# 32bpp_optimized.cpp

    00001 /* $Id: 32bpp_optimized.cpp 11828 2008-01-13 01:21:35Z rubidium $ */
    00002
    00003 #include "../stdafx.h"
    00004 #include "../zoom_func.h"
    00005 #include "../gfx_func.h"
    00006 #include "../debug.h"
    00007 #include "32bpp_optimized.hpp"
    00008
    00009 static FBlitter_32bppOptimized iFBlitter_32bppOptimized;
    00010
    00011 void Blitter_32bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
    00012 {
    00013   const SpriteLoader::CommonPixel *src, *src_line;
    00014   uint32 *dst, *dst_line;
    00015
    00016   /* Find where to start reading in the source sprite */
    00017   src_line = (const SpriteLoader::CommonPixel *)bp->sprite + (bp->skip_top * bp->sprite_width + bp->skip_left) * ScaleByZoom(1, zoom);
    00018   dst_line = (uint32 *)bp->dst + bp->top * bp->pitch + bp->left;
    00019
    00020   for (int y = 0; y < bp->height; y++) {
    00021     dst = dst_line;
    00022     dst_line += bp->pitch;
    00023
    00024     src = src_line;
    00025     src_line += bp->sprite_width * ScaleByZoom(1, zoom);
    00026
    00027     for (int x = 0; x < bp->width; x++) {
    00028       if (src->a == 0) {
    00029         /* src->r is 'misused' here to indicate how much more pixels are following with an alpha of 0 */
    00030         int skip = UnScaleByZoom(src->r, zoom);
    00031
    00032         dst += skip;
    00033         x   += skip - 1;
    00034         src += ScaleByZoom(1, zoom) * skip;
    00035         continue;
    00036       }
    00037
    00038       switch (mode) {
    00039         case BM_COLOUR_REMAP:
    00040           /* In case the m-channel is zero, do not remap this pixel in any way */
    00041           if (src->m == 0) {
    00042             *dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
    00043           } else {
    00044             if (bp->remap[src->m] != 0) *dst = ComposeColourPA(this->LookupColourInPalette(bp->remap[src->m]), src->a, *dst);
    00045           }
    00046           break;
    00047
    00048         case BM_TRANSPARENT:
    00049           /* TODO -- We make an assumption here that the remap in fact is transparency, not some color.
    00050            *  This is never a problem with the code we produce, but newgrfs can make it fail... or at least:
    00051            *  we produce a result the newgrf maker didn't expect ;) */
    00052
    00053           /* Make the current color a bit more black, so it looks like this image is transparent */
    00054           *dst = MakeTransparent(*dst, 192);
    00055           break;
    00056
    00057         default:
    00058           *dst = ComposeColourRGBA(src->r, src->g, src->b, src->a, *dst);
    00059           break;
    00060       }
    00061       dst++;
    00062       src += ScaleByZoom(1, zoom);
    00063     }
    00064   }
    00065 }
    00066
    00067 Sprite *Blitter_32bppOptimized::Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator)
    00068 {
    00069   Sprite *dest_sprite;
    00070   SpriteLoader::CommonPixel *dst;
    00071   dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
    00072
    00073   dest_sprite->height = sprite->height;
    00074   dest_sprite->width  = sprite->width;
    00075   dest_sprite->x_offs = sprite->x_offs;
    00076   dest_sprite->y_offs = sprite->y_offs;
    00077
    00078   dst = (SpriteLoader::CommonPixel *)dest_sprite->data;
    00079
    00080   memcpy(dst, sprite->data, sprite->height * sprite->width * sizeof(SpriteLoader::CommonPixel));
    00081   /* Skip to the end of the array, and work backwards to find transparent blocks */
    00082   dst = dst + sprite->height * sprite->width - 1;
    00083
    00084   for (uint y = sprite->height; y > 0; y--) {
    00085     int trans = 0;
    00086     /* Process sprite line backwards, to compute lengths of transparent blocks */
    00087     for (uint x = sprite->width; x > 0; x--) {
    00088       if (dst->a == 0) {
    00089         /* Save transparent block length in red channel; max value is 255 the red channel can contain */
    00090         if (trans < 255) trans++;
    00091         dst->r = trans;
    00092         dst->g = 0;
    00093         dst->b = 0;
    00094         dst->m = 0;
    00095       } else {
    00096         trans = 0;
    00097         if (dst->m != 0) {
    00098           /* Pre-convert the mapping channel to a RGB value */
    00099           uint color = this->LookupColourInPalette(dst->m);
    00100           dst->r = GB(color, 16, 8);
    00101           dst->g = GB(color, 8,  8);
    00102           dst->b = GB(color, 0,  8);
    00103         }
    00104       }
    00105       dst--;
    00106     }
    00107   }
    00108   return dest_sprite;
    00109 }