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heightmap.cpp
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1 /* $Id: heightmap.cpp 27044 2014-10-25 22:24:05Z frosch $ */
2
3 /*
4 * This file is part of OpenTTD.
5 * 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.
6 * 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.
7 * 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/>.
8 */
9
12 #include "stdafx.h"
13 #include "heightmap.h"
14 #include "clear_map.h"
15 #include "void_map.h"
16 #include "error.h"
17 #include "saveload/saveload.h"
18 #include "bmp.h"
19 #include "gfx_func.h"
20 #include "fios.h"
21 #include "fileio_func.h"
22
23 #include "table/strings.h"
24
25 #include "safeguards.h"
26
31 static inline byte RGBToGrayscale(byte red, byte green, byte blue)
32 {
33 /* To avoid doubles and stuff, multiply it with a total of 65536 (16bits), then
34 * divide by it to normalize the value to a byte again. */
35 return ((red * 19595) + (green * 38470) + (blue * 7471)) / 65536;
36 }
37
38
39 #ifdef WITH_PNG
40
41 #include <png.h>
42
46 static void ReadHeightmapPNGImageData(byte *map, png_structp png_ptr, png_infop info_ptr)
47 {
48 uint x, y;
49 byte gray_palette[256];
50 png_bytep *row_pointers = NULL;
51 bool has_palette = png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE;
52 uint channels = png_get_channels(png_ptr, info_ptr);
53
54 /* Get palette and convert it to grayscale */
55 if (has_palette) {
56 int i;
57 int palette_size;
58 png_color *palette;
59 bool all_gray = true;
60
61 png_get_PLTE(png_ptr, info_ptr, &palette, &palette_size);
62 for (i = 0; i < palette_size && (palette_size != 16 || all_gray); i++) {
63 all_gray &= palette[i].red == palette[i].green && palette[i].red == palette[i].blue;
64 gray_palette[i] = RGBToGrayscale(palette[i].red, palette[i].green, palette[i].blue);
65 }
66
73 if (palette_size == 16 && !all_gray) {
74 for (i = 0; i < palette_size; i++) {
75 gray_palette[i] = 256 * i / palette_size;
76 }
77 }
78 }
79
80 row_pointers = png_get_rows(png_ptr, info_ptr);
81
82 /* Read the raw image data and convert in 8-bit grayscale */
83 for (x = 0; x < png_get_image_width(png_ptr, info_ptr); x++) {
84 for (y = 0; y < png_get_image_height(png_ptr, info_ptr); y++) {
85 byte *pixel = &map[y * png_get_image_width(png_ptr, info_ptr) + x];
86 uint x_offset = x * channels;
87
88 if (has_palette) {
89 *pixel = gray_palette[row_pointers[y][x_offset]];
90 } else if (channels == 3) {
91 *pixel = RGBToGrayscale(row_pointers[y][x_offset + 0],
92 row_pointers[y][x_offset + 1], row_pointers[y][x_offset + 2]);
93 } else {
94 *pixel = row_pointers[y][x_offset];
95 }
96 }
97 }
98 }
99
105 static bool ReadHeightmapPNG(char *filename, uint *x, uint *y, byte **map)
106 {
107 FILE *fp;
108 png_structp png_ptr = NULL;
109 png_infop info_ptr = NULL;
110
111 fp = FioFOpenFile(filename, "rb", HEIGHTMAP_DIR);
112 if (fp == NULL) {
113 ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, WL_ERROR);
114 return false;
115 }
116
117 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
118 if (png_ptr == NULL) {
119 ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, WL_ERROR);
120 fclose(fp);
121 return false;
122 }
123
124 info_ptr = png_create_info_struct(png_ptr);
125 if (info_ptr == NULL || setjmp(png_jmpbuf(png_ptr))) {
126 ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, WL_ERROR);
127 fclose(fp);
128 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
129 return false;
130 }
131
132 png_init_io(png_ptr, fp);
133
134 /* Allocate memory and read image, without alpha or 16-bit samples
135 * (result is either 8-bit indexed/grayscale or 24-bit RGB) */
136 png_set_packing(png_ptr);
137 png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_PACKING | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_STRIP_16, NULL);
138
139 /* Maps of wrong colour-depth are not used.
