Added predictive frame limiter. Rather than busy looping, we keep tra…

…ck of the time it takes to render, run the game loop, and present the frame. We then compare this against the time we last presented a frame, and once it crosses the point at which we don't have enough time to run the game loop again, we run a render loop and present it. By default there is a saftey zone of 10% (frameLimitPercent 0.90). On fast machines without power saving options enabled this can be pushed as small as 2% before frames start being late during gameplay, allowing for ~0.7 millisecond worst case scenario latency with Vsync on.

src/Actor.cpp

@@ -305,10 +305,11 @@ void Actor::Draw()
 {
 	if( !m_bVisible ||
 		m_fHibernateSecondsLeft > 0 || 
-		this->EarlyAbortDraw() )
+		this->EarlyAbortDraw() || !DISPLAY->ShouldRenderFrame() )
 	{
 		return; // early abort
 	}
+
 	if(m_FakeParent)
 	{
 		if(!m_FakeParent->m_bVisible || m_FakeParent->m_fHibernateSecondsLeft > 0

src/ActorFrame.cpp

@@ -222,6 +222,9 @@ void ActorFrame::BeginDraw()
 
 void ActorFrame::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	if( m_bClearZBuffer )
 	{
 		LuaHelpers::ReportScriptErrorFmt( "ClearZBuffer not supported on ActorFrames" );

src/ActorFrameTexture.cpp

@@ -74,6 +74,9 @@ void ActorFrameTexture::DrawPrimitives()
 	if( m_pRenderTarget == NULL )
 		return;
 
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	m_pRenderTarget->BeginRenderingTo( m_bPreserveTexture );
 
 	ActorFrame::DrawPrimitives();

src/ActorMultiTexture.cpp

@@ -89,6 +89,9 @@ void ActorMultiTexture::SetTextureMode( int iIndex, TextureMode tm )
 
 void ActorMultiTexture::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	Actor::SetGlobalRenderStates();	// set Actor-specified render states
 
 	RectF quadVerticies;

src/ActorMultiVertex.cpp

@@ -216,6 +216,9 @@ void ActorMultiVertex::SetVertexCoords( int index, float TexCoordX, float TexCoo
 
 void ActorMultiVertex::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	Actor::SetGlobalRenderStates();	// set Actor-specified render states
 
 	DISPLAY->ClearAllTextures();

src/Background.cpp

@@ -843,6 +843,9 @@ void BackgroundImpl::Update( float fDeltaTime )
 
 void BackgroundImpl::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	if( g_fBGBrightness == 0.0f )
 		return;
 

src/BeginnerHelper.cpp

@@ -234,6 +234,9 @@ void BeginnerHelper::DrawPrimitives()
 	if( !m_bInitialized )
 		return;
 
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	ActorFrame::DrawPrimitives();
 	m_sFlash.Draw();
 

src/BitmapText.cpp

@@ -347,9 +347,11 @@ void BitmapText::BuildChars()
 void BitmapText::DrawChars( bool bUseStrokeTexture )
 {
 	// bail if cropped all the way
-	if( m_pTempState->crop.left + m_pTempState->crop.right >= 1  || 
-		m_pTempState->crop.top + m_pTempState->crop.bottom >= 1 ) 
-		return; 
+	if (m_pTempState->crop.left + m_pTempState->crop.right >= 1 ||
+		m_pTempState->crop.top + m_pTempState->crop.bottom >= 1 || !DISPLAY->ShouldRenderFrame())
+	{
+		return;
+	}
 
 	const int iNumGlyphs = m_vpFontPageTextures.size();
 	int iStartGlyph = lround( SCALE( m_pTempState->crop.left, 0, 1, 0, iNumGlyphs ) );
@@ -670,6 +672,9 @@ bool BitmapText::EarlyAbortDraw() const
 // draw text at x, y using colorTop blended down to colorBottom, with size multiplied by scale
 void BitmapText::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	Actor::SetGlobalRenderStates(); // set Actor-specified render states
 	DISPLAY->SetTextureMode( TextureUnit_1, TextureMode_Modulate );
 

