Use premultiplied alpha for plDynamicTextMaps on GUI controls.

This fixes the irregular dark fringes around light text when not exactly pixel-aligned that are caused by independent interpolation of color and alpha. It also makes calculations simpler for things to come.

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/CoreLib/hsColorRGBA.h

@@ -71,6 +71,7 @@ struct hsColorRGBA {
 
 	hsColorRGBA&	FromARGB32(UInt32 c);
 	UInt32			ToARGB32() const;
+	UInt32			ToARGB32Premultiplied() const;
 
 	void Read(hsStream *stream);
 	void Write(hsStream *stream) const;
@@ -109,6 +110,14 @@ inline UInt32 hsColorRGBA::ToARGB32() const
 		| (UInt32(b * 255.99f) << 0);
 }
 
+inline UInt32 hsColorRGBA::ToARGB32Premultiplied() const
+{
+	return (UInt32(a * 255.0f + 0.5f) << 24)
+		| (UInt32(a * r * 255.0f + 0.5f) << 16)
+		| (UInt32(a * g * 255.0f + 0.5f) << 8)
+		| (UInt32(a * b * 255.0f + 0.5f) << 0);
+}
+
 inline hsColorRGBA operator+(const hsColorRGBA& s, const hsColorRGBA& t)
 {
 	hsColorRGBA res;

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/FeatureLib/pfGameGUIMgr/pfGUIControlMod.cpp

@@ -695,7 +695,7 @@ hsBool	pfGUIControlMod::ISetUpDynTextMap( plPipeline *pipe )
 	extraH -= height;
 
 	fDynTextMap->Reset();
-	fDynTextMap->Create( width, height, HasFlag( kXparentBgnd ), extraW, extraH );
+	fDynTextMap->Create( width, height, HasFlag( kXparentBgnd ), extraW, extraH, true );
 
 	fDynTextMap->SetFont( GetColorScheme()->fFontFace, GetColorScheme()->fFontSize, GetColorScheme()->fFontFlags,
 							HasFlag( kXparentBgnd ) ? false : true );
@@ -706,6 +706,7 @@ hsBool	pfGUIControlMod::ISetUpDynTextMap( plPipeline *pipe )
 	// out with 1:1 mapping from textel to pixel
 	plLayer	*layer = (plLayer *)fDynTextLayer;
 	layer->SetTransform( fDynTextMap->GetLayerTransform() );
+	layer->SetBlendFlags( layer->GetBlendFlags() | hsGMatState::kBlendAlphaPremultiplied );
 
 	// Let the derived classes do their things
 	IPostSetUpDynTextMap();

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/NucleusLib/inc/hsGMatState.h

@@ -85,7 +85,8 @@ enum hsGMatBlendFlags {
 	kBlendEnvBumpNext				= 0x800000,
 	kBlendSubtract					= 0x1000000,
 	kBlendRevSubtract				= 0x2000000,
-	kBlendAlphaTestHigh				= 0x4000000
+	kBlendAlphaTestHigh				= 0x4000000,
+	kBlendAlphaPremultiplied		= 0x8000000
 };
 enum hsGMatClampFlags {
 

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plDynamicTextMap.cpp

@@ -75,20 +75,12 @@ plProfile_Extern(MemMipmaps);
 
 //// Constructor & Destructor /////////////////////////////////////////////////
 
-plDynamicTextMap::plDynamicTextMap() : plMipmap()
+plDynamicTextMap::plDynamicTextMap()
+	: fVisWidth(0), fVisHeight(0), fHasAlpha(false), fPremultipliedAlpha(false), fJustify(kLeftJustify),
+	  fInitBuffer(nil), fFontFace(nil), fFontSize(0), fFontFlags(0),
+	  fFontAntiAliasRGB(false), fFontBlockRGB(false), fHasCreateBeenCalled(false)
 {
-	fVisWidth = fVisHeight = 0;
-	fHasAlpha = false;
-	fJustify = kLeftJustify;
-	fInitBuffer = nil;
-	fFontFace = nil;
-	fFontSize = 0;
-	fFontFlags = 0;
-	fFontAntiAliasRGB = false;
-	fFontColor.Set( 0, 0, 0, 1 );
-	fFontBlockRGB = false;
-	fHasCreateBeenCalled = false;
-
+	fFontColor.Set(0, 0, 0, 1);
 }
 
 plDynamicTextMap::~plDynamicTextMap()
@@ -96,11 +88,10 @@ plDynamicTextMap::~plDynamicTextMap()
 	Reset();
 }
 
