vcl/inc/opengl/RenderState.hxx

   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 #ifndef INCLUDED_VCL_INC_OPENGL_RENDER_STATE_H
  12 #define INCLUDED_VCL_INC_OPENGL_RENDER_STATE_H
  13
  14 #include <opengl/TextureState.hxx>
  15
  16 template<GLenum ENUM_TYPE, typename TYPE>
  17 class GenericCapabilityState
  18 {
  19 protected:
  20     bool mbTest;
  21
  22     GenericCapabilityState()
  23         : mbTest(false)
  24     {
  25     }
  26
  27     static bool readState()
  28     {
  29         return glIsEnabled(ENUM_TYPE);
  30     }
  31
  32 public:
  33     void sync()
  34     {
  35         mbTest = readState();
  36     }
  37
  38     void enable()
  39     {
  40         if (!mbTest)
  41         {
  42             glEnable(ENUM_TYPE);
  43             CHECK_GL_ERROR();
  44             mbTest = true;
  45         }
  46         else
  47         {
  48             VCL_GL_INFO(TYPE::className() << ": enable called but already enabled");
  49         }
  50 #ifdef DBG_UTIL
  51         checkState();
  52 #endif
  53     }
  54
  55     void disable()
  56     {
  57         if (mbTest)
  58         {
  59             glDisable(ENUM_TYPE);
  60             CHECK_GL_ERROR();
  61             mbTest = false;
  62         }
  63         else
  64         {
  65             VCL_GL_INFO(TYPE::className() << ": disable called but already disabled");
  66         }
  67 #ifdef DBG_UTIL
  68         checkState();
  69 #endif
  70     }
  71
  72 #ifdef DBG_UTIL
  73     void checkState()
  74     {
  75         bool bRealState = readState();
  76         if (mbTest != bRealState)
  77         {
  78             VCL_GL_INFO(TYPE::className() << " mismatch! "
  79                             << "Expected: " << (mbTest ? "enabled" : "disabled")
  80                             << " but is: "        << (bRealState ? "enabled" : "disabled"));
  81         }
  82     }
  83 #endif
  84 };
  85
  86 class ScissorState : public GenericCapabilityState<GL_SCISSOR_TEST, ScissorState>
  87 {
  88 private:
  89     int mX;
  90     int mY;
  91     int mWidth;
  92     int mHeight;
  93
  94 public:
  95     static std::string className() { return std::string("ScissorState"); }
  96
  97     ScissorState()
  98         : mX(0)
  99         , mY(0)
 100         , mWidth(0)
 101         , mHeight(0)
 102     {}
 103
 104     void set(int x, int y, int width, int height)
 105     {
 106         if (x != mX || y != mY || width != mWidth || height != mHeight)
 107         {
 108             glScissor(x, y, width, height);
 109             CHECK_GL_ERROR();
 110
 111             mX = x;
 112             mY = y;
 113             mWidth = width;
 114             mHeight = height;
 115         }
 116     }
 117 };
 118
 119 class StencilState : public GenericCapabilityState<GL_STENCIL_TEST, StencilState>
 120 {
 121 public:
 122     static std::string className() { return std::string("StencilState"); }
 123 };
 124
 125 class BlendState : public GenericCapabilityState<GL_BLEND, BlendState>
 126 {
 127     GLenum mnSourceMode;
 128     GLenum mnDestinationMode;
 129 public:
 130     BlendState()
 131         : mnSourceMode(GL_ZERO)
 132         , mnDestinationMode(GL_ZERO)
 133     {}
 134
 135     static std::string className() { return std::string("BlendState"); }
 136
 137     void func(GLenum nSource, GLenum nDestination)
 138     {
 139         if (mnSourceMode != nSource || mnDestinationMode != nDestination)
 140         {
 141             glBlendFunc(nSource, nDestination);
 142             CHECK_GL_ERROR();
 143             mnSourceMode = nSource;
 144             mnDestinationMode = nDestination;
 145         }
 146     }
 147 };
 148
 149 class RenderState
 150 {
 151     TextureState maTexture;
 152     ScissorState maScissor;
 153     StencilState maStencil;
 154     BlendState   maBlend;
 155
 156     tools::Rectangle maCurrentViewport;
 157
 158 public:
 159     RenderState()
 160     {}
 161
 162     void viewport(tools::Rectangle aViewPort)
 163     {
 164         if (aViewPort != maCurrentViewport)
 165         {
 166             glViewport(aViewPort.Left(), aViewPort.Top(), aViewPort.GetWidth(), aViewPort.GetHeight());
 167             CHECK_GL_ERROR();
 168             maCurrentViewport = aViewPort;
 169         }
 170     }
 171
 172     TextureState& texture() { return maTexture; }
 173     ScissorState& scissor() { return maScissor; }
 174     StencilState& stencil() { return maStencil; }
 175     BlendState&   blend()   { return maBlend; }
 176
 177     void sync()
 178     {
 179         VCL_GL_INFO("RenderState::sync");
 180         maScissor.sync();
 181         maStencil.sync();
 182         maBlend.sync();
 183     }
 184 };
 185
 186 #endif // INCLUDED_VCL_INC_OPENGL_RENDER_STATE_H
 187
 188 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */