# 8bpp_optimized.cpp

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    00001 /* $Id$ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
    00006  * OpenTTD 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.
    00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
    00008  */
    00009
    00012 #include "../stdafx.h"
    00013 #include "../zoom_func.h"
    00014 #include "../core/math_func.hpp"
    00015 #include "8bpp_optimized.hpp"
    00016
    00018 static FBlitter_8bppOptimized iFBlitter_8bppOptimized;
    00019
    00020 void Blitter_8bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
    00021 {
    00022   /* Find the offset of this zoom-level */
    00023   const SpriteData *sprite_src = (const SpriteData *)bp->sprite;
    00024   uint offset = sprite_src->offset[zoom];
    00025
    00026   /* Find where to start reading in the source sprite */
    00027   const uint8 *src = sprite_src->data + offset;
    00028   uint8 *dst_line = (uint8 *)bp->dst + bp->top * bp->pitch + bp->left;
    00029
    00030   /* Skip over the top lines in the source image */
    00031   for (int y = 0; y < bp->skip_top; y++) {
    00032     for (;;) {
    00033       uint trans = *src++;
    00034       uint pixels = *src++;
    00035       if (trans == 0 && pixels == 0) break;
    00036       src += pixels;
    00037     }
    00038   }
    00039
    00040   const uint8 *src_next = src;
    00041
    00042   for (int y = 0; y < bp->height; y++) {
    00043     uint8 *dst = dst_line;
    00044     dst_line += bp->pitch;
    00045
    00046     uint skip_left = bp->skip_left;
    00047     int width = bp->width;
    00048
    00049     for (;;) {
    00050       src = src_next;
    00051       uint trans = *src++;
    00052       uint pixels = *src++;
    00053       src_next = src + pixels;
    00054       if (trans == 0 && pixels == 0) break;
    00055       if (width <= 0) continue;
    00056
    00057       if (skip_left != 0) {
    00058         if (skip_left < trans) {
    00059           trans -= skip_left;
    00060           skip_left = 0;
    00061         } else {
    00062           skip_left -= trans;
    00063           trans = 0;
    00064         }
    00065         if (skip_left < pixels) {
    00066           src += skip_left;
    00067           pixels -= skip_left;
    00068           skip_left = 0;
    00069         } else {
    00070           src += pixels;
    00071           skip_left -= pixels;
    00072           pixels = 0;
    00073         }
    00074       }
    00075       if (skip_left != 0) continue;
    00076
    00077       /* Skip transparent pixels */
    00078       dst += trans;
    00079       width -= trans;
    00080       if (width <= 0 || pixels == 0) continue;
    00081       pixels = min<uint>(pixels, (uint)width);
    00082       width -= pixels;
    00083
    00084       switch (mode) {
    00085         case BM_COLOUR_REMAP: {
    00086           const uint8 *remap = bp->remap;
    00087           do {
    00088             uint m = remap[*src];
    00089             if (m != 0) *dst = m;
    00090             dst++; src++;
    00091           } while (--pixels != 0);
    00092           break;
    00093         }
    00094
    00095         case BM_TRANSPARENT: {
    00096           const uint8 *remap = bp->remap;
    00097           src += pixels;
    00098           do {
    00099             *dst = remap[*dst];
    00100             dst++;
    00101           } while (--pixels != 0);
    00102           break;
    00103         }
    00104
    00105         default:
    00106           memcpy(dst, src, pixels);
    00107           dst += pixels; src += pixels;
    00108           break;
    00109       }
    00110     }
    00111   }
    00112 }
    00113
    00114 Sprite *Blitter_8bppOptimized::Encode(SpriteLoader::Sprite *sprite, AllocatorProc *allocator)
    00115 {
    00116   /* Make memory for all zoom-levels */
    00117   uint memory = sizeof(SpriteData);
    00118
