skia2/gm/cubicpaths.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/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkFont.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPath.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/utils/SkRandom.h"
#include "tools/ToolUtils.h"

// https://bug.skia.org/1316 shows that this cubic, when slightly clipped, creates big
// (incorrect) changes to its control points.
class ClippedCubicGM : public skiagm::GM {
    SkString onShortName() override { return SkString("clippedcubic"); }

    SkISize onISize() override { return {1240, 390}; }

    void onDraw(SkCanvas* canvas) override {
        SkPath path;
        path.moveTo(0, 0);
        path.cubicTo(140, 150, 40, 10, 170, 150);

        SkPaint paint;
        SkRect bounds = path.getBounds();

        for (SkScalar dy = -1; dy <= 1; dy += 1) {
            canvas->save();
            for (SkScalar dx = -1; dx <= 1; dx += 1) {
                canvas->save();
                canvas->clipRect(bounds);
                canvas->translate(dx, dy);
                canvas->drawPath(path, paint);
                canvas->restore();

                canvas->translate(bounds.width(), 0);
            }
            canvas->restore();
            canvas->translate(0, bounds.height());
        }
    }
};


class ClippedCubic2GM : public skiagm::GM {
    SkString onShortName() override { return SkString("clippedcubic2"); }

    SkISize onISize() override { return {1240, 390}; }

    void onDraw(SkCanvas* canvas) override {
        canvas->save();
        canvas->translate(-2, 120);
        drawOne(canvas, fPath, SkRect::MakeLTRB(0, 0, 80, 150));
        canvas->translate(0, 170);
        drawOne(canvas, fPath, SkRect::MakeLTRB(0, 0, 80, 100));
        canvas->translate(0, 170);
        drawOne(canvas, fPath, SkRect::MakeLTRB(0, 0, 30, 150));
        canvas->translate(0, 170);
        drawOne(canvas, fPath, SkRect::MakeLTRB(0, 0, 10, 150));
        canvas->restore();
        canvas->save();
        canvas->translate(20, -2);
        drawOne(canvas, fFlipped, SkRect::MakeLTRB(0, 0, 150, 80));
        canvas->translate(170, 0);
        drawOne(canvas, fFlipped, SkRect::MakeLTRB(0, 0, 100, 80));
        canvas->translate(170, 0);
        drawOne(canvas, fFlipped, SkRect::MakeLTRB(0, 0, 150, 30));
        canvas->translate(170, 0);
        drawOne(canvas, fFlipped, SkRect::MakeLTRB(0, 0, 150, 10));
        canvas->restore();
    }

    void drawOne(SkCanvas* canvas, const SkPath& path, const SkRect& clip) {
        SkPaint framePaint, fillPaint;
        framePaint.setStyle(SkPaint::kStroke_Style);
        canvas->drawRect(clip, framePaint);
        canvas->drawPath(path, framePaint);
        canvas->save();
        canvas->clipRect(clip);
        canvas->drawPath(path, fillPaint);
        canvas->restore();
    }

    void onOnceBeforeDraw() override {
        fPath.moveTo(69.7030518991886f, 0);
        fPath.cubicTo( 69.7030518991886f, 21.831149999999997f,
                58.08369508178456f, 43.66448333333333f, 34.8449814469765f, 65.5f);
        fPath.cubicTo( 11.608591683531916f, 87.33115f, -0.010765133872116195f, 109.16448333333332f,
                -0.013089005235602302f, 131);
        fPath.close();
        fFlipped = fPath;
        SkMatrix matrix;
        matrix.reset();
        matrix.setScaleX(0);
        matrix.setScaleY(0);
        matrix.setSkewX(1);
        matrix.setSkewY(1);
        fFlipped.transform(matrix);
    }

    SkPath fPath;
    SkPath fFlipped;
private:
    using INHERITED = skiagm::GM;
};


class CubicPathGM : public skiagm::GM {
    SkString onShortName() override { return SkString("cubicpath"); }

