diff options
Diffstat (limited to 'src/SDL_gfxBlitFunc.h')
| -rw-r--r-- | src/SDL_gfxBlitFunc.h | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/SDL_gfxBlitFunc.h b/src/SDL_gfxBlitFunc.h new file mode 100644 index 000000000..f233aa617 --- /dev/null +++ b/src/SDL_gfxBlitFunc.h @@ -0,0 +1,128 @@ +/* + + 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 */ |