gm/thinstrokedrects.cpp

/*
 * Copyright 2013 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/SkPaint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypes.h"

#include <array>

namespace skiagm {

// Draw rects with various stroke widths at 1/8 pixel increments
class ThinStrokedRectsGM : public GM {
public:
    ThinStrokedRectsGM() {
        this->setBGColor(0xFF000000);
    }

protected:
    SkString getName() const override { return SkString("thinstrokedrects"); }

    SkISize getISize() override { return SkISize::Make(240, 320); }

    void onDraw(SkCanvas* canvas) override {

        SkPaint paint;
        paint.setColor(SK_ColorWHITE);
        paint.setStyle(SkPaint::kStroke_Style);
        paint.setAntiAlias(true);

        constexpr SkRect rect = { 0, 0, 10, 10 };
        constexpr SkRect rect2 = { 0, 0, 20, 20 };

        constexpr auto gStrokeWidths = std::to_array<SkScalar>({4, 2, 1, 0.5f, 0.25f, 0.125f, 0});

        canvas->translate(5, 5);
        for (int i = 0; i < 8; ++i) {
            canvas->save();
            canvas->translate(i*0.125f, i*30.0f);
            for (size_t j = 0; j < std::size(gStrokeWidths); ++j) {
                paint.setStrokeWidth(gStrokeWidths[j]);
                canvas->drawRect(rect, paint);
                canvas->translate(15, 0);
            }
            canvas->restore();
        }

        // Draw a second time in red with a scale
        paint.setColor(SK_ColorRED);
        canvas->translate(0, 15);
        for (int i = 0; i < 8; ++i) {
            canvas->save();
            canvas->translate(i*0.125f, i*30.0f);
            canvas->scale(0.5f, 0.5f);
            for (size_t j = 0; j < std::size(gStrokeWidths); ++j) {
                paint.setStrokeWidth(2.0f * gStrokeWidths[j]);
                canvas->drawRect(rect2, paint);
                canvas->translate(30, 0);
            }
            canvas->restore();
        }
    }

private:
    using INHERITED = GM;
};

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

DEF_GM(return new ThinStrokedRectsGM;)
}  // namespace skiagm