ref: 1ae6334bfaeb53c301a553e45733ad2a50b74689
dir: /Source/blitter.cpp/
// blitter.c
#include "SDL.h"
#include "SDLU.h"
#include "SDL_endian.h"
#include "main.h"
#include "gworld.h"
#include "blitter.h"
#include "font.h"
#include "level.h"
#include "graphics.h"
MBoolean update[2][kGridAcross][kGridDown];
MBoolean refresh[2];
void InitBlitter( void )
{
int player, x, y;
for( player=0; player<=1; player++ )
{
refresh[player] = false;
for( x=0; x<kGridAcross; x++ )
{
for( y=0; y<kGridDown; y++ )
{
update[player][x][y] = false;
}
}
}
}
void UpdatePlayerWindow( int player )
{
SDL_Rect fullSDLRect, offsetSDLRect;
int x, y;
if( control[player] == kNobodyControl ) return;
if( playerWindowVisible[player] && refresh[player] )
{
MRect updateRect = {0, 0, 0, 0}, fullRect, offsetRect;
MBoolean first = true;
for( x=0; x<kGridAcross; x++ )
{
for( y=1; y<kGridDown; y++ )
{
if( update[player][x][y] )
{
updateRect.top = y * kBlobVertSize;
updateRect.left = x * kBlobHorizSize;
updateRect.bottom = updateRect.top + kBlobVertSize;
updateRect.right = updateRect.left + kBlobHorizSize;
if( first )
{
fullRect = updateRect;
first = false;
}
else
{
UnionMRect( &fullRect, &updateRect, &fullRect );
}
update[player][x][y] = false;
}
}
}
if( !first )
{
offsetRect = fullRect;
OffsetMRect( &offsetRect, playerWindowRect[player].left, playerWindowRect[player].top - kBlobVertSize );
SDLU_BlitFrontSurface( playerSpriteSurface[player],
SDLU_MRectToSDLRect( &fullRect, &fullSDLRect ),
SDLU_MRectToSDLRect( &offsetRect, &offsetSDLRect ) );
}
}
}
void SetUpdateRect( int player, MRect *where )
{
int x,y;
int xMin, xMax, yMin, yMax;
xMin = where->left / kBlobHorizSize;
xMax = ( where->right + kBlobHorizSize - 1 ) / kBlobHorizSize;
if( xMin < 0 ) xMin = 0;
if( xMin > (kGridAcross-1) ) xMin = kGridAcross-1;
if( xMax < 0 ) xMax = 0;
if( xMax > kGridAcross ) xMax = kGridAcross;
yMin = where->top / kBlobVertSize;
yMax = ( where->bottom + kBlobVertSize - 1 ) / kBlobVertSize;
if( yMin < 0 ) yMin = 0;
if( yMin > (kGridDown-1) ) yMin = kGridDown-1;
if( yMax < 0 ) yMax = 0;
if( yMax > kGridDown ) yMax = kGridDown;
for( x=xMin; x<xMax; x++ )
{
for( y=yMin; y<yMax; y++ )
{
update[player][x][y] = true;
}
}
refresh[player] = true;
}
void SurfaceBlitMask( SDL_Surface* object, SDL_Surface* mask, SDL_Surface* dest,
const MRect* objectRect, const MRect* maskRect, const MRect* destRect )
{
int startX = 0, startY = 0, endX, endY, x, y, srcRowBytes, mskRowBytes, dstRowBytes;
unsigned long bit, startBit, maskBits;
unsigned char *src, *msk, *dst;
MRect destBounds;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
endX = objectRect->right - objectRect->left;
endY = objectRect->bottom - objectRect->top;
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
src = (unsigned char*) object->pixels;
msk = (unsigned char*) mask->pixels;
dst = (unsigned char*) dest->pixels;
srcRowBytes = object->pitch;
mskRowBytes = mask->pitch;
dstRowBytes = dest->pitch;
src += (objectRect->top * srcRowBytes) + (objectRect->left * 2);
msk += (maskRect->top * mskRowBytes) + (maskRect->left / 8);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
startBit = 0x80000000 >> (startX & 31);
