1 | /* |
---|---|
2 | * Copyright 2019 Google Inc. |
3 | * |
4 | * Use of this source code is governed by a BSD-style license that can be |
5 | * found in the LICENSE file. |
6 | */ |
7 | #ifndef SkScalingCodec_DEFINED |
8 | #define SkScalingCodec_DEFINED |
9 | |
10 | #include "include/codec/SkCodec.h" |
11 | |
12 | // Helper class for an SkCodec that supports arbitrary downscaling. |
13 | class SkScalingCodec : public SkCodec { |
14 | protected: |
15 | SkScalingCodec(SkEncodedInfo&& info, XformFormat srcFormat, std::unique_ptr<SkStream> stream, |
16 | SkEncodedOrigin origin = kTopLeft_SkEncodedOrigin) |
17 | : INHERITED(std::move(info), srcFormat, std::move(stream), origin) {} |
18 | |
19 | SkISize onGetScaledDimensions(float desiredScale) const override { |
20 | SkISize dim = this->dimensions(); |
21 | // SkCodec treats zero dimensional images as errors, so the minimum size |
22 | // that we will recommend is 1x1. |
23 | dim.fWidth = std::max(1, SkScalarRoundToInt(desiredScale * dim.fWidth)); |
24 | dim.fHeight = std::max(1, SkScalarRoundToInt(desiredScale * dim.fHeight)); |
25 | return dim; |
26 | } |
27 | |
28 | bool onDimensionsSupported(const SkISize& requested) override { |
29 | SkISize dim = this->dimensions(); |
30 | int w = requested.width(); |
31 | int h = requested.height(); |
32 | return 1 <= w && w <= dim.width() && 1 <= h && h <= dim.height(); |
33 | } |
34 | |
35 | private: |
36 | typedef SkCodec INHERITED; |
37 | }; |
38 | |
39 | #endif // SkScalingCodec_DEFINED |
40 |