(svn r10092) -Codechange: code-seperated the spriteloader and blitter from the rest of the code

-Add: make it possible to pick your own blitter (-b <blitter>, -h for overview)
-Add: added a new optimized 8bpp blitter (default, caches sprites of all zoom-levels)
-Add: added a debug 8bpp blitter and a very slow normal 8bpp blitter

20 files changed, 907 insertions, 290 deletions

diff --git a/projects/openttd.vcproj b/projects/openttd.vcproj
index 472860713..3b2d8268a 100644
--- a/projects/openttd.vcproj
+++ b/projects/openttd.vcproj
@@ -959,6 +959,44 @@
 			</File>
 		</Filter>
 		<Filter
+			Name="Blitters"
+			Filter="">
+			<File
+				RelativePath=".\..\src\blitter\8bpp_debug.cpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_debug.hpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_optimized.cpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_optimized.hpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_slow.cpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_slow.hpp">
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\blitter.hpp">
+			</File>
+		</Filter>
+		<Filter
+			Name="Sprite loaders"
+			Filter="">
+			<File
+				RelativePath=".\..\src\spriteloader\grf.cpp">
+			</File>
+			<File
+				RelativePath=".\..\src\spriteloader\grf.hpp">
+			</File>
+			<File
+				RelativePath=".\..\src\spriteloader\spriteloader.hpp">
+			</File>
+		</Filter>
+		<Filter
 			Name="NewGRF"
 			Filter="">
 			<File
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index 4845bd184..c9ffd5aee 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -952,7 +952,7 @@
 				>
 			</File>
 			<File
-				RelativePath="..\src\newgrf_industries.h"
+				RelativePath=".\..\src\newgrf_industries.h"
 				>
 			</File>
 			<File
@@ -1501,6 +1501,54 @@
 			</File>
 		</Filter>
 		<Filter
+			Name="Blitters"
+			>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_debug.cpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_debug.hpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_optimized.cpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_optimized.hpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_slow.cpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\8bpp_slow.hpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\blitter\blitter.hpp"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Sprite loaders"
+			>
+			<File
+				RelativePath=".\..\src\spriteloader\grf.cpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\spriteloader\grf.hpp"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\spriteloader\spriteloader.hpp"
+				>
+			</File>
+		</Filter>
+		<Filter
 			Name="NewGRF"
 			>
 			<File
@@ -1532,7 +1580,7 @@
 				>
 			</File>
 			<File
-				RelativePath="..\src\newgrf_industries.cpp"
+				RelativePath=".\..\src\newgrf_industries.cpp"
 				>
 			</File>
 			<File
diff --git a/source.list b/source.list
index 4ba3a7b29..143d74cab 100644
--- a/source.list
+++ b/source.list
@@ -290,6 +290,20 @@ ai/trolly/pathfinder.cpp
 ai/trolly/shared.cpp
 ai/trolly/trolly.cpp
 
