source/renderer/PostprocManager.h

   1 /* Copyright (C) 2012 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef INCLUDED_POSTPROCMANAGER
  19 #define INCLUDED_POSTPROCMANAGER
  20
  21
  22 #include "graphics/ShaderTechnique.h"
  23
  24 class CPostprocManager
  25 {
  26 private:
  27
  28         // Two framebuffers, that we flip between at each shader pass.
  29         GLuint m_PingFbo, m_PongFbo;
  30
  31         // Unique colour textures for the framebuffers.
  32         GLuint m_ColourTex1, m_ColourTex2;
  33
  34         // The framebuffers share a depth/stencil texture.
  35         GLuint m_DepthTex;
  36
  37         // A framebuffer and textures x2 for each blur level we render.
  38         GLuint m_BloomFbo, m_BlurTex2a, m_BlurTex2b, m_BlurTex4a, m_BlurTex4b, m_BlurTex8a, m_BlurTex8b;
  39
  40         // Indicates which of the ping-pong buffers is used for reading and which for drawing.
  41         bool m_WhichBuffer;
  42
  43         // The name and shader technique we are using. "default" name means no technique is used
  44         // (i.e. while we do allocate the buffers, no effects are rendered).
  45         CStrW m_PostProcEffect;
  46         CShaderTechniquePtr m_PostProcTech;
  47
  48         // The current screen dimensions in pixels.
  49         int m_Width, m_Height;
  50
  51         // Is the postproc manager initialised? Buffers created? Default effect loaded?
  52         bool m_IsInitialised;
  53
  54         // Creates blur textures at various scales, for bloom, DOF, etc.
  55         void ApplyBlur();
  56
  57         // High quality GPU image scaling to half size. outTex must have exactly half the size
  58         // of inTex. inWidth and inHeight are the dimensions of inTex in texels.
  59         void ApplyBlurDownscale2x(GLuint inTex, GLuint outTex, int inWidth, int inHeight);
  60
  61         // GPU-based Gaussian blur in two passes. inOutTex contains the input image and will be filled
  62         // with the blurred image. tempTex must have the same size as inOutTex.
  63         // inWidth and inHeight are the dimensions of the images in texels.
  64         void ApplyBlurGauss(GLuint inOutTex, GLuint tempTex, int inWidth, int inHeight);
  65
  66         // Applies a pass of a given effect to the entire current framebuffer. The shader is
  67         // provided with a number of general-purpose variables, including the rendered screen so far,
  68         // the depth buffer, a number of blur textures, the screen size, the zNear/zFar planes and
  69         // some other parameters used by the optional bloom/HDR pass.
  70         void ApplyEffect(CShaderTechniquePtr &shaderTech1, int pass);
  71
  72 public:
  73         CPostprocManager();
  74         ~CPostprocManager();
  75
  76         // Create all buffers/textures in GPU memory and set default effect.
  77         void Initialize();
  78
  79         // Delete all allocated buffers/textures from GPU memory.
  80         void Cleanup();
  81
  82         // Delete existing buffers/textures and create them again, using a new screen size if needed.
  83         // (the textures are also attached to the framebuffers)
  84         void RecreateBuffers();
  85
  86         // Loads a new postproc effect. "default" effect does NOT load anything.
  87         void LoadEffect(CStrW &name);
  88
  89         // Returns a list of xml files found in shaders/effects/postproc.
  90         std::vector<CStrW> GetPostEffects() const;
  91
  92         // Returns the name of the current effect.
  93         inline const CStrW& GetPostEffect() const
  94         {
  95                 return m_PostProcEffect;
  96         }
  97
  98         // Matching setter that calls LoadEffect.
  99         void SetPostEffect(CStrW name);
 100
 101         // Clears the two colour buffers and depth buffer, and redirects all rendering
 102         // to our textures instead of directly to the system framebuffer.
 103         void CaptureRenderOutput();
 104
 105         // First renders blur textures, then calls ApplyEffect for each effect pass,
 106         // ping-ponging the buffers at each step.
 107         void ApplyPostproc();
 108
 109         // Blits the final postprocessed texture to the system framebuffer. The system framebuffer
 110         // is selected as the output buffer. Should be called before silhouette rendering.
 111         void ReleaseRenderOutput();
 112 };
 113
 114
 115 #endif //INCLUDED_POSTPROCMANAGER