view docs/man3/SDL_Color.3 @ 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
parents 546f7c1eb755
children 1238da4a7112
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.TH "SDL_Color" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_Color \- Format independent color description
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 r;
  Uint8 g;
  Uint8 b;
  Uint8 unused;
} SDL_Color;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBr\fR
Red intensity
.TP 20
\fBg\fR
Green intensity
.TP 20
\fBb\fR
Blue intensity
.TP 20
\fBunused\fR
Unused
.SH "DESCRIPTION"
.PP
\fBSDL_Color\fR describes a color in a format independent way\&. You can convert a \fBSDL_Color\fR to a pixel value for a certain pixel format using \fI\fBSDL_MapRGB\fP\fR\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_SetColors\fP\fR, \fI\fBSDL_Palette\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01