Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_MMX.h @ 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 | c121d94672cb |
children | 4d46850be3f6 |
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/* headers for MMX assembler version of SDL_MixAudio Copyright 2002 Stephane Marchesin (stephane.marchesin@wanadoo.fr) This code is licensed under the LGPL (see COPYING for details) Assumes buffer size in bytes is a multiple of 16 Assumes SDL_MIX_MAXVOLUME = 128 */ #include "SDL_config.h" #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES) void SDL_MixAudio_MMX_S16(char *, char *, unsigned int, int); void SDL_MixAudio_MMX_S8(char *, char *, unsigned int, int); #endif /* vi: set ts=4 sw=4 expandtab: */