1 files changed, 419 insertions, 0 deletions
diff --git a/src/spritecache.cpp b/src/spritecache.cpp
new file mode 100644
index 000000000..fd881bb2a
--- /dev/null
+++ b/src/spritecache.cpp
@@ -0,0 +1,419 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "debug.h"
+#include "functions.h"
+#include "macros.h"
+#include "spritecache.h"
+#include "table/sprites.h"
+#include "fileio.h"
+
+#define SPRITE_CACHE_SIZE 1024*1024
+
+
+typedef struct SpriteCache {
+	void *ptr;
+	uint32 file_pos;
+	int16 lru;
+} SpriteCache;
+
+
+static uint _spritecache_items = 0;
+static SpriteCache *_spritecache = NULL;
+
+
+static inline SpriteCache *GetSpriteCache(uint index)
+{
+	return &_spritecache[index];
+}
+
+
+static SpriteCache *AllocateSpriteCache(uint index)
+{
+	if (index >= _spritecache_items) {
+		/* Add another 1024 items to the 'pool' */
+		uint items = ALIGN(index + 1, 1024);
+
+		DEBUG(sprite, 4, "Increasing sprite cache to %d items (%d bytes)", items, items * sizeof(*_spritecache));
+
+		_spritecache = realloc(_spritecache, items * sizeof(*_spritecache));
+
+		if (_spritecache == NULL) {
+			error("Unable to allocate sprite cache of %d items (%d bytes)", items, items * sizeof(*_spritecache));
+		}
+
+		/* Reset the new items and update the count */
+		memset(_spritecache + _spritecache_items, 0, (items - _spritecache_items) * sizeof(*_spritecache));
+		_spritecache_items = items;
+	}
+
+	return GetSpriteCache(index);
+}
+
+
+typedef struct MemBlock {
+	uint32 size;
+	byte data[VARARRAY_SIZE];
+} MemBlock;
+
+static uint _sprite_lru_counter;
+static MemBlock *_spritecache_ptr;
+static int _compact_cache_counter;
+
+static void CompactSpriteCache(void);
+
+static bool ReadSpriteHeaderSkipData(void)
+{
+	uint16 num = FioReadWord();
+	byte type;
+
+	if (num == 0) return false;
+
+	type = FioReadByte();
+	if (type == 0xFF) {
+		FioSkipBytes(num);
+		/* Some NewGRF files have "empty" pseudo-sprites which are 1
+		 * byte long. Catch these so the sprites won't be displayed. */
+		return num != 1;
+	}
+
+	FioSkipBytes(7);
+	num -= 8;
+	if (num == 0) return true;
+
+	if (type & 2) {
+		FioSkipBytes(num);
+	} else {
+		while (num > 0) {
+			int8 i = FioReadByte();
+			if (i >= 0) {
+				num -= i;
+				FioSkipBytes(i);
+			} else {
+				i = -(i >> 3);
+				num -= i;
+				FioReadByte();
+			}
+		}
+	}
+
+	return true;
+}
+
+/* Check if the given Sprite ID exists */
+bool SpriteExists(SpriteID id)
+{
+	/* Special case for Sprite ID zero -- its position is also 0... */
+	if (id == 0) return true;
+
+	return GetSpriteCache(id)->file_pos != 0;
+}
+
+static void* AllocSprite(size_t);
+
+static void* ReadSprite(SpriteCache *sc, SpriteID id)
+{
+	uint num;
+	byte type;
+
+	DEBUG(sprite, 9, "Load sprite %d", id);
+
+	if (!SpriteExists(id)) {
+		error(
+			"Tried to load non-existing sprite #%d.\n"
