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annotate README.pandora @ 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 | 494559cc723b |
children |
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3161
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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1 SDL 1.3 with open pandora console support ( http://openpandora.org/ ) |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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2 ===================================================================== |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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3 |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
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4 - A pandora specific video driver was writed to allow SDL 1.3 with OpenGL ES |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
5 support to work on the pandora under the framebuffer. This driver do not have |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
6 input support for now, so if you use it you will have to add your own control code. |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
7 The video driver name is "pandora" so if you have problem running it from |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
8 the framebuffer, try to set the following variable before starting your application : |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
9 "export SDL_VIDEODRIVER=pandora" |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
10 |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
11 - OpenGL ES support was added to the x11 driver, so it's working like the normal |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
12 x11 driver one with OpenGLX support, with SDL input event's etc.. |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
13 |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
14 |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
15 David Carré (Cpasjuste) |
494559cc723b
OpenPandora support added by David Carré
Sam Lantinga <slouken@libsdl.org>
parents:
diff
changeset
|
16 cpasjuste@gmail.com |