    SkISize onISize() override { return {1240, 390}; }

    void drawPath(SkPath& path,SkCanvas* canvas,SkColor color,
                  const SkRect& clip,SkPaint::Cap cap, SkPaint::Join join,
                  SkPaint::Style style, SkPathFillType fill,
                  SkScalar strokeWidth) {
        path.setFillType(fill);
        SkPaint paint;
        paint.setStrokeCap(cap);
        paint.setStrokeWidth(strokeWidth);
        paint.setStrokeJoin(join);
        paint.setColor(color);
        paint.setStyle(style);
        canvas->save();
        canvas->clipRect(clip);
        canvas->drawPath(path, paint);
        canvas->restore();
    }

    void onDraw(SkCanvas* canvas) override {
        struct FillAndName {
            SkPathFillType fFill;
            const char*      fName;
        };
        constexpr FillAndName gFills[] = {
            {SkPathFillType::kWinding, "Winding"},
            {SkPathFillType::kEvenOdd, "Even / Odd"},
            {SkPathFillType::kInverseWinding, "Inverse Winding"},
            {SkPathFillType::kInverseEvenOdd, "Inverse Even / Odd"},
        };
        struct StyleAndName {
            SkPaint::Style fStyle;
            const char*    fName;
        };
        constexpr StyleAndName gStyles[] = {
            {SkPaint::kFill_Style, "Fill"},
            {SkPaint::kStroke_Style, "Stroke"},
            {SkPaint::kStrokeAndFill_Style, "Stroke And Fill"},
        };
        struct CapAndName {
            SkPaint::Cap  fCap;
            SkPaint::Join fJoin;
            const char*   fName;
        };
        constexpr CapAndName gCaps[] = {
            {SkPaint::kButt_Cap, SkPaint::kBevel_Join, "Butt"},
            {SkPaint::kRound_Cap, SkPaint::kRound_Join, "Round"},
            {SkPaint::kSquare_Cap, SkPaint::kBevel_Join, "Square"}
        };
        struct PathAndName {
            SkPath      fPath;
            const char* fName;
        };
        PathAndName path;
        path.fPath.moveTo(25*SK_Scalar1, 10*SK_Scalar1);
        path.fPath.cubicTo(40*SK_Scalar1, 20*SK_Scalar1,
                           60*SK_Scalar1, 20*SK_Scalar1,
                           75*SK_Scalar1, 10*SK_Scalar1);
        path.fName = "moveTo-cubic";

        SkPaint titlePaint;
        titlePaint.setColor(SK_ColorBLACK);
        titlePaint.setAntiAlias(true);
        SkFont     font(ToolUtils::create_portable_typeface(), 15);
        const char title[] = "Cubic Drawn Into Rectangle Clips With "
                             "Indicated Style, Fill and Linecaps, with stroke width 10";
        canvas->drawString(title, 20, 20, font, 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 cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
            if (0 < cap) {
                canvas->translate((rect.width() + 40 * SK_Scalar1) * SK_ARRAY_COUNT(gStyles), 0);
            }
            canvas->save();
            for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
                if (0 < fill) {
                    canvas->translate(0, rect.height() + 40 * SK_Scalar1);
                }
                canvas->save();
                for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
                    if (0 < style) {
                        canvas->translate(rect.width() + 40 * SK_Scalar1, 0);
                    }

                    SkColor color = 0xff007000;
                    this->drawPath(path.fPath, canvas, color, rect,
                                    gCaps[cap].fCap, gCaps[cap].fJoin, 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);
                    font.setSize(10);
                    canvas->drawString(gStyles[style].fName, 0, rect.height() + 12, font, labelPaint);
                    canvas->drawString(gFills[fill].fName, 0, rect.height() + 24, font, labelPaint);
                    canvas->drawString(gCaps[cap].fName, 0, rect.height() + 36, font, labelPaint);
                }
                canvas->restore();
            }
            canvas->restore();
        }
        canvas->restore();
        canvas->restore();
    }
};

class CubicClosePathGM : public skiagm::GM {
    SkString onShortName() override { return SkString("cubicclosepath"); }

    SkISize onISize() override { return {1240, 390}; }

    void drawPath(SkPath& path,SkCanvas* canvas,SkColor color,
                  const SkRect& clip,SkPaint::Cap cap, SkPaint::Join join,
                  SkPaint::Style style, SkPathFillType fill,
                  SkScalar strokeWidth) {
        path.setFillType(fill);
        SkPaint paint;
        paint.setStrokeCap(cap);
        paint.setStrokeWidth(strokeWidth);
        paint.setStrokeJoin(join);
        paint.setColor(color);
        paint.setStyle(style);
        canvas->save();
        canvas->clipRect(clip);
        canvas->drawPath(path, paint);
        canvas->restore();
    }

