	}           
+
+	/*
+	 *  Read the siganture of the file.
+	 */
+
+	Signature = BufferedFileRead(ThePNG, PNG_Signature_Size);
+	if(!Signature)
+	{
+		CloseBufferedFile(ThePNG);
+
+		return;
+	}
+
+	/*
+	 *  Is it a PNG?
+	 */
+
+	if(memcmp(Signature, PNG_Signature, PNG_Signature_Size))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Read the first chunk-header.
+	 */
+
+	CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
+	if(!CH)
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  PNG multi-byte types are in Big Endian
+	 */
+
+	ChunkHeaderLength = BigLong(CH->Length);
+	ChunkHeaderType   = BigLong(CH->Type);
+
+	/*
+	 *  Check if the first chunk is an IHDR.
+	 */
+
+	if(!((ChunkHeaderType == PNG_ChunkType_IHDR) && (ChunkHeaderLength == PNG_Chunk_IHDR_Size)))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Read the IHDR.
+	 */ 
+
+	IHDR = BufferedFileRead(ThePNG, PNG_Chunk_IHDR_Size);
+	if(!IHDR)
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Read the CRC for IHDR
+	 */
+
+	CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
+	if(!CRC)
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Here we could check the CRC if we wanted to.
+	 */
+
+	/*
+	 *  multi-byte type swapping
+	 */
+
+	IHDR_Width  = BigLong(IHDR->Width);
+	IHDR_Height = BigLong(IHDR->Height);
+
+	/*
+	 *  Check if Width and Height are valid.
+	 */
+
+	if(!((IHDR_Width > 0) && (IHDR_Height > 0)))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Do we need to check if the dimensions of the image are valid for Quake3?
+	 */
+
+	/*
+	 *  Check if CompressionMethod and FilterMethod are valid.
+	 */
+
+	if(!((IHDR->CompressionMethod == PNG_CompressionMethod_0) && (IHDR->FilterMethod == PNG_FilterMethod_0)))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Check if InterlaceMethod is valid.
+	 */
+
+	if(!((IHDR->InterlaceMethod == PNG_InterlaceMethod_NonInterlaced)  || (IHDR->InterlaceMethod == PNG_InterlaceMethod_Interlaced)))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return;
+	}
+
+	/*
+	 *  Read palette for an indexed image.
+	 */
+
+	if(IHDR->ColourType == PNG_ColourType_Indexed)
+	{
+		/*
+		 *  We need the palette first.
+		 */
+
+		if(!FindChunk(ThePNG, PNG_ChunkType_PLTE))
+		{
+			CloseBufferedFile(ThePNG);
+
+			return;
+		}
+
+		/*
+		 *  Read the chunk-header.
+		 */
+
+		CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
+		if(!CH)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  PNG multi-byte types are in Big Endian
+		 */
+
+		ChunkHeaderLength = BigLong(CH->Length);
+		ChunkHeaderType   = BigLong(CH->Type);
+
+		/*
+		 *  Check if the chunk is an PLTE.
+		 */
+
+		if(!(ChunkHeaderType == PNG_ChunkType_PLTE))
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  Check if Length is divisible by 3
+		 */
+
+		if(ChunkHeaderLength % 3)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return;   
+		}
+
+		/*
+		 *  Read the raw palette data
+		 */
+
+		InPal = BufferedFileRead(ThePNG, ChunkHeaderLength);
+		if(!InPal)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  Read the CRC for the palette
+		 */
+
+		CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
+		if(!CRC)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  Set some default values.
+		 */
+
+		for(i = 0; i < 256; i++)
+		{
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = 0x00;
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = 0x00;
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = 0x00;
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;  
+		}
+
+		/*
+		 *  Convert to the Quake3 RGBA-format.
+		 */
+
+		for(i = 0; i < (ChunkHeaderLength / 3); i++)
+		{
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 0] = InPal[i*3+0];
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 1] = InPal[i*3+1];
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 2] = InPal[i*3+2];
+			OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = 0xFF;
+		}
+	}
+
+	/*
+	 *  transparency information is sometimes stored in an tRNS chunk
+	 */
+
+	/*
+	 *  Let's see if there is a tRNS chunk
+	 */
+
+	if(FindChunk(ThePNG, PNG_ChunkType_tRNS))
+	{
+		uint8_t *Trans;
+
+		/*
+		 *  Read the chunk-header.
+		 */
+
+		CH = BufferedFileRead(ThePNG, PNG_ChunkHeader_Size);
+		if(!CH)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  PNG multi-byte types are in Big Endian
+		 */
+
+		ChunkHeaderLength = BigLong(CH->Length);
+		ChunkHeaderType   = BigLong(CH->Type);
+
+		/*
+		 *  Check if the chunk is an tRNS.
+		 */
+
+		if(!(ChunkHeaderType == PNG_ChunkType_tRNS))
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  Read the transparency information.
+		 */
+
+		Trans = BufferedFileRead(ThePNG, ChunkHeaderLength);
+		if(!Trans)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return;  
+		}
+
+		/*
+		 *  Read the CRC.
+		 */
+
+		CRC = BufferedFileRead(ThePNG, PNG_ChunkCRC_Size);
+		if(!CRC)
+		{
+			CloseBufferedFile(ThePNG);
+
+			return; 
+		}
+
+		/*
+		 *  Only for Grey, True and Indexed ColourType should tRNS exist.
