memory.c

著名物理引擎Hawk的源代码

/* memory.c, HAWK game engine
 *
 * Copyright 1997-1998 by Phil Frisbie, Jr.
 * for Hawk Software
 *
 */

#ifdef WIN32
#include "hardware.h"
#endif
#include "hawk.h"
#include "internal.h"
#include <io.h>


/* Memory functions */
#define MAX_BLOCKS	4
#define TEMP_BLOCK_SIZE	((256*256 *4)+2<<16)	/* largest texture size used */

void	*blocks[MAX_BLOCKS];
int		blockused[MAX_BLOCKS];
int		level_memory = 0;
int		game_memory = 0;

#define MAX_TAGS 32000

void	**tags = NULL;
int		*tagused = NULL;


/* Temp memory is used to speed up common tasks like loading textures */
BOOL initTempMemory(void)
{
	int i;

	for(i=0;i<MAX_BLOCKS;i++)
	{
			blocks[i]= TagMalloc(TEMP_BLOCK_SIZE, TAG_GAME);
			if(!blocks[i])
				return FALSE;
			blockused[i] = FALSE;
	}
	return TRUE;
}

void *TempMalloc(int size)
{
	int i;

	if(size > TEMP_BLOCK_SIZE)
		return(malloc(size));
	for(i=0;i<MAX_BLOCKS;i++)
	{
		if(!blockused[i])
		{
			blockused[i] = TRUE;
			return blocks[i];
		}
	}
	if(i==MAX_BLOCKS) /* we could not find an unused block */
		return(malloc(size));
}

void TempFree(void *p)
{
	int i;

	for(i=0;i<MAX_BLOCKS;i++)
	{
		if(blockused[i])
		{
			if(blocks[i] == p)
			{
				blockused[i] = FALSE;
				return;
			}
		}
	}
	if(i==MAX_BLOCKS) /* we could not find the block */
	{
		free(p);
		return;
	}
}

void *TagMalloc(int size, int tag)
{
	static int i = 0;

	tagused[i] = tag;
	tags[i] = malloc(size);
	if(tag==TAG_LEVEL)
		level_memory += size;
	else if(tag==TAG_GAME)
		game_memory += size;
	return tags[i++];
}

void FreeTags(int tag)
{
	int i;
	for(i=0;i<MAX_TAGS;i++)
	{
		if(tagused[i]==tag)
		{
			void *t = tags[i];

			free(tags[i]);
			tags[i] = NULL;
			tagused[i] = FALSE;
		}
	}
}

BOOL initTagMemory(void)
{
	int i;

	tags = malloc(MAX_TAGS * sizeof(void *));
	if(!tags)
	{
		free(tags);
		tags = NULL;
		return FALSE;
	}
	tagused = malloc(MAX_TAGS * sizeof(int));
	if(!tagused)
	{
		free(tags);
		tags = NULL;
		free(tagused);
		tagused = NULL;
		return FALSE;
	}
	for(i=1;i<MAX_TAGS;i++)
	{
		tagused[i] = FALSE;
		tags[i] = NULL;
	}
	return TRUE;
}

BOOL initMemory(void)
{
	if(!initTagMemory())
	{
		return FALSE;
	}
	if(!initTempMemory())
	{
		return FALSE;
	}
	return TRUE;
}

void memShutdown(void)
{
	logf("\nFreeing memory\n");
	logf("Level memory allocated: %d\n", level_memory);
	logf("Game memory allocated: %d\n", game_memory);
	if(tags)
	{
		FreeTags(TAG_GAME);
		FreeTags(TAG_LEVEL);
		free(tags);
	}
	if(tagused)
		free(tagused);
}