Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SetColors.3 @ 2359:b70b96e615d2 gsoc2008_iphone
These files are the OpenGL ES render driver. You should be able to use them on any platform that supports OpenGL ES -- not just iPhone. The driver is based off the OpenGL render driver.
There are a few differences between OpenGL and OpenGL ES that present difficulties for this driver:
- OpenGL ES does NOT support many pixel formats (for example, no GL_BGR). Also, when using texture functions format and internalFormat must be the same -- this means 32 bit packed formats like SDL_PIXELFORMAT_BGR888 cannot be automatically converted to GL_RGB (which is 24bpp).
- OpenGL ES doesn't have GL_PACK_ROW_LENGTH, which means data must be reformatted before uploading changes to dirty rects. This change has been added.
- OpenGL ES doesn't support paletted textures, though there is an extension. I'm looking into this.
Some other notable differences:
- OpenGL ES has an extension called GL_OES_draw_texture which allows for quicker 2D sprite-type drawing. I use this in GL_RenderCopy when it is available. The iPhone supports the extension, but the iPhone Simulator does not (presently).
- No glBegin() / glEnd() and no GL_QUADS! I'm using glDrawArrays with GL_TRIANGLE_STRIP instead!
| author | Holmes Futrell <hfutrell@umail.ucsb.edu> |
|---|---|
| date | Thu, 17 Jul 2008 23:31:42 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| rev | line source |
|---|---|
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1 .TH "SDL_SetColors" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
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Merged revision 3472 from SDL 1.2, fixing bug #493
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3 SDL_SetColors \- Sets a portion of the colormap for the given 8-bit surface\&. |
| 0 | 4 .SH "SYNOPSIS" |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 .sp | |
| 8 \fBint \fBSDL_SetColors\fP\fR(\fBSDL_Surface *surface, SDL_Color *colors, int firstcolor, int ncolors\fR); | |
| 9 .SH "DESCRIPTION" | |
| 10 .PP | |
| 11 Sets a portion of the colormap for the given 8-bit surface\&. | |
| 12 .PP | |
| 13 When \fBsurface\fR is the surface associated with the current display, the display colormap will be updated with the requested colors\&. If \fBSDL_HWPALETTE\fP was set in \fISDL_SetVideoMode\fR flags, \fBSDL_SetColors\fP will always return \fB1\fR, and the palette is guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation\&. | |
| 14 .PP | |
| 15 The color components of a \fI\fBSDL_Color\fR\fR structure are 8-bits in size, giving you a total of 256^3 =16777216 colors\&. | |
| 16 .PP | |
| 17 Palettized (8-bit) screen surfaces with the \fBSDL_HWPALETTE\fP flag have two palettes, a logical palette that is used for mapping blits to/from the surface and a physical palette (that determines how the hardware will map the colors to the display)\&. \fBSDL_SetColors\fP modifies both palettes (if present), and is equivalent to calling \fISDL_SetPalette\fR with the \fBflags\fR set to \fB(SDL_LOGPAL | SDL_PHYSPAL)\fP\&. | |
| 18 .SH "RETURN VALUE" | |
| 19 .PP | |
| 20 If \fBsurface\fR is not a palettized surface, this function does nothing, returning \fB0\fR\&. If all of the colors were set as passed to \fBSDL_SetColors\fP, it will return \fB1\fR\&. If not all the color entries were set exactly as given, it will return \fB0\fR, and you should look at the surface palette to determine the actual color palette\&. | |
| 21 .SH "EXAMPLE" | |
| 22 .PP | |
| 23 .nf | |
| 24 \f(CW/* Create a display surface with a grayscale palette */ | |
| 25 SDL_Surface *screen; | |
| 26 SDL_Color colors[256]; | |
| 27 int i; | |
| 28 \&. | |
| 29 \&. | |
| 30 \&. | |
| 31 /* Fill colors with color information */ | |
| 32 for(i=0;i<256;i++){ | |
| 33 colors[i]\&.r=i; | |
| 34 colors[i]\&.g=i; | |
| 35 colors[i]\&.b=i; | |
| 36 } | |
| 37 | |
| 38 /* Create display */ | |
| 39 screen=SDL_SetVideoMode(640, 480, 8, SDL_HWPALETTE); | |
| 40 if(!screen){ | |
| 41 printf("Couldn\&'t set video mode: %s | |
| 42 ", SDL_GetError()); | |
| 43 exit(-1); | |
| 44 } | |
| 45 | |
| 46 /* Set palette */ | |
| 47 SDL_SetColors(screen, colors, 0, 256); | |
| 48 \&. | |
| 49 \&. | |
| 50 \&. | |
| 51 \&.\fR | |
| 52 .fi | |
| 53 .PP | |
| 54 .SH "SEE ALSO" | |
| 55 .PP | |
| 56 \fI\fBSDL_Color\fR\fR \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_SetPalette\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR | |
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57 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01 |