140 * (this should have been taken care of by stripping alpha and 16-bit samples on load) */
141 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)) {
142 ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_IMAGE_TYPE, WL_ERROR);
143 fclose(fp);
144 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
145 return false;
146 }
147
148 uint width = png_get_image_width(png_ptr, info_ptr);
149 uint height = png_get_image_height(png_ptr, info_ptr);
150
151 /* Check if image dimensions don't overflow a size_t to avoid memory corruption. */
152 if ((uint64)width * height >= (size_t)-1) {
153 ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_HEIGHTMAP_TOO_LARGE, WL_ERROR);
154 fclose(fp);
155 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
156 return false;
157 }
158
159 if (map != NULL) {
160 *map = MallocT<byte>(width * height);
161 ReadHeightmapPNGImageData(*map, png_ptr, info_ptr);
162 }
163
164 *x = width;
165 *y = height;
166
167 fclose(fp);
168 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
169 return true;
170 }
171
172 #endif /* WITH_PNG */
173
174
178 static void ReadHeightmapBMPImageData(byte *map, BmpInfo *info, BmpData *data)
179 {
180 uint x, y;
181 byte gray_palette[256];
182
183 if (data->palette != NULL) {
184 uint i;
185 bool all_gray = true;
186
187 if (info->palette_size != 2) {
188 for (i = 0; i < info->palette_size && (info->palette_size != 16 || all_gray); i++) {
189 all_gray &= data->palette[i].r == data->palette[i].g && data->palette[i].r == data->palette[i].b;
190 gray_palette[i] = RGBToGrayscale(data->palette[i].r, data->palette[i].g, data->palette[i].b);
191 }
192
199 if (info->palette_size == 16 && !all_gray) {
200 for (i = 0; i < info->palette_size; i++) {
201 gray_palette[i] = 256 * i / info->palette_size;
202 }
203 }
204 } else {
209 gray_palette[0] = 0;
210 gray_palette[1] = 16;
211 }
212 }
213
214 /* Read the raw image data and convert in 8-bit grayscale */
215 for (y = 0; y < info->height; y++) {
216 byte *pixel = &map[y * info->width];
217 byte *bitmap = &data->bitmap[y * info->width * (info->bpp == 24 ? 3 : 1)];
218
219 for (x = 0; x < info->width; x++) {
220 if (info->bpp != 24) {
221 *pixel++ = gray_palette[*bitmap++];
222 } else {
223 *pixel++ = RGBToGrayscale(*bitmap, *(bitmap + 1), *(bitmap + 2));
224 bitmap += 3;
225 }
226 }
227 }
228 }
229
235 static bool ReadHeightmapBMP(char *filename, uint *x, uint *y, byte **map)
236 {
237 FILE *f;
238 BmpInfo info;
239 BmpData data;
240 BmpBuffer buffer;
241
242 /* Init BmpData */
243 memset(&data, 0, sizeof(data));
244
245 f = FioFOpenFile(filename, "rb", HEIGHTMAP_DIR);
246 if (f == NULL) {
247 ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, WL_ERROR);
248 return false;
249 }
250
251 BmpInitializeBuffer(&buffer, f);
252
253 if (!BmpReadHeader(&buffer, &info, &data)) {
254 ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, WL_ERROR);
255 fclose(f);
256 BmpDestroyData(&data);
257 return false;
258 }
259
260 /* Check if image dimensions don't overflow a size_t to avoid memory corruption. */
261 if ((uint64)info.width * info.height >= (size_t)-1 / (info.bpp == 24 ? 3 : 1)) {
262 ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_HEIGHTMAP_TOO_LARGE, WL_ERROR);
263 fclose(f);
264 BmpDestroyData(&data);
265 return false;
266 }
267
268 if (map != NULL) {
269 if (!BmpReadBitmap(&buffer, &info, &data)) {
270 ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, WL_ERROR);
271 fclose(f);
272 BmpDestroyData(&data);
273 return false;
274 }
275
276 *map = MallocT<byte>(info.width * info.height);
277 ReadHeightmapBMPImageData(*map, &info, &data);
278 }
279
280 BmpDestroyData(&data);
281
282 *x = info.width;
283 *y = info.height;
284
285 fclose(f);
286 return true;
287 }
288
296 static void GrayscaleToMapHeights(uint img_width, uint img_height, byte *map)
297 {
298 /* Defines the detail of the aspect ratio (to avoid doubles) */
299 const uint num_div = 16384;
300
301 uint width, height;
302 uint row, col;
303 uint row_pad = 0, col_pad = 0;
304 uint img_scale;
305 uint img_row, img_col;
306 TileIndex tile;
307
308 /* Get map size and calculate scale and padding values */
309 switch (_settings_game.game_creation.heightmap_rotation) {
310 default: NOT_REACHED();
311 case HM_COUNTER_CLOCKWISE:
312 width = MapSizeX();
313 height = MapSizeY();
314 break;
315 case HM_CLOCKWISE:
316 width = MapSizeY();
317 height = MapSizeX();
318 break;
319 }
320
321 if ((img_width * num_div) / img_height > ((width * num_div) / height)) {
322 /* Image is wider than map - center vertically */
323 img_scale = (width * num_div) / img_width;
324 row_pad = (1 + height - ((img_height * img_scale) / num_div)) / 2;
325 } else {
326 /* Image is taller than map - center horizontally */
327 img_scale = (height * num_div) / img_height;
328 col_pad = (1 + width - ((img_width * img_scale) / num_div)) / 2;
329 }
330
331 if (_settings_game.construction.freeform_edges) {
332 for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
333 for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
334 }
335
336 /* Form the landscape */
337 for (row = 0; row < height; row++) {
338 for (col = 0; col < width; col++) {
339 switch (_settings_game.game_creation.heightmap_rotation) {
340 default: NOT_REACHED();
341 case HM_COUNTER_CLOCKWISE: tile = TileXY(col, row); break;
342 case HM_CLOCKWISE: tile = TileXY(row, col); break;
343 }
344
345 /* Check if current tile is within the 1-pixel map edge or padding regions */
346 if ((!_settings_game.construction.freeform_edges && DistanceFromEdge(tile) <= 1) ||
347 (row < row_pad) || (row >= (height - row_pad - (_settings_game.construction.freeform_edges ? 0 : 1))) ||
348 (col < col_pad) || (col >= (width - col_pad - (_settings_game.construction.freeform_edges ? 0 : 1)))) {
349 SetTileHeight(tile, 0);
350 } else {
351 /* Use nearest neighbour resizing to scale map data.