+# Blitters
+blitter/8bpp_debug.cpp
+blitter/8bpp_debug.hpp
+blitter/8bpp_optimized.cpp
+blitter/8bpp_optimized.hpp
+blitter/8bpp_slow.cpp
+blitter/8bpp_slow.hpp
+blitter/blitter.hpp
+
+# Sprite loaders
+spriteloader/grf.cpp
+spriteloader/grf.hpp
+spriteloader/spriteloader.hpp
+
 # NewGRF
 newgrf.cpp
 newgrf_canal.cpp
diff --git a/src/blitter/8bpp_debug.cpp b/src/blitter/8bpp_debug.cpp
new file mode 100644
index 000000000..dea100c3f
--- /dev/null
+++ b/src/blitter/8bpp_debug.cpp
@@ -0,0 +1,53 @@
+#include "../stdafx.h"
+#include "../zoom.hpp"
+#include "../gfx.h"
+#include "../functions.h"
+#include "8bpp_debug.hpp"
+
+static FBlitter_8bppDebug iFBlitter_8bppDebug;
+
+extern void* AllocSprite(size_t);
+
+void Blitter_8bppDebug::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
+{
+	const byte *src, *src_line;
+	Pixel8 *dst, *dst_line;
+
+	/* Find where to start reading in the source sprite */
+	src_line = (const byte *)bp->sprite + (bp->skip_top * bp->sprite_width + bp->skip_left) * ScaleByZoom(1, zoom);
+	dst_line = (Pixel8 *)bp->dst + bp->top * bp->pitch + bp->left;
+
+	for (int y = 0; y < bp->height; y++) {
+		dst = dst_line;
+		dst_line += bp->pitch;
+
+		src = src_line;
+		src_line += bp->sprite_width * ScaleByZoom(1, zoom);
+
+		for (int x = 0; x < bp->width; x++) {
+			if (*src != 0) *dst = *src;
+			dst++;
+			src += ScaleByZoom(1, zoom);
+		}
+		assert(src <= src_line);
+	}
+}
+
+Sprite *Blitter_8bppDebug::Encode(SpriteLoader::Sprite *sprite)
+{
+	Sprite *dest_sprite;
+	dest_sprite = (Sprite *)AllocSprite(sizeof(*dest_sprite) + sprite->height * sprite->width);
+
+	dest_sprite->height = sprite->height;
+	dest_sprite->width  = sprite->width;
+	dest_sprite->x_offs = sprite->x_offs;
+	dest_sprite->y_offs = sprite->y_offs;
+
+	/* Write a random color as sprite; this makes debugging really easy */
+	uint color = InteractiveRandom() % 150 + 2;
+	for (int i = 0; i < sprite->height * sprite->width; i++) {
+		dest_sprite->data[i] = (sprite->data[i].m == 0) ? 0 : color;
+	}
+
+	return dest_sprite;
+}
diff --git a/src/blitter/8bpp_debug.hpp b/src/blitter/8bpp_debug.hpp
new file mode 100644
index 000000000..67b12b652
--- /dev/null
+++ b/src/blitter/8bpp_debug.hpp
@@ -0,0 +1,30 @@
+/* $Id$ */
+
+/** @file debug.hpp */
+
+#ifndef BLITTER_8BPP_DEBUG_HPP
+#define BLITTER_8BPP_DEBUG_HPP
+
+#include "blitter.hpp"
+
+typedef Pixel Pixel8;
+
+class Blitter_8bppDebug : public Blitter {
+public:
+	uint8 GetScreenDepth() { return 8; }
+
+	void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
+
+	Sprite *Encode(SpriteLoader::Sprite *sprite);
+};
+
+class FBlitter_8bppDebug: public BlitterFactory<FBlitter_8bppDebug> {
+public:
+	/* virtual */ const char *GetName() { return "8bpp-debug"; }
+
+	/* virtual */ const char *GetDescription() { return "8bpp Debug Blitter (testing only)"; }
+
+	/* virtual */ Blitter *CreateInstance() { return new Blitter_8bppDebug(); }
+};
+
+#endif /* BLITTER_8BPP_DEBUG_HPP */
diff --git a/src/blitter/8bpp_optimized.cpp b/src/blitter/8bpp_optimized.cpp
new file mode 100644
index 000000000..00c427441
--- /dev/null
+++ b/src/blitter/8bpp_optimized.cpp
@@ -0,0 +1,199 @@
+#include "../stdafx.h"
+#include "../zoom.hpp"
+#include "../gfx.h"
+#include "../debug.h"
+#include "8bpp_optimized.hpp"
+
+static FBlitter_8bppOptimized iFBlitter_8bppOptimized;
+
+extern void* AllocSprite(size_t);
+
+void Blitter_8bppOptimized::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
+{
+	const byte *src, *src_next;
+	Pixel8 *dst, *dst_line;
+	uint offset = 0;
+
+	/* Find the offset of this zoom-level */
+	offset = ((const byte *)bp->sprite)[(int)zoom * 2] | ((const byte *)bp->sprite)[(int)zoom * 2 + 1] << 8;
+
+	/* Find where to start reading in the source sprite */
+	src = (const byte *)bp->sprite + offset;
+	dst_line = (Pixel8 *)bp->dst + bp->top * bp->pitch + bp->left;
+
+	/* Skip over the top lines in the source image */
+	for (int y = 0; y < bp->skip_top; y++) {
+		uint trans, pixels;
+		for (;;) {
+			trans = *src++;
+			pixels = *src++;
+			if (trans == 0 && pixels == 0) break;
+			src += pixels;
+		}
+	}
+
+	src_next = src;
+
+	for (int y = 0; y < bp->height; y++) {
+		dst = dst_line;
+		dst_line += bp->pitch;
+
+		uint skip_left = bp->skip_left;
+		int width = bp->width;
+
+		for (;;) {
+			src = src_next;
+			uint8 trans = *src++;
+			uint8 pixels = *src++;
+			src_next = src + pixels;
+			if (trans == 0 && pixels == 0) break;
+			if (width <= 0) continue;
+
+			if (skip_left != 0) {
+				if (skip_left < trans) {
+					trans -= skip_left;
+					skip_left = 0;
+				} else {
+					skip_left -= trans;
+					trans = 0;
+				}
+				if (skip_left < pixels) {
+					src += skip_left;
+					pixels -= skip_left;
+					skip_left = 0;
+				} else {
+					src += pixels;
+					skip_left -= pixels;
+					pixels = 0;
+				}
+			}
+			if (skip_left != 0) continue;
+
+			/* Skip transparent pixels */
+			dst += trans;
+			width -= trans;
+			if (width <= 0) continue;
+			if (pixels > width) pixels = width;
+			width -= pixels;
+
+			switch (mode) {
+				case BM_COLOUR_REMAP:
+					for (uint x = 0; x < pixels; x++) {
+						if (bp->remap[*src] != 0) *dst = bp->remap[*src];
+						dst++; src++;
+					}
+					break;
+
+				case BM_TRANSPARENT:
+					for (uint x = 0; x < pixels; x++) {
+						*dst = bp->remap[*dst];
+						dst++; src++;
+					}
+					break;
+
+				default:
+					memcpy(dst, src, pixels);
+					dst += pixels; src += pixels;
+					break;
+			}
+		}
+	}
+}
+
+Sprite *Blitter_8bppOptimized::Encode(SpriteLoader::Sprite *sprite)
+{
+	Sprite *dest_sprite;
+	byte *temp_dst;
+	uint memory = 0;
+	uint index = 0;
+
+	/* Make memory for all zoom-levels */
+	memory += (int)ZOOM_LVL_END * sizeof(uint16);
+	for (int i = 0; i < (int)ZOOM_LVL_END; i++) {
+		memory += UnScaleByZoom(sprite->height, (ZoomLevel)i) * UnScaleByZoom(sprite->width, (ZoomLevel)i);
+		index += 2;
+	}
+
+	/* We have no idea how much memory we really need, so just guess something */
+	memory *= 5;
+	temp_dst = MallocT<byte>(memory);
+
+	/* Make the sprites per zoom-level */
+	for (int i = 0; i < (int)ZOOM_LVL_END; i++) {
+		/* Store the scaled image */
+		const SpriteLoader::CommonPixel *src;
+
+		/* Store the index table */
+		temp_dst[i * 2] = index & 0xFF;
+		temp_dst[i * 2 + 1] = (index >> 8) & 0xFF;
+
+		byte *dst = &temp_dst[index];
+
+		for (int y = 0; y < UnScaleByZoom(sprite->height, (ZoomLevel)i); y++) {
+			uint trans = 0;
+			uint pixels = 0;
+			uint last_color = 0;
+			uint count_index = 0;
+			src = &sprite->data[ScaleByZoom(y, (ZoomLevel)i) * sprite->width];
+
+			for (int x = 0; x < UnScaleByZoom(sprite->width, (ZoomLevel)i); x++) {
+				uint color = 0;
+				int count = 0;
+
+				/* Get the color keeping in mind the zoom-level */
+				for (int j = 0; j < ScaleByZoom(1, (ZoomLevel)i); j++) {
+					if (src->m != 0) { color = src->m; count++; }
+					src++;
+				}
+				/* If more than 12.5% of the pixels are non-transparent, make thisone non-transparent too */
+				if (count < ScaleByZoom(1, (ZoomLevel)i) / 8) color = 0;
+
+				if (last_color == 0 || color == 0) {
+					if (count_index != 0) {
+						/* Write how many non-transparent bytes we get */
+						temp_dst[count_index] = pixels;
+						pixels = 0;
+						count_index = 0;
+					}
+					/* As long as we find transparency bytes, keep counting */
+					if (color == 0) {
+						last_color = 0;
+						trans++;
+						continue;
+					}
+					/* No longer transparency, so write the amount of transparent bytes */
+					*dst = trans;
+					dst++; index++;
+					trans = 0;
+					/* Reserve a byte for the pixel counter */
+					count_index = index;
+					dst++; index++;
+				}
+				last_color = color;
+				pixels++;
+				*dst = color;
+				dst++; index++;
+			}
+
+			if (count_index != 0) temp_dst[count_index] = pixels;
+
+			/* Write line-ending */
+			*dst = 0; dst++; index++;
+			*dst = 0; dst++; index++;
+		}
+	}
+
+	/* Safety check, to make sure we guessed the size correctly */
+	assert(index < memory);
+
+	/* Allocate the exact amount of memory we need */
+	dest_sprite = (Sprite *)AllocSprite(sizeof(*dest_sprite) + index);
+
+	dest_sprite->height = sprite->height;
+	dest_sprite->width  = sprite->width;
+	dest_sprite->x_offs = sprite->x_offs;
+	dest_sprite->y_offs = sprite->y_offs;
+	memcpy(dest_sprite->data, temp_dst, index);
+
+	return dest_sprite;
+}
diff --git a/src/blitter/8bpp_optimized.hpp b/src/blitter/8bpp_optimized.hpp
new file mode 100644
