skia2/docs/examples/Pixmap_005.cpp
Hal Canary 83c2f70b51 Compile all fiddle examples locally
Motivation: it would be a good idea if the API documentation examples
were checked into the skia repository, so we could make sure they
compile as part of the commit queue.

Fiddle would make/update a named fiddle each time it gets a new
commit of Skia, extracted from the code in the examples/ directory.
The docs would point at those named fiddles.  Named fiddles have urls
in the form:

    https://fiddle.skia.org/c/@Bitmap_000

Then we would stick a link to the example into the header documentation
like this:

    /** Allocates the pixel memory for the bitmap, given its dimensions
        and SkColorType. Returns true on success, where success means
        either setPixels() or setPixelRef() was called.

        @param bitmap  SkBitmap containing SkImageInfo as input, and
                       SkPixelRef as output
        @return        true if SkPixelRef was allocated

        @example       https://fiddle.skia.org/c/@Bitmap_000
    */
    bool allocPixelRef(SkBitmap* bitmap) override;

There are still around 200 disabled examples that need to be fixed
(these result from API changes since the author left).

Change-Id: I14a31348a9ccaaa31f65424b91e3a3533d2583a7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/198824
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
2019-03-15 15:19:18 +00:00

20 lines
788 B
C++

// 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 "fiddle/examples.h"
// HASH=febdbfac6cf4cde69837643be2e1f6dd
REG_FIDDLE(Pixmap_005, 256, 128, false, 3) {
void draw(SkCanvas* canvas) {
std::vector<int32_t> pixels;
pixels.resize(image->height() * image->width() * 4);
SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType,
image->alphaType()), (const void*) &pixels.front(), image->width() * 4);
image->readPixels(pixmap, 0, 0);
SkPixmap inset;
if (pixmap.extractSubset(&inset, {128, 128, 512, 512})) {
SkBitmap bitmap;
bitmap.installPixels(inset);
canvas->drawBitmap(bitmap, 0, 0);
}
}
} // END FIDDLE