aboutsummaryrefslogtreecommitdiffstats
path: root/src/win32/init.rs
blob: c3352b6dd7979fe2b974e205e333e5a3398f3fd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
use std::sync::atomic::AtomicBool;
use std::ptr;
use super::callback;
use super::Window;
use BuilderAttribs;
use CreationError;
use CreationError::OsError;

use std::ffi::CString;
use std::sync::mpsc::channel;

use libc;
use super::gl;
use winapi;
use kernel32;
use user32;
use gdi32;

/// Work-around the fact that HGLRC doesn't implement Send
pub struct ContextHack(pub winapi::HGLRC);
unsafe impl Send for ContextHack {}

pub fn new_window(builder: BuilderAttribs<'static>, builder_sharelists: Option<ContextHack>)
                  -> Result<Window, CreationError>
{
    use std::mem;
    use std::os;

    // initializing variables to be sent to the task
    let title = builder.title.as_slice().utf16_units()
        .chain(Some(0).into_iter()).collect::<Vec<u16>>();    // title to utf16
    //let hints = hints.clone();
    let (tx, rx) = channel();

    // GetMessage must be called in the same thread as CreateWindow,
    //  so we create a new thread dedicated to this window.
    // This is the only safe method. Using `nosend` wouldn't work for non-native runtime.
    ::std::thread::Thread::spawn(move || {
        let builder_sharelists = builder_sharelists.map(|s| s.0);

        // registering the window class
        let class_name = {
            let class_name: Vec<u16> = "Window Class".utf16_units().chain(Some(0).into_iter())
                .collect::<Vec<u16>>();
            
            let class = winapi::WNDCLASSEXW {
                cbSize: mem::size_of::<winapi::WNDCLASSEXW>() as winapi::UINT,
                style: winapi::CS_HREDRAW | winapi::CS_VREDRAW | winapi::CS_OWNDC,
                lpfnWndProc: callback::callback,
                cbClsExtra: 0,
                cbWndExtra: 0,
                hInstance: unsafe { kernel32::GetModuleHandleW(ptr::null()) },
                hIcon: ptr::null_mut(),
                hCursor: ptr::null_mut(),
                hbrBackground: ptr::null_mut(),
                lpszMenuName: ptr::null(),
                lpszClassName: class_name.as_ptr(),
                hIconSm: ptr::null_mut(),
            };

            // We ignore errors because registering the same window class twice would trigger
            //  an error, and because errors here are detected during CreateWindowEx anyway.
            // Also since there is no weird element in the struct, there is no reason for this
            //  call to fail.
            unsafe { user32::RegisterClassExW(&class) };

            class_name
        };

        // building a RECT object with coordinates
        let mut rect = winapi::RECT {
            left: 0, right: builder.dimensions.unwrap_or((1024, 768)).0 as winapi::LONG,
            top: 0, bottom: builder.dimensions.unwrap_or((1024, 768)).1 as winapi::LONG,
        };

        // switching to fullscreen if necessary
        // this means adjusting the window's position so that it overlaps the right monitor,
        //  and change the monitor's resolution if necessary
        if builder.monitor.is_some() {
            let monitor = builder.monitor.as_ref().unwrap();

            // adjusting the rect
            {
                let pos = monitor.get_position();
                rect.left += pos.0 as winapi::LONG;
                rect.right += pos.0 as winapi::LONG;
                rect.top += pos.1 as winapi::LONG;
                rect.bottom += pos.1 as winapi::LONG;
            }

            // changing device settings
            let mut screen_settings: winapi::DEVMODEW = unsafe { mem::zeroed() };
            screen_settings.dmSize = mem::size_of::<winapi::DEVMODEW>() as winapi::WORD;
            screen_settings.dmPelsWidth = (rect.right - rect.left) as winapi::DWORD;
            screen_settings.dmPelsHeight = (rect.bottom - rect.top) as winapi::DWORD;
            screen_settings.dmBitsPerPel = 32;      // TODO: ?
            screen_settings.dmFields = winapi::DM_BITSPERPEL | winapi::DM_PELSWIDTH | winapi::DM_PELSHEIGHT;

            let result = unsafe { user32::ChangeDisplaySettingsExW(monitor.get_system_name().as_ptr(),
                &mut screen_settings, ptr::null_mut(), winapi::CDS_FULLSCREEN, ptr::null_mut()) };
            
            if result != winapi::DISP_CHANGE_SUCCESSFUL {
                tx.send(Err(OsError(format!("ChangeDisplaySettings failed: {}", result))));
                return;
            }
        }

        // computing the style and extended style of the window
        let (ex_style, style) = if builder.monitor.is_some() {
            (winapi::WS_EX_APPWINDOW, winapi::WS_POPUP | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
        } else {
            (winapi::WS_EX_APPWINDOW | winapi::WS_EX_WINDOWEDGE,
                winapi::WS_OVERLAPPEDWINDOW | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
        };

