add Skew for faux italic fonts

stepmania/src/Actor.cpp

@@ -371,6 +371,12 @@ void Actor::BeginDraw()		// set the world matrix and calculate actor properties
 
 		DISPLAY->MultMatrix(mat);
 	}
+
+	if( m_pTempState->fSkewX != 0 )
+	{
+		DISPLAY->SkewX( m_pTempState->fSkewX );
+	}
+
 }
 
 void Actor::SetGlobalRenderStates()
@@ -925,6 +931,7 @@ void Actor::TweenState::Init()
 	rotation = RageVector3( 0, 0, 0 );
 	quat = RageVector4( 0, 0, 0, 1 );
 	scale = RageVector3( 1, 1, 1 );
+	fSkewX = 0;
 	crop = RectF( 0,0,0,0 );
 	fade = RectF( 0,0,0,0 );
 	for(int i=0; i<4; i++) 
@@ -938,6 +945,7 @@ void Actor::TweenState::MakeWeightedAverage( TweenState& average_out, const Twee
 	average_out.scale		= ts1.scale	   + (ts2.scale		- ts1.scale   )*fPercentBetween;
 	average_out.rotation	= ts1.rotation + (ts2.rotation	- ts1.rotation)*fPercentBetween;
 	RageQuatSlerp(&average_out.quat, ts1.quat, ts2.quat, fPercentBetween);
+	average_out.fSkewX		= ts1.fSkewX + (ts2.fSkewX	- ts1.fSkewX)*fPercentBetween;
 	
 	average_out.crop.left	= ts1.crop.left  + (ts2.crop.left	- ts1.crop.left  )*fPercentBetween;
 	average_out.crop.top	= ts1.crop.top   + (ts2.crop.top	- ts1.crop.top   )*fPercentBetween;

stepmania/src/Actor.h

@@ -57,6 +57,7 @@ public:
 		RageVector3 rotation;
 		RageVector4 quat;
 		RageVector3 scale;
+		float		fSkewX;
 		RectF		crop;	// 0 = no cropping, 1 = fully cropped
 		RectF		fade;	// 0 = no fade
 		RageColor   diffuse[4];
@@ -171,6 +172,9 @@ public:
 	void  AddRotationP( float rot );
 	void  AddRotationR( float rot );
 
+	void SetSkewX( float fAmount )	{ DestTweenState().fSkewX = fAmount; }
+	float GetSkewX( float fAmount )	{ return DestTweenState().fSkewX; }
+
 	float GetCropLeft()					{ return DestTweenState().crop.left; }
 	float GetCropTop()					{ return DestTweenState().crop.top;	}
 	float GetCropRight()				{ return DestTweenState().crop.right;}
@@ -523,6 +527,7 @@ public:
 	static int rotationx( T* p, lua_State *L )		{ p->SetRotationX(FArg(1)); return 0; }
 	static int rotationy( T* p, lua_State *L )		{ p->SetRotationY(FArg(1)); return 0; }
 	static int rotationz( T* p, lua_State *L )		{ p->SetRotationZ(FArg(1)); return 0; }
+	static int skewx( T* p, lua_State *L )			{ p->SetSkewX(FArg(1)); return 0; }
 	static int heading( T* p, lua_State *L )		{ p->AddRotationH(FArg(1)); return 0; }
 	static int pitch( T* p, lua_State *L )			{ p->AddRotationP(FArg(1)); return 0; }
 	static int roll( T* p, lua_State *L )			{ p->AddRotationR(FArg(1)); return 0; }
@@ -631,6 +636,7 @@ public:
 		ADD_METHOD( rotationx )
 		ADD_METHOD( rotationy )
 		ADD_METHOD( rotationz )
+		ADD_METHOD( skewx )
 		ADD_METHOD( heading )
 		ADD_METHOD( pitch )
 		ADD_METHOD( roll )

stepmania/src/RageDisplay.cpp

@@ -326,6 +326,13 @@ public:
 		MultMatrixLocal( m );
 	}
 
+	void SkewX( float fAmount )
+	{		
+		RageMatrix m;
+		RageMatrixSkewX( &m, fAmount );
+		MultMatrixLocal( m );
+	}
+
 	// Obtain the current matrix at the top of the stack
 	const RageMatrix* GetTop() { return &stack.back(); }
 };
@@ -396,6 +403,11 @@ void RageDisplay::RotateZ( float deg )
 	g_WorldStack.RotateZLocal( deg );
 }
 
+void RageDisplay::SkewX( float fAmount )
+{
+	g_WorldStack.SkewX( fAmount );
+}
+
 void RageDisplay::PostMultMatrix( const RageMatrix &m )
 {
 	g_WorldStack.MultMatrix( m );

stepmania/src/RageDisplay.h

@@ -268,6 +268,7 @@ public:
 	void RotateX( float deg );
 	void RotateY( float deg );
 	void RotateZ( float deg );
+	void SkewX( float fAmount );
 	void MultMatrix( const RageMatrix &f ) { this->PostMultMatrix(f); } /* alias */
 	void PostMultMatrix( const RageMatrix &f );
 	void PreMultMatrix( const RageMatrix &f );

stepmania/src/RageMath.cpp

@@ -158,6 +158,12 @@ void RageMatrixScaling( RageMatrix* pOut, float x, float y, float z )
 	pOut->m[2][2] = z;
 }
 
+void RageMatrixSkewX( RageMatrix* pOut, float fAmount )
+{
+	RageMatrixIdentity(pOut);
+	pOut->m[1][0] = fAmount;
+}
+
 /*
  * Return:
  *

stepmania/src/RageMath.h

@@ -25,6 +25,7 @@ void RageMatrixIdentity( RageMatrix* pOut );
 void RageMatrixMultiply( RageMatrix* pOut, const RageMatrix* pA, const RageMatrix* pB );
 void RageMatrixTranslation( RageMatrix* pOut, float x, float y, float z );
 void RageMatrixScaling( RageMatrix* pOut, float x, float y, float z );
+void RageMatrixSkewX( RageMatrix* pOut, float fAmount );
 void RageMatrixTranslateAndScale( RageMatrix* pOut, float fTransX, float fTransY, float fTransZ, float fScaleX, float fScaleY, float fScaleZ );
 void RageMatrixRotationX( RageMatrix* pOut, float fTheta );
 void RageMatrixRotationY( RageMatrix* pOut, float fTheta );