support for the rest of the drawing modes

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@11099 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/server/Painter/drawing_modes/DrawingModeFactory.cpp

@@ -1,32 +1,51 @@
 // DrawingModeFactory.h
 
+#include <stdio.h>
 
 #include "DrawingModeAdd.h"
+#include "DrawingModeAlphaCC.h"
+#include "DrawingModeAlphaCO.h"
+#include "DrawingModeAlphaPC.h"
+#include "DrawingModeAlphaPO.h"
 #include "DrawingModeBlend.h"
 #include "DrawingModeCopy.h"
+#include "DrawingModeErase.h"
 #include "DrawingModeInvert.h"
 #include "DrawingModeMax.h"
 #include "DrawingModeMin.h"
 #include "DrawingModeOver.h"
+#include "DrawingModeSelect.h"
 #include "DrawingModeSubtract.h"
 
 #include "DrawingModeFactory.h"
 
 // DrawingModeFor
 agg::DrawingMode*
-DrawingModeFactory::DrawingModeFor(drawing_mode mode)
+DrawingModeFactory::DrawingModeFor(drawing_mode mode,
+								   source_alpha alphaSrcMode,
+								   alpha_function alphaFncMode)
 {
 	switch (mode) {
-		case B_OP_INVERT:
+		// these drawing modes discard source pixels
-			return new agg::DrawingModeBGRA32Invert();
+		// which have the current low color
-			break;
-		case B_OP_COPY:
-			return new agg::DrawingModeBGRA32Copy();
-			break;
 		case B_OP_OVER:
 			return new agg::DrawingModeBGRA32Over();
 			break;
+		case B_OP_ERASE:
+			return new agg::DrawingModeBGRA32Erase();
+			break;
+		case B_OP_INVERT:
+			return new agg::DrawingModeBGRA32Invert();
+			break;
+		case B_OP_SELECT:
+			return new agg::DrawingModeBGRA32Select();
+			break;
 
+		// in these drawing modes, the current high
+		// and low color are treated equally
+		case B_OP_COPY:
+			return new agg::DrawingModeBGRA32Copy();
+			break;
 		case B_OP_ADD:
 			return new agg::DrawingModeBGRA32Add();
 			break;
@@ -36,7 +55,6 @@ DrawingModeFactory::DrawingModeFor(drawing_mode mode)
 		case B_OP_BLEND:
 			return new agg::DrawingModeBGRA32Blend();
 			break;
-
 		case B_OP_MIN:
 			return new agg::DrawingModeBGRA32Min();
 			break;
@@ -44,8 +62,34 @@ DrawingModeFactory::DrawingModeFor(drawing_mode mode)
 			return new agg::DrawingModeBGRA32Max();
 			break;
 
+		// this drawing mode is the only one considering
+		// alpha at all. In B_CONSTANT_ALPHA, the alpha
+		// value from the current high color is used for
+		// all computations. In B_PIXEL_ALPHA, the alpha
+		// is considered at every source pixel.
+		// To simplify the implementation, four separate
+		// DrawingMode classes are used to cover the
+		// four possible combinations of alpha enabled drawing.
+		case B_OP_ALPHA:
+			if (alphaSrcMode == B_CONSTANT_ALPHA) {
+				if (alphaFncMode == B_ALPHA_OVERLAY) {
+					return new agg::DrawingModeBGRA32AlphaCO();
+				} else if (alphaFncMode == B_ALPHA_COMPOSITE) {
+					return new agg::DrawingModeBGRA32AlphaCC();
+				}
+			} else if (alphaSrcMode == B_PIXEL_ALPHA){
+				if (alphaFncMode == B_ALPHA_OVERLAY) {
+					return new agg::DrawingModeBGRA32AlphaPO();
+				} else if (alphaFncMode == B_ALPHA_COMPOSITE) {
+					return new agg::DrawingModeBGRA32AlphaPC();
+				}
+			}
+			break;
+
 		default:
+fprintf(stderr, "DrawingModeFactory::DrawingModeFor() - drawing_mode not implemented\n");
 			return new agg::DrawingModeBGRA32Copy();
 	}
+	return NULL;
 }
 

src/servers/app/server/Painter/drawing_modes/DrawingModeFactory.h

@@ -12,7 +12,9 @@ class DrawingModeFactory {
 								DrawingModeFactory() {}
 	virtual						~DrawingModeFactory() {}
 
-	static	agg::DrawingMode*		DrawingModeFor(drawing_mode mode);
+	static	agg::DrawingMode*		DrawingModeFor(drawing_mode mode,
+												   source_alpha alphaSrcMode,
+												   alpha_function alphaFncMode);
 };
 
 #endif // DRAWING_MODE_FACTORY_H