        // adjusting the window coordinates using the style
        unsafe { user32::AdjustWindowRectEx(&mut rect, style, 0, ex_style) };

        // getting the address of wglCreateContextAttribsARB and the pixel format
        //  that we will use
        let (extra_functions, pixel_format) = {
            // creating a dummy invisible window for GL initialization
            let dummy_window = unsafe {
                let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(),
                    title.as_ptr() as winapi::LPCWSTR,
                    style | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN,
                    winapi::CW_USEDEFAULT, winapi::CW_USEDEFAULT,
                    rect.right - rect.left, rect.bottom - rect.top,
                    ptr::null_mut(), ptr::null_mut(), kernel32::GetModuleHandleW(ptr::null()),
                    ptr::null_mut());

                if handle.is_null() {
                    use std::os;
                    tx.send(Err(OsError(format!("CreateWindowEx function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    return;
                }

                handle
            };

            // getting the HDC of the dummy window
            let dummy_hdc = {
                let hdc = unsafe { user32::GetDC(dummy_window) };
                if hdc.is_null() {
                    tx.send(Err(OsError(format!("GetDC function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    unsafe { user32::DestroyWindow(dummy_window); }
                    return;
                }
                hdc
            };

            // getting the pixel format that we will use
            let pixel_format = {
                // initializing a PIXELFORMATDESCRIPTOR that indicates what we want
                let mut output: winapi::PIXELFORMATDESCRIPTOR = unsafe { mem::zeroed() };
                output.nSize = mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::WORD;
                output.nVersion = 1;
                output.dwFlags = winapi::PFD_DRAW_TO_WINDOW | winapi::PFD_DOUBLEBUFFER |
                    winapi::PFD_SUPPORT_OPENGL | winapi::PFD_GENERIC_ACCELERATED;
                output.iPixelType = winapi::PFD_TYPE_RGBA;
                output.cColorBits = 24;
                output.cAlphaBits = 8;
                output.cAccumBits = 0;
                output.cDepthBits = 24;
                output.cStencilBits = 8;
                output.cAuxBuffers = 0;
                output.iLayerType = winapi::PFD_MAIN_PLANE;

                let pf_index = unsafe { gdi32::ChoosePixelFormat(dummy_hdc, &output) };

                if pf_index == 0 {
                    tx.send(Err(OsError(format!("ChoosePixelFormat function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    unsafe { user32::DestroyWindow(dummy_window); }
                    return;
                }

                if unsafe { gdi32::DescribePixelFormat(dummy_hdc, pf_index,
                    mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::UINT, &mut output) } == 0
                {
                    tx.send(Err(OsError(format!("DescribePixelFormat function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    unsafe { user32::DestroyWindow(dummy_window); }
                    return;
                }

                output
            };

            // calling SetPixelFormat
            unsafe {
                if gdi32::SetPixelFormat(dummy_hdc, 1, &pixel_format) == 0 {
                    tx.send(Err(OsError(format!("SetPixelFormat function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    user32::DestroyWindow(dummy_window);
                    return;
                }
            }

            // creating the dummy OpenGL context
            let dummy_context = {
                let ctxt = unsafe { gl::wgl::CreateContext(dummy_hdc as *const libc::c_void) };
                if ctxt.is_null() {
                    tx.send(Err(OsError(format!("wglCreateContext function failed: {}",
                        os::error_string(os::errno() as usize)))));
                    unsafe { user32::DestroyWindow(dummy_window); }
                    return;
                }
                ctxt
            };

            // making context current
            unsafe { gl::wgl::MakeCurrent(dummy_hdc as *const libc::c_void, dummy_context); }

            // loading the extra WGL functions
            let extra_functions = gl::wgl_extra::Wgl::load_with(|addr| {
                use libc;

                let addr = CString::from_slice(addr.as_bytes());
                let addr = addr.as_slice_with_nul().as_ptr();

                unsafe {
                    gl::wgl::GetProcAddress(addr) as *const libc::c_void
                }
            });

            // removing current context
            unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }

            // destroying the context and the window
            unsafe { gl::wgl::DeleteContext(dummy_context); }
            unsafe { user32::DestroyWindow(dummy_window); }

            // returning the address
            (extra_functions, pixel_format)
        };

        // creating the real window this time
        let real_window = unsafe {
            let (width, height) = if builder.monitor.is_some() || builder.dimensions.is_some() {
                (Some(rect.right - rect.left), Some(rect.bottom - rect.top))
            } else {
                (None, None)
            };

            let style = if !builder.visible || builder.headless {
                style
            } else {
                style | winapi::WS_VISIBLE
            };

            let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(),
                title.as_ptr() as winapi::LPCWSTR,
                style | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN,
                if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
                if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
                width.unwrap_or(winapi::CW_USEDEFAULT), height.unwrap_or(winapi::CW_USEDEFAULT),
                ptr::null_mut(), ptr::null_mut(), kernel32::GetModuleHandleW(ptr::null()),
                ptr::null_mut());

            if handle.is_null() {
                use std::os;
                tx.send(Err(OsError(format!("CreateWindowEx function failed: {}",
                    os::error_string(os::errno() as usize)))));
                return;
            }

            handle
        };

