/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
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
slouken@devolution.com
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL_error.h"
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_blit.h"
#include "SDL_RLEaccel_c.h"
#include "SDL_pixels_c.h"
#include "SDL_memops.h"
/* The general purpose software blit routine */
static int SDL_SoftBlit(SDL_Surface *src, SDL_Rect *srcrect,
SDL_Surface *dst, SDL_Rect *dstrect)
{
int okay;
int src_locked;
int dst_locked;
/* Everything is okay at the beginning... */
okay = 1;
/* Lock the destination if it's in hardware */
dst_locked = 0;
if ( dst->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT) ) {
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
if ( video->LockHWSurface(this, dst) < 0 ) {
okay = 0;
} else {
dst_locked = 1;
}
}
/* Lock the source if it's in hardware */
src_locked = 0;
if ( src->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT) ) {
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
if ( video->LockHWSurface(this, src) < 0 ) {
okay = 0;
} else {
src_locked = 1;
}
}
/* Unencode the destination if it's RLE encoded */
if ( dst->flags & SDL_RLEACCEL ) {
SDL_UnRLESurface(dst, 1);
dst->flags |= SDL_RLEACCEL; /* save accel'd state */
}
/* Set up source and destination buffer pointers, and BLIT! */
if ( okay && srcrect->w && srcrect->h ) {
SDL_BlitInfo info;
SDL_loblit RunBlit;
/* Set up the blit information */
info.s_pixels = (Uint8 *)src->pixels + src->offset +
(Uint16)srcrect->y*src->pitch +
(Uint16)srcrect->x*src->format->BytesPerPixel;
info.s_width = srcrect->w;
info.s_height = srcrect->h;
info.s_skip=src->pitch-info.s_width*src->format->BytesPerPixel;
info.d_pixels = (Uint8 *)dst->pixels + dst->offset +
(Uint16)dstrect->y*dst->pitch +
(Uint16)dstrect->x*dst->format->BytesPerPixel;
info.d_width = dstrect->w;
info.d_height = dstrect->h;
info.d_skip=dst->pitch-info.d_width*dst->format->BytesPerPixel;
info.aux_data = src->map->sw_data->aux_data;
info.src = src->format;
info.table = src->map->table;
info.dst = dst->format;
RunBlit = src->map->sw_data->blit;
/* Run the actual software blit */
RunBlit(&info);
}
/* Re-encode the destination if it's RLE encoded */
if ( dst->flags & SDL_RLEACCEL ) {
dst->flags &= ~SDL_RLEACCEL; /* stop lying */
SDL_RLESurface(dst);
}
/* We need to unlock the surfaces if they're locked */
if ( dst_locked ) {
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
video->UnlockHWSurface(this, dst);
} else
if ( src_locked ) {
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
video->UnlockHWSurface(this, src);
}
/* Blit is done! */
return(okay ? 0 : -1);
}
static void SDL_BlitCopy(SDL_BlitInfo *info)
{
Uint8 *src, *dst;
int w, h;
int srcskip, dstskip;
w = info->d_width*info->dst->BytesPerPixel;
h = info->d_height;
src = info->s_pixels;
dst = info->d_pixels;
srcskip = w+info->s_skip;
dstskip = w+info->d_skip;
while ( h-- ) {
SDL_memcpy(dst, src, w);
src += srcskip;
dst += dstskip;
}
}
static void SDL_BlitCopyOverlap(SDL_BlitInfo *info)
{
Uint8 *src, *dst;
int w, h;
int srcskip, dstskip;
w = info->d_width*info->dst->BytesPerPixel;
h = info->d_height;
src = info->s_pixels;
dst = info->d_pixels;
srcskip = w+info->s_skip;
dstskip = w+info->d_skip;
if ( dst < src ) {
while ( h-- ) {
SDL_memcpy(dst, src, w);
src += srcskip;
dst += dstskip;
}
} else {
src += ((h-1) * srcskip);
dst += ((h-1) * dstskip);
while ( h-- ) {
SDL_revcpy(dst, src, w);
src -= srcskip;
dst -= dstskip;
}
}
}
/* Figure out which of many blit routines to set up on a surface */
int SDL_CalculateBlit(SDL_Surface *surface)
{
int blit_index;
/* Clean everything out to start */
if ( (surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
SDL_UnRLESurface(surface, 1);
}
surface->map->sw_blit = NULL;
/* Figure out if an accelerated hardware blit is possible */
surface->flags &= ~SDL_HWACCEL;
if ( surface->map->identity ) {
int hw_blit_ok;
if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
/* We only support accelerated blitting to hardware */
if ( surface->map->dst->flags & SDL_HWSURFACE ) {
hw_blit_ok = current_video->info.blit_hw;
} else {
hw_blit_ok = 0;
}
if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
hw_blit_ok = current_video->info.blit_hw_CC;
}
if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
hw_blit_ok = current_video->info.blit_hw_A;
}
} else {
/* We only support accelerated blitting to hardware */
if ( surface->map->dst->flags & SDL_HWSURFACE ) {
hw_blit_ok = current_video->info.blit_sw;
} else {
hw_blit_ok = 0;
}
if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
hw_blit_ok = current_video->info.blit_sw_CC;
}
if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
hw_blit_ok = current_video->info.blit_sw_A;
}
}
if ( hw_blit_ok ) {
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
video->CheckHWBlit(this, surface, surface->map->dst);
}
}
/* Get the blit function index, based on surface mode */
/* { 0 = nothing, 1 = colorkey, 2 = alpha, 3 = colorkey+alpha } */
blit_index = 0;
blit_index |= (!!(surface->flags & SDL_SRCCOLORKEY)) << 0;
if ( surface->flags & SDL_SRCALPHA
&& (surface->format->alpha != SDL_ALPHA_OPAQUE
|| surface->format->Amask) ) {
blit_index |= 2;
}
/* Check for special "identity" case -- copy blit */
if ( surface->map->identity && blit_index == 0 ) {
surface->map->sw_data->blit = SDL_BlitCopy;
/* Handle overlapping blits on the same surface */
if ( surface == surface->map->dst ) {
surface->map->sw_data->blit = SDL_BlitCopyOverlap;
}
} else {
if ( surface->format->BitsPerPixel < 8 ) {
surface->map->sw_data->blit =
SDL_CalculateBlit0(surface, blit_index);
} else {
switch ( surface->format->BytesPerPixel ) {
case 1:
surface->map->sw_data->blit =
SDL_CalculateBlit1(surface, blit_index);
break;
case 2:
case 3:
case 4:
surface->map->sw_data->blit =
SDL_CalculateBlitN(surface, blit_index);
break;
default:
surface->map->sw_data->blit = NULL;
break;
}
}
}
/* Make sure we have a blit function */
if ( surface->map->sw_data->blit == NULL ) {
SDL_InvalidateMap(surface->map);
SDL_SetError("Blit combination not supported");
return(-1);
}
/* Choose software blitting function */
if(surface->flags & SDL_RLEACCELOK
&& (surface->flags & SDL_HWACCEL) != SDL_HWACCEL) {
if(surface->map->identity
&& (blit_index == 1
|| (blit_index == 3 && !surface->format->Amask))) {
if ( SDL_RLESurface(surface) == 0 )
surface->map->sw_blit = SDL_RLEBlit;
} else if(blit_index == 2 && surface->format->Amask) {
if ( SDL_RLESurface(surface) == 0 )
surface->map->sw_blit = SDL_RLEAlphaBlit;
}
}
if ( surface->map->sw_blit == NULL ) {
surface->map->sw_blit = SDL_SoftBlit;
}
return(0);
}