Line data    Source code

       1             : /*
       2             :  * Copyright 2013 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             : 
       8             : #ifndef SkMipMap_DEFINED
       9             : #define SkMipMap_DEFINED
      10             : 
      11             : #include "SkCachedData.h"
      12             : #include "SkPixmap.h"
      13             : #include "SkScalar.h"
      14             : #include "SkSize.h"
      15             : #include "SkShader.h"
      16             : 
      17             : class SkBitmap;
      18             : class SkDiscardableMemory;
      19             : 
      20             : typedef SkDiscardableMemory* (*SkDiscardableFactoryProc)(size_t bytes);
      21             : 
      22             : /*
      23             :  * SkMipMap will generate mipmap levels when given a base mipmap level image.
      24             :  *
      25             :  * Any function which deals with mipmap levels indices will start with index 0
      26             :  * being the first mipmap level which was generated. Said another way, it does
      27             :  * not include the base level in its range.
      28             :  */
      29           0 : class SkMipMap : public SkCachedData {
      30             : public:
      31             :     static SkMipMap* Build(const SkPixmap& src, SkDestinationSurfaceColorMode,
      32             :                            SkDiscardableFactoryProc);
      33             :     static SkMipMap* Build(const SkBitmap& src, SkDestinationSurfaceColorMode,
      34             :                            SkDiscardableFactoryProc);
      35             : 
      36             :     static SkDestinationSurfaceColorMode DeduceColorMode(const SkShader::ContextRec& rec) {
      37             :         return (SkShader::ContextRec::kPMColor_DstType == rec.fPreferredDstType)
      38             :             ? SkDestinationSurfaceColorMode::kLegacy
      39             :             : SkDestinationSurfaceColorMode::kGammaAndColorSpaceAware;
      40             :     }
      41             : 
      42             :     // Determines how many levels a SkMipMap will have without creating that mipmap.
      43             :     // This does not include the base mipmap level that the user provided when
      44             :     // creating the SkMipMap.
      45             :     static int ComputeLevelCount(int baseWidth, int baseHeight);
      46             : 
      47             :     // Determines the size of a given mipmap level.
      48             :     // |level| is an index into the generated mipmap levels. It does not include
      49             :     // the base level. So index 0 represents mipmap level 1.
      50             :     static SkISize ComputeLevelSize(int baseWidth, int baseHeight, int level);
      51             : 
      52           0 :     struct Level {
      53             :         SkPixmap    fPixmap;
      54             :         SkSize      fScale; // < 1.0
      55             :     };
      56             : 
      57             :     bool extractLevel(const SkSize& scale, Level*) const;
      58             : 
      59             :     // countLevels returns the number of mipmap levels generated (which does not
      60             :     // include the base mipmap level).
      61             :     int countLevels() const;
      62             : 
      63             :     // |index| is an index into the generated mipmap levels. It does not include
      64             :     // the base level. So index 0 represents mipmap level 1.
      65             :     bool getLevel(int index, Level*) const;
      66             : 
      67             : protected:
      68           0 :     void onDataChange(void* oldData, void* newData) override {
      69           0 :         fLevels = (Level*)newData; // could be nullptr
      70           0 :     }
      71             : 
      72             : private:
      73             :     sk_sp<SkColorSpace> fCS;
      74             :     Level*              fLevels;    // managed by the baseclass, may be null due to onDataChanged.
      75             :     int                 fCount;
      76             : 
      77           0 :     SkMipMap(void* malloc, size_t size) : INHERITED(malloc, size) {}
      78           0 :     SkMipMap(size_t size, SkDiscardableMemory* dm) : INHERITED(size, dm) {}
      79             : 
      80             :     static size_t AllocLevelsSize(int levelCount, size_t pixelSize);
      81             : 
      82             :     typedef SkCachedData INHERITED;
      83             : };
      84             : 
      85             : #endif