-plDynamicTextMap::plDynamicTextMap( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth, UInt32 extraHeight ) : plMipmap()
+plDynamicTextMap::plDynamicTextMap( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth, UInt32 extraHeight, hsBool premultipliedAlpha )
+	: fInitBuffer(nil), fFontFace(nil)
 {
-	fInitBuffer = nil;
-	fFontFace = nil;
-	Create( width, height, hasAlpha, extraWidth, extraHeight );
+	Create( width, height, hasAlpha, extraWidth, extraHeight, premultipliedAlpha );
 }
 
 //// SetNoCreate //////////////////////////////////////////////////////////////
@@ -122,7 +113,7 @@ void	plDynamicTextMap::SetNoCreate( UInt32 width, UInt32 height, hsBool hasAlpha
 
 //// Create ///////////////////////////////////////////////////////////////////
 
-void	plDynamicTextMap::Create( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth, UInt32 extraHeight )
+void	plDynamicTextMap::Create( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth, UInt32 extraHeight, hsBool premultipliedAlpha )
 {
 	SetConfig( hasAlpha ? kARGB32Config : kRGB32Config );
 
@@ -130,6 +121,7 @@ void	plDynamicTextMap::Create( UInt32 width, UInt32 height, hsBool hasAlpha, UIn
 	fVisWidth = (UInt16)width;
 	fVisHeight = (UInt16)height;
 	fHasAlpha = hasAlpha;
+	fPremultipliedAlpha = premultipliedAlpha;
 
 	for( fWidth = 1; fWidth < width + extraWidth; fWidth <<= 1 );
 	for( fHeight = 1; fHeight < height + extraHeight; fHeight <<= 1 );
@@ -395,7 +387,7 @@ void	plDynamicTextMap::ClearToColor( hsColorRGBA &color )
 	if( !IIsValid() )
 		return;
 
-	UInt32		i, hex = color.ToARGB32();
+	UInt32		i, hex = fPremultipliedAlpha ? color.ToARGB32Premultiplied() : color.ToARGB32();
 	UInt32		*data = (UInt32 *)fImage;
 
 	// Buffer is of size fVisWidth x fVisHeight, so we need a bit of work to do this right
@@ -520,6 +512,7 @@ void	plDynamicTextMap::DrawString( UInt16 x, UInt16 y, const wchar_t *text )
 	fCurrFont->SetRenderClipRect( 0, 0, fVisWidth, fVisHeight );
 	fCurrFont->SetRenderColor( fFontColor.ToARGB32() );
 	fCurrFont->SetRenderFlag( plFont::kRenderIntoAlpha, fFontBlockRGB );
+	fCurrFont->SetRenderFlag( plFont::kRenderAlphaPremultiplied, fPremultipliedAlpha );
 	fCurrFont->RenderString( this, x, y, text );
 }
 
@@ -541,6 +534,7 @@ void	plDynamicTextMap::DrawClippedString( Int16 x, Int16 y, const wchar_t *text,
 	fCurrFont->SetRenderClipping( x, y, width, height );
 	fCurrFont->SetRenderColor( fFontColor.ToARGB32() );
 	fCurrFont->SetRenderFlag( plFont::kRenderIntoAlpha, fFontBlockRGB );
+	fCurrFont->SetRenderFlag( plFont::kRenderAlphaPremultiplied, fPremultipliedAlpha );
 	fCurrFont->RenderString( this, x, y, text );
 }
 
