summaryrefslogtreecommitdiff
path: root/src/heightmap.cpp
blob: 97e525725ed6df849ec03ba4b1f98a124ee3c31e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
/* $Id$ */

/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */

/** @file heightmap.cpp Creating of maps from heightmaps. */

#include "stdafx.h"
#include "heightmap.h"
#include "clear_map.h"
#include "void_map.h"
#include "error.h"
#include "saveload/saveload.h"
#include "bmp.h"
#include "gfx_func.h"
#include "fios.h"
#include "fileio_func.h"

#include "table/strings.h"

#include "safeguards.h"

/**
 * Convert RGB colours to Grayscale using 29.9% Red, 58.7% Green, 11.4% Blue
 *  (average luminosity formula, NTSC Colour Space)
 */
static inline byte RGBToGrayscale(byte red, byte green, byte blue)
{
	/* To avoid doubles and stuff, multiply it with a total of 65536 (16bits), then
	 *  divide by it to normalize the value to a byte again. */
	return ((red * 19595) + (green * 38470) + (blue * 7471)) / 65536;
}


#ifdef WITH_PNG

#include <png.h>

/**
 * The PNG Heightmap loader.
 */
static void ReadHeightmapPNGImageData(byte *map, png_structp png_ptr, png_infop info_ptr)
{
	uint x, y;
	byte gray_palette[256];
	png_bytep *row_pointers = NULL;
	bool has_palette = png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_PALETTE;
	uint channels = png_get_channels(png_ptr, info_ptr);

	/* Get palette and convert it to grayscale */
	if (has_palette) {
		int i;
		int palette_size;
		png_color *palette;
		bool all_gray = true;

		png_get_PLTE(png_ptr, info_ptr, &palette, &palette_size);
		for (i = 0; i < palette_size && (palette_size != 16 || all_gray); i++) {
			all_gray &= palette[i].red == palette[i].green && palette[i].red == palette[i].blue;
			gray_palette[i] = RGBToGrayscale(palette[i].red, palette[i].green, palette[i].blue);
		}

		/**
		 * For a non-gray palette of size 16 we assume that
		 * the order of the palette determines the height;
		 * the first entry is the sea (level 0), the second one
		 * level 1, etc.
		 */
		if (palette_size == 16 && !all_gray) {
			for (i = 0; i < palette_size; i++) {
				gray_palette[i] = 256 * i / palette_size;
			}
		}
	}

	row_pointers = png_get_rows(png_ptr, info_ptr);

	/* Read the raw image data and convert in 8-bit grayscale */
	for (x = 0; x < png_get_image_width(png_ptr, info_ptr); x++) {
		for (y = 0; y < png_get_image_height(png_ptr, info_ptr); y++) {
			byte *pixel = &map[y * png_get_image_width(png_ptr, info_ptr) + x];
			uint x_offset = x * channels;

			if (has_palette) {
				*pixel = gray_palette[row_pointers[y][x_offset]];
			} else if (channels == 3) {
				*pixel = RGBToGrayscale(row_pointers[y][x_offset + 0],
						row_pointers[y][x_offset + 1], row_pointers[y][x_offset + 2]);
			} else {
				*pixel = row_pointers[y][x_offset];
			}
		}
	}
}

/**
 * Reads the heightmap and/or size of the heightmap from a PNG file.
 * If map == NULL only the size of the PNG is read, otherwise a map
 * with grayscale pixels is allocated and assigned to *map.
 */
static bool ReadHeightmapPNG(char *filename, uint *x, uint *y, byte **map)
{
	FILE *fp;
	png_structp png_ptr = NULL;
	png_infop info_ptr  = NULL;

	fp = FioFOpenFile(filename, "rb", HEIGHTMAP_DIR);
	if (fp == NULL) {
		ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, WL_ERROR);
		return false;
	}

	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (png_ptr == NULL) {
		ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, WL_ERROR);
		fclose(fp);
		return false;
	}

	info_ptr = png_create_info_struct(png_ptr);
	if (info_ptr == NULL || setjmp(png_jmpbuf(png_ptr))) {
		ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_MISC, WL_ERROR);
		fclose(fp);
		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
		return false;
	}

	png_init_io(png_ptr, fp);

