gm/linepaths.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 "gm.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkRandom.h"

namespace skiagm {

class LinePathsGM : public GM {
public:
    LinePathsGM() {}

protected:
    SkString onShortName() {
        return SkString("linepaths");
    }
        
    SkISize onISize() { return make_isize(1800, 1110); }
    
    void drawPath(SkPath& path,SkCanvas* canvas,SkColor color,
                  const SkRect& clip,SkPaint::Cap cap,
                  SkPaint::Style style, SkPath::FillType fill,
                  SkScalar strokeWidth) {
        path.setFillType(fill);
        SkPaint paint;
        paint.setStrokeCap(cap);
        paint.setStrokeWidth(strokeWidth);
        paint.setColor(color);
        paint.setStyle(style);
        canvas->save();
        canvas->clipRect(clip);
        canvas->drawPath(path, paint);
        canvas->restore();
    }
    
    virtual void onDraw(SkCanvas* canvas) {
        struct FillAndName {
            SkPath::FillType fFill;
            const char*      fName;
        };
        static const FillAndName gFills[] = {
            {SkPath::kWinding_FillType, "Winding"},
            {SkPath::kEvenOdd_FillType, "Even / Odd"},
            {SkPath::kInverseWinding_FillType, "Inverse Winding"},
            {SkPath::kInverseEvenOdd_FillType, "Inverse Even / Odd"},
        };
        struct StyleAndName {
            SkPaint::Style fStyle;
            const char*    fName;
        };
        static const StyleAndName gStyles[] = {
            {SkPaint::kFill_Style, "Fill"},
            {SkPaint::kStroke_Style, "Stroke"},
            {SkPaint::kStrokeAndFill_Style, "Stroke And Fill"},
        };
        struct CapAndName {
            SkPaint::Cap fCap;
            const char*  fName;
        };
        static const CapAndName gCaps[] = {
            {SkPaint::kButt_Cap, "Butt"},
            {SkPaint::kRound_Cap, "Round"},
            {SkPaint::kSquare_Cap, "Square"},
        };
        struct PathAndName {
            SkPath      fPath;
            const char* fName;
        };
        PathAndName gPaths[4];
        gPaths[0].fPath.moveTo(50*SK_Scalar1, 15*SK_Scalar1);
        gPaths[0].fPath.lineTo(50*SK_Scalar1, 15*SK_Scalar1);
        gPaths[0].fName = "moveTo-zeroline";
        gPaths[1].fPath.moveTo(50*SK_Scalar1, 15*SK_Scalar1);
        gPaths[1].fPath.lineTo(50*SK_Scalar1, 15*SK_Scalar1);
        gPaths[1].fPath.close();
        gPaths[1].fName = "moveTo-zeroline-close";
        gPaths[2].fPath.moveTo(30*SK_Scalar1, 15*SK_Scalar1);
        gPaths[2].fPath.lineTo(70*SK_Scalar1, 15*SK_Scalar1);
        gPaths[2].fName = "moveTo-line";
        gPaths[3].fPath.moveTo(30*SK_Scalar1, 15*SK_Scalar1);
        gPaths[3].fPath.lineTo(70*SK_Scalar1, 15*SK_Scalar1);
        gPaths[3].fPath.close();
        gPaths[3].fName = "moveTo-line-close";

        SkPaint titlePaint;
        titlePaint.setColor(SK_ColorBLACK);
        titlePaint.setAntiAlias(true);
        titlePaint.setLCDRenderText(true);
        titlePaint.setTextSize(15 * SK_Scalar1);
        const char title[] = "Line Paths Drawn Into Rectangle Clips With "
                             "Indicated Style, Fill and Linecaps, "
                             "with random stroke widths";
        canvas->drawText(title, strlen(title),
                            20 * SK_Scalar1,
                            20 * SK_Scalar1,
                            titlePaint);

        SkRandom rand;
        SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
        canvas->save();
        canvas->translate(10 * SK_Scalar1, 30 * SK_Scalar1);
        canvas->save();
        for (size_t path = 0; path < SK_ARRAY_COUNT(gPaths); ++path) {
            if (0 < path) {
                canvas->translate(0, (rect.height() + 60 * SK_Scalar1) * 3);
            }
            canvas->save();
            for (size_t cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
                if (0 < cap) {
                    canvas->translate((rect.width() + 40 * SK_Scalar1) * 4, 0);
                }
                canvas->save();
                for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
                    if (0 < style) {
                        canvas->translate(0, rect.height() + 60 * SK_Scalar1);
                    }
                    canvas->save();
                    for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
                        if (0 < fill) {
                            canvas->translate(rect.width() + 40 * SK_Scalar1, 0);
                        }
        
                        SkColor color = 0xff007000;
                        this->drawPath(gPaths[path].fPath, canvas, color, rect,
                                       gCaps[cap].fCap, gStyles[style].fStyle,
                                       gFills[fill].fFill, SK_Scalar1*10);
        
                        SkPaint rectPaint;
                        rectPaint.setColor(SK_ColorBLACK);
                        rectPaint.setStyle(SkPaint::kStroke_Style);
                        rectPaint.setStrokeWidth(-1);
                        rectPaint.setAntiAlias(true);
                        canvas->drawRect(rect, rectPaint);
        
                        SkPaint labelPaint;
                        labelPaint.setColor(color);
                        labelPaint.setAntiAlias(true);
                        labelPaint.setLCDRenderText(true);
                        labelPaint.setTextSize(10 * SK_Scalar1);
                        canvas->drawText(gStyles[style].fName,
                                         strlen(gStyles[style].fName),
                                         0, rect.height() + 12 * SK_Scalar1,
                                         labelPaint);
                        canvas->drawText(gFills[fill].fName,
                                         strlen(gFills[fill].fName),
                                         0, rect.height() + 24 * SK_Scalar1,
                                         labelPaint);
                        canvas->drawText(gCaps[cap].fName,
                                         strlen(gCaps[cap].fName),
                                         0, rect.height() + 36 * SK_Scalar1,
                                         labelPaint);
                        canvas->drawText(gPaths[path].fName,
                                         strlen(gPaths[path].fName),
                                         0, rect.height() + 48 * SK_Scalar1,
                                         labelPaint);
                    }
                    canvas->restore();
                }
                canvas->restore();
            }
            canvas->restore();
        }
        canvas->restore();
        canvas->restore();
    }
    
private:
    typedef GM INHERITED;
};

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

static GM* MyFactory(void*) { return new LinePathsGM; }
static GMRegistry reg(MyFactory);

}