msk += (mskRowBytes * startY) + ((startX & ~31) / 8);
src += (srcRowBytes * startY) + (startX * 2);
dst += (dstRowBytes * startY) + (startX * 2);
for( y=startY; y<endY; y++ )
{
unsigned char *tSrc = src, *tDst = dst, *tMsk = msk;
maskBits = SDL_SwapBE32( *(unsigned long*)msk );
bit = startBit;
for( x=startX; x<endX; x++ )
{
if( maskBits & bit )
{
*(short*)dst = *(short*)src;
}
if( !(bit >>= 1) ) { msk += 4; maskBits = SDL_SwapBE32( *(unsigned long*)msk ); bit = 0x80000000; }
src += 2; dst += 2;
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
msk = tMsk + mskRowBytes;
}
}
void SurfaceBlitBlob( const MRect* blobRect, const MRect* destRect )
{
SurfaceBlitMask( blobSurface, maskSurface, SDLU_GetCurrentSurface(),
blobRect, blobRect, destRect );
}
void SurfaceBlitColor( SDL_Surface* mask, SDL_Surface* dest,
const MRect* maskRect, const MRect* destRect,
int r, int g, int b, int weight )
{
int startX = 0, startY = 0, endX, endY, x, y, mskRowBytes, dstRowBytes;
unsigned long bit, startBit, maskBits;
unsigned char *msk, *dst;
MRect destBounds;
endX = maskRect->right - maskRect->left;
endY = maskRect->bottom - maskRect->top;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
msk = (unsigned char*) mask->pixels;
dst = (unsigned char*) dest->pixels;
mskRowBytes = mask->pitch;
dstRowBytes = dest->pitch;
msk += (maskRect->top * mskRowBytes) + (maskRect->left / 8);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
startBit = 0x80000000 >> (startX & 31);
msk += (mskRowBytes * startY) + ((startX & ~31) / 8);
dst += (dstRowBytes * startY) + (startX * 2);
r *= weight;
g *= weight;
b *= weight;
weight = 32 - weight;
for( y=startY; y<endY; y++ )
{
unsigned char *tMsk = msk, *tDst = dst;
int work, workB, workG, workR;
maskBits = SDL_SwapBE32( *(unsigned long*)msk );
bit = startBit;
for( x=startX; x<endX; x++ )
{
if( maskBits & bit )
{
work = *(short*)dst;
workB = ((((work ) & 0x001F)*weight) + b) >> 5;
workG = ((((work>> 5) & 0x001F)*weight) + g);
workR = ((((work>>10) & 0x001F)*weight) + r) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
if( !(bit >>= 1) ) { msk += 4; maskBits = SDL_SwapBE32( *(unsigned long*)msk ); bit = 0x80000000; }
dst += 2;
}
msk = tMsk + mskRowBytes;
dst = tDst + dstRowBytes;
}
}
void SurfaceBlitAlpha( SDL_Surface* back, SDL_Surface* source, SDL_Surface* alpha, SDL_Surface* dest,
const MRect* backRect, const MRect* sourceRect, const MRect* alphaRect, const MRect* destRect )
{
int startX = 0, startY = 0, endX, endY, x, y, srcRowBytes, alfRowBytes, dstRowBytes, bckRowBytes;
unsigned char *bck, *src, *alf, *dst;
MRect destBounds;
endX = sourceRect->right - sourceRect->left;
endY = sourceRect->bottom - sourceRect->top;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
bck = (unsigned char*) back->pixels;
src = (unsigned char*) source->pixels;
alf = (unsigned char*) alpha->pixels;
dst = (unsigned char*) dest->pixels;
bckRowBytes = back->pitch;
srcRowBytes = source->pitch;
alfRowBytes = alpha->pitch;
dstRowBytes = dest->pitch;
bck += (backRect->top * bckRowBytes) + (backRect->left * 2);
src += (sourceRect->top * srcRowBytes) + (sourceRect->left * 2);
