SDL_blit.h
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga
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This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
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slouken@libsdl.org
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*/
#ifdef SAVE_RCSID
static char rcsid =
"@(#) $Id$";
#endif
#ifndef _SDL_blit_h
#define _SDL_blit_h
#include "SDL_endian.h"
/* 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_BlitInfo;
/* The type definition for the low level blit functions */
typedef void (*SDL_loblit)(SDL_BlitInfo *info);
/* This is the private info structure for software accelerated blits */
struct private_swaccel {
SDL_loblit blit;
void *aux_data;
};
/* Blit mapping definition */
typedef struct SDL_BlitMap {
SDL_Surface *dst;
int identity;
Uint8 *table;
SDL_blit hw_blit;
SDL_blit sw_blit;
struct private_hwaccel *hw_data;
struct private_swaccel *sw_data;
/* the version count matches the destination; mismatch indicates
an invalid mapping */
unsigned int format_version;
} SDL_BlitMap;
/* Functions found in SDL_blit.c */
extern int SDL_CalculateBlit(SDL_Surface *surface);
/* Functions found in SDL_blit_{0,1,N,A}.c */
extern SDL_loblit SDL_CalculateBlit0(SDL_Surface *surface, int complex);
extern SDL_loblit SDL_CalculateBlit1(SDL_Surface *surface, int complex);
extern SDL_loblit SDL_CalculateBlitN(SDL_Surface *surface, int complex);
extern SDL_loblit SDL_CalculateAlphaBlit(SDL_Surface *surface, int complex);
/*
* Useful macros for blitting routines
*/
#define FORMAT_EQUAL(A, B) \
((A)->BitsPerPixel == (B)->BitsPerPixel \
&& ((A)->Rmask == (B)->Rmask) && ((A)->Amask == (B)->Amask))
/* Load pixel of the specified format from a buffer and get its R-G-B values */
/* FIXME: rescale values to 0..255 here? */
#define RGB_FROM_PIXEL(pixel, fmt, r, g, b) \
{ \
r = (((pixel&fmt->Rmask)>>fmt->Rshift)<<fmt->Rloss); \
g = (((pixel&fmt->Gmask)>>fmt->Gshift)<<fmt->Gloss); \
b = (((pixel&fmt->Bmask)>>fmt->Bshift)<<fmt->Bloss); \
}
#define RGB_FROM_RGB565(pixel, r, g, b) \
{ \
r = (((pixel&0xF800)>>11)<<3); \
g = (((pixel&0x07E0)>>5)<<2); \
b = ((pixel&0x001F)<<3); \
}
#define RGB_FROM_RGB555(pixel, r, g, b) \
{ \
r = (((pixel&0x7C00)>>10)<<3); \
g = (((pixel&0x03E0)>>5)<<3); \
b = ((pixel&0x001F)<<3); \
}
#define RGB_FROM_RGB888(pixel, r, g, b) \
{ \
r = ((pixel&0xFF0000)>>16); \
g = ((pixel&0xFF00)>>8); \
b = (pixel&0xFF); \
}
#define RETRIEVE_RGB_PIXEL(buf, bpp, pixel) \
do { \
switch (bpp) { \
case 2: \
pixel = *((Uint16 *)(buf)); \
break; \
\
case 3: { \
Uint8 *B = (Uint8 *)(buf); \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
pixel = B[0] + (B[1] << 8) + (B[2] << 16); \
} else { \
pixel = (B[0] << 16) + (B[1] << 8) + B[2]; \
} \
} \
break; \
\
case 4: \
pixel = *((Uint32 *)(buf)); \
break; \
\
default: \
pixel = 0; /* appease gcc */ \
break; \
} \
} while(0)
#define DISEMBLE_RGB(buf, bpp, fmt, pixel, r, g, b) \
do { \
switch (bpp) { \
case 2: \
pixel = *((Uint16 *)(buf)); \
break; \
\
case 3: { \
Uint8 *B = (Uint8 *)buf; \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
