(svn r4486) - NewGRF: Create and use a memory pool to manage sprite groups. This

reduces the amount of house keeping we do and the chance of memory 
leaks.

1 files changed, 68 insertions, 0 deletions

diff --git a/newgrf_spritegroup.c b/newgrf_spritegroup.c
new file mode 100644
index 000000000..9fd43efca
--- /dev/null
+++ b/newgrf_spritegroup.c
@@ -0,0 +1,68 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "pool.h"
+#include "sprite.h"
+
+enum {
+	SPRITEGROUP_POOL_BLOCK_SIZE_BITS = 4, /* (1 << 4) == 16 items */
+	SPRITEGROUP_POOL_MAX_BLOCKS      = 8000,
+};
+
+static uint _spritegroup_count = 0;
+static MemoryPool _spritegroup_pool;
+
+
+static void SpriteGroupPoolCleanBlock(uint start_item, uint end_item)
+{
+	uint i;
+
+	for (i = start_item; i <= end_item; i++) {
+		SpriteGroup *group = (SpriteGroup*)GetItemFromPool(&_spritegroup_pool, i);
+
+		/* Free dynamically allocated memory */
+		switch (group->type) {
+			case SGT_REAL:
+				free(group->g.real.loaded);
+				free(group->g.real.loading);
+				break;
+
+			case SGT_DETERMINISTIC:
+				free(group->g.determ.ranges);
+				break;
+
+			case SGT_RANDOMIZED:
+				free(group->g.random.groups);
+				break;
+
+			default:
+				break;
+		}
+	}
+}
+
+
+/* Initialize the SpriteGroup pool */
+static MemoryPool _spritegroup_pool = { "SpriteGr", SPRITEGROUP_POOL_MAX_BLOCKS, SPRITEGROUP_POOL_BLOCK_SIZE_BITS, sizeof(SpriteGroup), NULL, &SpriteGroupPoolCleanBlock, 0, 0, NULL };
+
+
+/* Allocate a new SpriteGroup */
+SpriteGroup *AllocateSpriteGroup(void)
+{
+	/* This is totally different to the other pool allocators, as we never remove an item from the pool. */
+	if (_spritegroup_count == _spritegroup_pool.total_items) {
+		if (!AddBlockToPool(&_spritegroup_pool)) return NULL;
+	}
+
+	return (SpriteGroup*)GetItemFromPool(&_spritegroup_pool, _spritegroup_count++);
+}
+
+
+void InitializeSpriteGroupPool(void)
+{
+	CleanPool(&_spritegroup_pool);
+	AddBlockToPool(&_spritegroup_pool);
+
+	_spritegroup_count = 0;
+}