index 000000000..8f251fb2c
--- /dev/null
+++ b/src/blitter/8bpp_optimized.hpp
@@ -0,0 +1,30 @@
+/* $Id$ */
+
+/** @file 8bpp_nice.hpp */
+
+#ifndef BLITTER_8BPP_OPTIMIZED_HPP
+#define BLITTER_8BPP_OPTIMIZED_HPP
+
+#include "blitter.hpp"
+
+typedef Pixel Pixel8;
+
+class Blitter_8bppOptimized : public Blitter {
+public:
+	uint8 GetScreenDepth() { return 8; }
+
+	void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
+
+	Sprite *Encode(SpriteLoader::Sprite *sprite);
+};
+
+class FBlitter_8bppOptimized: public BlitterFactory<FBlitter_8bppOptimized> {
+public:
+	/* virtual */ const char *GetName() { return "8bpp-optimzed"; }
+
+	/* virtual */ const char *GetDescription() { return "8bpp Optimized Blitter (compression + all-ZoomLevel cache)"; }
+
+	/* virtual */ Blitter *CreateInstance() { return new Blitter_8bppOptimized(); }
+};
+
+#endif /* BLITTER_8BPP_OPTIMIZED_HPP */
diff --git a/src/blitter/8bpp_slow.cpp b/src/blitter/8bpp_slow.cpp
new file mode 100644
index 000000000..99c43a4f5
--- /dev/null
+++ b/src/blitter/8bpp_slow.cpp
@@ -0,0 +1,65 @@
+#include "../stdafx.h"
+#include "../zoom.hpp"
+#include "../gfx.h"
+#include "8bpp_slow.hpp"
+
+static FBlitter_8bppSimple iFBlitter_8bppSimple;
+
+extern void* AllocSprite(size_t);
+
+void Blitter_8bppSimple::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
+{
+	const byte *src, *src_line;
+	Pixel8 *dst, *dst_line;
+
+	/* Find where to start reading in the source sprite */
+	src_line = (const byte *)bp->sprite + (bp->skip_top * bp->sprite_width + bp->skip_left) * ScaleByZoom(1, zoom);
+	dst_line = (Pixel8 *)bp->dst + bp->top * bp->pitch + bp->left;
+
+	for (int y = 0; y < bp->height; y++) {
+		dst = dst_line;
+		dst_line += bp->pitch;
+
+		src = src_line;
+		src_line += bp->sprite_width * ScaleByZoom(1, zoom);
+
+		for (int x = 0; x < bp->width; x++) {
+			uint color = 0;
+
+			switch (mode) {
+				case BM_COLOUR_REMAP:
+					color = bp->remap[*src];
+					break;
+
+				case BM_TRANSPARENT:
+					if (*src != 0) color = bp->remap[*dst];
+					break;
+
+				default:
+					color = *src;
+					break;
+			}
+			if (color != 0) *dst = color;
+			dst++;
+			src += ScaleByZoom(1, zoom);
+		}
+	}
+}
+
+Sprite *Blitter_8bppSimple::Encode(SpriteLoader::Sprite *sprite)
+{
+	Sprite *dest_sprite;
+	dest_sprite = (Sprite *)AllocSprite(sizeof(*dest_sprite) + sprite->height * sprite->width);
+
+	dest_sprite->height = sprite->height;
+	dest_sprite->width  = sprite->width;
+	dest_sprite->x_offs = sprite->x_offs;
+	dest_sprite->y_offs = sprite->y_offs;
+
+	/* Copy over only the 'remap' channel, as that is what we care about in 8bpp */
+	for (int i = 0; i < sprite->height * sprite->width; i++) {
+		dest_sprite->data[i] = sprite->data[i].m;
+	}
+
+	return dest_sprite;
+}
diff --git a/src/blitter/8bpp_slow.hpp b/src/blitter/8bpp_slow.hpp
new file mode 100644
index 000000000..ac60e3262
--- /dev/null
+++ b/src/blitter/8bpp_slow.hpp
@@ -0,0 +1,30 @@
+/* $Id$ */
+
+/** @file 8bpp.hpp */
+
+#ifndef BLITTER_8BPP_SIMPLE_HPP
+#define BLITTER_8BPP_SIMPLE_HPP
+
+#include "blitter.hpp"
+
+typedef Pixel Pixel8;
+
+class Blitter_8bppSimple : public Blitter {
+public:
+	uint8 GetScreenDepth() { return 8; }
+
+	void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
+
+	Sprite *Encode(SpriteLoader::Sprite *sprite);
+};
+
+class FBlitter_8bppSimple: public BlitterFactory<FBlitter_8bppSimple> {
+public:
+	/* virtual */ const char *GetName() { return "8bpp-simple"; }
+
+	/* virtual */ const char *GetDescription() { return "8bpp Simple Blitter (relative slow, but never wrong)"; }
+
+	/* virtual */ Blitter *CreateInstance() { return new Blitter_8bppSimple(); }
+};
+
+#endif /* BLITTER_8BPP_SIMPLE_HPP */
diff --git a/src/blitter/blitter.hpp b/src/blitter/blitter.hpp
new file mode 100644
index 000000000..4920da426
--- /dev/null
+++ b/src/blitter/blitter.hpp
@@ -0,0 +1,168 @@
+/* $Id$ */
+
+/** @file blitter.hpp */
+
+#ifndef BLITTER_HPP
+#define BLITTER_HPP
+
+#include "../spriteloader/spriteloader.hpp"
+#include "../spritecache.h"
+#include <string>
+#include <map>
+
+enum BlitterMode {
+	BM_NORMAL,
+	BM_COLOUR_REMAP,
+	BM_TRANSPARENT,
+};
+
+/**
+ * How all blitters should look like. Extend this class to make your own.
+ */
+class Blitter {
+public:
+	struct BlitterParams {
+		const void *sprite;      ///< Pointer to the sprite how ever the encoder stored it
+		const byte *remap;       ///< XXX -- Temporary storage for remap array
+
+		int skip_left, skip_top; ///< How much pixels of the source to skip on the left and top (based on zoom of dst)
+		int width, height;       ///< The width and height in pixels that needs to be drawn to dst
+		int sprite_width;        ///< Real width of the sprite
+		int sprite_height;       ///< Real height of the sprite
+		int left, top;           ///< The offset in the 'dst' in pixels to start drawing
+
+		void *dst;               ///< Destination buffer
+		int pitch;               ///< The pitch of the destination buffer
+	};
+
+	/**
+	 * Get the screen depth this blitter works for.
+	 *  This is either: 8, 16, 24 or 32.
+	 */
+	virtual uint8 GetScreenDepth() = 0;
+
+	/**
+	 * Draw an image to the screen, given an amount of params defined above.
+	 */
+	virtual void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom) = 0;
+
+	/**
+	 * Convert a sprite from the loader to our own format.
+	 */
+	virtual Sprite *Encode(SpriteLoader::Sprite *sprite) = 0;
+
+	virtual ~Blitter() { }
+};
+
+/**
+ * The base factory, keeping track of all blitters.
+ */
+class BlitterFactoryBase {
+private:
+	char *name;
+	typedef std::map<std::string, BlitterFactoryBase *> Blitters;
+
+	static Blitters &GetBlitters()
+	{
+		static Blitters &s_blitters = *new Blitters();
+		return s_blitters;
+	}
+
+	static Blitter **GetActiveBlitter()
+	{
+		static Blitter *s_blitter = NULL;
+		return &s_blitter;
+	}
+
+protected:
+	/**
+	 * Register a blitter internally, based on his name.
+	 * @param name the name of the blitter.
+	 * @note an assert() will be trigger if 2 blitters with the same name try to register.
+	 */
+	void RegisterBlitter(const char *name)
+	{
+		/* Don't register nameless Blitters */
+		if (name == NULL) return;
+
+		this->name = strdup(name);
+		std::pair<Blitters::iterator, bool> P = GetBlitters().insert(Blitters::value_type(name, this));
+		assert(P.second);
+	}
+
+public:
+	BlitterFactoryBase() :
+		name(NULL)
+	{}
+
+	virtual ~BlitterFactoryBase() { if (this->name != NULL) GetBlitters().erase(this->name); free(this->name); }
+
+	/**
+	 * Find the requested blitter and return his class.
+	 * @param name the blitter to select.
+	 * @post Sets the blitter so GetCurrentBlitter() returns it too.
+	 */
+	static Blitter *SelectBlitter(const char *name)
+	{
+		if (GetBlitters().size() == 0) return NULL;
+
+		Blitters::iterator it = GetBlitters().begin();
+		for (; it != GetBlitters().end(); it++) {
+			BlitterFactoryBase *b = (*it).second;
+			if (strcasecmp(name, b->name) == 0) {
+				Blitter *newb = b->CreateInstance();
+				*GetActiveBlitter() = newb;
+				return newb;
+			}
+		}
+		return NULL;
+	}
+
+	/**
+	 * Get the current active blitter (always set by calling SelectBlitter).
+	 */
+	static Blitter *GetCurrentBlitter()
+	{
+		return *GetActiveBlitter();
+	}
+
+
+	static char *GetBlittersInfo(char *p, const char *last)
+	{
+		p += snprintf(p, last - p, "List of blitters:\n");
+		Blitters::iterator it = GetBlitters().begin();
+		for (; it != GetBlitters().end(); it++) {
+			BlitterFactoryBase *b = (*it).second;
+			p += snprintf(p, last - p, "%18s: %s\n", b->name, b->GetDescription());
+		}
+		p += snprintf(p, last - p, "\n");
+
+		return p;
+	}
+
+	/**
+	 * Get a nice description of the blitter-class.
+	 */
+	virtual const char *GetDescription() = 0;
+
+	/**
+	 * Create an instance of this Blitter-class.
+	 */
+	virtual Blitter *CreateInstance() = 0;
+};
+
+/**
+ * A template factory, so ->GetName() works correctly. This because else some compiler will complain.
+ */
+template <class T>
+class BlitterFactory: public BlitterFactoryBase {
+public:
+	BlitterFactory() { this->RegisterBlitter(((T *)this)->GetName()); }
+
+	/**
+	 * Get the long, human readable, name for the Blitter-class.
+	 */
+	const char *GetName();
+};
+
+#endif /* BLITTER_HPP */
diff --git a/src/fontcache.cpp b/src/fontcache.cpp
index 36a0c6523..49a5d15be 100644
--- a/src/fontcache.cpp
+++ b/src/fontcache.cpp
@@ -399,7 +399,6 @@ const Sprite *GetGlyph(FontSize size, WChar key)
 