    00119   for (ZoomLevel i = ZOOM_LVL_BEGIN; i < ZOOM_LVL_END; i++) {
    00120     memory += UnScaleByZoom(sprite->height, i) * UnScaleByZoom(sprite->width, i);
    00121   }
    00122
    00123   /* We have no idea how much memory we really need, so just guess something */
    00124   memory *= 5;
    00125
    00126   /* Don't allocate memory each time, but just keep some
    00127    * memory around as this function is called quite often
    00128    * and the memory usage is quite low. */
    00129   static ReusableBuffer<byte> temp_buffer;
    00130   SpriteData *temp_dst = (SpriteData *)temp_buffer.Allocate(memory);
    00131   byte *dst = temp_dst->data;
    00132
    00133   /* Make the sprites per zoom-level */
    00134   for (ZoomLevel i = ZOOM_LVL_BEGIN; i < ZOOM_LVL_END; i++) {
    00135     /* Store the index table */
    00136     uint offset = dst - temp_dst->data;
    00137     temp_dst->offset[i] = offset;
    00138
    00139     /* cache values, because compiler can't cache it */
    00140     int scaled_height = UnScaleByZoom(sprite->height, i);
    00141     int scaled_width  = UnScaleByZoom(sprite->width,  i);
    00142     int scaled_1      =   ScaleByZoom(1,              i);
    00143
    00144     for (int y = 0; y < scaled_height; y++) {
    00145       uint trans = 0;
    00146       uint pixels = 0;
    00147       uint last_colour = 0;
    00148       byte *count_dst = NULL;
    00149
    00150       /* Store the scaled image */
    00151       const SpriteLoader::CommonPixel *src = &sprite->data[ScaleByZoom(y, i) * sprite->width];
    00152       const SpriteLoader::CommonPixel *src_end = &src[sprite->width];
    00153
    00154       for (int x = 0; x < scaled_width; x++) {
    00155         uint colour = 0;
    00156
    00157         /* Get the colour keeping in mind the zoom-level */
    00158         for (int j = 0; j < scaled_1; j++) {
    00159           if (src->m != 0) colour = src->m;
    00160           /* Because of the scaling it might happen we read outside the buffer. Avoid that. */
    00161           if (++src == src_end) break;
    00162         }
    00163
    00164         if (last_colour == 0 || colour == 0 || pixels == 255) {
    00165           if (count_dst != NULL) {
    00166             /* Write how many non-transparent bytes we get */
    00167             *count_dst = pixels;
    00168             pixels = 0;
    00169             count_dst = NULL;
    00170           }
    00171           /* As long as we find transparency bytes, keep counting */
    00172           if (colour == 0) {
    00173             last_colour = 0;
    00174             trans++;
    00175             continue;
    00176           }
    00177           /* No longer transparency, so write the amount of transparent bytes */
    00178           *dst = trans;
    00179           dst++;
    00180           trans = 0;
    00181           /* Reserve a byte for the pixel counter */
    00182           count_dst = dst;
    00183           dst++;
    00184         }
    00185         last_colour = colour;
    00186         pixels++;
    00187         *dst = colour;
    00188         dst++;
    00189       }
    00190
    00191       if (count_dst != NULL) *count_dst = pixels;
    00192
    00193       /* Write line-ending */
    00194       *dst = 0; dst++;
    00195       *dst = 0; dst++;
    00196     }
    00197   }
    00198
    00199   uint size = dst - (byte *)temp_dst;
    00200
    00201   /* Safety check, to make sure we guessed the size correctly */
    00202   assert(size < memory);
    00203
    00204   /* Allocate the exact amount of memory we need */
    00205   Sprite *dest_sprite = (Sprite *)allocator(sizeof(*dest_sprite) + size);
    00206
    00207   dest_sprite->height = sprite->height;
    00208   dest_sprite->width  = sprite->width;
    00209   dest_sprite->x_offs = sprite->x_offs;
    00210   dest_sprite->y_offs = sprite->y_offs;
    00211   memcpy(dest_sprite->data, temp_dst, size);
    00212
    00213   return dest_sprite;
    00214 }