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view README.WinCE @ 3333:b334b4f7dfa0
[SDL] Bad math in SDL_RenderCopy
Mason Wheeler to sdl
When I tried to render an image using something other than NULL for srcrect, it got horribly distorted. I traced it down to the fact that the math in the rectangle adjustments performed just before the call to renderer->RenderCopy is written inside out. It should look like this:
if (dstrect->w != real_dstrect.w) {
int deltax = (dstrect->x - real_dstrect.x);
int deltaw = (dstrect->w - real_dstrect.w);
real_srcrect.x += (deltax * real_srcrect.w) / dstrect->w;
real_srcrect.w += (deltaw * real_srcrect.w) / dstrect->w;
}
if (dstrect->h != real_dstrect.h) {
int deltay = (dstrect->y - real_dstrect.y);
int deltah = (dstrect->h - real_dstrect.h);
real_srcrect.y += (deltay * real_srcrect.h) / dstrect->h;
real_srcrect.h += (deltah * real_srcrect.h) / dstrect->h;
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sat, 03 Oct 2009 16:23:16 +0000 |
| parents | 86d0d01290ea |
| children |
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Project files for embedded Visual C++ 3.0, 4.0 and Visual Studio 2005 can be found in VisualCE.zip SDL supports GAPI and WinDib output for Windows CE. GAPI driver supports: - all possible WinCE devices (Pocket PC, Smartphones, HPC) with different orientations of video memory and resolutions. - 4, 8 and 16 bpp devices - special handling of 8bpp on 8bpp devices - VGA mode, you can even switch between VGA and GAPI in runtime (between 240x320 and 480x640 for example). On VGA devices you can use either GAPI or VGA. - Landscape mode and automatic rotation of buttons and stylus coordinates. To enable landscape mode make width of video screen bigger than height. For example: SDL_SetVideoMode(320,240,16,SDL_FULLSCREEN) - WM2005 - SDL_ListModes NOTE: There are several SDL features not available in the WinCE port of SDL. - DirectX is not yet available - Semaphores are not available - Joystick support is not available - CD-ROM control is not available In addition, there are several features that run in "degraded" mode: Preprocessor Symbol Effect =================== ================================= SDL_systimer.c: USE_GETTICKCOUNT Less accurate values for SDL time functions USE_SETTIMER Use only a single marginally accurate timer SDL_syswm.c: DISABLE_ICON_SUPPORT Can't set the runtime window icon SDL_sysmouse.c: USE_STATIC_CURSOR Only the arrow cursor is available SDL_sysevents.c: NO_GETKEYBOARDSTATE Can't get modifier state on keyboard focus SDL_dibevents.c: NO_GETKEYBOARDSTATE Very limited keycode translation SDL_dibvideo.c: NO_GETDIBITS Can't distinguish between 15 bpp and 16 bpp NO_CHANGEDISPLAYSETTINGS No fullscreen support NO_GAMMA_SUPPORT Gamma correction not available