Previously, alignment had to be implemented by each actor, so it was

only ever supported by Sprite and BitmapText.  Handle it globally, using
m_size.  This way, an actor only needs to set m_size to support alignment.

This means alignment can be set for non-drawing ActorFrames, if a size
is set explicitly.  This allows stretching from the border of a frame
without playing games with extra nested frames.  "setsize,100,100;valign,4;zoomx,.5"

This adds an extra matrix multiply.  This will only happen for actors
actually set to non-centered alignment, which is the exception.

BitmapText still overrides this behavior a bit.  Alignment for text
does two things: changes the alignment of the bounding box vs. the
X/Y position (the generic behavior), and changes the alignment of
the text within the bounding box.

stepmania/src/Actor.cpp

@@ -72,8 +72,8 @@ void Actor::InitState()
 	m_start.Init();
 	m_current.Init();
 
-	m_fHorizAlign = 0.0f;
-	m_fVertAlign = 0.0f;
+	m_fHorizAlign = 0.5f;
+	m_fVertAlign = 0.5f;
 
 	m_Effect =  no_effect;
 	m_fSecsIntoEffect = 0;
@@ -467,6 +467,20 @@ void Actor::BeginDraw()		// set the world matrix and calculate actor properties
 		}
 	}
 
+	if( unlikely(m_fHorizAlign != 0.5f || m_fVertAlign != 0.5f) )
+	{
+		float fX = SCALE( m_fHorizAlign, 0.0f, 1.0f, +m_size.x/2.0f, -m_size.x/2.0f );
+		float fY = SCALE( m_fVertAlign, 0.0f, 1.0f, +m_size.y/2.0f, -m_size.y/2.0f );
+		RageMatrix m;
+		RageMatrixTranslate( 
+			&m, 
+			fX,
+			fY,
+			0
+			);
+		DISPLAY->PreMultMatrix( m );
+	}
+
 	if( m_pTempState->quat.x != 0 ||  m_pTempState->quat.y != 0 ||  m_pTempState->quat.z != 0 || m_pTempState->quat.w != 1 )
 	{
 		RageMatrix mat;
@@ -730,8 +744,8 @@ void Actor::ScaleTo( const RectF &rect, StretchType st )
 		break;
 	}
 
-	SetX( rect.left + rect_width * SCALE( m_fHorizAlign, -1.0f, +1.0f, 0.0f, 1.0f ) );
-	SetY( rect.top + rect_height * SCALE( m_fVertAlign, -1.0f, +1.0f, 0.0f, 1.0f ) );
+	SetX( rect.left + rect_width * m_fHorizAlign );
+	SetY( rect.top + rect_height * m_fVertAlign );
 
 	SetZoom( fNewZoom );
 }

stepmania/src/Actor.h

@@ -251,8 +251,8 @@ public:
 	//
 	// Alignment settings.  These need to be virtual for BitmapText
 	//
-	virtual void SetHorizAlign( HorizAlign ha ) { m_fHorizAlign = (ha == HorizAlign_Left)? -1.0f: (ha == HorizAlign_Center)? 0.0f: +1.0f; }
-	virtual void SetVertAlign( VertAlign va ) { m_fVertAlign = (va == VertAlign_Top)? -1.0f: (va == VertAlign_Middle)? 0.0f: +1.0f; }
+	virtual void SetHorizAlign( HorizAlign ha ) { m_fHorizAlign = (ha == HorizAlign_Left)? 0.0f: (ha == HorizAlign_Center)? 0.5f: +1.0f; }
+	virtual void SetVertAlign( VertAlign va ) { m_fVertAlign = (va == VertAlign_Top)? 0.0f: (va == VertAlign_Middle)? 0.5f: +1.0f; }
 
 
 	//
@@ -423,8 +423,8 @@ protected:
 	//
 	// Stuff for alignment
 	//
-	float	m_fHorizAlign; /* -1 left 0 center +1 right */
-	float	m_fVertAlign;  /* -1 top  0 center +1 bottom */
+	float	m_fHorizAlign; /* 0.0 left 0.5 center 1.0 right */
+	float	m_fVertAlign;  /* 0.0 top  0.5 center 1.0 bottom */
 
 
 	//

stepmania/src/ActorMultiTexture.cpp

@@ -83,15 +83,11 @@ void ActorMultiTexture::DrawPrimitives()
 {
 	Actor::SetGlobalRenderStates();	// set Actor-specified render states
 
-	RageVector2 center = m_size;
-	center.x *= m_fHorizAlign * -0.5f;
-	center.y *= m_fVertAlign * -0.5f;
-
 	RectF quadVerticies;
-	quadVerticies.left   = center.x - m_size.x/2.0f;
-	quadVerticies.right  = center.x + m_size.x/2.0f;
-	quadVerticies.top    = center.y - m_size.y/2.0f;
-	quadVerticies.bottom = center.y + m_size.y/2.0f;
+	quadVerticies.left   = -m_size.x/2.0f;
+	quadVerticies.right  = +m_size.x/2.0f;
+	quadVerticies.top    = -m_size.y/2.0f;
+	quadVerticies.bottom = +m_size.y/2.0f;
 
 	DISPLAY->ClearAllTextures();
 	for( size_t i = 0; i < m_aTextureUnits.size(); ++i )

stepmania/src/BitmapText.cpp

@@ -188,12 +188,8 @@ void BitmapText::BuildChars()
 	/* There's padding between every line: */
 	m_size.y += iPadding * int(m_wTextLines.size()-1);
 
-	RageVector2 center = m_size;
-//	center.x *= m_fHorizAlign*-0.5f;
-	center.y *= m_fVertAlign*-0.5f;
-
 	// the top position of the first row of characters
-	int iY = lrintf(center.y - m_size.y/2.0f);
+	int iY = lrintf(-m_size.y/2.0f);
 
 	for( unsigned i=0; i<m_wTextLines.size(); i++ )		// foreach line
 	{
@@ -203,9 +199,9 @@ void BitmapText::BuildChars()
 		if( m_pFont->IsRightToLeft() )
 			reverse( sLine.begin(), sLine.end() );
 		const int iLineWidth = m_iLineWidths[i];
-		
-		float fCenterX = iLineWidth * m_fHorizAlign * -0.5f;
-		int iX = lrintf(fCenterX - iLineWidth/2.0f);
+
+		float fX = SCALE( m_fHorizAlign, 0.0f, 1.0f, -m_size.x/2.0f, +m_size.x/2.0f - iLineWidth );
+		int iX = lrintf( fX );
 
 		for( unsigned i = 0; i < sLine.size(); ++i )
 		{

stepmania/src/Sprite.cpp

@@ -426,15 +426,11 @@ void Sprite::DrawTexture( const TweenState *state )
 		return; 
 
 	// use m_temp_* variables to draw the object
-	RageVector2 center = m_size;
-	center.x *= m_fHorizAlign * -0.5f;
-	center.y *= m_fVertAlign * -0.5f;
-
 	RectF quadVerticies;
-	quadVerticies.left   = center.x - m_size.x/2.0f;
-	quadVerticies.right  = center.x + m_size.x/2.0f;
-	quadVerticies.top    = center.y - m_size.y/2.0f;
-	quadVerticies.bottom = center.y + m_size.y/2.0f;
+	quadVerticies.left   = -m_size.x/2.0f;
+	quadVerticies.right  = +m_size.x/2.0f;
+	quadVerticies.top    = -m_size.y/2.0f;
+	quadVerticies.bottom = +m_size.y/2.0f;
 
 
 	/* Don't draw anything outside of the texture's image area.  Texels outside