diff --git a/src/heightmap.c b/src/heightmap.c
deleted file mode 100644
--- a/src/heightmap.c
+++ /dev/null
@@ -1,459 +0,0 @@
-/* $Id$ */
-
-#include "stdafx.h"
-#include "openttd.h"
-#include "variables.h"
-#include "functions.h"
-#include "heightmap.h"
-#include "clear_map.h"
-#include "table/strings.h"
-#include "void_map.h"
-#include "debug.h"
-#include "gfx.h"
-#include "gui.h"
-#include "saveload.h"
-#include "bmp.h"
-
-/**
- * Convert RGB colors to Grayscale using 29.9% Red, 58.7% Green, 11.4% Blue
- *  (average luminosity formula) -- Dalestan
- * This in fact is the NTSC Color Space -- TrueLight
- */
-static inline byte RGBToGrayscale(byte red, byte green, byte blue)
-{
-	/* To avoid doubles and stuff, multiple 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;
-
-	/* Get palette and convert it to grayscale */
-	if (info_ptr->color_type == PNG_COLOR_TYPE_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 < info_ptr->width; x++) {
-		for (y = 0; y < info_ptr->height; y++) {
-			byte *pixel = &map[y * info_ptr->width + x];
-			uint x_offset = x * info_ptr->channels;
-
-			if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) {
-				*pixel = gray_palette[row_pointers[y][x_offset]];
-			} else if (info_ptr->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 = fopen(filename, "rb");
-	if (fp == NULL) {
-		ShowErrorMessage(STR_PNGMAP_ERR_FILE_NOT_FOUND, STR_PNGMAP_ERROR, 0, 0);
-		return false;
-	}
-
-	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-	if (png_ptr == NULL) {
-		ShowErrorMessage(STR_PNGMAP_ERR_MISC, STR_PNGMAP_ERROR, 0, 0);
-		fclose(fp);
-		return false;
-	}
-
-	info_ptr = png_create_info_struct(png_ptr);
-	if (info_ptr == NULL || setjmp(png_jmpbuf(png_ptr))) {
-		ShowErrorMessage(STR_PNGMAP_ERR_MISC, STR_PNGMAP_ERROR, 0, 0);
-		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 color-depth are not used.
-	 * (this should have been taken care of by stripping alpha and 16-bit samples on load) */
-	if ((info_ptr->channels != 1) && (info_ptr->channels != 3) && (info_ptr->bit_depth != 8)) {
-		ShowErrorMessage(STR_PNGMAP_ERR_IMAGE_TYPE, STR_PNGMAP_ERROR, 0, 0);
-		fclose(fp);
-		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-		return false;
-	}
-
-	if (map != NULL) {
-		*map = malloc(info_ptr->width * info_ptr->height * sizeof(byte));
-
-		if (*map == NULL) {
-			ShowErrorMessage(STR_PNGMAP_ERR_MISC, STR_PNGMAP_ERROR, 0, 0);
-			fclose(fp);
-			png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-			return false;
-		}
-
-		ReadHeightmapPNGImageData(*map, png_ptr, info_ptr);
-	}
-
-	*x = info_ptr->width;
-	*y = info_ptr->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;
-
-	f = fopen(filename, "rb");
-	if (f == NULL) {
-		ShowErrorMessage(STR_PNGMAP_ERR_FILE_NOT_FOUND, STR_BMPMAP_ERROR, 0, 0);
-		return false;
-	}
-
-	BmpInitializeBuffer(&buffer, f);
-
-	if (!BmpReadHeader(&buffer, &info, &data)) {
-		ShowErrorMessage(STR_BMPMAP_ERR_IMAGE_TYPE, STR_BMPMAP_ERROR, 0, 0);
-		fclose(f);
-		BmpDestroyData(&data);
-		return false;
-	}
-
-	if (map != NULL) {
-		if (!BmpReadBitmap(&buffer, &info, &data)) {
-			ShowErrorMessage(STR_BMPMAP_ERR_IMAGE_TYPE, STR_BMPMAP_ERROR, 0, 0);
-			fclose(f);
-			BmpDestroyData(&data);
-			return false;
-		}
-
-		*map = malloc(info.width * info.height * sizeof(byte));
-		if (*map == NULL) {
-			ShowErrorMessage(STR_PNGMAP_ERR_MISC, STR_BMPMAP_ERROR, 0, 0);
-			fclose(f);
-			BmpDestroyData(&data);
-			return false;
-		}
-
-		ReadHeightmapBMPImageData(*map, &info, &data);
-
-	}
-
