Mercurial > sdl-ios-xcode
view INSTALL @ 1259:36f24cdfcda7
te: Thu, 17 Apr 2003 11:25:26 -0700
From: "Jim"
Subject: [SDL] Frame buffer patches...
Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression...
for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y
ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu
lated patch to typecast the unsigned values to (int)
- *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
+ *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);
and also to provide quite failure to operations which have the screen currently locked...
The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr
ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well.
..
Jim
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 24 Jan 2006 06:36:43 +0000 |
parents | 0a45995a7fc3 |
children | 00e7c6b7eb03 |
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To compile and install SDL: 1. Run './configure; make; make install' If you are compiling for Windows using gcc, read the FAQ at: http://www.libsdl.org/faq.php?action=listentries&category=4#42 If you are compiling using Visual C++ on Win32, you should read the file VisualC.html 2. Look at the example programs in ./test, and check out the HTML documentation in ./docs to see how to use the SDL library. 3. Join the SDL developer mailing list by sending E-mail to sdl-request@libsdl.org and put "subscribe" in the subject of the message. Or alternatively you can use the web interface: http://www.libsdl.org/mailing-list.php That's it! Sam Lantinga <slouken@libsdl.org>