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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 e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_FillRect" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_FillRect\- This function performs a fast fill of the given rectangle with some color
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_FillRect\fP\fR(\fBSDL_Surface *dst, SDL_Rect *dstrect, Uint32 color\fR);
.SH "DESCRIPTION"
.PP
This function performs a fast fill of the given rectangle with \fBcolor\fR\&. If \fBdstrect\fR is \fBNULL\fP, the whole surface will be filled with \fBcolor\fR\&.
.PP
The color should be a pixel of the format used by the surface, and can be generated by the \fISDL_MapRGB\fR or \fISDL_MapRGBA\fR functions\&. If the color value contains an alpha value then the destination is simply "filled" with that alpha information, no blending takes place\&.
.PP
If there is a clip rectangle set on the destination (set via \fISDL_SetClipRect\fR) then this function will clip based on the intersection of the clip rectangle and the \fBdstrect\fR rectangle and the dstrect rectangle will be modified to represent the area actually filled\&.
.SH "RETURN VALUE"
.PP
This function returns \fB0\fR on success, or \fB-1\fR on error\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_MapRGB\fP\fR, \fI\fBSDL_MapRGBA\fP\fR, \fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_Rect\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01