heightmap.cpp

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00001 /* $Id: heightmap.cpp 18756 2010-01-08 03:17:12Z glx $ */
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 "heightmap.h"
00014 #include "clear_map.h"
00015 #include "void_map.h"
00016 #include "gui.h"
00017 #include "saveload/saveload.h"
00018 #include "bmp.h"
00019 #include "gfx_func.h"
00020 #include "fios.h"
00021 #include "fileio_func.h"
00022 
00023 #include "table/strings.h"
00024 
00030 static inline byte RGBToGrayscale(byte red, byte green, byte blue)
00031 {
00032   /* To avoid doubles and stuff, multiple it with a total of 65536 (16bits), then
00033    *  divide by it to normalize the value to a byte again. */
00034   return ((red * 19595) + (green * 38470) + (blue * 7471)) / 65536;
00035 }
00036 
00037 
00038 #ifdef WITH_PNG
00039 
00040 #include <png.h>
00041 
00045 static void ReadHeightmapPNGImageData(byte *map, png_structp png_ptr, png_infop info_ptr)
00046 {
00047   uint x, y;
00048   byte gray_palette[256];
00049   png_bytep *row_pointers = NULL;
00050 
00051   /* Get palette and convert it to grayscale */
00052   if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE) {
00053     int i;
00054     int palette_size;
00055     png_color *palette;
00056     bool all_gray = true;
00057 
00058     png_get_PLTE(png_ptr, info_ptr, &palette, &palette_size);
00059     for (i = 0; i < palette_size && (palette_size != 16 || all_gray); i++) {
00060       all_gray &= palette[i].red == palette[i].green && palette[i].red == palette[i].blue;
00061       gray_palette[i] = RGBToGrayscale(palette[i].red, palette[i].green, palette[i].blue);
00062     }
00063 
00070     if (palette_size == 16 && !all_gray) {
00071       for (i = 0; i < palette_size; i++) {
00072         gray_palette[i] = 256 * i / palette_size;
00073       }
00074     }
00075   }
00076 
00077   row_pointers = png_get_rows(png_ptr, info_ptr);
00078 
00079   /* Read the raw image data and convert in 8-bit grayscale */
00080   for (x = 0; x < png_get_image_width(png_ptr, info_ptr); x++) {
00081     for (y = 0; y < png_get_image_height(png_ptr, info_ptr); y++) {
00082       byte *pixel = &map[y * png_get_image_width(png_ptr, info_ptr) + x];
00083       uint x_offset = x * png_get_channels(png_ptr, info_ptr);
00084 
00085       if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE) {
00086         *pixel = gray_palette[row_pointers[y][x_offset]];
00087       } else if (png_get_channels(png_ptr, info_ptr) == 3) {
00088         *pixel = RGBToGrayscale(row_pointers[y][x_offset + 0],
00089             row_pointers[y][x_offset + 1], row_pointers[y][x_offset + 2]);
00090       } else {
00091         *pixel = row_pointers[y][x_offset];
00092       }
00093     }
00094   }
00095 }
00096 
00102 static bool ReadHeightmapPNG(char *filename, uint *x, uint *y, byte **map)
00103 {
00104   FILE *fp;
00105   png_structp png_ptr = NULL;
00106   png_infop info_ptr  = NULL;
00107 
00108   fp = FioFOpenFile(filename, "rb");
00109   if (fp == NULL) {
00110     ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, 0, 0);
00111     return false;
00112   }
00113 
00114   png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
00115   if (png_ptr == NULL) {
00116     ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, 0, 0);
00117     fclose(fp);
00118     return false;
00119   }
00120 
00121   info_ptr = png_create_info_struct(png_ptr);
00122   if (info_ptr == NULL || setjmp(png_jmpbuf(png_ptr))) {
00123     ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, 0, 0);
00124     fclose(fp);
00125     png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
00126     return false;
00127   }
00128 
00129   png_init_io(png_ptr, fp);
00130 
00131   /* Allocate memory and read image, without alpha or 16-bit samples
00132    * (result is either 8-bit indexed/grayscale or 24-bit RGB) */
00133   png_set_packing(png_ptr);
00134   png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_PACKING | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_STRIP_16, NULL);
00135 
00136   /* Maps of wrong colour-depth are not used.
