Better altivec cvar handling. Should fix crashes at startup, or curious

people that toggle it on at runtime on a G3.


git-svn-id: svn://svn.icculus.org/quake3/trunk@410 edf5b092-35ff-0310-97b2-ce42778d08ea

2 files changed, 30 insertions, 2 deletions

diff --git a/code/qcommon/common.c b/code/qcommon/common.c
index 690d5bd..3839f7b 100644
--- a/code/qcommon/common.c
+++ b/code/qcommon/common.c
@@ -2353,6 +2353,24 @@ out:
 #endif
 
 
+static void Com_DetectAltivec(void)
+{
+	// Only detect if user hasn't forcibly disabled it.
+	if (com_altivec->integer) {
+		static qboolean altivec = qfalse;
+		static qboolean detected = qfalse;
+		if (!detected) {
+			altivec = Sys_DetectAltivec();
+			detected = qtrue;
+		}
+
+		if (!altivec) {
+			Cvar_Set( "com_altivec", "0" );  // we don't have it! Disable support!
+		}
+	}
+}
+
+
 /*
 =================
 Com_Init
@@ -2510,9 +2528,11 @@ void Com_Init( char *commandLine ) {
 
 	com_fullyInitialized = qtrue;
 
-    #if idppc_altivec
+	// always set the cvar, but only print the info if it makes sense.
+	Com_DetectAltivec();
+	#if idppc
 	Com_Printf ("Altivec support is %s\n", com_altivec->integer ? "enabled" : "disabled");
-    #endif
+	#endif
 
 	Com_Printf ("--- Common Initialization Complete ---\n");
 }
@@ -2713,6 +2733,12 @@ void Com_Frame( void ) {
 	} while ( msec < minMsec );
 	Cbuf_Execute ();
 
+	if (com_altivec->modified)
+	{
+		Com_DetectAltivec();
+		com_altivec->modified = qfalse;
+	}
+
 	lastTime = com_frameTime;
 
 	// mess with msec if needed
diff --git a/code/qcommon/qcommon.h b/code/qcommon/qcommon.h
index 35e44dd..01f4564 100644
--- a/code/qcommon/qcommon.h
+++ b/code/qcommon/qcommon.h
@@ -1033,6 +1033,8 @@ unsigned int Sys_ProcessorCount( void );
 
 int Sys_MonkeyShouldBeSpanked( void );
 
+qboolean Sys_DetectAltivec( void );
+
 /* This is based on the Adaptive Huffman algorithm described in Sayood's Data
  * Compression book.  The ranks are not actually stored, but implicitly defined
  * by the location of a node within a doubly-linked list */