	/* Allocate memory and read image, without alpha or 16-bit samples
	 * (result is either 8-bit indexed/grayscale or 24-bit RGB) */
	png_set_packing(png_ptr);
	png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_PACKING | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_STRIP_16, NULL);

	/* Maps of wrong colour-depth are not used.
	 * (this should have been taken care of by stripping alpha and 16-bit samples on load) */
	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)) {
		ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_PNGMAP_IMAGE_TYPE, WL_ERROR);
		fclose(fp);
		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
		return false;
	}

	uint width = png_get_image_width(png_ptr, info_ptr);
	uint height = png_get_image_height(png_ptr, info_ptr);

	/* Check if image dimensions don't overflow a size_t to avoid memory corruption. */
	if ((uint64)width * height >= (size_t)-1) {
		ShowErrorMessage(STR_ERROR_PNGMAP, STR_ERROR_HEIGHTMAP_TOO_LARGE, WL_ERROR);
		fclose(fp);
		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
		return false;
	}

	if (map != NULL) {
		*map = MallocT<byte>(width * height);
		ReadHeightmapPNGImageData(*map, png_ptr, info_ptr);
	}

	*x = width;
	*y = height;

	fclose(fp);
	png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
	return true;
}

#endif /* WITH_PNG */


/**
 * The BMP Heightmap loader.
 */
static void ReadHeightmapBMPImageData(byte *map, BmpInfo *info, BmpData *data)
{
	uint x, y;
	byte gray_palette[256];

	if (data->palette != NULL) {
		uint i;
		bool all_gray = true;

		if (info->palette_size != 2) {
			for (i = 0; i < info->palette_size && (info->palette_size != 16 || all_gray); i++) {
				all_gray &= data->palette[i].r == data->palette[i].g && data->palette[i].r == data->palette[i].b;
				gray_palette[i] = RGBToGrayscale(data->palette[i].r, data->palette[i].g, data->palette[i].b);
			}

			/**
			 * For a non-gray palette of size 16 we assume that
			 * the order of the palette determines the height;
			 * the first entry is the sea (level 0), the second one
			 * level 1, etc.
			 */
			if (info->palette_size == 16 && !all_gray) {
				for (i = 0; i < info->palette_size; i++) {
					gray_palette[i] = 256 * i / info->palette_size;
				}
			}
		} else {
			/**
			 * For a palette of size 2 we assume that the order of the palette determines the height;
			 * the first entry is the sea (level 0), the second one is the land (level 1)
			 */
			gray_palette[0] = 0;
			gray_palette[1] = 16;
		}
	}

	/* Read the raw image data and convert in 8-bit grayscale */
	for (y = 0; y < info->height; y++) {
		byte *pixel = &map[y * info->width];
		byte *bitmap = &data->bitmap[y * info->width * (info->bpp == 24 ? 3 : 1)];

		for (x = 0; x < info->width; x++) {
			if (info->bpp != 24) {
				*pixel++ = gray_palette[*bitmap++];
			} else {
				*pixel++ = RGBToGrayscale(*bitmap, *(bitmap + 1), *(bitmap + 2));
				bitmap += 3;
			}
		}
	}
}

/**
 * Reads the heightmap and/or size of the heightmap from a BMP file.
 * If map == NULL only the size of the BMP is read, otherwise a map
 * with grayscale pixels is allocated and assigned to *map.
 */
static bool ReadHeightmapBMP(char *filename, uint *x, uint *y, byte **map)
{
	FILE *f;
	BmpInfo info;
	BmpData data;
	BmpBuffer buffer;

	/* Init BmpData */
	memset(&data, 0, sizeof(data));

	f = FioFOpenFile(filename, "rb", HEIGHTMAP_DIR);
	if (f == NULL) {
		ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_PNGMAP_FILE_NOT_FOUND, WL_ERROR);
		return false;
	}

	BmpInitializeBuffer(&buffer, f);

	if (!BmpReadHeader(&buffer, &info, &data)) {
		ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, WL_ERROR);
		fclose(f);
		BmpDestroyData(&data);
		return false;
	}