00137    * (this should have been taken care of by stripping alpha and 16-bit samples on load) */
00138   if ((png_get_channels(png_ptr, info_ptr) != 1) && (png_get_channels(png_ptr, info_ptr) != 3) && (png_get_bit_depth(png_ptr, info_ptr) != 8)) {
00139     ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_IMAGE_TYPE, 0, 0);
00140     fclose(fp);
00141     png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
00142     return false;
00143   }
00144 
00145   if (map != NULL) {
00146     *map = MallocT<byte>(png_get_image_width(png_ptr, info_ptr) * png_get_image_height(png_ptr, info_ptr));
00147     ReadHeightmapPNGImageData(*map, png_ptr, info_ptr);
00148   }
00149 
00150   *x = png_get_image_width(png_ptr, info_ptr);
00151   *y = png_get_image_height(png_ptr, info_ptr);
00152 
00153   fclose(fp);
00154   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
00155   return true;
00156 }
00157 
00158 #endif /* WITH_PNG */
00159 
00160 
00164 static void ReadHeightmapBMPImageData(byte *map, BmpInfo *info, BmpData *data)
00165 {
00166   uint x, y;
00167   byte gray_palette[256];
00168 
00169   if (data->palette != NULL) {
00170     uint i;
00171     bool all_gray = true;
00172 
00173     if (info->palette_size != 2) {
00174       for (i = 0; i < info->palette_size && (info->palette_size != 16 || all_gray); i++) {
00175         all_gray &= data->palette[i].r == data->palette[i].g && data->palette[i].r == data->palette[i].b;
00176         gray_palette[i] = RGBToGrayscale(data->palette[i].r, data->palette[i].g, data->palette[i].b);
00177       }
00178 
00185       if (info->palette_size == 16 && !all_gray) {
00186         for (i = 0; i < info->palette_size; i++) {
00187           gray_palette[i] = 256 * i / info->palette_size;
00188         }
00189       }
00190     } else {
00195       gray_palette[0] = 0;
00196       gray_palette[1] = 16;
00197     }
00198   }
00199 
00200   /* Read the raw image data and convert in 8-bit grayscale */
00201   for (y = 0; y < info->height; y++) {
00202     byte *pixel = &map[y * info->width];
00203     byte *bitmap = &data->bitmap[y * info->width * (info->bpp == 24 ? 3 : 1)];
00204 
00205     for (x = 0; x < info->width; x++) {
00206       if (info->bpp != 24) {
00207         *pixel++ = gray_palette[*bitmap++];
00208       } else {
00209         *pixel++ = RGBToGrayscale(*bitmap, *(bitmap + 1), *(bitmap + 2));
00210         bitmap += 3;
00211       }
00212     }
00213   }
00214 }
00215 
00221 static bool ReadHeightmapBMP(char *filename, uint *x, uint *y, byte **map)
00222 {
00223   FILE *f;
00224   BmpInfo info;
00225   BmpData data;
00226   BmpBuffer buffer;
00227 
00228   /* Init BmpData */
00229   memset(&data, 0, sizeof(data));
00230 
00231   f = FioFOpenFile(filename, "rb");
00232   if (f == NULL) {
00233     ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, 0, 0);
00234     return false;
00235   }
00236 
00237   BmpInitializeBuffer(&buffer, f);
00238 
00239   if (!BmpReadHeader(&buffer, &info, &data)) {
00240     ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, 0, 0);
00241     fclose(f);
