experiment

git-svn-id: http://skia.googlecode.com/svn/trunk@396 2bbb7eff-a529-9590-31e7-b0007b416f81

samplecode/ClockFaceView.cpp

@@ -0,0 +1,255 @@
+#include "SampleCode.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkPath.h"
+#include "SkRegion.h"
+#include "SkShader.h"
+#include "SkUtils.h"
+#include "SkColorPriv.h"
+#include "SkColorFilter.h"
+#include "SkTypeface.h"
+#include "SkAvoidXfermode.h"
+
+static inline SkPMColor rgb2gray(SkPMColor c)
+{
+    unsigned r = SkGetPackedR32(c);
+    unsigned g = SkGetPackedG32(c);
+    unsigned b = SkGetPackedB32(c);
+    
+    unsigned x = r * 5 + g * 7 + b * 4 >> 4;
+    
+    return SkPackARGB32(0, x, x, x) | (c & (SK_A32_MASK << SK_A32_SHIFT));
+}
+
+class SkGrayScaleColorFilter : public SkColorFilter {
+public:
+    virtual void filterSpan(const SkPMColor src[], int count, SkPMColor result[])
+    {
+        for (int i = 0; i < count; i++)
+            result[i] = rgb2gray(src[i]);
+    }
+};
+
+class SkChannelMaskColorFilter : public SkColorFilter {
+public:
+    SkChannelMaskColorFilter(U8CPU redMask, U8CPU greenMask, U8CPU blueMask)
+    {
+        fMask = SkPackARGB32(0xFF, redMask, greenMask, blueMask);
+    }
+
+    virtual void filterSpan(const SkPMColor src[], int count, SkPMColor result[])
+    {
+        SkPMColor mask = fMask;
+        for (int i = 0; i < count; i++)
+            result[i] = src[i] & mask;
+    }
+    
+private:
+    SkPMColor   fMask;
+};
+
+///////////////////////////////////////////////////////////
+
+#include "SkGradientShader.h"
+#include "SkLayerRasterizer.h"
+#include "SkBlurMaskFilter.h"
+
+#include "Sk2DPathEffect.h"
+
+class Dot2DPathEffect : public Sk2DPathEffect {
+public:
+    Dot2DPathEffect(SkScalar radius, const SkMatrix& matrix,
+                    SkTDArray<SkPoint>* pts)
+    : Sk2DPathEffect(matrix), fRadius(radius), fPts(pts) {}
+
+    virtual void flatten(SkFlattenableWriteBuffer& buffer)
+    {
+        this->INHERITED::flatten(buffer);
+        
+        buffer.writeScalar(fRadius);
+    }
+    virtual Factory getFactory() { return CreateProc; }
+
+protected:
+    virtual void begin(const SkIRect& uvBounds, SkPath* dst) {
+        if (fPts) {
+            fPts->reset();
+        }
+        this->INHERITED::begin(uvBounds, dst);
+    }
+//    virtual void end(SkPath* dst) {}
+	virtual void next(const SkPoint& loc, int u, int v, SkPath* dst)
+    {
+        if (fPts) {
+            *fPts->append() = loc;
+        }
+        dst->addCircle(loc.fX, loc.fY, fRadius);
+    }
+    
+    Dot2DPathEffect(SkFlattenableReadBuffer& buffer) : Sk2DPathEffect(buffer)
+    {
+        fRadius = buffer.readScalar();
+        fPts = NULL;
+    }
+private:
+    SkScalar fRadius;
+    SkTDArray<SkPoint>* fPts;
+
+    static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer)
+    {
+        return new Dot2DPathEffect(buffer);
+    }
+
+    typedef Sk2DPathEffect INHERITED;
+};
+
+class InverseFillPE : public SkPathEffect {
+public:
+    InverseFillPE() {}
+    virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width) {
+        *dst = src;
+        dst->setFillType(SkPath::kInverseWinding_FillType);
+        return true;
+    }
+    virtual Factory getFactory() { return Factory; }
+protected:
+//    InverseFillPE(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
+private:
+    static SkFlattenable* Factory(SkFlattenableReadBuffer& buffer) {
+        return new InverseFillPE;
+    }