	/* Check if image dimensions don't overflow a size_t to avoid memory corruption. */
	if ((uint64)info.width * info.height >= (size_t)-1 / (info.bpp == 24 ? 3 : 1)) {
		ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_HEIGHTMAP_TOO_LARGE, WL_ERROR);
		fclose(f);
		BmpDestroyData(&data);
		return false;
	}

	if (map != NULL) {
		if (!BmpReadBitmap(&buffer, &info, &data)) {
			ShowErrorMessage(STR_ERROR_BMPMAP, STR_ERROR_BMPMAP_IMAGE_TYPE, WL_ERROR);
			fclose(f);
			BmpDestroyData(&data);
			return false;
		}

		*map = MallocT<byte>(info.width * info.height);
		ReadHeightmapBMPImageData(*map, &info, &data);
	}

	BmpDestroyData(&data);

	*x = info.width;
	*y = info.height;

	fclose(f);
	return true;
}

/**
 * Converts a given grayscale map to something that fits in OTTD map system
 * and create a map of that data.
 * @param img_width  the with of the image in pixels/tiles
 * @param img_height the height of the image in pixels/tiles
 * @param map        the input map
 */
static void GrayscaleToMapHeights(uint img_width, uint img_height, byte *map)
{
	/* Defines the detail of the aspect ratio (to avoid doubles) */
	const uint num_div = 16384;

	uint width, height;
	uint row, col;
	uint row_pad = 0, col_pad = 0;
	uint img_scale;
	uint img_row, img_col;
	TileIndex tile;

	/* Get map size and calculate scale and padding values */
	switch (_settings_game.game_creation.heightmap_rotation) {
		default: NOT_REACHED();
		case HM_COUNTER_CLOCKWISE:
			width   = MapSizeX();
			height  = MapSizeY();
			break;
		case HM_CLOCKWISE:
			width   = MapSizeY();
			height  = MapSizeX();
			break;
	}

	if ((img_width * num_div) / img_height > ((width * num_div) / height)) {
		/* Image is wider than map - center vertically */
		img_scale = (width * num_div) / img_width;
		row_pad = (1 + height - ((img_height * img_scale) / num_div)) / 2;
	} else {
		/* Image is taller than map - center horizontally */
		img_scale = (height * num_div) / img_height;
		col_pad = (1 + width - ((img_width * img_scale) / num_div)) / 2;
	}

	if (_settings_game.construction.freeform_edges) {
		for (uint x = 0; x < MapSizeX(); x++) MakeVoid(TileXY(x, 0));
		for (uint y = 0; y < MapSizeY(); y++) MakeVoid(TileXY(0, y));
	}

	/* Form the landscape */
	for (row = 0; row < height; row++) {
		for (col = 0; col < width; col++) {
			switch (_settings_game.game_creation.heightmap_rotation) {
				default: NOT_REACHED();
				case HM_COUNTER_CLOCKWISE: tile = TileXY(col, row); break;
				case HM_CLOCKWISE:         tile = TileXY(row, col); break;
			}

			/* Check if current tile is within the 1-pixel map edge or padding regions */
			if ((!_settings_game.construction.freeform_edges && DistanceFromEdge(tile) <= 1) ||
					(row < row_pad) || (row >= (height - row_pad - (_settings_game.construction.freeform_edges ? 0 : 1))) ||
					(col < col_pad) || (col >= (width  - col_pad - (_settings_game.construction.freeform_edges ? 0 : 1)))) {
				SetTileHeight(tile, 0);
			} else {
				/* Use nearest neighbour resizing to scale map data.
				 *  We rotate the map 45 degrees (counter)clockwise */
				img_row = (((row - row_pad) * num_div) / img_scale);
				switch (_settings_game.game_creation.heightmap_rotation) {
					default: NOT_REACHED();
					case HM_COUNTER_CLOCKWISE:
						img_col = (((width - 1 - col - col_pad) * num_div) / img_scale);
						break;
					case HM_CLOCKWISE:
						img_col = (((col - col_pad) * num_div) / img_scale);
						break;
				}

				assert(img_row < img_height);
				assert(img_col < img_width);

				/* The height in 1/256ths. */
				uint heightmap_height = map[img_row * img_width + img_col];

				/* The height in 1/256ths of the maximum height. */
				heightmap_height *= (1 + _settings_game.construction.max_heightlevel);