00242     BmpDestroyData(&data);
00243     return false;
00244   }
00245 
00246   if (map != NULL) {
00247     if (!BmpReadBitmap(&buffer, &info, &data)) {
00248       ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, 0, 0);
00249       fclose(f);
00250       BmpDestroyData(&data);
00251       return false;
00252     }
00253 
00254     *map = MallocT<byte>(info.width * info.height);
00255     ReadHeightmapBMPImageData(*map, &info, &data);
00256   }
00257 
00258   BmpDestroyData(&data);
00259 
00260   *x = info.width;
00261   *y = info.height;
00262 
00263   fclose(f);
00264   return true;
00265 }
00266 
00274 static void GrayscaleToMapHeights(uint img_width, uint img_height, byte *map)
00275 {
00276   /* Defines the detail of the aspect ratio (to avoid doubles) */
00277   const uint num_div = 16384;
00278 
00279   uint width, height;
00280   uint row, col;
00281   uint row_pad = 0, col_pad = 0;
00282   uint img_scale;
00283   uint img_row, img_col;
00284   TileIndex tile;
00285 
00286   /* Get map size and calculate scale and padding values */
00287   switch (_settings_game.game_creation.heightmap_rotation) {
00288     default: NOT_REACHED();
00289     case HM_COUNTER_CLOCKWISE:
00290       width   = MapSizeX();
00291       height  = MapSizeY();
00292       break;
00293     case HM_CLOCKWISE:
00294       width   = MapSizeY();
00295       height  = MapSizeX();
00296       break;
00297   }
00298 
00299   if ((img_width * num_div) / img_height > ((width * num_div) / height)) {
00300     /* Image is wider than map - center vertically */
00301     img_scale = (width * num_div) / img_width;
00302     row_pad = (1 + height - ((img_height * img_scale) / num_div)) / 2;
00303   } else {
00304     /* Image is taller than map - center horizontally */
00305     img_scale = (height * num_div) / img_height;
00306     col_pad = (1 + width - ((img_width * img_scale) / num_div)) / 2;
00307   }
00308 
00309   if (_settings_game.construction.freeform_edges) {
00310     for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
00311     for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
00312   }
00313 
00314   /* Form the landscape */
00315   for (row = 0; row < height; row++) {
00316     for (col = 0; col < width; col++) {
00317       switch (_settings_game.game_creation.heightmap_rotation) {
00318         default: NOT_REACHED();
00319         case HM_COUNTER_CLOCKWISE: tile = TileXY(col, row); break;
00320         case HM_CLOCKWISE:         tile = TileXY(row, col); break;
00321       }
00322 
00323       /* Check if current tile is within the 1-pixel map edge or padding regions */
00324       if ((!_settings_game.construction.freeform_edges && DistanceFromEdge(tile) <= 1) ||
00325           (row < row_pad) || (row >= (height - row_pad - (_settings_game.construction.freeform_edges ? 0 : 1))) ||
00326           (col < col_pad) || (col >= (width  - col_pad - (_settings_game.construction.freeform_edges ? 0 : 1)))) {
00327         SetTileHeight(tile, 0);
00328       } else {
00329         /* Use nearest neighbor resizing to scale map data.