+		 */
+
+		switch(IHDR->ColourType)
+		{
+			case PNG_ColourType_Grey :
+			{
+				if(!ChunkHeaderLength == 2)
+				{
+					CloseBufferedFile(ThePNG);
+
+					return;    
+				}
+
+				HasTransparentColour = qtrue;
+
+				/*
+				 *  Grey can have one colour which is completely transparent.
+				 *  This colour is always stored in 16 bits.
+				 */
+
+				TransparentColour[0] = Trans[0];
+				TransparentColour[1] = Trans[1];
+
+				break;
+			}
+
+			case PNG_ColourType_True :
+			{
+				if(!ChunkHeaderLength == 6)
+				{
+					CloseBufferedFile(ThePNG);
+
+					return;    
+				}
+
+				HasTransparentColour = qtrue;
+
+				/*
+				 *  True can have one colour which is completely transparent.
+				 *  This colour is always stored in 16 bits.
+				 */
+
+				TransparentColour[0] = Trans[0];
+				TransparentColour[1] = Trans[1];
+				TransparentColour[2] = Trans[2];
+				TransparentColour[3] = Trans[3];
+				TransparentColour[4] = Trans[4];
+				TransparentColour[5] = Trans[5];
+
+				break;
+			}
+
+			case PNG_ColourType_Indexed :
+			{
+				/*
+				 *  Maximum of 256 one byte transparency entries.
+				 */
+
+				if(ChunkHeaderLength > 256)
+				{
+					CloseBufferedFile(ThePNG);
+
+					return;    
+				}
+
+				HasTransparentColour = qtrue;
+
+				/*
+				 *  alpha values for palette entries
+				 */
+
+				for(i = 0; i < ChunkHeaderLength; i++)
+				{
+					OutPal[i * Q3IMAGE_BYTESPERPIXEL + 3] = Trans[i];
+				}
+
+				break;
+			}
+
+			/*
+			 *  All other ColourTypes should not have tRNS chunks
+			 */
+
+			default :
+			{
+				CloseBufferedFile(ThePNG);
+
+				return;
+			}
+		} 
+	}
+
+	/*
+	 *  Rewind to the start of the file.
+	 */
+
+	if(!BufferedFileRewind(ThePNG, -1))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Skip the signature
+	 */
+
+	if(!BufferedFileSkip(ThePNG, PNG_Signature_Size))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return; 
+	}
+
+	/*
+	 *  Decompress all IDAT chunks
+	 */
+
+	DecompressedDataLength = DecompressIDATs(ThePNG, &DecompressedData);
+	if(!(DecompressedDataLength && DecompressedData))
+	{
+		CloseBufferedFile(ThePNG);
+
+		return;
+	}
+
+	/*
+	 *  Allocate output buffer.
+	 */
+
+	OutBuffer = ri.Malloc(IHDR_Width * IHDR_Height * Q3IMAGE_BYTESPERPIXEL); 
+	if(!OutBuffer)
+	{
+		ri.Free(DecompressedData); 
+		CloseBufferedFile(ThePNG);
+
+		return;  
+	}
+
+	/*
+	 *  Interlaced and Non-interlaced images need to be handled differently.
+	 */
+
+	switch(IHDR->InterlaceMethod)
+	{
+		case PNG_InterlaceMethod_NonInterlaced :
+		{
+			if(!DecodeImageNonInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
+			{
+				ri.Free(OutBuffer); 
+				ri.Free(DecompressedData); 
+				CloseBufferedFile(ThePNG);
+
+				return;
+			}
+
+			break;
+		}
+
+		case PNG_InterlaceMethod_Interlaced :
+		{
+			if(!DecodeImageInterlaced(IHDR, OutBuffer, DecompressedData, DecompressedDataLength, HasTransparentColour, TransparentColour, OutPal))
+			{
+				ri.Free(OutBuffer); 
+				ri.Free(DecompressedData); 
+				CloseBufferedFile(ThePNG);
+
+				return;
+			}
+
+			break;
+		}
+
+		default :
+		{
+			ri.Free(OutBuffer); 
+			ri.Free(DecompressedData); 
+			CloseBufferedFile(ThePNG);
+
+			return;
+		}
+	}
+
+	/*
+	 *  update the pointer to the image data
+	 */
+
+	*pic = OutBuffer;
+
+	/*
+	 *  Fill width and height.
+	 */
+
+	if(width)
+	{
+		*width = IHDR_Width;
+	}
+
+	if(height)
+	{
+		*height = IHDR_Height;
+	}
+
+	/*
+	 *  DecompressedData is not needed anymore.
+	 */
+
+	ri.Free(DecompressedData); 
+
+	/*
+	 *  We have all data, so close the file.
+	 */
+
+	CloseBufferedFile(ThePNG);
+}
diff --git a/code/renderer/tr_image_png.h b/code/renderer/tr_image_png.h
new file mode 100644
index 0000000..a313e68
--- /dev/null
+++ b/code/renderer/tr_image_png.h
@@ -0,0 +1 @@
+void LoadPNG( const char *name, byte **pic, int *width, int *height );