+			"Probable cause: Wrong/missing NewGRFs",
+			id
+		);
+	}
+
+	FioSeekToFile(sc->file_pos);
+
+	num  = FioReadWord();
+	type = FioReadByte();
+	if (type == 0xFF) {
+		byte* dest = 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 = 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;
+
+				for (; i > 0; --i) *dest++ = *rel++;
+			}
+		}
+
+		return sprite;
+	}
+}
+
+
+bool LoadNextSprite(int load_index, byte file_index)
+{
+	SpriteCache *sc;
+	uint32 file_pos = FioGetPos() | (file_index << 24);
+
+	if (!ReadSpriteHeaderSkipData()) return false;
+
+	if (load_index >= MAX_SPRITES) {
+		error("Tried to load too many sprites (#%d; max %d)", load_index, MAX_SPRITES);
+	}
+
+	sc = AllocateSpriteCache(load_index);
+	sc->file_pos = file_pos;
+	sc->ptr = NULL;
+	sc->lru = 0;
+
+	return true;
+}
+
+
+void DupSprite(SpriteID old, SpriteID new)
+{
+	SpriteCache *scold = GetSpriteCache(old);
+	SpriteCache *scnew = AllocateSpriteCache(new);
+
+	scnew->file_pos = scold->file_pos;
+	scnew->ptr = NULL;
+}
+
+
+void SkipSprites(uint count)
+{
+	for (; count > 0; --count) {
+		if (!ReadSpriteHeaderSkipData()) return;
+	}
+}
+
+
+#define S_FREE_MASK 1
+
+static inline MemBlock* NextBlock(MemBlock* block)
+{
+	return (MemBlock*)((byte*)block + (block->size & ~S_FREE_MASK));
+}
+
+static uint32 GetSpriteCacheUsage(void)
+{
+	uint32 tot_size = 0;
+	MemBlock* s;
+
+	for (s = _spritecache_ptr; s->size != 0; s = NextBlock(s))
+		if (!(s->size & S_FREE_MASK)) tot_size += s->size;
+
+	return tot_size;
+}
+
+
+void IncreaseSpriteLRU(void)
+{
+	// Increase all LRU values
+	if (_sprite_lru_counter > 16384) {
+		SpriteID i;
+
+		DEBUG(sprite, 3, "Fixing lru %d, inuse=%d", _sprite_lru_counter, GetSpriteCacheUsage());
+
+		for (i = 0; i != _spritecache_items; i++) {
+			SpriteCache *sc = GetSpriteCache(i);
+			if (sc->ptr != NULL) {
+				if (sc->lru >= 0) {
+					sc->lru = -1;
+				} else if (sc->lru != -32768) {
+					sc->lru--;
+				}
+			}
+		}
+		_sprite_lru_counter = 0;
+	}
+
+	// Compact sprite cache every now and then.
+	if (++_compact_cache_counter >= 740) {
+		CompactSpriteCache();
+		_compact_cache_counter = 0;
+	}
+}
+
+// Called when holes in the sprite cache should be removed.
+// That is accomplished by moving the cached data.
+static void CompactSpriteCache(void)
+{
+	MemBlock *s;
+
+	DEBUG(sprite, 3, "Compacting sprite cache, inuse=%d", GetSpriteCacheUsage());
+
+	for (s = _spritecache_ptr; s->size != 0;) {
+		if (s->size & S_FREE_MASK) {
+			MemBlock* next = NextBlock(s);
+			MemBlock temp;
+			SpriteID i;
+
+			// Since free blocks are automatically coalesced, this should hold true.
+			assert(!(next->size & S_FREE_MASK));
+
+			// If the next block is the sentinel block, we can safely return
+			if (next->size == 0)
+				break;
+
+			// Locate the sprite belonging to the next pointer.