352 * We rotate the map 45 degrees (counter)clockwise */
353 img_row = (((row - row_pad) * num_div) / img_scale);
354 switch (_settings_game.game_creation.heightmap_rotation) {
355 default: NOT_REACHED();
356 case HM_COUNTER_CLOCKWISE:
357 img_col = (((width - 1 - col - col_pad) * num_div) / img_scale);
358 break;
359 case HM_CLOCKWISE:
360 img_col = (((col - col_pad) * num_div) / img_scale);
361 break;
362 }
363
364 assert(img_row < img_height);
365 assert(img_col < img_width);
366
367 uint heightmap_height = map[img_row * img_width + img_col];
368
369 if (heightmap_height > 0) {
370 /* 0 is sea level.
371 * Other grey scales are scaled evenly to the available height levels > 0.
372 * (The coastline is independent from the number of height levels) */
373 heightmap_height = 1 + (heightmap_height - 1) * _settings_game.construction.max_heightlevel / 255;
374 }
375
376 SetTileHeight(tile, heightmap_height);
377 }
378 /* Only clear the tiles within the map area. */
379 if (IsInnerTile(tile)) {
380 MakeClear(tile, CLEAR_GRASS, 3);
381 }
382 }
383 }
384 }
385
390 void FixSlopes()
391 {
392 uint width, height;
393 int row, col;
394 byte current_tile;
395
396 /* Adjust height difference to maximum one horizontal/vertical change. */
397 width = MapSizeX();
398 height = MapSizeY();
399
400 /* Top and left edge */
401 for (row = 0; (uint)row < height; row++) {
402 for (col = 0; (uint)col < width; col++) {
403 current_tile = MAX_TILE_HEIGHT;
404 if (col != 0) {
405 /* Find lowest tile; either the top or left one */
406 current_tile = TileHeight(TileXY(col - 1, row)); // top edge
407 }
408 if (row != 0) {
409 if (TileHeight(TileXY(col, row - 1)) < current_tile) {
410 current_tile = TileHeight(TileXY(col, row - 1)); // left edge
411 }
412 }
413
414 /* Does the height differ more than one? */
415 if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
416 /* Then change the height to be no more than one */
417 SetTileHeight(TileXY(col, row), current_tile + 1);
418 }
419 }
420 }
421
422 /* Bottom and right edge */
423 for (row = height - 1; row >= 0; row--) {
424 for (col = width - 1; col >= 0; col--) {
425 current_tile = MAX_TILE_HEIGHT;
426 if ((uint)col != width - 1) {
427 /* Find lowest tile; either the bottom and right one */
428 current_tile = TileHeight(TileXY(col + 1, row)); // bottom edge
429 }
430
431 if ((uint)row != height - 1) {
432 if (TileHeight(TileXY(col, row + 1)) < current_tile) {
433 current_tile = TileHeight(TileXY(col, row + 1)); // right edge
434 }
435 }
436
437 /* Does the height differ more than one? */
438 if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
439 /* Then change the height to be no more than one */
440 SetTileHeight(TileXY(col, row), current_tile + 1);
441 }
442 }
443 }
444 }
445
449 static bool ReadHeightMap(char *filename, uint *x, uint *y, byte **map)
450 {
451 switch (_file_to_saveload.mode) {
452 default: NOT_REACHED();
453 #ifdef WITH_PNG
454 case SL_PNG:
455 return ReadHeightmapPNG(filename, x, y, map);
456 #endif /* WITH_PNG */
457 case SL_BMP:
458 return ReadHeightmapBMP(filename, x, y, map);
459 }
460 }
461
469 bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
470 {
471 return ReadHeightMap(filename, x, y, NULL);
472 }
473
480 void LoadHeightmap(char *filename)
481 {
482 uint x, y;
483 byte *map = NULL;
484
485 if (!ReadHeightMap(filename, &x, &y, &map)) {
486 free(map);
487 return;
488 }
489
490 GrayscaleToMapHeights(x, y, map);
491 free(map);
492
493 FixSlopes();
494 MarkWholeScreenDirty();
495 }
496
501 void FlatEmptyWorld(byte tile_height)
502 {
503 int edge_distance = _settings_game.construction.freeform_edges ? 0 : 2;
504 for (uint row = edge_distance; row < MapSizeY() - edge_distance; row++) {
505 for (uint col = edge_distance; col < MapSizeX() - edge_distance; col++) {
506 SetTileHeight(TileXY(col, row), tile_height);
507 }
508 }
509
510 FixSlopes();
511 MarkWholeScreenDirty();
512 }