/// <summary>
/// Renders one frame.
/// </summary>
/// <remarks>
/// Updates all the render targets automatically and then returns, raising frame events before and after.
/// </remarks>
/// <returns>True if execution should continue, false if a quit was requested.</returns>
public void RenderOneFrame()
{
// If we're capping the maximum frame rate, check to see
// if we should sleep
if (microsecondsPerFrame != 0)
{
long current = CaptureCurrentTime();
long diff = Math.Abs(current - lastFrameStartTime);
float microsecondsSinceLastFrame = diff * microsecondsPerTick;
float mdiff = microsecondsPerFrame - microsecondsSinceLastFrame;
// If the difference is greater than 500usec and less
// than 1000 ms, sleep
if (mdiff > 500f && mdiff < 1000000f)
{
Thread.Sleep((int)(Math.Min(mdiff / 1000f, 200f)));
lastFrameStartTime = CaptureCurrentTime();
}
else
{
lastFrameStartTime = current;
}
}
if (queuedEnd)
{
// bail out before continuing
return;
}
// Stop rendering if frame callback says so
oneFrameMeter.Enter();
oneFrameStartedMeter.Enter();
OnFrameStarted();
oneFrameStartedMeter.Exit();
if (!queuedEnd && !dontUpdateRenderTargets)
{
// update all current render targets
updateRenderTargetsMeter.Enter();
UpdateAllRenderTargets();
updateRenderTargetsMeter.Exit();
}
// Stop rendering if frame callback says so
oneFrameEndedMeter.Enter();
OnFrameEnded();
oneFrameEndedMeter.Exit();
oneFrameMeter.Exit();
}
/// <summary>
/// Starts the default rendering loop.
/// </summary>
public void StartRendering()
{
bool cachedMeterLongestFrame = false;
int frameStartTime = 0;
Debug.Assert(activeRenderSystem != null, "Engine cannot start rendering without an active RenderSystem.");
activeRenderSystem.InitRenderTargets();
// initialize the vars
lastStartTime = lastEndTime = timer.Milliseconds;
// reset to false so that rendering can begin
queuedEnd = false;
while (!queuedEnd)
{
// Make sure we're collecting if it's called for
if (meterFrameCount > 0)
{
MeterManager.Collecting = true;
}
else if (meterLongestFrame)
{
cachedMeterLongestFrame = true;
MeterManager.Collecting = true;
frameStartTime = System.Environment.TickCount;
}
// allow OS events to process (if the platform requires it
frameMeter.Enter();
eventMeter.Enter();
PlatformManager.Instance.DoEvents();
eventMeter.Exit();
if (suspendRendering)
{
Thread.Sleep(100);
frameMeter.Exit();
continue;
}
renderMeter.Enter();
RenderOneFrame();
renderMeter.Exit();
if (activeRenderSystem.RenderTargetCount == 0)
{
QueueEndRendering();
}
frameMeter.Exit();
// Turn metering on or off, and generate the report if
// we're done
if (meterFrameCount > 0)
{
meterFrameCount--;
if (meterFrameCount == 0)
{
MeterManager.Collecting = false;
MeterManager.Report("Frame Processing");
}
}
else if (pendingMeterFrameCount > 0)
{
// We'll start metering next frame
meterFrameCount = pendingMeterFrameCount;
pendingMeterFrameCount = 0;
}
else if (cachedMeterLongestFrame)
{
MeterManager.Collecting = false;
int frameTime = System.Environment.TickCount - frameStartTime;
if (frameTime > longestFrameTime)
{
longestFrameTime = frameTime;
longestFrameMeterEvents = MeterManager.ReturnEvents();
}
else
{
MeterManager.ClearEvents();
}
}
}
}
