/* * Copyright 2019 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkScalingCodec_DEFINED #define SkScalingCodec_DEFINED #include "include/codec/SkCodec.h" // Helper class for an SkCodec that supports arbitrary downscaling. class SkScalingCodec : public SkCodec { protected: SkScalingCodec(SkEncodedInfo&& info, XformFormat srcFormat, std::unique_ptr stream, SkEncodedOrigin origin = kTopLeft_SkEncodedOrigin) : INHERITED(std::move(info), srcFormat, std::move(stream), origin) {} SkISize onGetScaledDimensions(float desiredScale) const override { SkISize dim = this->dimensions(); // SkCodec treats zero dimensional images as errors, so the minimum size // that we will recommend is 1x1. dim.fWidth = SkTMax(1, SkScalarRoundToInt(desiredScale * dim.fWidth)); dim.fHeight = SkTMax(1, SkScalarRoundToInt(desiredScale * dim.fHeight)); return dim; } bool onDimensionsSupported(const SkISize& requested) override { SkISize dim = this->dimensions(); int w = requested.width(); int h = requested.height(); return 1 <= w && w <= dim.width() && 1 <= h && h <= dim.height(); } private: typedef SkCodec INHERITED; }; #endif // SkScalingCodec_DEFINED