pixel = B[0] + (B[1] << 8) + (B[2] << 16); \
} else { \
pixel = (B[0] << 16) + (B[1] << 8) + B[2]; \
} \
} \
break; \
\
case 4: \
pixel = *((Uint32 *)(buf)); \
break; \
\
default: \
pixel = 0; /* prevent gcc from complaining */ \
break; \
} \
RGB_FROM_PIXEL(pixel, fmt, r, g, b); \
} while(0)
/* Assemble R-G-B values into a specified pixel format and store them */
#define PIXEL_FROM_RGB(pixel, fmt, r, g, b) \
{ \
pixel = ((r>>fmt->Rloss)<<fmt->Rshift)| \
((g>>fmt->Gloss)<<fmt->Gshift)| \
((b>>fmt->Bloss)<<fmt->Bshift); \
}
#define RGB565_FROM_RGB(pixel, r, g, b) \
{ \
pixel = ((r>>3)<<11)|((g>>2)<<5)|(b>>3); \
}
#define RGB555_FROM_RGB(pixel, r, g, b) \
{ \
pixel = ((r>>3)<<10)|((g>>3)<<5)|(b>>3); \
}
#define RGB888_FROM_RGB(pixel, r, g, b) \
{ \
pixel = (r<<16)|(g<<8)|b; \
}
#define ASSEMBLE_RGB(buf, bpp, fmt, r, g, b) \
{ \
switch (bpp) { \
case 2: { \
Uint16 pixel; \
\
PIXEL_FROM_RGB(pixel, fmt, r, g, b); \
*((Uint16 *)(buf)) = pixel; \
} \
break; \
\
case 3: { \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
*((buf)+fmt->Rshift/8) = r; \
*((buf)+fmt->Gshift/8) = g; \
*((buf)+fmt->Bshift/8) = b; \
} else { \
*((buf)+2-fmt->Rshift/8) = r; \
*((buf)+2-fmt->Gshift/8) = g; \
*((buf)+2-fmt->Bshift/8) = b; \
} \
} \
break; \
\
case 4: { \
Uint32 pixel; \
\
PIXEL_FROM_RGB(pixel, fmt, r, g, b); \
*((Uint32 *)(buf)) = pixel; \
} \
break; \
} \
}
#define ASSEMBLE_RGB_AMASK(buf, bpp, fmt, r, g, b, Amask) \
{ \
switch (bpp) { \
case 2: { \
Uint16 *bufp; \
Uint16 pixel; \
\
bufp = (Uint16 *)buf; \
PIXEL_FROM_RGB(pixel, fmt, r, g, b); \
*bufp = pixel | (*bufp & Amask); \
} \
break; \
\
case 3: { \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
*((buf)+fmt->Rshift/8) = r; \
*((buf)+fmt->Gshift/8) = g; \
*((buf)+fmt->Bshift/8) = b; \
} else { \
*((buf)+2-fmt->Rshift/8) = r; \
*((buf)+2-fmt->Gshift/8) = g; \
*((buf)+2-fmt->Bshift/8) = b; \
} \
} \
break; \
\
case 4: { \
Uint32 *bufp; \
Uint32 pixel; \
\
bufp = (Uint32 *)buf; \
PIXEL_FROM_RGB(pixel, fmt, r, g, b); \
*bufp = pixel | (*bufp & Amask); \
} \
break; \
} \
}
/* FIXME: Should we rescale alpha into 0..255 here? */
#define 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 RGBA_FROM_8888(pixel, fmt, r, g, b, a) \
{ \
r = (pixel&fmt->Rmask)>>fmt->Rshift; \
g = (pixel&fmt->Gmask)>>fmt->Gshift; \
b = (pixel&fmt->Bmask)>>fmt->Bshift; \
a = (pixel&fmt->Amask)>>fmt->Ashift; \
}
#define RGBA_FROM_RGBA8888(pixel, r, g, b, a) \
{ \
r = (pixel>>24); \
g = ((pixel>>16)&0xFF); \
b = ((pixel>>8)&0xFF); \
a = (pixel&0xFF); \
}
#define RGBA_FROM_ARGB8888(pixel, r, g, b, a) \
{ \
r = ((pixel>>16)&0xFF); \
g = ((pixel>>8)&0xFF); \
b = (pixel&0xFF); \
a = (pixel>>24); \
}
#define RGBA_FROM_ABGR8888(pixel, r, g, b, a) \
{ \
r = (pixel&0xFF); \
g = ((pixel>>8)&0xFF); \
b = ((pixel>>16)&0xFF); \
a = (pixel>>24); \
}
#define DISEMBLE_RGBA(buf, bpp, fmt, pixel, r, g, b, a) \
do { \
switch (bpp) { \
case 2: \
pixel = *((Uint16 *)(buf)); \
break; \
\
case 3: {/* FIXME: broken code (no alpha) */ \
