Mercurial > sdl-ios-xcode
annotate README.BeOS @ 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> |
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date | Sat, 03 Oct 2009 16:23:16 +0000 |
parents | e2641c13bf33 |
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1371
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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1 |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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2 SDL on BeOS R5 |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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3 ============== |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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4 |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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5 You can build SDL on BeOS like any other GNU style package. |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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6 e.g. ./configure && make && make install |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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7 By default it is installed in /boot/develop/tools/gnupro/{bin,lib,etc.} |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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8 |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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9 Once you install SDL, you need to copy libSDL.so to /boot/home/config/lib, |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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10 so it can be found by the dynamic linker. |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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11 |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
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12 Enjoy! |
e2641c13bf33
Added a reminder on where to put libSDL.so
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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13 Sam Lantinga (slouken@libsdl.org) |