/*

SDL - Simple DirectMedia Layer

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

*/

#ifdef SAVE_RCSID

static char rcsid =

"@(#) $Id$";

#endif

#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 ( SDL_MUSTLOCK(dst) ) {

if ( SDL_LockSurface(dst) < 0 ) {

okay = 0;

} else {

dst_locked = 1;

}

}

/* Lock the source if it's in hardware */

src_locked = 0;

if ( SDL_MUSTLOCK(src) ) {

if ( SDL_LockSurface(src) < 0 ) {

okay = 0;

} else {

src_locked = 1;

}

}

/* 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 */

(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;

(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);

}

/* We need to unlock the surfaces if they're locked */

if ( dst_locked ) {

}

/* 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);

}