(svn r14229) -Feature: allow overriding the palette of the base GRFs. This way you can play with NewGRFs made for the Windows palette with the DOS palettes base GRFs (and vice versa). Note that for this to work correctly ALL NewGRFs must use the same palette; mix and match is not yet supported.

src/gfx_func.h

@@ -180,5 +180,8 @@ extern DrawPixelInfo *_cur_dpi;
 extern byte _colour_gradient[COLOUR_END][8];
 
 extern PaletteType _use_palette;
+extern bool _palette_remap_grf[];
+extern const byte *_palette_remap;
+extern const byte *_palette_reverse_remap;
 
 #endif /* GFX_FUNC_H */

src/gfxinit.cpp

@@ -23,9 +23,17 @@
 #include "ini_type.h"
 
 #include "table/sprites.h"
+#include "table/palette_convert.h"
 
 /** The currently used palette */
 PaletteType _use_palette = PAL_AUTODETECT;
+/** Whether the given NewGRFs must get a palette remap or not. */
+bool _palette_remap_grf[MAX_FILE_SLOTS];
+/** Palette map to go from the !_use_palette to the _use_palette */
+const byte *_palette_remap = NULL;
+/** Palette map to go from the _use_palette to the !_use_palette */
+const byte *_palette_reverse_remap = NULL;
+
 char _ini_graphics_set[32];
 
 /** Structure holding filename and MD5 information about a single file */
@@ -176,7 +184,9 @@ static bool DetermineGraphicsPack()
 	const GraphicsSet *best = _available_graphics_sets;
 	for (const GraphicsSet *c = _available_graphics_sets; c != NULL; c = c->next) {
 		if (best->found_grfs < c->found_grfs ||
-				(best->found_grfs == c->found_grfs && best->shortname == c->shortname && best->version < c->version)) {
+				(best->found_grfs == c->found_grfs && (
+					(best->shortname == c->shortname && best->version < c->version) ||
+					(best->palette != _use_palette && c->palette == _use_palette)))) {
 			best = c;
 		}
 	}
@@ -193,9 +203,22 @@ static bool DetermineGraphicsPack()
 static void DeterminePalette()
 {
 	assert(_used_graphics_set != NULL);
-	if (_use_palette < MAX_PAL) return;
+	if (_use_palette >= MAX_PAL) _use_palette = _used_graphics_set->palette;
+
+	switch (_use_palette) {
+		case PAL_DOS:
+			_palette_remap = _palmap_w2d;
+			_palette_reverse_remap = _palmap_d2w;
+			break;
+
+		case PAL_WINDOWS:
+			_palette_remap = _palmap_d2w;
+			_palette_reverse_remap = _palmap_w2d;
+			break;
 
-	_use_palette = _used_graphics_set->palette;
+		default:
+			NOT_REACHED();
+	}
 }
 
 /**
@@ -207,6 +230,8 @@ void CheckExternalFiles()
 {
 	DeterminePalette();
 
+	DEBUG(grf, 1, "Using the %s base graphics set with the %s palette", _used_graphics_set->name, _use_palette == PAL_DOS ? "DOS" : "Windows");
+
 	static const size_t ERROR_MESSAGE_LENGTH = 128;
 	char error_msg[ERROR_MESSAGE_LENGTH * (MAX_GFT + 1)];
 	error_msg[0] = '\0';
@@ -233,8 +258,10 @@ void CheckExternalFiles()
 
 static void LoadSpriteTables()
 {
+	memset(_palette_remap_grf, 0, sizeof(_palette_remap_grf));
 	uint i = FIRST_GRF_SLOT;
 
+	_palette_remap_grf[i] = (_use_palette != _used_graphics_set->palette);
 	LoadGrfFile(_used_graphics_set->files[GFT_BASE].filename, 0, i++);
 
 	/*
@@ -243,6 +270,7 @@ static void LoadSpriteTables()
 	 * has a few sprites less. However, we do not care about those missing
 	 * sprites as they are not shown anyway (logos in intro game).
 	 */
+	_palette_remap_grf[i] = (_use_palette != _used_graphics_set->palette);
 	LoadGrfFile(_used_graphics_set->files[GFT_LOGOS].filename, 4793, i++);
 
 	/*
@@ -251,6 +279,7 @@ static void LoadSpriteTables()
 	 * and the ground sprites.
 	 */
 	if (_settings_game.game_creation.landscape != LT_TEMPERATE) {
+		_palette_remap_grf[i] = (_use_palette != _used_graphics_set->palette);
 		LoadGrfIndexed(
 			_used_graphics_set->files[GFT_ARCTIC + _settings_game.game_creation.landscape - 1].filename,
 			_landscape_spriteindexes[_settings_game.game_creation.landscape - 1],
@@ -274,6 +303,7 @@ static void LoadSpriteTables()
 	master->next = top;
 	_grfconfig = master;
 