alf += (alphaRect->top * alfRowBytes) + (alphaRect->left * 2);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
bck += (bckRowBytes * startY) + (startX * 2);
src += (srcRowBytes * startY) + (startX * 2);
alf += (alfRowBytes * startY) + (startX * 2);
dst += (dstRowBytes * startY) + (startX * 2);
for( y=startY; y<endY; y++ )
{
unsigned char *tSrc = src, *tAlf = alf, *tDst = dst, *tBck = bck;
int pixS, pixB, weightS, weightB, workB, workG, workR;
for( x=startX; x<endX; x++ )
{
weightB = *(short*)alf;
if( weightB == 0x7FFF )
{
*(short*)dst = *(short*)bck;
}
else if( weightB == 0 )
{
*(short*)dst = *(short*)src;
}
else
{
weightS = ~weightB;
pixS = *(short*)src;
pixB = *(short*)bck;
workB = ((((pixS ) & 0x001F) * ((weightS ) & 0x001F)) + (((pixB ) & 0x001F) * ((weightB ) & 0x001F))) >> 5;
workG = ((((pixS >> 5) & 0x001F) * ((weightS >> 5) & 0x001F)) + (((pixB >> 5) & 0x001F) * ((weightB >> 5) & 0x001F)));
workR = ((((pixS >> 10) & 0x001F) * ((weightS >> 10) & 0x001F)) + (((pixB >> 10) & 0x001F) * ((weightB >> 10) & 0x001F))) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
src += 2;
alf += 2;
bck += 2;
dst += 2;
}
bck = tBck + bckRowBytes;
src = tSrc + srcRowBytes;
alf = tAlf + alfRowBytes;
dst = tDst + dstRowBytes;
}
}
void SurfaceBlitWeightedDualAlpha( SDL_Surface* back, SDL_Surface* source, SDL_Surface* mask, SDL_Surface* alpha, SDL_Surface* dest,
const MRect* backRect, const MRect* sourceRect, const MRect* maskRect, const MRect* alphaRect, const MRect* destRect,
int inWeight )
{
int startX = 0, startY = 0, endX, endY, x, y,
srcRowBytes, alfRowBytes, mskRowBytes, dstRowBytes, bckRowBytes;
unsigned long bit, startBit, maskBits;
unsigned char *bck, *src, *alf, *msk, *dst;
MRect destBounds;
endX = sourceRect->right - sourceRect->left;
endY = sourceRect->bottom - sourceRect->top;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
bck = (unsigned char*) back->pixels;
src = (unsigned char*) source->pixels;
msk = (unsigned char*) mask->pixels;
alf = (unsigned char*) alpha->pixels;
dst = (unsigned char*) dest->pixels;
bckRowBytes = back->pitch;
srcRowBytes = source->pitch;
mskRowBytes = mask->pitch;
alfRowBytes = alpha->pitch;
dstRowBytes = dest->pitch;
bck += (backRect->top * bckRowBytes) + (backRect->left * 2);
src += (sourceRect->top * srcRowBytes) + (sourceRect->left * 2);
alf += (alphaRect->top * alfRowBytes) + (alphaRect->left * 2);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
msk += (maskRect->top * mskRowBytes) + (maskRect->left / 8);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
bck += (bckRowBytes * startY) + (startX * 2);
src += (srcRowBytes * startY) + (startX * 2);
alf += (alfRowBytes * startY) + (startX * 2);
dst += (dstRowBytes * startY) + (startX * 2);
msk += (mskRowBytes * startY) + ((startX & ~31) / 8);
startBit = 0x80000000 >> (startX & 31);
for( y=startY; y<endY; y++ )
{
unsigned char *tSrc = src, *tAlf = alf, *tDst = dst, *tBck = bck, *tMsk = msk;
int pixS, pixB, weightS, weightB, work, workB, workG, workR;
maskBits = SDL_SwapBE32( *(unsigned long*)msk );
bit = startBit;
for( x=startX; x<endX; x++ )
{
if( maskBits & bit )
{
work = *(short*)alf;
workB = ((((work ) & 0x001F)*inWeight) ) >> 5;
workG = ((((work>> 5) & 0x001F)*inWeight) );
workR = ((((work>>10) & 0x001F)*inWeight) ) << 5;
weightB = ~((workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F));
if( weightB == 0x7FFF )
{
*(short*)dst = *(short*)bck;
}
else if( weightB == 0 )
{
*(short*)dst = *(short*)src;
}
else
{
weightS = ~weightB;
pixS = *(short*)src;
pixB = *(short*)bck;
workB = ((((pixS ) & 0x001F) * ((weightS ) & 0x001F)) + (((pixB ) & 0x001F) * ((weightB ) & 0x001F))) >> 5;
workG = ((((pixS >> 5) & 0x001F) * ((weightS >> 5) & 0x001F)) + (((pixB >> 5) & 0x001F) * ((weightB >> 5) & 0x001F)));
workR = ((((pixS >> 10) & 0x001F) * ((weightS >> 10) & 0x001F)) + (((pixB >> 10) & 0x001F) * ((weightB >> 10) & 0x001F))) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
}
if( !(bit >>= 1) ) { msk += 4; maskBits = SDL_SwapBE32( *(unsigned long*)msk ); bit = 0x80000000; }
src += 2;
alf += 2;
bck += 2;
dst += 2;
}
bck = tBck + bckRowBytes;
src = tSrc + srcRowBytes;
alf = tAlf + alfRowBytes;
dst = tDst + dstRowBytes;
msk = tMsk + mskRowBytes;
}
}
void SurfaceBlitWeightedCharacter( SkittlesFontPtr font, unsigned char text, MPoint *dPoint, int r, int g, int b, int alpha )
{
if( alpha == 31 )
{
SurfaceBlitCharacter( font, text, dPoint, r, g, b, 0 );
}
else if( alpha == 0 )
{
return;
}
else
{
SDL_Surface* destSurface;
unsigned char* src;
unsigned char* dst;
int srcRowBytes;
int dstRowBytes;
int index;
MRect destBounds;
int height = font->surface->h;
int width = font->width[text];
int across = font->across[text];
destSurface = SDLU_GetCurrentSurface();
SDLU_SDLRectToMRect( &destSurface->clip_rect, &destBounds );
if( (dPoint->h + width) > destBounds.right || // clipped?
(dPoint->v + height) > destBounds.bottom ||
dPoint->h < destBounds.left ||
dPoint->v < destBounds.top )
{
dPoint->h += width;
return; // do nothing
}
srcRowBytes = font->surface->pitch;
dstRowBytes = destSurface->pitch;
src = (unsigned char*) font->surface->pixels + across;
dst = (unsigned char*) destSurface->pixels + (dPoint->h * 2) + (dPoint->v * dstRowBytes);
while( height-- )
{
unsigned char *tSrc = src, *tDst = dst;
for( index=0; index<width; index++ )
{
int workR, workG, workB, work, weightS, weightD;
weightS = (*src >> 3) & 0x1F;
weightS = (weightS * alpha) >> 5;
if( weightS )
{
weightD = 32 - weightS;
work = *(short*)dst;
workB = ((((work ) & 0x001F) * weightD) + (b * weightS)) >> 5;
workG = ((((work>> 5) & 0x001F) * weightD) + (g * weightS));
workR = ((((work>>10) & 0x001F) * weightD) + (r * weightS)) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
src++;
dst+=2;
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
}
dPoint->h += width;
}
}
void SurfaceBlitCharacter( SkittlesFontPtr font, unsigned char text, MPoint *dPoint, int r, int g, int b, int dropShadow )
{
SDL_Surface* destSurface;
unsigned char* src;
unsigned char* dst;
int srcRowBytes;
int dstRowBytes;
int index;
int rgb555;
MRect destBounds;
int height = font->surface->h;
int width = font->width[text];
int across = font->across[text];
destSurface = SDLU_GetCurrentSurface();
SDLU_SDLRectToMRect( &destSurface->clip_rect, &destBounds );
if( (dPoint->h + width) > destBounds.right || // clipped?
