void a_fps__reset(int NumFramesToSkip)
{
g_skipNum = NumFramesToSkip;
g_skipCounter = 0;
g_fpsRate = g_idealFps / (1 + g_skipNum);
g_msPerFrame = 1000 / g_fpsRate;
g_fps = g_fpsRate;
g_maxFps = g_fpsRate;
for(int i = g_bufferLen; i--; ) {
g_fpsBuffer[i] = g_fpsRate;
g_maxFpsBuffer[i] = g_fpsRate;
}
g_fpsBufferSum = g_fpsRate * g_bufferLen;
g_maxFpsBufferSum = g_fpsRate * g_bufferLen;
if(g_skipNum > 0) {
g_fpsThresholdFast = g_idealFps / g_skipNum;
}
g_fpsThresholdSlow = g_fpsRate - 2;
if(g_timer == NULL) {
g_timer = a_timer_new(g_msPerFrame);
} else {
a_timer_setPeriod(g_timer, g_msPerFrame);
}
a_timer_start(g_timer);
}
void a_fps__set(void)
{
milisPerFrame = 1000 / a2x_int("fps");
timer = a_timer_set(milisPerFrame);
a_timer_start(timer);
fps = 0;
max = 0;
if(a2x_bool("trackFps")) {
for(int i = BUFFER_SIZE; i--; ) {
fpsBuffer[i] = milisPerFrame;
maxBuffer[i] = milisPerFrame;
}
}
counter = 0;
}
void a_fps__init(void)
{
g_idealFps = a_settings_getInt("video.fps");
g_skipFrames = a_settings_getBool("video.fps.skip");
g_skipMax = a_settings_getInt("video.fps.skip.max");
g_timer = NULL;
g_frameCounter = 0;
g_bufferHead = 0;
g_bufferLen = g_idealFps * AVERAGE_WINDOW_SEC;
g_fpsBuffer = a_mem_malloc(g_bufferLen * sizeof(uint32_t));
g_maxFpsBuffer = a_mem_malloc(g_bufferLen * sizeof(uint32_t));
g_skipAdjustTimer = a_timer_new(FRAMESKIP_ADJUST_DELAY_SEC * 1000);
a_timer_start(g_skipAdjustTimer);
g_noSleepTimer = a_timer_new(NO_SLEEP_RESET_SEC * 1000);
g_canSleep = true;
a_fps__reset(0);
}
void a_fps_frame(void)
{
if(a_fps_notSkipped()) {
a_screen_show();
const bool done = a_timer_expired(g_timer);
const uint32_t elapsedMs = a_timer_elapsed(g_timer);
if(elapsedMs > 0) {
g_maxFpsBufferSum -= g_maxFpsBuffer[g_bufferHead];
g_maxFpsBuffer[g_bufferHead] = 1000 / elapsedMs;
g_maxFpsBufferSum += g_maxFpsBuffer[g_bufferHead];
g_maxFps = g_maxFpsBufferSum / g_bufferLen;
}
if(!done) {
while(!a_timer_expired(g_timer)) {
if(!g_canSleep) {
continue;
}
const uint32_t waitMs = g_msPerFrame - a_timer_elapsed(g_timer);
#if A_PLATFORM_GP2X
// GP2X timer granularity is too coarse
if(waitMs >= 10) {
a_time_waitMs(10);
}
#else
a_time_waitMs(waitMs);
#endif
}
}
g_fpsBufferSum -= g_fpsBuffer[g_bufferHead];
g_fpsBuffer[g_bufferHead] = 1000 / a_timer_elapsed(g_timer);
g_fpsBufferSum += g_fpsBuffer[g_bufferHead];
g_fps = g_fpsBufferSum / g_bufferLen;
g_bufferHead = (g_bufferHead + 1) % g_bufferLen;
}
a_input__get();
g_frameCounter++;
if(g_skipFrames) {
if(a_fps_notSkipped() && a_timer_expired(g_skipAdjustTimer)) {
int newFrameSkip = -1;
if(g_maxFps <= g_fpsThresholdSlow && g_skipNum < g_skipMax) {
newFrameSkip = g_skipNum + 1;
} else if(g_maxFps >= g_fpsThresholdFast && g_skipNum > 0) {
newFrameSkip = g_skipNum - 1;
}
if(newFrameSkip != -1) {
if(newFrameSkip == 0) {
a_timer_start(g_noSleepTimer);
} else {
a_timer_stop(g_noSleepTimer);
}
g_canSleep = false;
a_fps__reset(newFrameSkip);
} else if(!g_canSleep && a_timer_expired(g_noSleepTimer)) {
g_canSleep = true;
}
}
if(g_skipCounter++ == g_skipNum) {
g_skipCounter = 0;
}
}
}