@@ -561,6 +555,7 @@ void	plDynamicTextMap::DrawClippedString( Int16 x, Int16 y, const wchar_t *text,
 	SetJustify( fJustify );
 	fCurrFont->SetRenderClipping( clipX, clipY, width, height );
 	fCurrFont->SetRenderColor( fFontColor.ToARGB32() );
+	fCurrFont->SetRenderFlag( plFont::kRenderAlphaPremultiplied, fPremultipliedAlpha );
 	fCurrFont->RenderString( this, x, y, text );
 }
 
@@ -582,6 +577,7 @@ void	plDynamicTextMap::DrawWrappedString( UInt16 x, UInt16 y, const wchar_t *tex
 	fCurrFont->SetRenderWrapping( x, y, width, height );
 	fCurrFont->SetRenderColor( fFontColor.ToARGB32() );
 	fCurrFont->SetRenderFlag( plFont::kRenderIntoAlpha, fFontBlockRGB );
+	fCurrFont->SetRenderFlag( plFont::kRenderAlphaPremultiplied, fPremultipliedAlpha );
 	fCurrFont->RenderString( this, x, y, text, lastX, lastY );
 }
 
@@ -665,7 +661,7 @@ void	plDynamicTextMap::FillRect( UInt16 x, UInt16 y, UInt16 width, UInt16 height
 		width = (UInt16)(fWidth - x);
 
 	// Gee, how hard can it REALLY be?
-	UInt32 i, hex = color.ToARGB32();
+	UInt32 i, hex = fPremultipliedAlpha ? color.ToARGB32Premultiplied() : color.ToARGB32();
 	height += y;
 	if( height > fHeight )
 		height = (UInt16)fHeight;
@@ -690,7 +686,7 @@ void	plDynamicTextMap::FrameRect( UInt16 x, UInt16 y, UInt16 width, UInt16 heigh
 		height = (UInt16)(fHeight - y);
 
 	// Shouldn't be much harder
-	UInt32 i, hex = color.ToARGB32();
+	UInt32 i, hex = fPremultipliedAlpha ? color.ToARGB32Premultiplied() : color.ToARGB32();
 	UInt32 *dest1, *dest2;
 
 	dest1 = GetAddr32( x, y );
@@ -725,6 +721,9 @@ void	plDynamicTextMap::DrawImage( UInt16 x, UInt16 y, plMipmap *image, DrawMetho
 	else if( method == kImgSprite )
 		opts.fFlags = plMipmap::kCopySrcAlpha;
 
+	if( fPremultipliedAlpha )
+		opts.fFlags |= plMipmap::kDestPremultiplied;
+
 	Composite( image, x, y, &opts );
 
 	/// HACK for now, since the alpha in the mipmap gets copied straight into the
@@ -763,6 +762,9 @@ void	plDynamicTextMap::DrawClippedImage( UInt16 x, UInt16 y, plMipmap *image,
 	else if( method == kImgSprite )
 		opts.fFlags = plMipmap::kCopySrcAlpha;
 
+	if( fPremultipliedAlpha )
+		opts.fFlags |= plMipmap::kDestPremultiplied;
+
 	opts.fSrcClipX = srcClipX;
 	opts.fSrcClipY = srcClipY;
 	opts.fSrcClipWidth = srcClipWidth;
@@ -909,6 +911,7 @@ void	plDynamicTextMap::Swap( plDynamicTextMap *other )
 
 	// Swap DTMap info
 	SWAP_ME( hsBool, fHasAlpha, other->fHasAlpha );
+	SWAP_ME( hsBool, fPremultipliedAlpha, other->fPremultipliedAlpha );
 	SWAP_ME( hsBool, fShadowed, other->fShadowed );
 
 	SWAP_ME( Justify, fJustify, other->fJustify );