        // getting the HDC of the window
        let hdc = {
            let hdc = unsafe { user32::GetDC(real_window) };
            if hdc.is_null() {
                tx.send(Err(OsError(format!("GetDC function failed: {}",
                    os::error_string(os::errno() as usize)))));
                unsafe { user32::DestroyWindow(real_window); }
                return;
            }
            hdc
        };

        // calling SetPixelFormat
        unsafe {
            if gdi32::SetPixelFormat(hdc, 1, &pixel_format) == 0 {
                tx.send(Err(OsError(format!("SetPixelFormat function failed: {}",
                    os::error_string(os::errno() as usize)))));
                user32::DestroyWindow(real_window);
                return;
            }
        }

        // creating the OpenGL context
        let context = {
            use libc;

            let mut attributes = Vec::new();

            if builder.gl_version.is_some() {
                let version = builder.gl_version.as_ref().unwrap();
                attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
                attributes.push(version.0 as libc::c_int);
                attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
                attributes.push(version.1 as libc::c_int);
            }

            if builder.gl_debug {
                attributes.push(gl::wgl_extra::CONTEXT_FLAGS_ARB as libc::c_int);
                attributes.push(gl::wgl_extra::CONTEXT_DEBUG_BIT_ARB as libc::c_int);
            }

            attributes.push(0);

            let ctxt = unsafe {
                if extra_functions.CreateContextAttribsARB.is_loaded() {
                    let share = if let Some(c) = builder_sharelists { c } else { ptr::null_mut() };
                    extra_functions.CreateContextAttribsARB(hdc as *const libc::c_void,
                                                            share as *const libc::c_void,
                                                            attributes.as_slice().as_ptr())

                } else {
                    let ctxt = gl::wgl::CreateContext(hdc as *const libc::c_void);
                    if let Some(c) = builder_sharelists {
                        gl::wgl::ShareLists(c as *const libc::c_void, ctxt);
                    };
                    ctxt
                }
            };

            if ctxt.is_null() {
                tx.send(Err(OsError(format!("OpenGL context creation failed: {}",
                    os::error_string(os::errno() as usize)))));
                unsafe { user32::DestroyWindow(real_window); }
                return;
            }

            ctxt
        };

        // calling SetForegroundWindow if fullscreen
        if builder.monitor.is_some() {
            unsafe { user32::SetForegroundWindow(real_window) };
        }

        // filling the WINDOW task-local storage
        let events_receiver = {
            let (tx, rx) = channel();
            let mut tx = Some(tx);
            callback::WINDOW.with(|window| {
                (*window.borrow_mut()) = Some((real_window, tx.take().unwrap()));
            });
            rx
        };

        // loading the opengl32 module
        let gl_library = {
            let name = "opengl32.dll".utf16_units().chain(Some(0).into_iter())
                .collect::<Vec<u16>>().as_ptr();
            let lib = unsafe { kernel32::LoadLibraryW(name) };
            if lib.is_null() {
                tx.send(Err(OsError(format!("LoadLibrary function failed: {}",
                    os::error_string(os::errno() as usize)))));
                unsafe { gl::wgl::DeleteContext(context); }
                unsafe { user32::DestroyWindow(real_window); }
                return;
            }
            lib
        };

        // handling vsync
        if builder.vsync {
            if extra_functions.SwapIntervalEXT.is_loaded() {
                unsafe { gl::wgl::MakeCurrent(hdc as *const libc::c_void, context) };
                if unsafe { extra_functions.SwapIntervalEXT(1) } == 0 {
                    tx.send(Err(OsError(format!("wglSwapIntervalEXT failed"))));
                    unsafe { gl::wgl::DeleteContext(context); }
                    unsafe { user32::DestroyWindow(real_window); }
                    return;
                }

                // it is important to remove the current context, otherwise you get very weird
                // errors
                unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }
            }
        }

        // building the struct
        let window = Window{
            window: real_window,
            hdc: hdc as winapi::HDC,
            context: context as winapi::HGLRC,
            gl_library: gl_library,
            events_receiver: events_receiver,
            is_closed: AtomicBool::new(false),
        };

        // sending
        tx.send(Ok(window));

        // now that the `Window` struct is initialized, the main `Window::new()` function will
        //  return and this events loop will run in parallel
        loop {
            let mut msg = unsafe { mem::uninitialized() };

            if unsafe { user32::GetMessageW(&mut msg, ptr::null_mut(), 0, 0) } == 0 {
                break;
            }

            unsafe { user32::TranslateMessage(&msg) };
            unsafe { user32::DispatchMessageW(&msg) };     // calls `callback` (see below)
        }
    });

    rx.recv().unwrap()
}