 	/* FreeType has rendered the glyph, now we allocate a sprite and copy the image into it */
 	sprite = (Sprite*)calloc(width * height + 8, 1);
-	sprite->info   = 1;
 	sprite->width  = width;
 	sprite->height = height;
 	sprite->x_offs = slot->bitmap_left;
diff --git a/src/gfx.cpp b/src/gfx.cpp
index d529728de..3117d1782 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -19,6 +19,7 @@
 #include "genworld.h"
 #include "debug.h"
 #include "zoom.hpp"
+#include "blitter/blitter.hpp"
 
 #ifdef _DEBUG
 bool _dbg_screen_rect;
@@ -45,14 +46,7 @@ int _pal_last_dirty;
 Colour _cur_palette[256];
 byte _stringwidth_table[FS_END][224];
 
-enum BlitterMode {
-	BM_NORMAL,
-	BM_COLOUR_REMAP,
-	BM_TRANSPARENT,
-};
-
-template <BlitterMode Tmode>
-static inline void GfxMainBlitter(const Sprite *sprite, int x, int y);
+static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode);
 
 FontSize _cur_fontsize;
 static FontSize _last_fontsize;
@@ -683,7 +677,7 @@ skip_cont:;
 		if (IsPrintable(c)) {
 			if (x >= dpi->left + dpi->width) goto skip_char;
 			if (x + 26 >= dpi->left) {
-				GfxMainBlitter<BM_COLOUR_REMAP>(GetGlyph(size, c), x, y);
+				GfxMainBlitter(GetGlyph(size, c), x, y, BM_COLOUR_REMAP);
 			}
 			x += GetCharacterWidth(size, c);
 		} else if (c == '\n') { // newline = {}
@@ -720,269 +714,81 @@ void DrawSprite(SpriteID img, SpriteID pal, int x, int y)
 {
 	if (HASBIT(img, PALETTE_MODIFIER_TRANSPARENT)) {
 		_color_remap_ptr = GetNonSprite(GB(pal, 0, PALETTE_WIDTH)) + 1;
-		GfxMainBlitter<BM_TRANSPARENT>(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y);
+		GfxMainBlitter(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y, BM_TRANSPARENT);
 	} else if (pal != PAL_NONE) {
 		_color_remap_ptr = GetNonSprite(GB(pal, 0, PALETTE_WIDTH)) + 1;
-		GfxMainBlitter<BM_COLOUR_REMAP>(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y);
+		GfxMainBlitter(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y, BM_COLOUR_REMAP);
 	} else {
-		GfxMainBlitter<BM_NORMAL>(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y);
-	}
-}
-
-struct BlitterParams {
-	int start_x, start_y;
-	const byte *sprite;
-	Pixel *dst;
-	int width, height;
-	int width_org;
-	int pitch;
-};
-
-template <BlitterMode Tmode, ZoomLevel Tzoom>
-static inline void GfxBlitZoomUncomp(BlitterParams *bp)
-{
-	const byte *src = bp->sprite + bp->start_y * bp->width_org + bp->start_x;
-	Pixel *dst = bp->dst;
-	int height = bp->height;
-	int width = bp->width;
-	int i;
-
-	assert(height > 0);
-	assert(width > 0);
-
-	height = UnScaleByZoom(height, Tzoom);
-
-	switch (Tmode) {
-		case BM_COLOUR_REMAP: {
-			const byte *ctab = _color_remap_ptr;
-
-			for (; height != 0; height--) {
-				for (i = 0; i != UnScaleByZoom(width, Tzoom); i++) {
-					byte b = ctab[src[ScaleByZoom(i, Tzoom)]];
-
-					if (b != 0) dst[i] = b;
-				}
-				src += ScaleByZoom(bp->width_org, Tzoom);
-				dst += bp->pitch;
-			}
-			break;
-		}
-
-		case BM_TRANSPARENT: {
-			const byte *ctab = _color_remap_ptr;
-
-			for (; height != 0; height--) {
-				for (i = 0; i != UnScaleByZoom(width, Tzoom); i++)
-					if (src[ScaleByZoom(i, Tzoom)] != 0) dst[i] = ctab[dst[i]];
-				src += ScaleByZoom(bp->width_org, Tzoom);
-				dst += bp->pitch;
-			}
-			break;
-		}
-
-		default:
-			for (; height != 0; height--) {
-				for (i = 0; i != UnScaleByZoom(width, Tzoom); i++)
-					if (src[ScaleByZoom(i, Tzoom)] != 0) dst[i] = src[ScaleByZoom(i, Tzoom)];
-				src += ScaleByZoom(bp->width_org, Tzoom);
-				dst += bp->pitch;
-			}
-			break;
+		GfxMainBlitter(GetSprite(GB(img, 0, SPRITE_WIDTH)), x, y, BM_NORMAL);
 	}
 }
 