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plDynamicTextMap.h

@@ -113,14 +113,14 @@ class plDynamicTextMap : public plMipmap
 
 
 		plDynamicTextMap();
-		plDynamicTextMap( UInt32 width, UInt32 height, hsBool hasAlpha = false, UInt32 extraWidth = 0, UInt32 extraHeight = 0 );
+		plDynamicTextMap( UInt32 width, UInt32 height, hsBool hasAlpha = false, UInt32 extraWidth = 0, UInt32 extraHeight = 0, hsBool premultipliedAlpha = false );
 		virtual ~plDynamicTextMap();
 
 		CLASSNAME_REGISTER( plDynamicTextMap );
 		GETINTERFACE_ANY( plDynamicTextMap, plMipmap );
 
 
-		void			Create( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth = 0, UInt32 extraHeight = 0 );
+		void			Create( UInt32 width, UInt32 height, hsBool hasAlpha, UInt32 extraWidth = 0, UInt32 extraHeight = 0, hsBool premultipliedAlpha = false );
 		void			SetNoCreate( UInt32 width, UInt32 height, hsBool hasAlpha );
 
 		virtual void	Reset( void );
@@ -222,7 +222,7 @@ class plDynamicTextMap : public plMipmap
 		UInt32		*IAllocateOSSurface( UInt16 width, UInt16 height );
 		void		IDestroyOSSurface( void );
 
-		hsBool		fHasAlpha, fShadowed;
+		hsBool		fHasAlpha, fPremultipliedAlpha, fShadowed;
 
 		Justify		fJustify;
 		char		*fFontFace;

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plFont.cpp

@@ -345,7 +345,9 @@ void	plFont::IRenderString( plMipmap *mip, UInt16 x, UInt16 y, const wchar_t *st
 		{
 			if( fRenderInfo.fFlags & kRenderIntoAlpha )
 			{
-				if( ( fRenderInfo.fColor & 0xff000000 ) != 0xff000000 )
+				if( fRenderInfo.fFlags & kRenderAlphaPremultiplied )
+					fRenderInfo.fRenderFunc = &plFont::IRenderChar8To32AlphaPremultiplied;
+				else if( ( fRenderInfo.fColor & 0xff000000 ) != 0xff000000 )
 					fRenderInfo.fRenderFunc = &plFont::IRenderChar8To32Alpha;
 				else
 					fRenderInfo.fRenderFunc = &plFont::IRenderChar8To32FullAlpha;
@@ -1032,6 +1034,65 @@ void	plFont::IRenderChar8To32Alpha( const plFont::plCharacter &c )
 	}
 }
 
+void	plFont::IRenderChar8To32AlphaPremultiplied( const plFont::plCharacter &c )
+{
+	UInt8   *src = fBMapData + c.fBitmapOff;
+	UInt32  *destPtr, *destBasePtr = (UInt32 *)( fRenderInfo.fDestPtr - c.fBaseline * fRenderInfo.fDestStride );
+	Int16   x, y, thisHeight, xstart, thisWidth;
+	UInt8   srcA, srcR, srcG, srcB;
+
+
+	// Unfortunately for some fonts, their right kern value actually is
+	// farther left than the right edge of the bitmap (think of overlapping
+	// script fonts). Ideally, we should store the actual width of each char's
+	// bitmap and use that here. However, it really shouldn't make too big of a
+	// difference, especially since the dest pixels that we end up overlapping
+	// should already be in the cache. If it does, time to upgrade the font
+	// format (again)
+	thisWidth = fWidth;// + (Int32)c.fRightKern;
+	if( thisWidth >= fRenderInfo.fMaxWidth )
+		thisWidth = fRenderInfo.fMaxWidth;
+
+	xstart = fRenderInfo.fClipRect.fX - fRenderInfo.fX;
+	if( xstart < 0 )
+		xstart = 0;
+
+	srcA = (UInt8)(( fRenderInfo.fColor >> 24 ) & 0x000000ff);
+	srcR = (UInt8)(( fRenderInfo.fColor >> 16 ) & 0x000000ff);
+	srcG = (UInt8)(( fRenderInfo.fColor >> 8	) & 0x000000ff);
+	srcB = (UInt8)(( fRenderInfo.fColor		) & 0x000000ff);
+
+	y = fRenderInfo.fClipRect.fY - fRenderInfo.fY + (Int16)c.fBaseline;
+	if( y < 0 )
+		y = 0;
+	else
+	{
+		destBasePtr = (UInt32 *)( (UInt8 *)destBasePtr + y*fRenderInfo.fDestStride );
+		src += y*fRenderInfo.fNumCols;
+	}
+
+	thisHeight = fRenderInfo.fMaxHeight + (Int16)c.fBaseline;
+	if( thisHeight > (Int16)c.fHeight )
+		thisHeight = (Int16)c.fHeight;
+
+	for( ; y < thisHeight; y++ )
+	{
+		destPtr = destBasePtr;
+		for( x = xstart; x < thisWidth; x++ )
+		{
+			UInt32 a = src[ x ];
+			if (a != 0)
+			{
+				if (srcA != 0xff)
+					a = (srcA*a + 127)/255;
+				destPtr[ x ] = ( a << 24 ) | (((srcR*a + 127)/255) << 16) | (((srcG*a + 127)/255) << 8) | ((srcB*a + 127)/255);
+			}
+		}
+		destBasePtr = (UInt32 *)( (UInt8 *)destBasePtr + fRenderInfo.fDestStride );
+		src += fWidth;
+	}
+}
+
 
