docs/examples/Surface_MakeRasterDirectReleaseProc.cpp

// Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "tools/fiddle/examples.h"
REG_FIDDLE(Surface_WrapPixels_WithReleaseProc, 256, 256, true, 0) {
    static void release_direct_surface_storage(void* pixels, void* context) {
        if (pixels == context) {
            SkDebugf("expected release context\n");
        }
        sk_free(pixels);
    }

    void draw(SkCanvas*) {
        SkImageInfo info = SkImageInfo::MakeN32Premul(3, 3);
        const size_t rowBytes = info.minRowBytes();
        void* pixels = sk_malloc_throw(info.computeByteSize(rowBytes));
        sk_sp<SkSurface> surface(SkSurfaces::WrapPixels(
                info, pixels, rowBytes, release_direct_surface_storage, pixels));
        SkCanvas* canvas = surface->getCanvas();
        canvas->clear(SK_ColorWHITE);
        SkPMColor* colorPtr = (SkPMColor*)pixels;
        SkPMColor pmWhite = colorPtr[0];
        SkPaint paint;
        canvas->drawPoint(1, 1, paint);
        for (int y = 0; y < info.height(); ++y) {
            for (int x = 0; x < info.width(); ++x) {
                SkDebugf("%c", *colorPtr++ == pmWhite ? '-' : 'x');
            }
            SkDebugf("\n");
        }
    }
}  // END FIDDLE