-template <BlitterMode Tmode, ZoomLevel Tzoom>
-static inline void GfxBlitTileZoom(BlitterParams *bp)
-{
-	const byte *src_o = bp->sprite;
-	const byte *src;
-	int num, skip;
-	byte done;
-	Pixel *dst;
-	const byte *ctab;
-
-	src_o += ReadLE16Aligned(src_o + bp->start_y * 2);
-
-	for (;;) {
-		do {
-			done = src_o[0];
-			num = done & 0x7F;
-			skip = src_o[1];
-			src = src_o + 2;
-			src_o += num + 2;
-
-			dst = bp->dst;
-
-			if (Tzoom >= ZOOM_LVL_OUT_2X && (skip & 1)) {
-				skip += 1;
-				src += 1;
-				num -= 1;
-				if (num <= 0) continue;
-			}
-
-			if (Tzoom >= ZOOM_LVL_OUT_4X && (skip & 2)) {
-				skip += 2;
-				src += 2;
-				num -= 2;
-				if (num <= 0) continue;
-			}
-
-			if (Tzoom >= ZOOM_LVL_OUT_8X && (skip & 4)) {
-				skip += 4;
-				src += 4;
-				num -= 4;
-				if (num <= 0) continue;
-			}
-
-			if (Tzoom >= ZOOM_LVL_OUT_16X && (skip & 8)) {
-				skip += 8;
-				src += 8;
-				num -= 8;
-				if (num <= 0) continue;
-			}
-
-			if ( (skip -= bp->start_x) > 0) {
-				dst += UnScaleByZoom(skip, Tzoom);
-			} else {
-				src -= skip;
-				num += skip;
-				if (num <= 0) continue;
-				skip = 0;
-			}
-
-			skip = skip + num - bp->width;
-			if (skip > 0) {
-				num -= skip;
-				if (num <= 0) continue;
-			}
-
-			num = UnScaleByZoom(num, Tzoom);
-
-			switch (Tmode) {
-				case BM_COLOUR_REMAP:
-					ctab = _color_remap_ptr;
-					for (; num != 0; num--) {
-							*dst = ctab[*src];
-							dst++;
-							src += ScaleByZoom(1, Tzoom);
-					}
-					break;
-
-				case BM_TRANSPARENT:
-					ctab = _color_remap_ptr;
-					for (; num != 0; num--) {
-							*dst = ctab[*dst];
-							dst++;
-					}
-					break;
-
-				default:
-					if (Tzoom == ZOOM_LVL_NORMAL) {
-						memcpy(dst, src, num);
-					} else {
-						for (; num != 0; num--) {
-								*dst = *src;
-								dst++;
-								src += ScaleByZoom(1, Tzoom);
-						}
-					}
-					break;
-			}
-
-
-		} while (!(done & 0x80));
-
-		bp->dst += bp->pitch;
-		if (--bp->height == 0) return;
-
-		for (int i = 0; i < ScaleByZoom(1, Tzoom) - 1; i++) {
-			do {
-				done = src_o[0];
-				src_o += (done & 0x7F) + 2;
-			} while (!(done & 0x80));
-			if (--bp->height == 0) return;
-		}
-	}
-}
-
-template <BlitterMode Tmode>
-static inline void GfxMainBlitter(const Sprite *sprite, int x, int y)
+static inline void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 {
 	const DrawPixelInfo *dpi = _cur_dpi;
-	int start_x, start_y;
-	BlitterParams bp;
-	int zoom_mask = ~(ScaleByZoom(1, dpi->zoom) - 1);
+	Blitter::BlitterParams bp;
 
-	/* decode sprite header */
+	/* Move to the correct offset */
 	x += sprite->x_offs;
 	y += sprite->y_offs;
-	bp.width_org = bp.width = sprite->width;
-	bp.height = sprite->height;
+
+	/* Copy the main data directly from the sprite */
 	bp.sprite = sprite->data;
+	bp.sprite_width = sprite->width;
+	bp.sprite_height = sprite->height;
+	bp.width = UnScaleByZoom(sprite->width, dpi->zoom);
+	bp.height = UnScaleByZoom(sprite->height, dpi->zoom);
+	bp.top = 0;
+	bp.left = 0;
+	bp.skip_left = 0;
+	bp.skip_top = 0;
 	bp.dst = dpi->dst_ptr;
 	bp.pitch = dpi->pitch;
+	bp.remap = _color_remap_ptr;
 
-	assert(bp.height > 0);
-	assert(bp.width > 0);
+	assert(sprite->width > 0);
+	assert(sprite->height > 0);
 
-	start_y = 0;
-	if (dpi->zoom > ZOOM_LVL_NORMAL) {
-		start_y += bp.height & ~zoom_mask;
-		bp.height &= zoom_mask;
-		if (bp.height == 0) return;
-		y &= zoom_mask;
-	}
+	if (bp.width <= 0) return;
+	if (bp.height <= 0) return;
 