+    typedef SkPathEffect INHERITED;
+};
+
+static SkPathEffect* makepe(float interp, SkTDArray<SkPoint>* pts) {
+    SkMatrix    lattice;
+    SkScalar    rad = 3 + SkIntToScalar(4) * (1 - interp);
+    lattice.setScale(rad*2, rad*2, 0, 0);
+    lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
+    return new Dot2DPathEffect(rad, lattice, pts);
+}
+
+static void r7(SkLayerRasterizer* rast, SkPaint& p, SkScalar interp) {
+    p.setPathEffect(makepe(interp, NULL))->unref();
+    rast->addLayer(p);
+#if 0
+    p.setPathEffect(new InverseFillPE())->unref();
+    p.setXfermodeMode(SkXfermode::kSrcIn_Mode);
+    p.setXfermodeMode(SkXfermode::kClear_Mode);
+    p.setAlpha((1 - interp) * 255);
+    rast->addLayer(p);
+#endif
+}
+
+typedef void (*raster_proc)(SkLayerRasterizer*, SkPaint&);
+
+#include "SkXfermode.h"
+
+static void apply_shader(SkPaint* paint, float scale)
+{    
+    SkPaint p;
+    SkLayerRasterizer*  rast = new SkLayerRasterizer;
+
+    p.setAntiAlias(true);
+    r7(rast, p, scale);
+    paint->setRasterizer(rast)->unref();
+
+    paint->setColor(SK_ColorBLUE);
+}
+
+class ClockFaceView : public SkView {
+    SkTypeface* fFace;
+    SkScalar fInterp;
+    SkScalar fDx;
+public:
+	ClockFaceView()
+    {
+        fFace = SkTypeface::CreateFromFile("/Users/reed/Downloads/p052024l.pfb");
+        fInterp = 0;
+        fDx = SK_Scalar1/64;
+    }
+    
+    virtual ~ClockFaceView()
+    {
+        fFace->safeUnref();
+    }
+
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt)
+    {
+        if (SampleCode::TitleQ(*evt))
+        {
+            SampleCode::TitleR(evt, "Text Effects");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+    
+    void drawBG(SkCanvas* canvas)
+    {
+//        canvas->drawColor(0xFFDDDDDD);
+        canvas->drawColor(SK_ColorWHITE);
+    }
+    
+    static void drawdots(SkCanvas* canvas, const SkPaint& orig) {
+        SkTDArray<SkPoint> pts;
+        SkPathEffect* pe = makepe(0, &pts);
+        
+        SkScalar width = -1;
+        SkPath path, dstPath;
+        orig.getTextPath("9", 1, 0, 0, &path);
+        pe->filterPath(&dstPath, path, &width);
+        
+        SkPaint p;
+        p.setAntiAlias(true);
+        p.setStrokeWidth(10);
+        p.setColor(SK_ColorRED);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, pts.count(), pts.begin(),
+                           p);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        this->drawBG(canvas);
+        
+        SkScalar    x = SkIntToScalar(20);
+        SkScalar    y = SkIntToScalar(300);
+        SkPaint     paint;
+        
+        paint.setAntiAlias(true);
+        paint.setTextSize(SkIntToScalar(240));
+        paint.setTypeface(SkTypeface::CreateFromName("sans-serif",
+                                                     SkTypeface::kBold));
+
+        SkString str("9");
+
+        paint.setTypeface(fFace);
+        
+        apply_shader(&paint, fInterp);
+        canvas->drawText(str.c_str(), str.size(), x, y, paint);
+
+    //    drawdots(canvas, paint);
+
+        if (false) {
+            fInterp += fDx;
+            if (fInterp > 1) {
+                fInterp = 1;
+                fDx = -fDx;
+            } else if (fInterp < 0) {
+                fInterp = 0;
+                fDx = -fDx;
+            }
+            this->inval(NULL);
+        }
+    }
+
+private:
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new ClockFaceView; }
+static SkViewRegister reg(MyFactory);
+