src/DancingCharacters.cpp

@@ -310,6 +310,9 @@ void DancingCharacters::Change2DAnimState( PlayerNumber pn, int iState )
 
 void DancingCharacters::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	DISPLAY->CameraPushMatrix();
 
 	float fPercentIntoSweep;

src/Model.cpp

@@ -293,6 +293,9 @@ bool Model::EarlyAbortDraw() const
 
 void Model::DrawCelShaded()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	// First pass: shell. We only want the backfaces for this.
 	DISPLAY->SetCelShaded(1);
 	DISPLAY->SetCullMode(CULL_FRONT);
@@ -310,6 +313,9 @@ void Model::DrawCelShaded()
 
 void Model::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	Actor::SetGlobalRenderStates();	// set Actor-specified render states
 
 	// Don't if we're fully transparent
@@ -465,6 +471,9 @@ void Model::DrawPrimitives()
 
 void Model::DrawMesh( int i ) const
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	const msMesh *pMesh = &m_pGeometry->m_Meshes[i];
 
 	// apply mesh-specific bone (if any)

src/NoteDisplay.cpp

@@ -470,6 +470,9 @@ bool NoteDisplay::DrawHoldsInRange(const NoteFieldRenderArgs& field_args,
 	const NoteColumnRenderArgs& column_args,
 	const vector<NoteData::TrackMap::const_iterator>& tap_set)
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return false;
+
 	bool any_upcoming = false;
 	for(vector<NoteData::TrackMap::const_iterator>::const_iterator tapit=
 		tap_set.begin(); tapit != tap_set.end(); ++tapit)
@@ -536,6 +539,9 @@ bool NoteDisplay::DrawTapsInRange(const NoteFieldRenderArgs& field_args,
 	const NoteColumnRenderArgs& column_args,
 	const vector<NoteData::TrackMap::const_iterator>& tap_set)
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return false;
+
 	bool any_upcoming= false;
 	// draw notes from furthest to closest
 	for(vector<NoteData::TrackMap::const_iterator>::const_iterator tapit=
@@ -726,7 +732,10 @@ struct StripBuffer
 	}
 	void Draw()
 	{
-		DISPLAY->DrawSymmetricQuadStrip( buf, v-buf );
+		if( DISPLAY->ShouldRenderFrame() )
+		{
+			DISPLAY->DrawSymmetricQuadStrip(buf, v - buf);
+		}
 	}
 	int Used() const { return v - buf; }
 	int Free() const { return size - Used(); }
@@ -1365,6 +1374,9 @@ void NoteDisplay::DrawTap(const TapNote& tn,
 	bool bOnSameRowAsHoldStart, bool bOnSameRowAsRollStart,
 	bool bIsAddition, float fPercentFadeToFail)
 {
+	if ( !DISPLAY->ShouldRenderFrame() )
+		return;
+
 	Actor* pActor = NULL;
 	NotePart part = NotePart_Tap;
 	/*
@@ -1511,6 +1523,9 @@ void NoteColumnRenderer::UpdateReceptorGhostStuff(Actor* receptor) const
 
 void NoteColumnRenderer::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	m_column_render_args.song_beat= m_field_render_args->player_state->GetDisplayedPosition().m_fSongBeatVisible;
 	m_column_render_args.pos_handler= &NCR_current.m_pos_handler;
 	m_column_render_args.rot_handler= &NCR_current.m_rot_handler;

src/NoteField.cpp

@@ -750,6 +750,9 @@ void NoteField::CalcPixelsBeforeAndAfterTargets()
 
 void NoteField::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	//LOG->Trace( "NoteField::DrawPrimitives()" );
 
 	// This should be filled in on the first update.

src/Player.cpp

@@ -1505,6 +1505,9 @@ void Player::ApplyWaitingTransforms()
 
 void Player::DrawPrimitives()
 {
+	if (!DISPLAY->ShouldRenderFrame())
+		return;
+
 	// TODO: Remove use of PlayerNumber.
 	PlayerNumber pn = m_pPlayerState->m_PlayerNumber;