samplecode/SampleXfermodesBlur.cpp

#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 test_gradient2(SkCanvas* canvas) {
/*
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);
    
    var g = ctx.createRadialGradient(-80, 25, 70, 0, 25, 150);
    g.addColorStop(0, '#f00');
    g.addColorStop(0.01, '#0f0');
    g.addColorStop(0.99, '#0f0');
    g.addColorStop(1, '#f00');
    ctx.fillStyle = g;
    ctx.fillRect(0, 0, 100, 50);
*/
    SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorGREEN, SK_ColorRED };
    SkScalar pos[] = { 0, SkFloatToScalar(0.01f), SkFloatToScalar(0.99f), SK_Scalar1 };
    SkPoint c0 = { -80, 25 };
    SkScalar r0 = 70;
    SkPoint c1 = { 0, 25 };
    SkScalar r1 = 150;
    SkShader* s = SkGradientShader::CreateTwoPointRadial(c0, r0, c1, r1, colors,
                                                         pos, SK_ARRAY_COUNT(pos),
                                                         SkShader::kClamp_TileMode);

    SkPaint paint;
    paint.setShader(s)->unref();

    canvas->drawPaint(paint);

    paint.setShader(NULL);
    paint.setStyle(SkPaint::kStroke_Style);
    SkRect r = { 0, 0, 100, 50 };
    canvas->drawRect(r, paint);
}

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) {
        if (false) {
            test_gradient2(canvas);
            return;
        }
        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);