-	if ( (y -= dpi->top) < 0) {
-		bp.height += y;
+	y -= dpi->top;
+	/* Check for top overflow */
+	if (y < 0) {
+		bp.height -= -UnScaleByZoom(y, dpi->zoom);
 		if (bp.height <= 0) return;
-		start_y -= y;
+		bp.skip_top += -UnScaleByZoom(y, dpi->zoom);
 		y = 0;
 	} else {
-		bp.dst += bp.pitch * UnScaleByZoom(y, dpi->zoom);
+		bp.top = UnScaleByZoom(y, dpi->zoom);
 	}
-	bp.start_y = start_y;
 
-	if ( (y = y + bp.height - dpi->height) > 0) {
-		bp.height -= y;
+	/* Check for bottom overflow */
+	y += ScaleByZoom(bp.height, dpi->zoom) - dpi->height;
+	if (y > 0) {
+		bp.height -= UnScaleByZoom(y, dpi->zoom);
 		if (bp.height <= 0) return;
 	}
 
-	start_x = 0;
-	x &= zoom_mask;
-	if ( (x -= dpi->left) < 0) {
-		bp.width += x;
+	x -= dpi->left;
+	/* Check for left overflow */
+	if (x < 0) {
+		bp.width -= -UnScaleByZoom(x, dpi->zoom);
 		if (bp.width <= 0) return;
-		start_x -= x;
+		bp.skip_left += -UnScaleByZoom(x, dpi->zoom);
 		x = 0;
+	} else {
+		bp.left = UnScaleByZoom(x, dpi->zoom);
 	}
-	bp.start_x = start_x;
-	bp.dst += UnScaleByZoom(x, dpi->zoom);
 
-	if ( (x = x + bp.width - dpi->width) > 0) {
-		bp.width -= x;
+	/* Check for right overflow */
+	x += ScaleByZoom(bp.width, dpi->zoom) - dpi->width;
+	if (x > 0) {
+		bp.width -= UnScaleByZoom(x, dpi->zoom);
 		if (bp.width <= 0) return;
 	}
 
-	if (sprite->info & 8) {
-		switch (dpi->zoom) {
-			case ZOOM_LVL_NORMAL:  GfxBlitTileZoom<Tmode, ZOOM_LVL_NORMAL>(&bp);  break;
-			case ZOOM_LVL_OUT_2X:  GfxBlitTileZoom<Tmode, ZOOM_LVL_OUT_2X>(&bp);  break;
-			case ZOOM_LVL_OUT_4X:  GfxBlitTileZoom<Tmode, ZOOM_LVL_OUT_4X>(&bp);  break;
-			case ZOOM_LVL_OUT_8X:  GfxBlitTileZoom<Tmode, ZOOM_LVL_OUT_8X>(&bp);  break;
-			case ZOOM_LVL_OUT_16X: GfxBlitTileZoom<Tmode, ZOOM_LVL_OUT_16X>(&bp); break;
-			default: NOT_REACHED();
-		}
-	} else {
-		switch (dpi->zoom) {
-			case ZOOM_LVL_NORMAL:  GfxBlitZoomUncomp<Tmode, ZOOM_LVL_NORMAL>(&bp);  break;
-			case ZOOM_LVL_OUT_2X:  GfxBlitZoomUncomp<Tmode, ZOOM_LVL_OUT_2X>(&bp);  break;
-			case ZOOM_LVL_OUT_4X:  GfxBlitZoomUncomp<Tmode, ZOOM_LVL_OUT_4X>(&bp);  break;
-			case ZOOM_LVL_OUT_8X:  GfxBlitZoomUncomp<Tmode, ZOOM_LVL_OUT_8X>(&bp);  break;
-			case ZOOM_LVL_OUT_16X: GfxBlitZoomUncomp<Tmode, ZOOM_LVL_OUT_16X>(&bp); break;
-			default: NOT_REACHED();
-		}
-	}
+	BlitterFactoryBase::GetCurrentBlitter()->Draw(&bp, mode, dpi->zoom);
 }
 
 void DoPaletteAnimations();
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 2e20074a7..1b7b46cda 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -64,6 +64,7 @@
 #include "newgrf_commons.h"
 #include "player_face.h"
 #include "group.h"
+#include "blitter/blitter.hpp"
 
 #include "bridge_map.h"
 #include "clear_map.h"
@@ -85,6 +86,8 @@ extern void SetDifficultyLevel(int mode, GameOptions *gm_opt);
 extern Player* DoStartupNewPlayer(bool is_ai);
 extern void ShowOSErrorBox(const char *buf);
 
+const char *_default_blitter = "8bpp-optimzed";
+
 /* TODO: usrerror() for errors which are not of an internal nature but
  * caused by the user, i.e. missing files or fatal configuration errors.
  * Post-0.4.0 since Celestar doesn't want this in SVN before. --pasky */
@@ -159,6 +162,7 @@ static void showhelp()
 		"  -v drv              = Set video driver (see below)\n"
 		"  -s drv              = Set sound driver (see below) (param bufsize,hz)\n"
 		"  -m drv              = Set music driver (see below)\n"
+		"  -b drv              = Set the blitter to use (see below)\n"
 		"  -r res              = Set resolution (for instance 800x600)\n"
 		"  -h                  = Display this help text\n"
 		"  -t year             = Set starting year\n"
@@ -183,6 +187,9 @@ static void showhelp()
 
 	p = GetDriverList(p, lastof(buf));
 
+	/* List the blitters */
+	p = BlitterFactoryBase::GetBlittersInfo(p, lastof(buf));
+
 	/* ShowInfo put output to stderr, but version information should go
 	 * to stdout; this is the only exception */
 #if !defined(WIN32) && !defined(WIN64)
@@ -350,7 +357,7 @@ int ttd_main(int argc, char *argv[])
 {
 	int i;
 	const char *optformat;
-	char musicdriver[32], sounddriver[32], videodriver[32];
+	char musicdriver[32], sounddriver[32], videodriver[32], blitter[32];
 	int resolution[2] = {0, 0};
 	Year startyear = INVALID_YEAR;
 	uint generation_seed = GENERATE_NEW_SEED;
@@ -364,7 +371,7 @@ int ttd_main(int argc, char *argv[])
 	uint16 dedicated_port = 0;
 #endif /* ENABLE_NETWORK */
 
-	musicdriver[0] = sounddriver[0] = videodriver[0] = '\0';
+	musicdriver[0] = sounddriver[0] = videodriver[0] = blitter[0] = '\0';
 
