| /* |
| * Copyright 2013 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkMipMap_DEFINED |
| #define SkMipMap_DEFINED |
| |
| #include "include/core/SkPixmap.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkSize.h" |
| #include "include/private/SkImageInfoPriv.h" |
| #include "src/core/SkCachedData.h" |
| #include "src/shaders/SkShaderBase.h" |
| |
| class SkBitmap; |
| class SkDiscardableMemory; |
| |
| typedef SkDiscardableMemory* (*SkDiscardableFactoryProc)(size_t bytes); |
| |
| /* |
| * SkMipMap will generate mipmap levels when given a base mipmap level image. |
| * |
| * Any function which deals with mipmap levels indices will start with index 0 |
| * being the first mipmap level which was generated. Said another way, it does |
| * not include the base level in its range. |
| */ |
| class SkMipMap : public SkCachedData { |
| public: |
| static SkMipMap* Build(const SkPixmap& src, SkDiscardableFactoryProc); |
| static SkMipMap* Build(const SkBitmap& src, SkDiscardableFactoryProc); |
| |
| // Determines how many levels a SkMipMap will have without creating that mipmap. |
| // This does not include the base mipmap level that the user provided when |
| // creating the SkMipMap. |
| static int ComputeLevelCount(int baseWidth, int baseHeight); |
| |
| // Determines the size of a given mipmap level. |
| // |level| is an index into the generated mipmap levels. It does not include |
| // the base level. So index 0 represents mipmap level 1. |
| static SkISize ComputeLevelSize(int baseWidth, int baseHeight, int level); |
| |
| // We use a block of (possibly discardable) memory to hold an array of Level structs, followed |
| // by the pixel data for each level. On 32-bit platforms, Level would naturally be 4 byte |
| // aligned, so the pixel data could end up with 4 byte alignment. If the pixel data is F16, |
| // it must be 8 byte aligned. To ensure this, keep the Level struct 8 byte aligned as well. |
| struct alignas(8) Level { |
| SkPixmap fPixmap; |
| SkSize fScale; // < 1.0 |
| }; |
| |
| bool extractLevel(const SkSize& scale, Level*) const; |
| |
| // countLevels returns the number of mipmap levels generated (which does not |
| // include the base mipmap level). |
| int countLevels() const; |
| |
| // |index| is an index into the generated mipmap levels. It does not include |
| // the base level. So index 0 represents mipmap level 1. |
| bool getLevel(int index, Level*) const; |
| |
| protected: |
| void onDataChange(void* oldData, void* newData) override { |
| fLevels = (Level*)newData; // could be nullptr |
| } |
| |
| private: |
| sk_sp<SkColorSpace> fCS; |
| Level* fLevels; // managed by the baseclass, may be null due to onDataChanged. |
| int fCount; |
| |
| SkMipMap(void* malloc, size_t size) : INHERITED(malloc, size) {} |
| SkMipMap(size_t size, SkDiscardableMemory* dm) : INHERITED(size, dm) {} |
| |
| static size_t AllocLevelsSize(int levelCount, size_t pixelSize); |
| |
| typedef SkCachedData INHERITED; |
| }; |
| |
| #endif |