/* SDL_gfxBlitFunc: custom blitters (part of SDL_gfx library) LGPL (c) A. Schiffler */ #ifndef _SDL_gfxBlitFunc_h #define _SDL_gfxBlitFunc_h /* Set up for C function definitions, even when using C++ */ #ifdef __cplusplus extern "C" { #endif #include <stdio.h> #include <stdlib.h> #include <SDL.h> #include <SDL_video.h> /* -------- Prototypes */ #ifdef WIN32 # ifdef DLL_EXPORT # define SDL_GFXBLITFUNC_SCOPE __declspec(dllexport) # else # ifdef LIBSDL_GFX_DLL_IMPORT # define SDL_GFXBLITFUNC_SCOPE __declspec(dllimport) # endif # endif #endif #ifndef SDL_GFXBLITFUNC_SCOPE # define SDL_GFXBLITFUNC_SCOPE extern #endif SDL_GFXBLITFUNC_SCOPE int SDL_gfxBlitRGBA(SDL_Surface * src, SDL_Rect * srcrect, SDL_Surface * dst, SDL_Rect * dstrect); SDL_GFXBLITFUNC_SCOPE int SDL_gfxSetAlpha(SDL_Surface * src, Uint8 a); /* -------- Macros */ /* Define SDL macros locally as a substitute for a #include "SDL_blit.h", */ /* which doesn't work since the include file doesn't get installed. */ /* The structure passed to the low level blit functions */ typedef struct { Uint8 *s_pixels; int s_width; int s_height; int s_skip; Uint8 *d_pixels; int d_width; int d_height; int d_skip; void *aux_data; SDL_PixelFormat *src; Uint8 *table; SDL_PixelFormat *dst; } SDL_gfxBlitInfo; #define GFX_RGBA_FROM_PIXEL(pixel, fmt, r, g, b, a) \ { \ r = ((pixel&fmt->Rmask)>>fmt->Rshift)<<fmt->Rloss; \ g = ((pixel&fmt->Gmask)>>fmt->Gshift)<<fmt->Gloss; \ b = ((pixel&fmt->Bmask)>>fmt->Bshift)<<fmt->Bloss; \ a = ((pixel&fmt->Amask)>>fmt->Ashift)<<fmt->Aloss; \ } #define GFX_DISEMBLE_RGBA(buf, bpp, fmt, pixel, r, g, b, a) \ do { \ pixel = *((Uint32 *)(buf)); \ GFX_RGBA_FROM_PIXEL(pixel, fmt, r, g, b, a); \ pixel &= ~fmt->Amask; \ } while(0) #define GFX_PIXEL_FROM_RGBA(pixel, fmt, r, g, b, a) \ { \ pixel = ((r>>fmt->Rloss)<<fmt->Rshift)| \ ((g>>fmt->Gloss)<<fmt->Gshift)| \ ((b>>fmt->Bloss)<<fmt->Bshift)| \ ((a<<fmt->Aloss)<<fmt->Ashift); \ } #define GFX_ASSEMBLE_RGBA(buf, bpp, fmt, r, g, b, a) \ { \ Uint32 pixel; \ \ GFX_PIXEL_FROM_RGBA(pixel, fmt, r, g, b, a); \ *((Uint32 *)(buf)) = pixel; \ } /* Blend the RGB values of two pixels based on a source alpha value */ #define GFX_ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB) \ do { \ dR = (((sR-dR)*(A))/255)+dR; \ dG = (((sG-dG)*(A))/255)+dG; \ dB = (((sB-dB)*(A))/255)+dB; \ } while(0) /* This is a very useful loop for optimizing blitters */ /* 4-times unrolled loop */ #define GFX_DUFFS_LOOP4(pixel_copy_increment, width) \ { int n = (width+3)/4; \ switch (width & 3) { \ case 0: do { pixel_copy_increment; \ case 3: pixel_copy_increment; \ case 2: pixel_copy_increment; \ case 1: pixel_copy_increment; \ } while ( --n > 0 ); \ } \ } //deleted /* --- */ /* Ends C function definitions when using C++ */ #ifdef __cplusplus } #endif #endif /* _SDL_gfxBlitFunc_h */