+	_palette_remap_grf[i] = (_use_palette != _used_graphics_set->palette);
 	LoadNewGRF(SPR_NEWGRFS_BASE, i);
 
 	/* Free and remove the top element. */

src/newgrf.cpp

@@ -3652,7 +3652,11 @@ bool GetGlobalVariable(byte param, uint32 *value)
 		}
 
 		case 0x0D: // TTD Version, 00=DOS, 01=Windows
-			*value = _use_palette;
+			if (_palette_remap_grf[_file_index]) {
+				*value = !_use_palette;
+			} else {
+				*value = _use_palette;
+			}
 			return true;
 
 		case 0x0E: // Y-offset for train sprites

src/spritecache.cpp

@@ -11,6 +11,7 @@
 #include "spriteloader/grf.hpp"
 #include "core/alloc_func.hpp"
 #include "core/math_func.hpp"
+#include "gfx_func.h"
 #ifdef WITH_PNG
 #include "spriteloader/png.hpp"
 #endif /* WITH_PNG */
@@ -188,11 +189,30 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id, SpriteType sprite_type)
 			return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL);
 		}
 
-		byte *dest = (byte *)AllocSprite(num);
+		/* "Normal" recolour sprites are ALWAYS 257 bytes. Then there is a small
+		 * number of recolour sprites that are 17 bytes that only exist in DOS
+		 * GRFs which are the same as 257 byte recolour sprites, but with the last
+		 * 240 bytes zeroed.  */
+		static const int RECOLOUR_SPRITE_SIZE = 257;
+		byte *dest = (byte *)AllocSprite(max(RECOLOUR_SPRITE_SIZE, num));
 
 		sc->ptr = dest;
 		sc->type = sprite_type;
-		FioReadBlock(dest, num);
+
+		if (_palette_remap_grf[sc->file_slot]) {
+			byte *dest_tmp = AllocaM(byte, max(RECOLOUR_SPRITE_SIZE, num));
+
+			/* Only a few recolour sprites are less than 257 bytes */
+			if (num < RECOLOUR_SPRITE_SIZE) memset(dest_tmp, 0, RECOLOUR_SPRITE_SIZE);
+			FioReadBlock(dest_tmp, num);
+
+			/* The data of index 0 is never used; "literal 00" according to the (New)GRF specs. */
+			for (int i = 1; i < RECOLOUR_SPRITE_SIZE; i++) {
+				dest[i] = _palette_remap[dest_tmp[_palette_reverse_remap[i - 1] + 1]];
+			}
+		} else {
+			FioReadBlock(dest, num);
+		}
 
 		return sc->ptr;
 	}

src/spriteloader/grf.cpp

@@ -83,7 +83,7 @@ bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, uint8 file_slot,
 				data = &sprite->data[y * sprite->width + skip];
 
 				for (int x = 0; x < length; x++) {
-					data->m = *dest;
+					data->m = ((sprite_type == ST_NORMAL && _palette_remap_grf[file_slot]) ? _palette_remap[*dest] : *dest);
 					dest++;
 					data++;
 				}
@@ -91,8 +91,10 @@ bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, uint8 file_slot,
 		}
 	} else {
 		dest = dest_orig;
-		for (int i = 0; i < sprite->width * sprite->height; i++)
-			sprite->data[i].m = dest[i];
+
+		for (int i = 0; i < sprite->width * sprite->height; i++) {
+			sprite->data[i].m = ((sprite_type == ST_NORMAL && _palette_remap_grf[file_slot]) ? _palette_remap[dest[i]] : dest[i]);
+		}
 	}
 
 	/* Make sure to mark all transparent pixels transparent on the alpha channel too */

