gm/emptypath.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/SkPaint.h"
#include "include/core/SkPathBuilder.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 "src/core/SkRandom.h"
#include "tools/ToolUtils.h"
#include "tools/fonts/FontToolUtils.h"

#include <array>

namespace skiagm {

class EmptyPathGM : public GM {
    SkString getName() const override { return SkString("emptypath"); }

    SkISize getISize() override { return {600, 280}; }

    void drawEmpty(SkCanvas* canvas,
                    SkColor color,
                    const SkRect& clip,
                    SkPaint::Style style,
                    SkPathFillType fill) {
        SkPath path;
        path.setFillType(fill);
        SkPaint paint;
        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;
        };
        static constexpr auto gFills = std::to_array<FillAndName>({
                FillAndName{       SkPathFillType::kWinding,            "Winding"},
                FillAndName{       SkPathFillType::kEvenOdd,         "Even / Odd"},
                FillAndName{SkPathFillType::kInverseWinding,    "Inverse Winding"},
                FillAndName{SkPathFillType::kInverseEvenOdd, "Inverse Even / Odd"},
        });
        struct StyleAndName {
            SkPaint::Style fStyle;
            const char*    fName;
        };
        static constexpr auto gStyles = std::to_array<StyleAndName>({
                StyleAndName{         SkPaint::kFill_Style,            "Fill"},
                StyleAndName{       SkPaint::kStroke_Style,          "Stroke"},
                StyleAndName{SkPaint::kStrokeAndFill_Style, "Stroke And Fill"},
        });

        SkFont     font(ToolUtils::DefaultPortableTypeface(), 15);
        const char title[] = "Empty Paths Drawn Into Rectangle Clips With "
                             "Indicated Style and Fill";
        canvas->drawString(title, 20.0f, 20.0f, font, SkPaint());

        SkRandom rand;
        SkRect rect = SkRect::MakeWH(100*SK_Scalar1, 30*SK_Scalar1);
        int i = 0;
        canvas->save();
        canvas->translate(10 * SK_Scalar1, 0);
        canvas->save();
        for (size_t style = 0; style < std::size(gStyles); ++style) {
            for (size_t fill = 0; fill < std::size(gFills); ++fill) {
                if (0 == i % 4) {
                    canvas->restore();
                    canvas->translate(0, rect.height() + 40 * SK_Scalar1);
                    canvas->save();
                } else {
                    canvas->translate(rect.width() + 40 * SK_Scalar1, 0);
                }
                ++i;


                SkColor color = rand.nextU();
                color = 0xff000000 | color; // force solid
                color         = ToolUtils::color_to_565(color);
                this->drawEmpty(canvas, color, rect,
                                gStyles[style].fStyle, gFills[fill].fFill);

                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);
                SkFont labelFont(ToolUtils::DefaultPortableTypeface(), 12);
                canvas->drawString(gStyles[style].fName, 0, rect.height() + 15.0f,
                                   labelFont, labelPaint);
                canvas->drawString(gFills[fill].fName, 0, rect.height() + 28.0f,
                                   labelFont, labelPaint);
            }
        }
        canvas->restore();
        canvas->restore();
    }
};
DEF_GM( return new EmptyPathGM; )

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

static constexpr SkPoint kPts[] = {
    {40, 40},
    {80, 40},
    {120, 40},
};

static SkPath make_path_move() {
    SkPathBuilder builder;
    for (SkPoint p : kPts) {
        builder.moveTo(p);
    }
    return builder.detach();
}

static SkPath make_path_move_close() {
    SkPathBuilder builder;
    for (SkPoint p : kPts) {
        builder.moveTo(p).close();
    }
    return builder.detach();
}

static SkPath make_path_move_line() {
    SkPathBuilder builder;
    for (SkPoint p : kPts) {
        builder.moveTo(p).lineTo(p);
    }
    return builder.detach();
}

static SkPath make_path_move_mix() {
    return SkPathBuilder().moveTo(kPts[0])
                          .moveTo(kPts[1]).close()
                          .moveTo(kPts[2]).lineTo(kPts[2])
                          .detach();
}

class EmptyStrokeGM : public GM {
    SkString getName() const override { return SkString("emptystroke"); }

    SkISize getISize() override { return {200, 240}; }

    void onDraw(SkCanvas* canvas) override {
        static constexpr SkPath (*kProcs[])() = {
            make_path_move,             // expect red red red
            make_path_move_close,       // expect black black black
            make_path_move_line,        // expect black black black
            make_path_move_mix,         // expect red black black,
        };

        SkPaint strokePaint;
        strokePaint.setStyle(SkPaint::kStroke_Style);
        strokePaint.setStrokeWidth(21);
        strokePaint.setStrokeCap(SkPaint::kSquare_Cap);

        SkPaint dotPaint;
        dotPaint.setColor(SK_ColorRED);
        strokePaint.setStyle(SkPaint::kStroke_Style);
        dotPaint.setStrokeWidth(7);

        for (auto proc : kProcs) {
            canvas->drawPoints(SkCanvas::kPoints_PointMode, kPts, dotPaint);
            canvas->drawPath(proc(), strokePaint);
            canvas->translate(0, 40);
        }
    }
};
DEF_GM( return new EmptyStrokeGM; )

}  // namespace skiagm