vcl/opengl/FixedTextureAtlas.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #include <memory>
  12 #include <sal/config.h>
  13 #include <vcl/opengl/OpenGLContext.hxx>
  14 #include <vcl/opengl/OpenGLHelper.hxx>
  15
  16 #include <opengl/framebuffer.hxx>
  17 #include <opengl/texture.hxx>
  18
  19 #include <opengl/FixedTextureAtlas.hxx>
  20
  21 struct FixedTexture
  22 {
  23     std::shared_ptr<ImplOpenGLTexture> mpTexture;
  24     int mnFreeSlots;
  25     std::vector<bool> maAllocatedSlots;
  26
  27     FixedTexture(int nTextureWidth, int nTextureHeight, int nNumberOfSlots)
  28         : mpTexture(std::make_shared<ImplOpenGLTexture>(nTextureWidth, nTextureHeight, true))
  29         , mnFreeSlots(nNumberOfSlots)
  30         , maAllocatedSlots(nNumberOfSlots, false)
  31     {
  32         auto aDeallocateFunction = [this] (int nSlotNumber)
  33         {
  34             deallocateSlot(nSlotNumber);
  35         };
  36
  37         mpTexture->SetSlotDeallocateCallback(aDeallocateFunction);
  38         mpTexture->InitializeSlotMechanism(nNumberOfSlots);
  39     }
  40
  41     ~FixedTexture()
  42     {
  43         mpTexture->ResetSlotDeallocateCallback();
  44     }
  45
  46     void allocateSlot(int nSlot)
  47     {
  48         maAllocatedSlots[nSlot] = true;
  49         mnFreeSlots--;
  50     }
  51
  52     void deallocateSlot(int nSlot)
  53     {
  54         maAllocatedSlots[nSlot] = false;
  55         mnFreeSlots++;
  56     }
  57
  58     int findAndAllocateFreeSlot()
  59     {
  60         for (size_t i = 0; i < maAllocatedSlots.size(); ++i)
  61         {
  62             if (!maAllocatedSlots[i])
  63             {
  64                 allocateSlot(i);
  65                 return i;
  66             }
  67         }
  68         return -1;
  69     }
  70
  71 private:
  72     FixedTexture(const FixedTexture&) = delete;
  73     FixedTexture& operator=(const FixedTexture&) = delete;
  74 };
  75
  76 FixedTextureAtlasManager::FixedTextureAtlasManager(int nWidthFactor, int nHeightFactor, int nSubTextureSize)
  77     : mWidthFactor(nWidthFactor)
  78     , mHeightFactor(nHeightFactor)
  79     , mSubTextureSize(nSubTextureSize)
  80 {
  81 }
  82
  83 FixedTextureAtlasManager::~FixedTextureAtlasManager()
  84 {
  85 }
  86
  87 void FixedTextureAtlasManager::CreateNewTexture()
  88 {
  89     int nTextureWidth = mWidthFactor  * mSubTextureSize;
  90     int nTextureHeight = mHeightFactor * mSubTextureSize;
  91     maFixedTextures.push_back(std::make_unique<FixedTexture>(nTextureWidth, nTextureHeight, mWidthFactor * mHeightFactor));
  92 }
  93
  94 OpenGLTexture FixedTextureAtlasManager::Reserve(int nWidth, int nHeight)
  95 {
  96     FixedTexture* pFixedTexture = nullptr;
  97
  98     auto funFreeSlot = [] (std::unique_ptr<FixedTexture>& inFixedTexture)
  99     {
 100         return inFixedTexture->mnFreeSlots > 0;
 101     };
 102
 103     auto it = std::find_if(maFixedTextures.begin(), maFixedTextures.end(), funFreeSlot);
 104
 105     if (it != maFixedTextures.end())
 106     {
 107         pFixedTexture = (*it).get();
 108     }
 109     else
 110     {
 111         CreateNewTexture();
 112         pFixedTexture = maFixedTextures.back().get();
 113     }
 114
 115     int nSlot = pFixedTexture->findAndAllocateFreeSlot();
 116
 117     // Calculate coordinates in texture
 118     int nX = (nSlot % mWidthFactor) * mSubTextureSize;
 119     int nY = (nSlot / mWidthFactor) * mSubTextureSize;
 120
 121     tools::Rectangle aRectangle(Point(nX, nY), Size(nWidth, nHeight));
 122
 123     return OpenGLTexture(pFixedTexture->mpTexture, aRectangle, nSlot);
 124 }
 125
 126 OpenGLTexture FixedTextureAtlasManager::InsertBuffer(int nWidth, int nHeight, int nFormat, int nType, sal_uInt8 const * pData)
 127 {
 128     OpenGLTexture aTexture = Reserve(nWidth, nHeight);
 129     if (pData == nullptr)
 130         return aTexture;
 131
 132     aTexture.CopyData(nWidth, nHeight, nFormat, nType, pData);
 133
 134     return aTexture;
 135 }
 136
 137 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */