smatz@8587: /* $Id$ */
smatz@8587: 
rubidium@10429: /** @file 32bpp_optimized.cpp Implementation of the optimized 32 bpp blitter. */
rubidium@10429: 
truelight@8049: #include "../stdafx.h"
rubidium@8619: #include "../zoom_func.h"
rubidium@8619: #include "../gfx_func.h"
truelight@8049: #include "../debug.h"
truelight@8049: #include "32bpp_optimized.hpp"
truelight@8049: 
truelight@8049: static FBlitter_32bppOptimized iFBlitter_32bppOptimized;
truelight@8049: 
truelight@8049: void Blitter_32bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
truelight@8049: {
truelight@8049: 	const SpriteLoader::CommonPixel *src, *src_line;
truelight@8049: 	uint32 *dst, *dst_line;
truelight@8049: 
truelight@8049: 	/* Find where to start reading in the source sprite */
truelight@8049: 	src_line = (const SpriteLoader::CommonPixel *)bp->sprite + (bp->skip_top * bp->sprite_width + bp->skip_left) * ScaleByZoom(1, zoom);
truelight@8049: 	dst_line = (uint32 *)bp->dst + bp->top * bp->pitch + bp->left;
truelight@8049: 
truelight@8049: 	for (int y = 0; y < bp->height; y++) {
truelight@8049: 		dst = dst_line;
truelight@8049: 		dst_line += bp->pitch;
truelight@8049: 
truelight@8049: 		src = src_line;
truelight@8049: 		src_line += bp->sprite_width * ScaleByZoom(1, zoom);
truelight@8049: 
truelight@8049: 		for (int x = 0; x < bp->width; x++) {
truelight@8049: 			if (src->a == 0) {
truelight@8049: 				/* src->r is 'misused' here to indicate how much more pixels are following with an alpha of 0 */
truelight@8049: 				int skip = UnScaleByZoom(src->r, zoom);
truelight@8049: 
truelight@8049: 				dst += skip;
truelight@8049: 				x   += skip - 1;
truelight@8049: 				src += ScaleByZoom(1, zoom) * skip;
truelight@8049: 				continue;
truelight@8049: 			}
truelight@8049: 
truelight@8049: 			switch (mode) {
truelight@8049: 				case BM_COLOUR_REMAP:
truelight@8049: 					/* In case the m-channel is zero, do not remap this pixel in any way */
truelight@8049: 					if (src->m == 0) {
truelight@8049: 						*dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
truelight@8049: 					} else {
truelight@8049: 						if (bp->remap[src->m] != 0) *dst = ComposeColourPA(this->LookupColourInPalette(bp->remap[src->m]), src->a, *dst);
truelight@8049: 					}
truelight@8049: 					break;
truelight@8049: 
truelight@8049: 				case BM_TRANSPARENT:
truelight@8049: 					/* TODO -- We make an assumption here that the remap in fact is transparency, not some color.
truelight@8049: 					 *  This is never a problem with the code we produce, but newgrfs can make it fail... or at least:
truelight@8049: 					 *  we produce a result the newgrf maker didn't expect ;) */
truelight@8049: 
truelight@8049: 					/* Make the current color a bit more black, so it looks like this image is transparent */
truelight@8049: 					*dst = MakeTransparent(*dst, 192);
truelight@8049: 					break;
truelight@8049: 
truelight@8049: 				default:
truelight@8049: 					*dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
truelight@8049: 					break;
truelight@8049: 			}
truelight@8049: 			dst++;
truelight@8049: 			src += ScaleByZoom(1, zoom);
truelight@8049: 		}
truelight@8049: 	}
truelight@8049: }
truelight@8049: 
truelight@8049: Sprite *Blitter_32bppOptimized::Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator)
truelight@8049: {
truelight@8049: 	Sprite *dest_sprite;
truelight@8049: 	SpriteLoader::CommonPixel *dst;
truelight@8049: 	dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
truelight@8049: 
truelight@8049: 	dest_sprite->height = sprite->height;
truelight@8049: 	dest_sprite->width  = sprite->width;
truelight@8049: 	dest_sprite->x_offs = sprite->x_offs;
truelight@8049: 	dest_sprite->y_offs = sprite->y_offs;
truelight@8049: 
truelight@8049: 	dst = (SpriteLoader::CommonPixel *)dest_sprite->data;
truelight@8049: 
truelight@8049: 	memcpy(dst, sprite->data, sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
truelight@8049: 	/* Skip to the end of the array, and work backwards to find transparent blocks */
truelight@8049: 	dst = dst + sprite->height * sprite->width - 1;
truelight@8049: 
truelight@8049: 	for (uint y = sprite->height; y > 0; y--) {
truelight@8049: 		int trans = 0;
truelight@8049: 		/* Process sprite line backwards, to compute lengths of transparent blocks */
truelight@8049: 		for (uint x = sprite->width; x > 0; x--) {
truelight@8049: 			if (dst->a == 0) {
truelight@8049: 				/* Save transparent block length in red channel; max value is 255 the red channel can contain */
truelight@8049: 				if (trans < 255) trans++;
truelight@8049: 				dst->r = trans;
truelight@8049: 				dst->g = 0;
truelight@8049: 				dst->b = 0;
truelight@8049: 				dst->m = 0;
truelight@8049: 			} else {
truelight@8049: 				trans = 0;
truelight@8049: 				if (dst->m != 0) {
truelight@8049: 					/* Pre-convert the mapping channel to a RGB value */
truelight@8049: 					uint color = this->LookupColourInPalette(dst->m);
truelight@8049: 					dst->r = GB(color, 16, 8);
truelight@8049: 					dst->g = GB(color, 8,  8);
truelight@8049: 					dst->b = GB(color, 0,  8);
truelight@8049: 				}
truelight@8049: 			}
truelight@8049: 			dst--;
truelight@8049: 		}
truelight@8049: 	}
truelight@8049: 	return dest_sprite;
truelight@8049: }