rlm@0: /* Measures performance of SPC emulator. Takes about 4 seconds.
rlm@0: NOTE: This assumes that the program is getting all processor time; you might need to
rlm@0: arrange for this or else the performance will be reported lower than it really is.
rlm@0: 
rlm@0: Usage: benchmark [test.spc]
rlm@0: */
rlm@0: 
rlm@0: #include "snes_spc/spc.h"
rlm@0: 
rlm@0: #include "demo_util.h" /* error(), load_file() */
rlm@0: #include <time.h>
rlm@0: 
rlm@0: clock_t start_timing( int seconds );
rlm@0: 
rlm@0: int main( int argc, char** argv )
rlm@0: {
rlm@0: 	/* Load SPC */
rlm@0: 	long spc_size;
rlm@0: 	void* spc = load_file( (argc > 1) ? argv [1] : "test.spc", &spc_size );
rlm@0: 	SNES_SPC* snes_spc = spc_new();
rlm@0: 	if ( !snes_spc ) error( "Out of memory" );
rlm@0: 	spc_load_spc( snes_spc, spc, spc_size );
rlm@0: 	free( spc );
rlm@0: 	
rlm@0: 	{
rlm@0: 		/* Repeatedly fill buffer for 4 seconds */
rlm@0: 		int const seconds = 4;
rlm@0: 		#define BUF_SIZE 4096
rlm@0: 		clock_t end = start_timing( seconds );
rlm@0: 		int count = 0;
rlm@0: 		while ( clock() < end )
rlm@0: 		{
rlm@0: 			static short buf [BUF_SIZE];
rlm@0: 			error( spc_play( snes_spc, BUF_SIZE, buf ) );
rlm@0: 			count++;
rlm@0: 		}
rlm@0: 		
rlm@0: 		/* Report performance based on how many buffer fills were possible */
rlm@0: 		{
rlm@0: 			double rate = (double) count * BUF_SIZE / (spc_sample_rate * 2 * seconds);
rlm@0: 			printf( "Performance: %.3fx real-time, or %.0f%% CPU for normal rate\n",
rlm@0: 					rate, 100.0 / rate );
rlm@0: 		}
rlm@0: 	}
rlm@0: 	
rlm@0: 	return 0;
rlm@0: }
rlm@0: 
rlm@0: /* Synchronizes with host clock and returns clock() time that is duration seconds from now */
rlm@0: clock_t start_timing( int duration )
rlm@0: {
rlm@0: 	clock_t clock_dur = duration * CLOCKS_PER_SEC;
rlm@0: 	clock_t time = clock();
rlm@0: 	while ( clock() == time ) { }
rlm@0: 	if ( clock() - time > clock_dur )
rlm@0: 		error( "Insufficient clock() time resolution" );
rlm@0: 	return clock() + clock_dur;
rlm@0: }