move xfermode modes from porterduff into xfermode itself

git-svn-id: http://skia.googlecode.com/svn/trunk@232 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 76 insertions, 0 deletions

diff --git a/src/effects/SkPorterDuff.cpp b/src/effects/SkPorterDuff.cpp
new file mode 100644
index 0000000000..42f93b8888
--- /dev/null
+++ b/src/effects/SkPorterDuff.cpp
@@ -0,0 +1,75 @@
+#include "SkPorterDuff.h"
+#include "SkXfermode.h"
+
+/*  This file just exists as a compatibility layer, gluing the PorterDuff API
+    into the (extended) SkXfermode API
+ */
+
+#define MAKE_PAIR(mode) { SkPorterDuff::k##mode##_Mode, SkXfermode::k##mode##_Mode }
+
+// this table must be in SkPorterDuff::Mode order, so it can be indexed directly
+// with a porterduff mode.
+static const struct Pair {
+    SkPorterDuff::Mode  fPD;
+    SkXfermode::Mode    fXF;
+} gPairs[] = {
+    MAKE_PAIR(Clear),
+    MAKE_PAIR(Src),
+    MAKE_PAIR(Dst),
+    MAKE_PAIR(SrcOver),
+    MAKE_PAIR(DstOver),
+    MAKE_PAIR(SrcIn),
+    MAKE_PAIR(DstIn),
+    MAKE_PAIR(SrcOut),
+    MAKE_PAIR(DstOut),
+    MAKE_PAIR(SrcATop),
+    MAKE_PAIR(DstATop),
+    MAKE_PAIR(Xor),
+    MAKE_PAIR(Darken),
+    MAKE_PAIR(Lighten),
+    MAKE_PAIR(Multiply),
+    MAKE_PAIR(Screen),
+    { SkPorterDuff::kAdd_Mode, SkXfermode::kPlus_Mode }
+};
+
+static bool find_pdmode(SkXfermode::Mode src, SkPorterDuff::Mode* dst) {
+    const Pair* pairs = gPairs;
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gPairs); i++) {
+        if (pairs[i].fXF == src) {
+            if (dst) {
+                *dst = pairs[i].fPD;
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+SkXfermode* SkPorterDuff::CreateXfermode(SkPorterDuff::Mode mode) {
+    const Pair& pair = gPairs[mode];
+    SkASSERT(pair.fPD == mode);
+    return SkXfermode::Create(pair.fXF);
+}
+
+bool SkPorterDuff::IsMode(SkXfermode* xfer, Mode* pdmode) {
+    SkXfermode::Mode xfmode;
+    if (!SkXfermode::IsMode(xfer, &xfmode)) {
+        return false;
+    }
+    return find_pdmode(xfmode, pdmode);
+}
+
+SkXfermodeProc SkPorterDuff::GetXfermodeProc(Mode mode) {
+    return SkXfermode::GetProc(gPairs[mode].fXF);
+}
+
+SkXfermodeProc16 SkPorterDuff::GetXfermodeProc16(Mode mode, SkColor srcColor) {
+    return SkXfermode::GetProc16(gPairs[mode].fXF, srcColor);
+}
+
+// DEPRECATED
+#include "SkPaint.h"
+SkXfermode* SkPaint::setPorterDuffXfermode(SkPorterDuff::Mode mode) {
+    return this->setXfermode(SkPorterDuff::CreateXfermode(mode));
+}
+
diff --git a/src/effects/effects_files.mk b/src/effects/effects_files.mk
index 6fa43f5ade..f570f15536 100644
--- a/src/effects/effects_files.mk
+++ b/src/effects/effects_files.mk
@@ -20,4 +20,5 @@ SOURCE := \
 	SkLayerRasterizer.cpp \
 	SkPaintFlagsDrawFilter.cpp \
 	SkPixelXorXfermode.cpp \
+	SkPorterDuff.cpp \
     SkRectShape.cpp