system.h

体现了lod(level of detail)算法 包括网格细分,空间层次

// This code based on engine "Engine1"
// which written by David Dufke
// http://www.efd.lth.se/~e98dd/home/

#ifndef _SYSTEM_H
#define _SYSTEM_H

/* Functions */
int sysTime();
int sysLoadSettings(char * config_file);
void sysLogPrintf(const char *string, ...);
void sysSnapshot();
int sysLog2(int i);
float sysNorm(float x, float y, float z);
void sysBuildNormTable();


#define SYS_MEMALIGN	64

void *sysMalloc(int size);
void *sysCalloc(int size);
void sysFree(void * ptr);

struct sys_memHdr_type
{
	void *orig_ptr;
	int size;
};

extern int sys_memUsed;

class SpeedMeter
{
public:
	void init(int storesize);
	float getAvg();
	int getSpot(int index);	//0 is most recent, 1 is one frame ago etc..
	int getSize();
	void startMeter();
	void stopMeter();
	~SpeedMeter();
private:
	int *m_buffer;
	int m_current;
	int m_storesize;
	int m_start;
};

void rDrawTimeGraph(SpeedMeter *times);


#endif /* _SYSTEM_H */