samplecode/SampleAAClip2.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SkAAClip.h"
#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 "SkImageDecoder.h"

#ifdef SK_BUILD_FOR_WIN
// windows doesn't have roundf
inline float roundf(float x) { return (x-floor(x))>0.5 ? ceil(x) : floor(x); }
#endif

static void drawClip(SkCanvas* canvas, const SkAAClip& clip) {
    SkMask mask;
    SkBitmap bm;
    
    clip.copyToMask(&mask);
    bm.setConfig(SkBitmap::kA8_Config, mask.fBounds.width(),
                 mask.fBounds.height(), mask.fRowBytes);
    bm.setPixels(mask.fImage);
    
    SkPaint paint;
    canvas->drawBitmap(bm, mask.fBounds.fLeft, mask.fBounds.fTop, &paint);
}

static void paint_rgn(SkCanvas* canvas, const SkAAClip& clip,
                      const SkPaint& paint) {
    SkMask mask;
    SkBitmap bm;
    
    clip.copyToMask(&mask);
    bm.setConfig(SkBitmap::kA8_Config, mask.fBounds.width(),
                 mask.fBounds.height(), mask.fRowBytes);
    bm.setPixels(mask.fImage);
    
    canvas->drawBitmap(bm, mask.fBounds.fLeft, mask.fBounds.fTop, &paint);
}

class AAClipView2 : public SampleView {
public:
	AAClipView2() {
        fBase.set(100, 100, 150, 150);
        fRect = fBase;
        fRect.inset(5, 5);
        fRect.offset(25, 25);
        this->setBGColor(0xFFDDDDDD);
    }

    void build_rgn(SkAAClip* clip, SkRegion::Op op) {
        clip->setRect(fBase);
#if 0
        SkIRect r = fBase;
        r.offset(75, 20);
        rgn->op(r, SkRegion::kUnion_Op);
#endif

        SkRect r;
        r.set(fRect);
        SkPath path;
        path.addOval(r);
        SkAAClip clip2;
        clip2.setPath(path);
        // hack
        op = SkRegion::kIntersect_Op;
        clip->op(clip2, op);
    }


protected:
    // overrides from SkEventSink
    virtual bool onQuery(SkEvent* evt) {
        if (SampleCode::TitleQ(*evt)) {
            SampleCode::TitleR(evt, "AAClips");
            return true;
        }
        return this->INHERITED::onQuery(evt);
    }
    
    void drawOrig(SkCanvas* canvas, bool bg) {
        SkRect      r;
        SkPaint     paint;
        
        paint.setStyle(SkPaint::kStroke_Style);
        if (bg)
            paint.setColor(0xFFBBBBBB);
        
        r.set(fBase);
        canvas->drawRect(r, paint);
        r.set(fRect);
        canvas->drawRect(r, paint);
    }
    
    void drawRgnOped(SkCanvas* canvas, SkRegion::Op op, SkColor color) {
        SkAAClip clip;

        this->build_rgn(&clip, op);
        
        this->drawOrig(canvas, true);

        SkPaint paint;
        paint.setColor((color & ~(0xFF << 24)) | (0x44 << 24));
        paint_rgn(canvas, clip, paint);

        paint.setStyle(SkPaint::kStroke_Style);
        paint.setColor(color);
        paint_rgn(canvas, clip, paint);
    }
    
    virtual void onDrawContent(SkCanvas* canvas) {

        static const struct {
            SkColor         fColor;
            const char*     fName;
            SkRegion::Op    fOp;
        } gOps[] = {
            { SK_ColorBLACK,    "Difference",   SkRegion::kDifference_Op    },
            { SK_ColorRED,      "Intersect",    SkRegion::kIntersect_Op     },
            { 0xFF008800,       "Union",        SkRegion::kUnion_Op         },
            { SK_ColorBLUE,     "XOR",          SkRegion::kXOR_Op           }
        };

        SkPaint textPaint;
        textPaint.setAntiAlias(true);
        textPaint.setTextSize(SK_Scalar1*24);

        this->drawOrig(canvas, false);
        canvas->save();
            canvas->translate(SkIntToScalar(200), 0);
            this->drawRgnOped(canvas, SkRegion::kUnion_Op, SK_ColorBLACK);
        canvas->restore();
        
        canvas->translate(0, SkIntToScalar(200));

        for (size_t op = 0; op < SK_ARRAY_COUNT(gOps); op++) {
            canvas->drawText(gOps[op].fName, strlen(gOps[op].fName), SkIntToScalar(75), SkIntToScalar(50), textPaint);

            this->drawRgnOped(canvas, gOps[op].fOp, gOps[op].fColor);
            
            canvas->translate(SkIntToScalar(200), 0);
        }
    }
    
    virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y) {
        return fRect.contains(SkScalarRound(x), SkScalarRound(y)) ? new Click(this) : NULL;
    }
    
    virtual bool onClick(Click* click) {
        fRect.offset(click->fICurr.fX - click->fIPrev.fX,
                     click->fICurr.fY - click->fIPrev.fY);
        this->inval(NULL);
        return true;
    }
    
private:
    SkIRect    fBase, fRect;
    
    typedef SampleView INHERITED;
};

//////////////////////////////////////////////////////////////////////////////

static SkView* MyFactory() { return new AAClipView2; }
static SkViewRegister reg(MyFactory);