src/table/palette_convert.h

@@ -0,0 +1,75 @@
+/* $Id$ */
+
+/** @file palette_convert.h Translation tables from one GRF to another GRF. */
+
+/** Converting from the Windows palette to the DOS palette */
+static const byte _palmap_w2d[] = {
+	  0,   1,   2,   3,   4,   5,   6,   7, //   0..7
+	  8,   9,  10,  11,  12,  13,  14,  15, //   8..15
+	 16,  17,  18,  19,  20,  21,  22,  23, //  16..23
+	 24,  25,  26,  27,  28,  29,  30,  31, //  24..31
+	  6,   7,  34,  35,  36,  37,  38,  39, //  32..39
+	  8,  41,  42,  43,  44,  45,  46,  47, //  40..47
+	 48,  49,  50,  51,  52,  53,  54,  55, //  48..55
+	 56,  57,  58,  59,  60,  61,  62,  63, //  56..63
+	 64,  65,  66,  67,  68,  69,  70,  71, //  64..71
+	 72,  73,  74,  75,  76,  77,  78,  79, //  72..79
+	 80,  81,  82,  83,  84,  85,  86,  87, //  80..87
+	  4,  89,  90,  91,  92,  93,  94,  95, //  88..95
+	 96,  97,  98,  99, 100, 101, 102, 103, //  96..103
+	104, 105,   5, 107, 108, 109, 110, 111, // 104..111
+	112, 113, 114, 115, 116, 117, 118, 119, // 112..119
+	120, 121, 122, 123, 124, 125, 126, 127, // 120..127
+	128, 129, 130, 131, 132, 133, 134, 135, // 128..135
+	  3, 137, 138, 139, 140, 141, 142, 143, // 136..143
+	144, 145, 146, 147, 148, 149, 150, 151, // 144..151
+	152, 153, 154, 155, 156, 157, 158, 159, // 152..159
+	160, 161, 162, 163, 164, 165, 166, 167, // 160..167
+	168, 169, 170, 171, 172, 173, 174, 175, // 168..175
+	176, 177, 178, 179, 180, 181, 182, 183, // 176..183
+	184, 185, 186, 187, 188, 189, 190, 191, // 184..191
+	192, 193, 194, 195, 196, 197, 198, 199, // 192..199
+	200, 201, 202, 203, 204, 205, 206, 207, // 200..207
+	208, 209, 210, 211, 212, 213, 214,   1, // 208..215
+	  2, 245, 246, 247, 248, 249, 250, 251, // 216..223
+	252, 253, 254, 229, 230, 231, 227, 228, // 224..231
+	235, 236, 237, 238, 232, 233, 234, 239, // 232..239
+	240, 241, 242, 244, 243,   9, 218, 219, // 240..247
+	220, 221, 222, 223, 224, 225, 226, 255, // 248..255
+};
+
+/** Converting from the DOS palette to the Windows palette */
+static const byte _palmap_d2w[] = {
+	  0, 215, 216, 136,  88, 106,  32,  33, //   0..7
+	 40, 245,  10,  11,  12,  13,  14,  15, //   8..15
+	 16,  17,  18,  19,  20,  21,  22,  23, //  16..23
+	 24,  25,  26,  27,  28,  29,  30,  31, //  24..31
+	 53,  54,  34,  35,  36,  37,  38,  39, //  32..39
+	178,  41,  42,  43,  44,  45,  46,  47, //  40..47
+	 48,  49,  50,  51,  52,  53,  54,  55, //  48..55
+	 56,  57,  58,  59,  60,  61,  62,  63, //  56..63
+	 64,  65,  66,  67,  68,  69,  70,  71, //  64..71
+	 72,  73,  74,  75,  76,  77,  78,  79, //  72..79
+	 80,  81,  82,  83,  84,  85,  86,  87, //  80..87
+	 96,  89,  90,  91,  92,  93,  94,  95, //  88..95
+	 96,  97,  98,  99, 100, 101, 102, 103, //  96..103
+	104, 105,  53, 107, 108, 109, 110, 111, // 104..111
+	112, 113, 114, 115, 116, 117, 118, 119, // 112..119
+	120, 121, 122, 123, 124, 125, 126, 127, // 120..127
+	128, 129, 130, 131, 132, 133, 134, 135, // 128..135
+	170, 137, 138, 139, 140, 141, 142, 143, // 136..143
+	144, 145, 146, 147, 148, 149, 150, 151, // 144..151
+	152, 153, 154, 155, 156, 157, 158, 159, // 152..159
+	160, 161, 162, 163, 164, 165, 166, 167, // 160..167
+	168, 169, 170, 171, 172, 173, 174, 175, // 168..175
+	176, 177, 178, 179, 180, 181, 182, 183, // 176..183
+	184, 185, 186, 187, 188, 189, 190, 191, // 184..191
+	192, 193, 194, 195, 196, 197, 198, 199, // 192..199
+	200, 201, 202, 203, 204, 205, 206, 207, // 200..207
+	208, 209, 210, 211, 212, 213, 214, 215, // 208..215
+	216, 217, 246, 247, 248, 249, 250, 251, // 216..223
+	252, 253, 254, 227, 228, 229, 230, 231, // 224..231
+	232, 233, 234, 235, 236, 237, 238, 239, // 232..239
+	240, 241, 242, 243, 244, 217, 218, 219, // 240..247
+	220, 221, 222, 223, 224, 225, 226, 255, // 248..255
+};