    void onDraw(SkCanvas* canvas) override {
        struct FillAndName {
            SkPathFillType fFill;
            const char*      fName;
        };
        constexpr FillAndName gFills[] = {
            {SkPathFillType::kWinding, "Winding"},
            {SkPathFillType::kEvenOdd, "Even / Odd"},
            {SkPathFillType::kInverseWinding, "Inverse Winding"},
            {SkPathFillType::kInverseEvenOdd, "Inverse Even / Odd"},
        };
        struct StyleAndName {
            SkPaint::Style fStyle;
            const char*    fName;
        };
        constexpr StyleAndName gStyles[] = {
            {SkPaint::kFill_Style, "Fill"},
            {SkPaint::kStroke_Style, "Stroke"},
            {SkPaint::kStrokeAndFill_Style, "Stroke And Fill"},
        };
        struct CapAndName {
            SkPaint::Cap  fCap;
            SkPaint::Join fJoin;
            const char*   fName;
        };
        constexpr CapAndName gCaps[] = {
            {SkPaint::kButt_Cap, SkPaint::kBevel_Join, "Butt"},
            {SkPaint::kRound_Cap, SkPaint::kRound_Join, "Round"},
            {SkPaint::kSquare_Cap, SkPaint::kBevel_Join, "Square"}
        };
        struct PathAndName {
            SkPath      fPath;
            const char* fName;
        };
        PathAndName path;
        path.fPath.moveTo(25*SK_Scalar1, 10*SK_Scalar1);
        path.fPath.cubicTo(40*SK_Scalar1, 20*SK_Scalar1,
                           60*SK_Scalar1, 20*SK_Scalar1,
                           75*SK_Scalar1, 10*SK_Scalar1);
        path.fPath.close();
        path.fName = "moveTo-cubic-close";

        SkPaint titlePaint;
        titlePaint.setColor(SK_ColorBLACK);
        titlePaint.setAntiAlias(true);
        SkFont     font(ToolUtils::create_portable_typeface(), 15);
        const char title[] = "Cubic Closed Drawn Into Rectangle Clips With "
                             "Indicated Style, Fill and Linecaps, with stroke width 10";
        canvas->drawString(title, 20, 20, font, 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 cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
            if (0 < cap) {
                canvas->translate((rect.width() + 40 * SK_Scalar1) * SK_ARRAY_COUNT(gStyles), 0);
            }
            canvas->save();
            for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
                if (0 < fill) {
                    canvas->translate(0, rect.height() + 40 * SK_Scalar1);
                }
                canvas->save();
                for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
                    if (0 < style) {
                        canvas->translate(rect.width() + 40 * SK_Scalar1, 0);
                    }

                    SkColor color = 0xff007000;
                    this->drawPath(path.fPath, canvas, color, rect,
                                    gCaps[cap].fCap, gCaps[cap].fJoin, 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);
                    font.setSize(10);
                    canvas->drawString(gStyles[style].fName, 0, rect.height() + 12, font, labelPaint);
                    canvas->drawString(gFills[fill].fName, 0, rect.height() + 24, font, labelPaint);
                    canvas->drawString(gCaps[cap].fName, 0, rect.height() + 36, font, labelPaint);
                }
                canvas->restore();
            }
            canvas->restore();
        }
        canvas->restore();
        canvas->restore();
    }
};

DEF_SIMPLE_GM(bug5099, canvas, 50, 50) {
    SkPaint p;
    p.setColor(SK_ColorRED);
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(10);

    SkPath path;
    path.moveTo(6, 27);
    path.cubicTo(31.5f, 1.5f, 3.5f, 4.5f, 29, 29);
    canvas->drawPath(path, p);
}

DEF_SIMPLE_GM(bug6083, canvas, 100, 50) {
    SkPaint p;
    p.setColor(SK_ColorRED);
    p.setAntiAlias(true);
    p.setStyle(SkPaint::kStroke_Style);
    p.setStrokeWidth(15);
    canvas->translate(-500, -130);
    SkPath path;
    path.moveTo(500.988f, 155.200f);
    path.lineTo(526.109f, 155.200f);
    SkPoint p1 = { 526.109f, 155.200f };
    SkPoint p2 = { 525.968f, 212.968f };
    SkPoint p3 = { 526.109f, 241.840f };
    path.cubicTo(p1, p2, p3);
    canvas->drawPath(path, p);
    canvas->translate(50, 0);
    path.reset();
    p2.set(525.968f, 213.172f);
    path.moveTo(500.988f, 155.200f);
    path.lineTo(526.109f, 155.200f);
    path.cubicTo(p1, p2, p3);
    canvas->drawPath(path, p);
}

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

DEF_GM( return new CubicPathGM; )
DEF_GM( return new CubicClosePathGM; )
DEF_GM( return new ClippedCubicGM; )
DEF_GM( return new ClippedCubic2GM; )