(dPoint->v + height) > destBounds.bottom ||
dPoint->h < destBounds.left ||
dPoint->v < destBounds.top )
{
dPoint->h += width;
return; // do nothing
}
srcRowBytes = font->surface->pitch;
dstRowBytes = destSurface->pitch;
src = (unsigned char*) font->surface->pixels + across;
dst = (unsigned char*) destSurface->pixels + (dPoint->h * 2) + (dPoint->v * dstRowBytes);
rgb555 = (r << 10) | (g << 5) | b;
switch( dropShadow )
{
case 0:
while( height-- )
{
unsigned char *tSrc = src, *tDst = dst;
for( index=0; index<width; index++ )
{
int workR, workG, workB, work, weightS, weightD;
weightS = (*src >> 3) & 0x1F;
if( weightS == 31 )
{
*(short*)dst = rgb555;
}
else if( weightS > 0 )
{
weightD = 32 - weightS;
work = *(short*)dst;
workB = ((((work ) & 0x001F) * weightD) + (b * weightS)) >> 5;
workG = ((((work>> 5) & 0x001F) * weightD) + (g * weightS));
workR = ((((work>>10) & 0x001F) * weightD) + (r * weightS)) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
src++;
dst+=2;
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
}
break;
default:
{
unsigned char *drp = dst + ((dstRowBytes + 2) * dropShadow);
while( height-- )
{
unsigned char *tSrc = src, *tDst = dst, *tDrp = drp;
for( index=0; index<width; index++ )
{
int workR, workG, workB, work, weightS, weightD;
weightS = (*src >> 3) & 0x1F;
if( weightS == 31 )
{
*(short*)drp = 0;
*(short*)dst = rgb555;
}
else if( weightS > 0 )
{
weightD = 32 - weightS;
work = *(short*)drp;
workB = ((((work ) & 0x001F) * weightD)) >> 5;
workG = ((((work>> 5) & 0x001F) * weightD));
workR = ((((work>>10) & 0x001F) * weightD)) << 5;
*(short*)drp = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
work = *(short*)dst;
workB = ((((work ) & 0x001F) * weightD) + (b * weightS)) >> 5;
workG = ((((work>> 5) & 0x001F) * weightD) + (g * weightS));
workR = ((((work>>10) & 0x001F) * weightD) + (r * weightS)) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
src++;
dst+=2;
drp+=2;
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
drp = tDrp + dstRowBytes;
}
break;
}
}
dPoint->h += width;
}
void SurfaceBlitColorOver( SDL_Surface* source, SDL_Surface* dest,
const MRect* sourceRect, const MRect* destRect,
int r, int g, int b, int weight )
{
int startX = 0, startY = 0, endX, endY, x, y, dstRowBytes, srcRowBytes;
unsigned char* src;
unsigned char* dst;
MRect destBounds;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
endX = destRect->right - destRect->left;
endY = destRect->bottom - destRect->top;
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
src = (unsigned char*) source->pixels;
dst = (unsigned char*) dest->pixels;
srcRowBytes = source->pitch;
dstRowBytes = dest->pitch;
src += (sourceRect->top * srcRowBytes) + (sourceRect->left * 2);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
src += (srcRowBytes * startY) + (startX * 2);
dst += (dstRowBytes * startY) + (startX * 2);
r *= weight;
g *= weight;
b *= weight;
weight = 32 - weight;
for( y=startY; y<endY; y++ )
{
unsigned char *tSrc = src, *tDst = dst;
int work, workB, workG, workR;
for( x=startX; x<endX; x++ )
{
work = *(short*)src;
workB = ((((work ) & 0x001F)*weight) + b) >> 5;
workG = ((((work>> 5) & 0x001F)*weight) + g);
workR = ((((work>>10) & 0x001F)*weight) + r) << 5;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
src += 2;
dst += 2;
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
}
}
// NOTE: due to rounding error, there should never be a case of transitioning all the way from 0 to 31.
// You'll overflow and get weird glitches on the edges.
void SurfaceBlitBlendOver( SDL_Surface* source, SDL_Surface* dest,
const MRect* sourceRect, const MRect* destRect,
int r1, int g1, int b1,
int r2, int g2, int b2,
int r3, int g3, int b3,
int r4, int g4, int b4,
int weight )
{
int startX = 0, startY = 0, endX, endY, x, y;
int rA, gA, bA;
int rB, gB, bB;
int rI, gI, bI;
int vrLI, vgLI, vbLI;
int vrRI, vgRI, vbRI;
int weight16, ditherDiff;
int width, height, dstRowBytes, srcRowBytes;
unsigned char *src, *dst;
MRect destBounds;
MBoolean oddX = false;
SDLU_SDLRectToMRect( &dest->clip_rect, &destBounds );
if( destRect->left > destBounds.right || // completely clipped?
