Add dual source blending support for proper blending with coverage.
Review URL: http://codereview.appspot.com/4535088/
git-svn-id: http://skia.googlecode.com/svn/trunk@1390 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleXfermodesBlur.cpp b/samplecode/SampleXfermodesBlur.cpp
new file mode 100644
index 0000000..166e4e5
--- /dev/null
+++ b/samplecode/SampleXfermodesBlur.cpp
@@ -0,0 +1,182 @@
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "Sk64.h"
+#include "SkCornerPathEffect.h"
+#include "SkGradientShader.h"
+#include "SkGraphics.h"
+#include "SkImageDecoder.h"
+#include "SkKernel33MaskFilter.h"
+#include "SkPath.h"
+#include "SkRandom.h"
+#include "SkRegion.h"
+#include "SkShader.h"
+#include "SkUtils.h"
+#include "SkColorPriv.h"
+#include "SkColorFilter.h"
+#include "SkTime.h"
+#include "SkTypeface.h"
+#include "SkXfermode.h"
+
+#include "SkStream.h"
+#include "SkXMLParser.h"
+#include "SkColorPriv.h"
+#include "SkImageDecoder.h"
+#include "SkBlurMaskFilter.h"
+
+static void setNamedTypeface(SkPaint* paint, const char name[]) {
+ SkTypeface* face = SkTypeface::CreateFromName(name, SkTypeface::kNormal);
+ paint->setTypeface(face);
+ SkSafeUnref(face);
+}
+
+static uint16_t gBG[] = { 0xFFFF, 0xCCCF, 0xCCCF, 0xFFFF };
+
+class XfermodesBlurView : public SampleView {
+ SkBitmap fBG;
+ SkBitmap fSrcB, fDstB;
+
+ void draw_mode(SkCanvas* canvas, SkXfermode* mode, int alpha,
+ SkScalar x, SkScalar y) {
+ SkPaint p;
+ SkMaskFilter* mf = SkBlurMaskFilter::Create(5, SkBlurMaskFilter::kNormal_BlurStyle, 0);
+ p.setMaskFilter(mf)->unref();
+
+ SkScalar ww = SkIntToScalar(W);
+ SkScalar hh = SkIntToScalar(H);
+
+ // draw a circle covering the upper
+ // left three quarters of the canvas
+ p.setColor(0xFFCC44FF);
+ SkRect r;
+ r.set(0, 0, ww*3/4, hh*3/4);
+ r.offset(x, y);
+ canvas->drawOval(r, p);
+
+ p.setXfermode(mode);
+
+ // draw a square overlapping the circle
+ // in the lower right of the canvas
+ p.setColor(0x00AA6633 | alpha << 24);
+ r.set(ww/3, hh/3, ww*19/20, hh*19/20);
+ r.offset(x, y);
+ canvas->drawRect(r, p);
+ }
+
+public:
+ const static int W = 64;
+ const static int H = 64;
+ XfermodesBlurView() {
+ const int W = 64;
+ const int H = 64;
+
+ fBG.setConfig(SkBitmap::kARGB_4444_Config, 2, 2, 4);
+ fBG.setPixels(gBG);
+ fBG.setIsOpaque(true);
+ }
+
+protected:
+ // overrides from SkEventSink
+ virtual bool onQuery(SkEvent* evt) {
+ if (SampleCode::TitleQ(*evt)) {
+ SampleCode::TitleR(evt, "XfermodesBlur");
+ return true;
+ }
+ return this->INHERITED::onQuery(evt);
+ }
+
+ virtual void onDrawContent(SkCanvas* canvas) {
+ canvas->translate(SkIntToScalar(10), SkIntToScalar(20));
+
+ const struct {
+ SkXfermode::Mode fMode;
+ const char* fLabel;
+ } gModes[] = {
+ { SkXfermode::kClear_Mode, "Clear" },
+ { SkXfermode::kSrc_Mode, "Src" },
+ { SkXfermode::kDst_Mode, "Dst" },
+ { SkXfermode::kSrcOver_Mode, "SrcOver" },
+ { SkXfermode::kDstOver_Mode, "DstOver" },
+ { SkXfermode::kSrcIn_Mode, "SrcIn" },
+ { SkXfermode::kDstIn_Mode, "DstIn" },
+ { SkXfermode::kSrcOut_Mode, "SrcOut" },
+ { SkXfermode::kDstOut_Mode, "DstOut" },
+ { SkXfermode::kSrcATop_Mode, "SrcATop" },
+ { SkXfermode::kDstATop_Mode, "DstATop" },
+ { SkXfermode::kXor_Mode, "Xor" },
+
+ { SkXfermode::kPlus_Mode, "Plus" },
+ /*{ SkXfermode::kMultiply_Mode, "Multiply" },
+ { SkXfermode::kScreen_Mode, "Screen" },
+ { SkXfermode::kOverlay_Mode, "Overlay" },
+ { SkXfermode::kDarken_Mode, "Darken" },
+ { SkXfermode::kLighten_Mode, "Lighten" },
+ { SkXfermode::kColorDodge_Mode, "ColorDodge" },
+ { SkXfermode::kColorBurn_Mode, "ColorBurn" },
+ { SkXfermode::kHardLight_Mode, "HardLight" },
+ { SkXfermode::kSoftLight_Mode, "SoftLight" },
+ { SkXfermode::kDifference_Mode, "Difference" },
+ { SkXfermode::kExclusion_Mode, "Exclusion" },*/
+ };
+
+ const SkScalar w = SkIntToScalar(W);
+ const SkScalar h = SkIntToScalar(H);
+ SkShader* s = SkShader::CreateBitmapShader(fBG,
+ SkShader::kRepeat_TileMode,
+ SkShader::kRepeat_TileMode);
+ SkMatrix m;
+ m.setScale(SkIntToScalar(6), SkIntToScalar(6));
+ s->setLocalMatrix(m);
+
+ SkPaint labelP;
+ labelP.setAntiAlias(true);
+ labelP.setLCDRenderText(true);
+ labelP.setTextAlign(SkPaint::kCenter_Align);
+ setNamedTypeface(&labelP, "Menlo Regular");
+
+ const int W = 5;
+
+ SkScalar x0 = 0;
+ for (int twice = 0; twice < 2; twice++) {
+ SkScalar x = x0, y = 0;
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); i++) {
+ SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
+ SkAutoUnref aur(mode);
+ SkRect r;
+ r.set(x, y, x+w, y+h);
+
+ SkPaint p;
+ p.setStyle(SkPaint::kFill_Style);
+ p.setShader(s);
+ canvas->drawRect(r, p);
+
+ canvas->saveLayer(&r, NULL, SkCanvas::kARGB_ClipLayer_SaveFlag);
+ draw_mode(canvas, mode, twice ? 0x88 : 0xFF, r.fLeft, r.fTop);
+ canvas->restore();
+
+ r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
+ p.setStyle(SkPaint::kStroke_Style);
+ p.setShader(NULL);
+ canvas->drawRect(r, p);
+
+ canvas->drawText(gModes[i].fLabel, strlen(gModes[i].fLabel),
+ x + w/2, y - labelP.getTextSize()/2, labelP);
+ x += w + SkIntToScalar(10);
+ if ((i % W) == W - 1) {
+ x = x0;
+ y += h + SkIntToScalar(30);
+ }
+ }
+ x0 += SkIntToScalar(400);
+ }
+ s->unref();
+ }
+
+private:
+ typedef SampleView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new XfermodesBlurView; }
+static SkViewRegister reg(MyFactory);