1 files changed, 108 insertions, 0 deletions
diff --git a/src/blitter/32bpp_optimized.cpp b/src/blitter/32bpp_optimized.cpp
new file mode 100644
index 000000000..460e7ad0e
--- /dev/null
+++ b/src/blitter/32bpp_optimized.cpp
@@ -0,0 +1,108 @@
+#include "../stdafx.h"
+#include "../zoom.hpp"
+#include "../gfx.h"
+#include "../debug.h"
+#include "../table/sprites.h"
+#include "32bpp_optimized.hpp"
+
+static FBlitter_32bppOptimized iFBlitter_32bppOptimized;
+
+void Blitter_32bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
+{
+	const SpriteLoader::CommonPixel *src, *src_line;
+	uint32 *dst, *dst_line;
+
+	/* Find where to start reading in the source sprite */
+	src_line = (const SpriteLoader::CommonPixel *)bp->sprite + (bp->skip_top * bp->sprite_width + bp->skip_left) * ScaleByZoom(1, zoom);
+	dst_line = (uint32 *)bp->dst + bp->top * bp->pitch + bp->left;
+
+	for (int y = 0; y < bp->height; y++) {
+		dst = dst_line;
+		dst_line += bp->pitch;
+
+		src = src_line;
+		src_line += bp->sprite_width * ScaleByZoom(1, zoom);
+
+		for (int x = 0; x < bp->width; x++) {
+			if (src->a == 0) {
+				/* src->r is 'misused' here to indicate how much more pixels are following with an alpha of 0 */
+				int skip = UnScaleByZoom(src->r, zoom);
+
+				dst += skip;
+				x   += skip - 1;
+				src += ScaleByZoom(1, zoom) * skip;
+				continue;
+			}
+
+			switch (mode) {
+				case BM_COLOUR_REMAP:
+					/* In case the m-channel is zero, do not remap this pixel in any way */
+					if (src->m == 0) {
+						*dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
+					} else {
+						if (bp->remap[src->m] != 0) *dst = ComposeColourPA(this->LookupColourInPalette(bp->remap[src->m]), src->a, *dst);
+					}
+					break;
+
+				case BM_TRANSPARENT:
+					/* TODO -- We make an assumption here that the remap in fact is transparency, not some color.
+					 *  This is never a problem with the code we produce, but newgrfs can make it fail... or at least:
+					 *  we produce a result the newgrf maker didn't expect ;) */
+
+					/* Make the current color a bit more black, so it looks like this image is transparent */
+					*dst = MakeTransparent(*dst, 192);
+					break;
+
+				default:
+					*dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
+					break;
+			}
+			dst++;
+			src += ScaleByZoom(1, zoom);
+		}
+	}
+}
+
+Sprite *Blitter_32bppOptimized::Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator)
+{
+	Sprite *dest_sprite;
+	SpriteLoader::CommonPixel *dst;
+	dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
+
+	dest_sprite->height = sprite->height;
+	dest_sprite->width  = sprite->width;
+	dest_sprite->x_offs = sprite->x_offs;
+	dest_sprite->y_offs = sprite->y_offs;
+
+	dst = (SpriteLoader::CommonPixel *)dest_sprite->data;
+
+	memcpy(dst, sprite->data, sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
+	/* Skip to the end of the array, and work backwards to find transparent blocks */
+	dst = dst + sprite->height * sprite->width - 1;
+
+	for (uint y = sprite->height; y > 0; y--) {
+		int trans = 0;
+		/* Process sprite line backwards, to compute lengths of transparent blocks */
+		for (uint x = sprite->width; x > 0; x--) {
+			if (dst->a == 0) {
+				/* Save transparent block length in red channel; max value is 255 the red channel can contain */
+				if (trans < 255) trans++;
+				dst->r = trans;
+				dst->g = 0;
+				dst->b = 0;
+				dst->m = 0;
+			} else {
+				trans = 0;
+				if (dst->m != 0) {
+					/* Pre-convert the mapping channel to a RGB value */
+					uint color = this->LookupColourInPalette(dst->m);
+					dst->r = GB(color, 16, 8);
+					dst->g = GB(color, 8,  8);
+					dst->b = GB(color, 0,  8);
+				}
+			}
+			dst--;
+		}
+	}
+	return dest_sprite;
+}