+			for (i = 0; GetSpriteCache(i)->ptr != next->data; i++) {
+				assert(i != _spritecache_items);
+			}
+
+			GetSpriteCache(i)->ptr = s->data; // Adjust sprite array entry
+			// Swap this and the next block
+			temp = *s;
+			memmove(s, next, next->size);
+			s = NextBlock(s);
+			*s = temp;
+
+			// Coalesce free blocks
+			while (NextBlock(s)->size & S_FREE_MASK) {
+				s->size += NextBlock(s)->size & ~S_FREE_MASK;
+			}
+		} else {
+			s = NextBlock(s);
+		}
+	}
+}
+
+static void DeleteEntryFromSpriteCache(void)
+{
+	SpriteID i;
+	uint best = -1;
+	MemBlock* s;
+	int cur_lru;
+
+	DEBUG(sprite, 3, "DeleteEntryFromSpriteCache, inuse=%d", GetSpriteCacheUsage());
+
+	cur_lru = 0xffff;
+	for (i = 0; i != _spritecache_items; i++) {
+		SpriteCache *sc = GetSpriteCache(i);
+		if (sc->ptr != NULL && sc->lru < cur_lru) {
+			cur_lru = sc->lru;
+			best = i;
+		}
+	}
+
+	// Display an error message and die, in case we found no sprite at all.
+	// This shouldn't really happen, unless all sprites are locked.
+	if (best == (uint)-1)
+		error("Out of sprite memory");
+
+	// Mark the block as free (the block must be in use)
+	s = (MemBlock*)GetSpriteCache(best)->ptr - 1;
+	assert(!(s->size & S_FREE_MASK));
+	s->size |= S_FREE_MASK;
+	GetSpriteCache(best)->ptr = NULL;
+
+	// And coalesce adjacent free blocks
+	for (s = _spritecache_ptr; s->size != 0; s = NextBlock(s)) {
+		if (s->size & S_FREE_MASK) {
+			while (NextBlock(s)->size & S_FREE_MASK) {
+				s->size += NextBlock(s)->size & ~S_FREE_MASK;
+			}
+		}
+	}
+}
+
+static void* AllocSprite(size_t mem_req)
+{
+	mem_req += sizeof(MemBlock);
+
+	/* Align this to an uint32 boundary. This also makes sure that the 2 least
+	 * bits are not used, so we could use those for other things. */
+	mem_req = ALIGN(mem_req, sizeof(uint32));
+
+	for (;;) {
+		MemBlock* s;
+
+		for (s = _spritecache_ptr; s->size != 0; s = NextBlock(s)) {
+			if (s->size & S_FREE_MASK) {
+				size_t cur_size = s->size & ~S_FREE_MASK;
+
+				/* Is the block exactly the size we need or
+				 * big enough for an additional free block? */
+				if (cur_size == mem_req ||
+						cur_size >= mem_req + sizeof(MemBlock)) {
+					// Set size and in use
+					s->size = mem_req;
+
+					// Do we need to inject a free block too?
+					if (cur_size != mem_req) {
+						NextBlock(s)->size = (cur_size - mem_req) | S_FREE_MASK;
+					}
+
+					return s->data;
+				}
+			}
+		}
+
+		// Reached sentinel, but no block found yet. Delete some old entry.
+		DeleteEntryFromSpriteCache();
+	}
+}
+
+
+const void *GetRawSprite(SpriteID sprite)
+{
+	SpriteCache *sc;
+	void* p;
+
+	assert(sprite < MAX_SPRITES);
+
+	sc = GetSpriteCache(sprite);
+
+	// Update LRU
+	sc->lru = ++_sprite_lru_counter;
+
+	p = sc->ptr;
+
+	// Load the sprite, if it is not loaded, yet
+	if (p == NULL) p = ReadSprite(sc, sprite);
+	return p;
+}
+
+
+void GfxInitSpriteMem(void)
+{
+	// initialize sprite cache heap
+	if (_spritecache_ptr == NULL) _spritecache_ptr = malloc(SPRITE_CACHE_SIZE);
+
+	// A big free block
+	_spritecache_ptr->size = (SPRITE_CACHE_SIZE - sizeof(MemBlock)) | S_FREE_MASK;
+	// Sentinel block (identified by size == 0)
+	NextBlock(_spritecache_ptr)->size = 0;
+
+	/* Reset the spritecache 'pool' */
+	free(_spritecache);
+	_spritecache_items = 0;
+	_spritecache = NULL;
+
+	_compact_cache_counter = 0;
+}