 void	plFont::IRenderCharNull( const plCharacter &c )
 {

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plFont.h

@@ -116,6 +116,7 @@ class plFont : public hsKeyedObject
 												// value between the renderColor and the destColor and
 												// leave the alpha as-is
 												// This flag has no effect on monochrome fonts
+			kRenderAlphaPremultiplied = 0x00001000, // Destination has color values premultiplied by alpha
 		};
 
 		enum Flags
@@ -231,6 +232,7 @@ class plFont : public hsKeyedObject
 		void	IRenderChar8To32( const plCharacter &c );
 		void	IRenderChar8To32Alpha( const plCharacter &c );
 		void	IRenderChar8To32FullAlpha( const plCharacter &c );
+		void	IRenderChar8To32AlphaPremultiplied( const plCharacter &c );
 		void	IRenderCharNull( const plCharacter &c );
 
 	public:

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plMipmap.cpp

@@ -1745,6 +1745,18 @@ void	plMipmap::Composite( plMipmap *source, UInt16 x, UInt16 y, plMipmap::Compos
 			for( pY = (UInt16)srcHeight; pY > 0; pY-- )
 			{
 				memcpy( dstPtr, srcPtr, srcRowBytesToCopy );
+				if( options->fFlags & kDestPremultiplied )
+				{
+					// multiply color values by alpha
+					for( pX = 0; pX < srcWidth; pX++ )
+					{
+						srcAlpha = ((dstPtr[ pX ] >> 24) & 0x000000ff);
+						dstPtr[ pX ] = ( srcAlpha << 24 )
+							| (((((dstPtr[ pX ] >> 16) & 0xff)*srcAlpha + 127)/255) << 16)
+							| (((((dstPtr[ pX ] >>	8) & 0xff)*srcAlpha + 127)/255) <<	8)
+							| (((((dstPtr[ pX ]      ) & 0xff)*srcAlpha + 127)/255)      );
+					}
+				}
 				dstPtr += dstRowBytes >> 2;
 				srcPtr += srcRowBytes >> 2;
 			}
@@ -1776,7 +1788,15 @@ void	plMipmap::Composite( plMipmap *source, UInt16 x, UInt16 y, plMipmap::Compos
 				{
 					srcAlpha = options->fOpacity * ( ( srcPtr[ pX ] >> 16 ) & 0x0000ff00 ) / 255 / 256;
 					if( srcAlpha != 0 )
-						dstPtr[ pX ] = ( srcPtr[ pX ] & 0x00ffffff ) | ( srcAlpha << 24 );
+					{
+						if( options->fFlags & kDestPremultiplied )
+							dstPtr[ pX ] = ( srcAlpha << 24 )
+								| (((((srcPtr[ pX ] >> 16) & 0xff)*srcAlpha + 127)/255) << 16)
+								| (((((srcPtr[ pX ] >>	8) & 0xff)*srcAlpha + 127)/255) <<	8)
+								| (((((srcPtr[ pX ]      ) & 0xff)*srcAlpha + 127)/255)      );
+						else
+							dstPtr[ pX ] = ( srcPtr[ pX ] & 0x00ffffff ) | ( srcAlpha << 24 );
+					}
 				}
 				dstPtr += dstRowBytes >> 2;
 				srcPtr += srcRowBytes >> 2;