				/* Scaling should not alter the coastline, thus values in the interval ]0..1] result in a heightlevel of 1 */
				if (IsInsideMM(heightmap_height, 1, 256)) heightmap_height = 256;

				SetTileHeight(tile, heightmap_height / 256);
			}
			/* Only clear the tiles within the map area. */
			if (IsInnerTile(tile)) {
				MakeClear(tile, CLEAR_GRASS, 3);
			}
		}
	}
}

/**
 * This function takes care of the fact that land in OpenTTD can never differ
 * more than 1 in height
 */
void FixSlopes()
{
	uint width, height;
	int row, col;
	byte current_tile;

	/* Adjust height difference to maximum one horizontal/vertical change. */
	width   = MapSizeX();
	height  = MapSizeY();

	/* Top and left edge */
	for (row = 0; (uint)row < height; row++) {
		for (col = 0; (uint)col < width; col++) {
			current_tile = MAX_TILE_HEIGHT;
			if (col != 0) {
				/* Find lowest tile; either the top or left one */
				current_tile = TileHeight(TileXY(col - 1, row)); // top edge
			}
			if (row != 0) {
				if (TileHeight(TileXY(col, row - 1)) < current_tile) {
					current_tile = TileHeight(TileXY(col, row - 1)); // left edge
				}
			}

			/* Does the height differ more than one? */
			if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
				/* Then change the height to be no more than one */
				SetTileHeight(TileXY(col, row), current_tile + 1);
			}
		}
	}

	/* Bottom and right edge */
	for (row = height - 1; row >= 0; row--) {
		for (col = width - 1; col >= 0; col--) {
			current_tile = MAX_TILE_HEIGHT;
			if ((uint)col != width - 1) {
				/* Find lowest tile; either the bottom and right one */
				current_tile = TileHeight(TileXY(col + 1, row)); // bottom edge
			}

			if ((uint)row != height - 1) {
				if (TileHeight(TileXY(col, row + 1)) < current_tile) {
					current_tile = TileHeight(TileXY(col, row + 1)); // right edge
				}
			}

			/* Does the height differ more than one? */
			if (TileHeight(TileXY(col, row)) >= (uint)current_tile + 2) {
				/* Then change the height to be no more than one */
				SetTileHeight(TileXY(col, row), current_tile + 1);
			}
		}
	}
}

/**
 * Reads the heightmap with the correct file reader
 */
static bool ReadHeightMap(char *filename, uint *x, uint *y, byte **map)
{
	switch (_file_to_saveload.mode) {
		default: NOT_REACHED();
#ifdef WITH_PNG
		case SL_PNG:
			return ReadHeightmapPNG(filename, x, y, map);
#endif /* WITH_PNG */
		case SL_BMP:
			return ReadHeightmapBMP(filename, x, y, map);
	}
}

/**
 * Get the dimensions of a heightmap.
 * @param filename to query
 * @param x dimension x
 * @param y dimension y
 * @return Returns false if loading of the image failed.
 */
bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
{
	return ReadHeightMap(filename, x, y, NULL);
}

/**
 * Load a heightmap from file and change the map in his current dimensions
 *  to a landscape representing the heightmap.
 * It converts pixels to height. The brighter, the higher.
 * @param filename of the heightmap file to be imported
 */
void LoadHeightmap(char *filename)
{
	uint x, y;
	byte *map = NULL;

	if (!ReadHeightMap(filename, &x, &y, &map)) {
		free(map);
		return;
	}

	GrayscaleToMapHeights(x, y, map);
	free(map);

	FixSlopes();
	MarkWholeScreenDirty();
}

/**
 * Make an empty world where all tiles are of height 'tile_height'.
 * @param tile_height of the desired new empty world
 */
void FlatEmptyWorld(byte tile_height)
{
	int edge_distance = _settings_game.construction.freeform_edges ? 0 : 2;
	for (uint row = edge_distance; row < MapSizeY() - edge_distance; row++) {
		for (uint col = edge_distance; col < MapSizeX() - edge_distance; col++) {
			SetTileHeight(TileXY(col, row), tile_height);
		}
	}

	FixSlopes();
	MarkWholeScreenDirty();
}