-	BmpDestroyData(&data);
-
-	*x = info.width;
-	*y = info.height;
-
-	fclose(f);
-	return true;
-}
-
-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 (_patches.heightmap_rotation) {
-	case HM_COUNTER_CLOCKWISE:
-		width   = MapSizeX();
-		height  = MapSizeY();
-		break;
-	case HM_CLOCKWISE:
-		width   = MapSizeY();
-		height  = MapSizeX();
-		break;
-	default:
-		NOT_REACHED();
-		/* Avoids compiler warnings */
-		return;
-	}
-
-	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 = (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 = (width - ((img_width * img_scale) / num_div)) / 2;
-	}
-
-	/* Form the landscape */
-	for (row = 0; row < height - 1; row++) {
-		for (col = 0; col < width - 1; col++) {
-			switch (_patches.heightmap_rotation) {
-			case HM_COUNTER_CLOCKWISE: tile = TileXY(col, row); break;
-			case HM_CLOCKWISE:         tile = TileXY(row, col); break;
-			default:                   NOT_REACHED(); return;
-			}
-
-			/* Check if current tile is within the 1-pixel map edge or padding regions */
-			if ((DistanceFromEdge(tile) <= 1) ||
-					(row < row_pad) || (row >= (img_height + row_pad)) ||
-					(col < col_pad) || (col >= (img_width  + col_pad))) {
-				SetTileHeight(tile, 0);
-			} else {
-				/* Use nearest neighbor resizing to scale map data.
-				 *  We rotate the map 45 degrees (counter)clockwise */
-				img_row = (((row - row_pad) * num_div) / img_scale);
-				switch (_patches.heightmap_rotation) {
-				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;
-				default:
-					NOT_REACHED();
-					/* Avoids compiler warnings */
-					return;
-				}
-
-				assert(img_row < img_height);
-				assert(img_col < img_width);
-
-				/* Color scales from 0 to 255, OpenTTD height scales from 0 to 15 */
-				SetTileHeight(tile, map[img_row * img_width + img_col] / 16);
-			}
-			MakeClear(tile, CLEAR_GRASS, 3);
-		}
-	}
-}
-
-/**
- * This function takes care of the fact that land in OpenTTD can never differ
- * more than 1 in height
- */
-static void FixSlopes(void)
-{
-	uint width, height;
-	uint row, col;
-	byte current_tile;
-
-	/* Adjust height difference to maximum one horizontal/vertical change. */
-	width   = MapSizeX();
-	height  = MapSizeY();
-
-	/* Top and left edge */
-	for (row = 1; row < height - 2; row++) {
-		for (col = 1; col < width - 2; col++) {
-			/* Find lowest tile; either the top or left one */
-			current_tile = TileHeight(TileXY(col - 1, row)); // top edge
-			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 - 2; row > 0; row--) {
-		for (col = width - 2; col > 0; col--) {
-			/* Find lowest tile; either the bottom and right one */
-			current_tile = TileHeight(TileXY(col + 1, row)); // bottom edge
-			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) {
-#ifdef WITH_PNG
-		case SL_PNG:
-			return ReadHeightmapPNG(filename, x, y, map);
-#endif /* WITH_PNG */
-		case SL_BMP:
-			return ReadHeightmapBMP(filename, x, y, map);
-
-		default:
-			NOT_REACHED();
-			/* Avoids compiler warnings */
-			return false;
-	}
-}
-
-bool GetHeightmapDimensions(char *filename, uint *x, uint *y)
-{
-	return ReadHeightMap(filename, x, y, NULL);
-}
-
-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();
-}
-
-void FlatEmptyWorld(byte tile_height)
-{
-	uint width, height;
-	uint row, col;
-
-	width  = MapSizeX();
-	height = MapSizeY();
-
-	for (row = 2; row < height - 2; row++) {
-		for (col = 2; col < width - 2; col++) {
-			SetTileHeight(TileXY(col, row), tile_height);
-		}
-	}
-
-	FixSlopes();
-	MarkWholeScreenDirty();
-}