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plGImage/plMipmap.h

@@ -233,11 +233,14 @@ class plMipmap : public plBitmap
 
 		enum CompositeFlags
 		{
-			kForceOpaque	= 0x0001,		// Copy src pixels raw, force dest alphas to opaque
-			kCopySrcAlpha	= 0x0002,		// Copy the src pixels raw, including alphas, overwrite dest
-			kBlendSrcAlpha	= 0x0004,		// Blend src pixels onto dest using src alpha, dest alpha = src alpha
-			kMaskSrcAlpha	= 0x0008,		// Same as copySrcAlpha, but dest is untouched when src alpha = 0
-			kBlendWriteAlpha= 0x0010		// Like default (0), but writes dest alpha values
+			kForceOpaque		= 0x0001,		// Copy src pixels raw, force dest alphas to opaque
+			kCopySrcAlpha		= 0x0002,		// Copy the src pixels raw, including alphas, overwrite dest
+			kBlendSrcAlpha		= 0x0004,		// Blend src pixels onto dest using src alpha, dest alpha = src alpha
+			kMaskSrcAlpha		= 0x0008,		// Same as copySrcAlpha, but dest is untouched when src alpha = 0
+			kBlendWriteAlpha	= 0x0010,		// Like default (0), but writes dest alpha values
+
+			kDestPremultiplied	= 0x0020,		// Dest has color premultiplied by alpha
+												// (src always assumed nonpremultiplied for now)
 		};
 
 		class CompositeOptions

MOULOpenSourceClientPlugin/Plasma20/Sources/Plasma/PubUtilLib/plPipeline/plDXPipeline.cpp

@@ -7229,12 +7229,26 @@ void	plDXPipeline::IHandleFirstStageBlend()
 				fD3DDevice->SetRenderState( D3DRS_ALPHABLENDENABLE,   TRUE );
 				if( fLayerState[0].fBlendFlags & hsGMatState::kBlendInvertFinalAlpha )
 				{
-					fD3DDevice->SetRenderState( D3DRS_SRCBLEND, D3DBLEND_INVSRCALPHA  );
+					if( fLayerState[0].fBlendFlags & hsGMatState::kBlendAlphaPremultiplied )
+					{
+						fD3DDevice->SetRenderState( D3DRS_SRCBLEND,  D3DBLEND_ONE );
+					}
+					else
+					{
+						fD3DDevice->SetRenderState( D3DRS_SRCBLEND,  D3DBLEND_INVSRCALPHA );
+					}
 					fD3DDevice->SetRenderState( D3DRS_DESTBLEND, D3DBLEND_SRCALPHA );
 				}
 				else
 				{
-					fD3DDevice->SetRenderState( D3DRS_SRCBLEND,  D3DBLEND_SRCALPHA );
+					if( fLayerState[0].fBlendFlags & hsGMatState::kBlendAlphaPremultiplied )
+					{
+						fD3DDevice->SetRenderState( D3DRS_SRCBLEND,  D3DBLEND_ONE );
+					}
+					else
+					{
+						fD3DDevice->SetRenderState( D3DRS_SRCBLEND,  D3DBLEND_SRCALPHA );
+					}
 					fD3DDevice->SetRenderState( D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA );
 				}
 				break;