gm/atlastext.cpp

/*
 * Copyright 2017 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"

#if SK_SUPPORT_ATLAS_TEXT

#include "SkAtlasTextContext.h"
#include "SkAtlasTextFont.h"
#include "SkAtlasTextTarget.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkTypeface.h"
#include "gpu/TestContext.h"
#include "gpu/atlastext/GLTestAtlasTextRenderer.h"
#include "gpu/atlastext/TestAtlasTextRenderer.h"
#include "sk_tool_utils.h"

// GM that draws text using the Atlas Text interface offscreen and then blits that to the canvas.

static SkScalar draw_string(SkAtlasTextTarget* target, const SkString& text, SkScalar x, SkScalar y,
                            uint32_t color, sk_sp<SkTypeface> typeface, float size) {
    auto font = SkAtlasTextFont::Make(std::move(typeface), size);
    target->drawText(text.c_str(), text.size(), x, y, color, *font);
    SkPaint paint;
    paint.setTextSize(size);
    return x + paint.measureText(text.c_str(), text.size());
}

class AtlasTextGM : public skiagm::GM {
public:
    AtlasTextGM() = default;

protected:
    SkString onShortName() override { return SkString("atlastext"); }

    SkISize onISize() override { return SkISize::Make(kSize, kSize); }

    void onOnceBeforeDraw() override {
        fRenderer = sk_gpu_test::MakeGLTestAtlasTextRenderer();
        if (!fRenderer) {
            return;
        }
        fContext = SkAtlasTextContext::Make(fRenderer);
        auto targetHandle = fRenderer->makeTargetHandle(kSize, kSize);
        fTarget = SkAtlasTextTarget::Make(fContext, kSize, kSize, targetHandle);

        fTypefaces[0] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Italic());
        fTypefaces[1] =
                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Italic());
        fTypefaces[2] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Normal());
        fTypefaces[3] =
                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Normal());
        fTypefaces[4] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Bold());
        fTypefaces[5] = sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Bold());
    }

    void onDraw(SkCanvas* canvas) override {
        if (!fRenderer) {
            canvas->clear(SK_ColorRED);
            return;
        }
        auto bmp = this->drawText();
        SkPaint paint;
        paint.setBlendMode(SkBlendMode::kSrc);
        canvas->drawBitmap(bmp, 0, 0);
    }

private:
    SkBitmap drawText() {
        static const int kSizes[] = {8, 13, 18, 23, 30};

        static const SkString kTexts[] = {SkString("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
                                          SkString("abcdefghijklmnopqrstuvwxyz"),
                                          SkString("0123456789"),
                                          SkString("!@#$%^&*()<>[]{}")};
        SkScalar x = 0;
        SkScalar y = 10;

        SkRandom random;
        do {
            for (auto s : kSizes) {
                auto size = 2 * s;
                for (const auto& typeface : fTypefaces) {
                    for (const auto& text : kTexts) {
                        uint32_t color = random.nextU();
                        x = size + draw_string(fTarget.get(), text, x, y, color, typeface, size);
                        x = SkScalarCeilToScalar(x);
                        if (x + 100 > kSize) {
                            x = 0;
                            y += SkScalarCeilToScalar(size + 3);
                            if (y > kSize) {
                                fTarget->flush();
                                return fRenderer->readTargetHandle(fTarget->handle());
                            }
                        }
                    }
                }
            }
        } while (true);
    }

    static constexpr int kSize = 1280;

    sk_sp<SkTypeface> fTypefaces[6];
    sk_sp<sk_gpu_test::TestAtlasTextRenderer> fRenderer;
    std::unique_ptr<SkAtlasTextTarget> fTarget;
    sk_sp<SkAtlasTextContext> fContext;

    typedef GM INHERITED;
};

constexpr int AtlasTextGM::kSize;

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

DEF_GM(return new AtlasTextGM;)

#endif