destRect->right < destBounds.left ||
destRect->top > destBounds.bottom ||
destRect->bottom < destBounds.top )
{
return; // do nothing
}
endX = destRect->right - destRect->left;
endY = destRect->bottom - destRect->top;
src = (unsigned char*) source->pixels;
dst = (unsigned char*) dest->pixels;
srcRowBytes = source->pitch;
dstRowBytes = dest->pitch;
src += (sourceRect->top * srcRowBytes) + (sourceRect->left * 2);
dst += (destRect->top * dstRowBytes) + (destRect->left * 2);
if( destRect->left < destBounds.left ) startX -= destRect->left - destBounds.left;
if( destRect->right > destBounds.right ) endX -= destRect->right - destBounds.right;
if( destRect->top < destBounds.top ) startY -= destRect->top - destBounds.top;
if( destRect->bottom > destBounds.bottom ) endY -= destRect->bottom - destBounds.bottom;
src += (srcRowBytes * startY) + (startX * 2);
dst += (dstRowBytes * startY) + (startX * 2);
height = endY - startY;
width = endX - startX;
weight16 = weight << 16;
r1 *= weight16; g1 *= weight16; b1 *= weight16;
r2 *= weight16; g2 *= weight16; b2 *= weight16;
r3 *= weight16; g3 *= weight16; b3 *= weight16;
r4 *= weight16; g4 *= weight16; b4 *= weight16;
ditherDiff = weight16 >> 1;
vrLI = (r3 - r1) / height;
vgLI = (g3 - g1) / height;
vbLI = (b3 - b1) / height;
vrRI = (r4 - r2) / height;
vgRI = (g4 - g2) / height;
vbRI = (b4 - b2) / height;
weight = 32 - weight;
if( (endX - startX) & 1 )
{
endX--;
oddX = true;
}
for( y=startY; y<endY; y++ )
{
unsigned char *tSrc = src, *tDst = dst;
int work, workB, workG, workR;
if( y & 1 )
{
rA = r1;
gA = g1;
bA = b1;
rB = r1 - ditherDiff; if( rB < 0 ) rB = 0;
gB = g1 - ditherDiff; if( gB < 0 ) gB = 0;
bB = b1 - ditherDiff; if( bB < 0 ) bB = 0;
}
else
{
rA = r1 - ditherDiff; if( rA < 0 ) rA = 0;
gA = g1 - ditherDiff; if( gA < 0 ) gA = 0;
bA = b1 - ditherDiff; if( bA < 0 ) bA = 0;
rB = r1;
gB = g1;
bB = b1;
}
rI = (2 * (r2 - r1)) / width;
gI = (2 * (g2 - g1)) / width;
bI = (2 * (b2 - b1)) / width;
for( x=startX; x<endX; x+=2 )
{
work = *(short*)src;
workB = ((((work<<16) & 0x001F0000)*weight) + bA) >> 21;
workG = ((((work<<11) & 0x001F0000)*weight) + gA) >> 16;
workR = ((((work<< 6) & 0x001F0000)*weight) + rA) >> 11;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
src+= 2;
dst+= 2;
rA += rI;
gA += gI;
bA += bI;
work = *(short*)src;
workB = ((((work<<16) & 0x001F0000)*weight) + bB) >> 21;
workG = ((((work<<11) & 0x001F0000)*weight) + gB) >> 16;
workR = ((((work<< 6) & 0x001F0000)*weight) + rB) >> 11;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
src+= 2;
dst+= 2;
rB += rI;
gB += gI;
bB += bI;
}
if( oddX )
{
work = *(short*)src;
workB = ((((work<<16) & 0x001F0000)*weight) + bA) >> 21;
workG = ((((work<<11) & 0x001F0000)*weight) + gA) >> 16;
workR = ((((work<< 6) & 0x001F0000)*weight) + rA) >> 11;
*(short*)dst = (workR & 0x7C00) | (workG & 0x03E0) | (workB & 0x001F);
}
src = tSrc + srcRowBytes;
dst = tDst + dstRowBytes;
r1 += vrLI; r2 += vrRI;
g1 += vgLI; g2 += vgRI;
b1 += vbLI; b2 += vbRI;
}
}