 	_game_mode = GM_MENU;
 	_switch_mode = SM_MENU;
@@ -376,7 +383,7 @@ int ttd_main(int argc, char *argv[])
 	 *   a letter means: it accepts that param (e.g.: -h)
 	 *   a ':' behind it means: it need a param (e.g.: -m<driver>)
 	 *   a '::' behind it means: it can optional have a param (e.g.: -d<debug>) */
-	optformat = "m:s:v:hD::n::eit:d::r:g::G:c:xl:"
+	optformat = "m:s:v:b:hD::n::eit:d::r:g::G:c:xl:"
 #if !defined(__MORPHOS__) && !defined(__AMIGA__) && !defined(WIN32)
 		"f"
 #endif
@@ -389,6 +396,7 @@ int ttd_main(int argc, char *argv[])
 		case 'm': ttd_strlcpy(musicdriver, mgo.opt, sizeof(musicdriver)); break;
 		case 's': ttd_strlcpy(sounddriver, mgo.opt, sizeof(sounddriver)); break;
 		case 'v': ttd_strlcpy(videodriver, mgo.opt, sizeof(videodriver)); break;
+		case 'b': ttd_strlcpy(blitter, mgo.opt, sizeof(blitter)); break;
 #if defined(ENABLE_NETWORK)
 		case 'D':
 			strcpy(musicdriver, "null");
@@ -461,6 +469,7 @@ int ttd_main(int argc, char *argv[])
 	if (!StrEmpty(musicdriver)) ttd_strlcpy(_ini_musicdriver, musicdriver, sizeof(_ini_musicdriver));
 	if (!StrEmpty(sounddriver)) ttd_strlcpy(_ini_sounddriver, sounddriver, sizeof(_ini_sounddriver));
 	if (!StrEmpty(videodriver)) ttd_strlcpy(_ini_videodriver, videodriver, sizeof(_ini_videodriver));
+	if (StrEmpty(blitter)) ttd_strlcpy(blitter, _default_blitter, sizeof(blitter));
 	if (resolution[0] != 0) { _cur_resolution[0] = resolution[0]; _cur_resolution[1] = resolution[1]; }
 	if (startyear != INVALID_YEAR) _patches_newgame.starting_year = startyear;
 	if (generation_seed != GENERATE_NEW_SEED) _patches_newgame.generation_seed = generation_seed;
@@ -500,6 +509,9 @@ int ttd_main(int argc, char *argv[])
 	/* Initialize game palette */
 	GfxInitPalettes();
 
+	DEBUG(misc, 1, "Loading blitter '%s'...", blitter);
+	if (BlitterFactoryBase::SelectBlitter(blitter) == NULL)
+		error("Failed to select requested blitter '%s'; does it exist?", blitter);
 	DEBUG(driver, 1, "Loading drivers...");
 	LoadDriver(SOUND_DRIVER, _ini_sounddriver);
 	LoadDriver(MUSIC_DRIVER, _ini_musicdriver);
diff --git a/src/settings.cpp b/src/settings.cpp
index 01065f4eb..aa1fbc6d1 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1258,7 +1258,7 @@ static const SettingDescGlobVarList _misc_settings[] = {
 	  SDTG_VAR("medium_size",      SLE_UINT, S, 0, _freetype.medium_size, 10, 0, 72, 0, STR_NULL, NULL),
 	  SDTG_VAR("large_size",       SLE_UINT, S, 0, _freetype.large_size,  16, 0, 72, 0, STR_NULL, NULL),
 #endif
-	  SDTG_VAR("sprite_cache_size",SLE_UINT, S, 0, _sprite_cache_size,     2, 1, 64, 0, STR_NULL, NULL),
+	  SDTG_VAR("sprite_cache_size",SLE_UINT, S, 0, _sprite_cache_size,     4, 1, 64, 0, STR_NULL, NULL),
 	  SDTG_END()
 };
 
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
index c45c92d96..f3ea8a1e4 100644
--- a/src/spritecache.cpp
+++ b/src/spritecache.cpp
@@ -11,10 +11,11 @@
 #include "table/sprites.h"
 #include "fileio.h"
 #include "helpers.hpp"
+#include "spriteloader/grf.hpp"
+#include "blitter/blitter.hpp"
 
-
-/* Default of 2MB spritecache */
-uint _sprite_cache_size = 2;
+/* Default of 4MB spritecache */
+uint _sprite_cache_size = 4;
 
 
 struct SpriteCache {
@@ -115,12 +116,10 @@ bool SpriteExists(SpriteID id)
 	return GetSpriteCache(id)->file_pos != 0;
 }
 
-static void* AllocSprite(size_t);
+void* AllocSprite(size_t);
 
 static void* ReadSprite(SpriteCache *sc, SpriteID id)
 {
-	uint num;
-	byte type;
 	uint32 file_pos = sc->file_pos;
 
 	DEBUG(sprite, 9, "Load sprite %d", id);
@@ -135,49 +134,28 @@ static void* ReadSprite(SpriteCache *sc, SpriteID id)
 
 	FioSeekToFile(file_pos);
 
-	num  = FioReadWord();
-	type = FioReadByte();
+	/* Read the size and type */
+	int num  = FioReadWord();
+	byte type = FioReadByte();
+	/* Type 0xFF indicates either a colormap or some other non-sprite info */
 	if (type == 0xFF) {
-		byte* dest = (byte*)AllocSprite(num);
+		byte *dest = (byte *)AllocSprite(num);
 
 		sc->ptr = dest;
 		FioReadBlock(dest, num);
 
 		return dest;
-	} else {
-		uint height = FioReadByte();
-		uint width  = FioReadWord();
-		Sprite* sprite;
-		byte* dest;
-
-		num = (type & 0x02) ? width * height : num - 8;
-		sprite = (Sprite*)AllocSprite(sizeof(*sprite) + num);
-		sc->ptr = sprite;
-		sprite->info   = type;
-		sprite->height = (id != 142) ? height : 10; // Compensate for a TTD bug
-		sprite->width  = width;
-		sprite->x_offs = FioReadWord();
-		sprite->y_offs = FioReadWord();
-
-		dest = sprite->data;
-		while (num > 0) {
-			int8 i = FioReadByte();
-
-			if (i >= 0) {
-				num -= i;
-				for (; i > 0; --i) *dest++ = FioReadByte();
-			} else {
-				const byte* rel = dest - (((i & 7) << 8) | FioReadByte());
+	}
 
-				i = -(i >> 3);
-				num -= i;
+	SpriteLoaderGrf sprite_loader;
+	SpriteLoader::Sprite sprite;
 
-				for (; i > 0; --i) *dest++ = *rel++;
-			}
-		}
+	if (!sprite_loader.LoadSprite(&sprite, file_pos)) return NULL;
+	if (id == 142) sprite.height = 10; // Compensate for a TTD bug
+	sc->ptr = BlitterFactoryBase::GetCurrentBlitter()->Encode(&sprite);
+	free(sprite.data);
 