Uint8 *b = (Uint8 *)buf; \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
pixel = b[0] + (b[1] << 8) + (b[2] << 16); \
} else { \
pixel = (b[0] << 16) + (b[1] << 8) + b[2]; \
} \
} \
break; \
\
case 4: \
pixel = *((Uint32 *)(buf)); \
break; \
\
default: \
pixel = 0; /* stop gcc complaints */ \
break; \
} \
RGBA_FROM_PIXEL(pixel, fmt, r, g, b, a); \
pixel &= ~fmt->Amask; \
} while(0)
/* FIXME: this isn't correct, especially for Alpha (maximum != 255) */
#define 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 ASSEMBLE_RGBA(buf, bpp, fmt, r, g, b, a) \
{ \
switch (bpp) { \
case 2: { \
Uint16 pixel; \
\
PIXEL_FROM_RGBA(pixel, fmt, r, g, b, a); \
*((Uint16 *)(buf)) = pixel; \
} \
break; \
\
case 3: { /* FIXME: broken code (no alpha) */ \
if(SDL_BYTEORDER == SDL_LIL_ENDIAN) { \
*((buf)+fmt->Rshift/8) = r; \
*((buf)+fmt->Gshift/8) = g; \
*((buf)+fmt->Bshift/8) = b; \
} else { \
*((buf)+2-fmt->Rshift/8) = r; \
*((buf)+2-fmt->Gshift/8) = g; \
*((buf)+2-fmt->Bshift/8) = b; \
} \
} \
break; \
\
case 4: { \
Uint32 pixel; \
\
PIXEL_FROM_RGBA(pixel, fmt, r, g, b, a); \
*((Uint32 *)(buf)) = pixel; \
} \
break; \
} \
}
/* Blend the RGB values of two pixels based on a source alpha value */
#define ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB) \
do { \
dR = (((sR-dR)*(A))>>8)+dR; \
dG = (((sG-dG)*(A))>>8)+dG; \
dB = (((sB-dB)*(A))>>8)+dB; \
} while(0)
/* This is a very useful loop for optimizing blitters */
#define USE_DUFFS_LOOP
#ifdef USE_DUFFS_LOOP
/* 8-times unrolled loop */
#define DUFFS_LOOP8(pixel_copy_increment, width) \
{ int n = (width+7)/8; \
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switch (width & 7) { \
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case 0: do { pixel_copy_increment; \
case 7: pixel_copy_increment; \
case 6: pixel_copy_increment; \
case 5: pixel_copy_increment; \
case 4: pixel_copy_increment; \
case 3: pixel_copy_increment; \
case 2: pixel_copy_increment; \
case 1: pixel_copy_increment; \
} while ( --n > 0 ); \
} \
}
/* 4-times unrolled loop */
#define DUFFS_LOOP4(pixel_copy_increment, width) \
{ int n = (width+3)/4; \
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switch (width & 3) { \
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case 0: do { pixel_copy_increment; \
case 3: pixel_copy_increment; \
case 2: pixel_copy_increment; \
case 1: pixel_copy_increment; \
} while ( --n > 0 ); \
} \
}
/* Use the 8-times version of the loop by default */
#define DUFFS_LOOP(pixel_copy_increment, width) \
DUFFS_LOOP8(pixel_copy_increment, width)
#else
/* Don't use Duff's device to unroll loops */
#define DUFFS_LOOP(pixel_copy_increment, width) \
{ int n; \
for ( n=width; n > 0; --n ) { \
pixel_copy_increment; \
} \
}
#define DUFFS_LOOP8(pixel_copy_increment, width) \
DUFFS_LOOP(pixel_copy_increment, width)
#define DUFFS_LOOP4(pixel_copy_increment, width) \
DUFFS_LOOP(pixel_copy_increment, width)
#endif /* USE_DUFFS_LOOP */
/* Prevent Visual C++ 6.0 from printing out stupid warnings */
#if defined(_MSC_VER) && (_MSC_VER >= 600)
#pragma warning(disable: 4550)
#endif
#endif /* _SDL_blit_h */