00330          *  We rotate the map 45 degrees (counter)clockwise */
00331         img_row = (((row - row_pad) * num_div) / img_scale);
00332         switch (_settings_game.game_creation.heightmap_rotation) {
00333           default: NOT_REACHED();
00334           case HM_COUNTER_CLOCKWISE:
00335             img_col = (((width - 1 - col - col_pad) * num_div) / img_scale);
00336             break;
00337           case HM_CLOCKWISE:
00338             img_col = (((col - col_pad) * num_div) / img_scale);
00339             break;
00340         }
00341 
00342         assert(img_row < img_height);
00343         assert(img_col < img_width);
00344 
00345         /* Colour scales from 0 to 255, OpenTTD height scales from 0 to 15 */
00346         SetTileHeight(tile, map[img_row * img_width + img_col] / 16);
00347       }
00348       /* Only clear the tiles within the map area. */
00349       if (TileX(tile) != MapMaxX() && TileY(tile) != MapMaxY() &&
00350           (!_settings_game.construction.freeform_edges || (TileX(tile) != 0 && TileY(tile) != 0))) {
00351         MakeClear(tile, CLEAR_GRASS, 3);
00352       }
00353     }
00354   }
00355 }
00356 
00361 void FixSlopes()
00362 {
00363   uint width, height;
00364   int row, col;
00365   byte current_tile;
00366 
00367   /* Adjust height difference to maximum one horizontal/vertical change. */
00368   width   = MapSizeX();
00369   height  = MapSizeY();
00370 
00371   /* Top and left edge */
00372   for (row = 0; (uint)row < height; row++) {
00373     for (col = 0; (uint)col < width; col++) {
00374       current_tile = MAX_TILE_HEIGHT;
00375       if (col != 0) {
00376         /* Find lowest tile; either the top or left one */
00377         current_tile = TileHeight(TileXY(col - 1, row)); // top edge
00378       }
00379       if (row != 0) {
00380         if (TileHeight(TileXY(col, row - 1)) < current_tile) {
00381           current_tile = TileHeight(TileXY(col, row - 1)); // left edge
00382         }
00383       }
00384 
00385       /* Does the height differ more than one? */
00386       if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
00387         /* Then change the height to be no more than one */
00388         SetTileHeight(TileXY(col, row), current_tile + 1);
00389       }
00390     }
00391   }
00392 
00393   /* Bottom and right edge */
00394   for (row = height - 1; row >= 0; row--) {
00395     for (col = width - 1; col >= 0; col--) {
00396       current_tile = MAX_TILE_HEIGHT;
00397       if ((uint)col != width - 1) {
00398         /* Find lowest tile; either the bottom and right one */
00399         current_tile = TileHeight(TileXY(col + 1, row)); // bottom edge
00400       }
00401 
00402       if ((uint)row != height - 1) {
00403         if (TileHeight(TileXY(col, row + 1)) < current_tile) {
00404           current_tile = TileHeight(TileXY(col, row + 1)); // right edge
00405         }
00406       }
00407 
00408       /* Does the height differ more than one? */
00409       if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
00410         /* Then change the height to be no more than one */
00411         SetTileHeight(TileXY(col, row), current_tile + 1);
00412       }
00413     }
00414   }
00415 }
00416 
00420 static bool ReadHeightMap(char *filename, uint *x, uint *y, byte **map)
00421 {
00422   switch (_file_to_saveload.mode) {
00423     default: NOT_REACHED();
00424 #ifdef WITH_PNG
00425     case SL_PNG:
00426       return ReadHeightmapPNG(filename, x, y, map);
00427 #endif /* WITH_PNG */
00428     case SL_BMP:
00429       return ReadHeightmapBMP(filename, x, y, map);
00430   }
00431 }
00432 
00433 bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
00434 {
00435   return ReadHeightMap(filename, x, y, NULL);
00436 }
00437 
00438 void LoadHeightmap(char *filename)
00439 {
00440   uint x, y;
00441   byte *map = NULL;
00442 
00443   if (!ReadHeightMap(filename, &x, &y, &map)) {
00444     free(map);
00445     return;
00446   }
00447 
00448   GrayscaleToMapHeights(x, y, map);
00449   free(map);
00450 
00451   FixSlopes();
00452   MarkWholeScreenDirty();
00453 }
00454 
00455 void FlatEmptyWorld(byte tile_height)
00456 {
00457   int edge_distance = _settings_game.construction.freeform_edges ? 0 : 2;
00458   for (uint row = edge_distance; row < MapSizeY() - edge_distance; row++) {
00459     for (uint col = edge_distance; col < MapSizeX() - edge_distance; col++) {
00460       SetTileHeight(TileXY(col, row), tile_height);
00461     }
00462   }
00463 
00464   FixSlopes();
00465   MarkWholeScreenDirty();
00466 }

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