-		return sprite;
-	}
+	return sc->ptr;
 }
 
 
@@ -348,7 +326,7 @@ static void DeleteEntryFromSpriteCache()
 	}
 }
 
-static void* AllocSprite(size_t mem_req)
+void* AllocSprite(size_t mem_req)
 {
 	mem_req += sizeof(MemBlock);
 
diff --git a/src/spritecache.h b/src/spritecache.h
index c979b73c5..8356d0ff6 100644
--- a/src/spritecache.h
+++ b/src/spritecache.h
@@ -6,7 +6,6 @@
 #define SPRITECACHE_H
 
 struct Sprite {
-	byte info;
 	byte height;
 	uint16 width;
 	int16 x_offs;
diff --git a/src/spriteloader/grf.cpp b/src/spriteloader/grf.cpp
new file mode 100644
index 000000000..4d412d6ea
--- /dev/null
+++ b/src/spriteloader/grf.cpp
@@ -0,0 +1,96 @@
+#include "../stdafx.h"
+#include "../gfx.h"
+#include "../fileio.h"
+#include "../debug.h"
+#include "grf.hpp"
+
+bool SpriteLoaderGrf::LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos)
+{
+	/* Open the right file and go to the correct position */
+	FioSeekToFile(file_pos);
+
+	/* Read the size and type */
+	int num = FioReadWord();
+	byte type = FioReadByte();
+
+	/* Type 0xFF indicates either a colormap or some other non-sprite info; we do not handle them here */
+	if (type == 0xFF) return false;
+
+	sprite->height = FioReadByte();
+	sprite->width  = FioReadWord();
+	sprite->x_offs = FioReadWord();
+	sprite->y_offs = FioReadWord();
+
+	/* 0x02 indicates it is a compressed sprite, so we can't rely on 'num' to be valid.
+	 *  In case it is uncompressed, the size is 'num' - 8 (header-size). */
+	num = (type & 0x02) ? sprite->width * sprite->height : num - 8;
+
+	/* XXX -- We should use a pre-located memory segment for this, malloc/free is pretty expensive */
+	byte *dest_orig = MallocT<byte>(num);
+	byte *dest = dest_orig;
+
+	/* Read the file, which has some kind of compression */
+	while (num > 0) {
+		int8 code = FioReadByte();
+
+		if (code >= 0) {
+			/* Plain bytes to read */
+			int size = (code == 0) ? 0x80 : code;
+			num -= size;
+			for (; size > 0; size--) {
+				*dest = FioReadByte();
+				dest++;
+			}
+		} else {
+			/* Copy bytes from earlier in the sprite */
+			const uint data_offset = ((code & 7) << 8) | FioReadByte();
+			int size = -(code >> 3);
+			num -= size;
+			for (; size > 0; size--) {
+				*dest = *(dest - data_offset);
+				dest++;
+			}
+		}
+	}
+
+	assert(num == 0);
+
+	sprite->data = CallocT<SpriteLoader::CommonPixel>(sprite->width * sprite->height);
+
+	/* When there are transparency pixels, this format has an other trick.. decode it */
+	if (type & 0x08) {
+		for (int y = 0; y < sprite->height; y++) {
+			bool last_item = false;
+			/* Look up in the header-table where the real data is stored for this row */
+			int offset = (dest_orig[y * 2 + 1] << 8) | dest_orig[y * 2];
+			/* Go to that row */
+			dest = &dest_orig[offset];
+
+			do {
+				SpriteLoader::CommonPixel *data;
+				/* Read the header:
+				 *  0 .. 14  - length
+				 *  15       - last_item
+				 *  16 .. 31 - transparency bytes */
+				last_item  = ((*dest) & 0x80) != 0;
+				int length =  (*dest++) & 0x7F;
+				int skip   =   *dest++;
+
+				data = &sprite->data[y * sprite->width + skip];
+
+				for (int x = 0; x < length; x++) {
+					data->m = *dest;
+					dest++;
+					data++;
+				}
+			} while (!last_item);
+		}
+	} else {
+		dest = dest_orig;
+		for (int i = 0; i < sprite->width * sprite->height; i++)
+			sprite->data[i].m = dest[i];
+	}
+
+	free(dest_orig);
+	return true;
+}
diff --git a/src/spriteloader/grf.hpp b/src/spriteloader/grf.hpp
new file mode 100644
index 000000000..27083f993
--- /dev/null
+++ b/src/spriteloader/grf.hpp
@@ -0,0 +1,18 @@
+/* $Id$ */
+
+/** @file grf.hpp */
+
+#ifndef SPRITELOADER_GRF_HPP
+#define SPRITELOADER_GRF_HPP
+
+#include "spriteloader.hpp"
+
+class SpriteLoaderGrf : public SpriteLoader {
+public:
+	/**
+	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
+	 */
+	bool LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos);
+};
+
+#endif /* SPRITELOADER_GRF_HPP */
diff --git a/src/spriteloader/spriteloader.hpp b/src/spriteloader/spriteloader.hpp
new file mode 100644
index 000000000..658277236
--- /dev/null
+++ b/src/spriteloader/spriteloader.hpp
@@ -0,0 +1,34 @@
+/* $Id$ */
+
+/** @file spriteloader.hpp */
+
+#ifndef SPRITELOADER_HPP
+#define SPRITELOADER_HPP
+
+class SpriteLoader {
+public:
+	struct CommonPixel {
+		uint8 r;  ///< Red-channel
+		uint8 g;  ///< Green-channel
+		uint8 b;  ///< Blue-channel
+		uint8 a;  ///< Alpha-channel
+		uint8 m;  ///< Remap-channel
+	};
+
+	struct Sprite {
+		uint16 height;                   ///< Height of the sprite
+		uint16 width;                    ///< Width of the sprite
+		int16 x_offs;                    ///< The x-offset of where the sprite will be drawn
+		int16 y_offs;                    ///< The y-offset of where the sprite will be drawn
+		SpriteLoader::CommonPixel *data; ///< The sprite itself
+	};
+
+	/**
+	 * Load a sprite from the disk and return a sprite struct which is the same for all loaders.
+	 */
+	virtual bool LoadSprite(SpriteLoader::Sprite *sprite, uint32 file_pos) = 0;
+
+	virtual ~SpriteLoader() { }
+};
+
+#endif /* SPRITELOADER_HPP */
diff --git a/src/zoom.hpp b/src/zoom.hpp
index 65937177b..19e64e615 100644
--- a/src/zoom.hpp
+++ b/src/zoom.hpp
@@ -25,7 +25,7 @@ enum ZoomLevel {
 	ZOOM_LVL_ROADVEH  = ZOOM_LVL_NORMAL,
 	ZOOM_LVL_WORLD_SCREENSHOT = ZOOM_LVL_NORMAL,
 
-	ZOOM_LVL_DETAIL   = ZOOM_LVL_OUT_2X, //! All zoomlevels below or equal to this, will result in details on the screen, like road-work, ...
+	ZOOM_LVL_DETAIL   = ZOOM_LVL_OUT_2X, ///< All zoomlevels below or equal to this, will result in details on the screen, like road-work, ...
 
 	ZOOM_LVL_MIN      = ZOOM_LVL_NORMAL,
 	ZOOM_LVL_MAX      = ZOOM_LVL_OUT_16X,