annotate INSTALL @ 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
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2 To compile and install SDL:
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4 1. Run './configure; make; make install'
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0a45995a7fc3 Date: Tue, 2 Mar 2004 11:34:54 +0100
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6 If you are compiling for Windows using gcc, read the FAQ at:
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7 http://www.libsdl.org/faq.php?action=listentries&category=4#42
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9 If you are compiling using Visual C++ on Win32, you should read
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10 the file VisualC.html
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12 2. Look at the example programs in ./test, and check out the HTML
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13 documentation in ./docs to see how to use the SDL library.
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15 3. Join the SDL developer mailing list by sending E-mail to
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16 sdl-request@libsdl.org
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17 and put "subscribe" in the subject of the message.
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19 Or alternatively you can use the web interface:
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20 http://www.libsdl.org/mailing-list.php
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22 That's it!
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23 Sam Lantinga <slouken@libsdl.org>