source/framebuffer.h

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2007  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #ifndef MSP_GL_FRAMEBUFFER_H_
   9 #define MSP_GL_FRAMEBUFFER_H_
  10
  11 #include <vector>
  12 #include "bindable.h"
  13 #include "gl.h"
  14
  15 namespace Msp {
  16 namespace GL {
  17
  18 class Renderbuffer;
  19 class Texture;
  20 class Texture2D;
  21
  22 enum FramebufferAttachment
  23 {
  24         COLOR_ATTACHMENT0  = GL_COLOR_ATTACHMENT0_EXT,
  25         COLOR_ATTACHMENT1  = GL_COLOR_ATTACHMENT1_EXT,
  26         COLOR_ATTACHMENT2  = GL_COLOR_ATTACHMENT2_EXT,
  27         COLOR_ATTACHMENT3  = GL_COLOR_ATTACHMENT3_EXT,
  28         DEPTH_ATTACHMENT   = GL_DEPTH_ATTACHMENT_EXT,
  29         STENCIL_ATTACHMENT = GL_STENCIL_ATTACHMENT_EXT
  30 };
  31
  32 enum FramebufferStatus
  33 {
  34         FRAMEBUFFER_INCOMPLETE_ATTACHMENT         = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT,
  35         FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT,
  36         FRAMEBUFFER_INCOMPLETE_DIMENSIONS         = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT,
  37         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT,
  38         FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT,
  39         FRAMEBUFFER_INCOMPLETE_READ_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT,
  40         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED_EXT,
  41         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE_EXT
  42 };
  43
  44 enum BufferBits
  45 {
  46         COLOR_BUFFER_BIT   = GL_COLOR_BUFFER_BIT,
  47         DEPTH_BUFFER_BIT   = GL_DEPTH_BUFFER_BIT,
  48         STENCIL_BUFFER_BIT = GL_STENCIL_BUFFER_BIT,
  49         ACCUM_BUFFER_BIT   = GL_ACCUM_BUFFER_BIT
  50 };
  51
  52 enum RWBuffer
  53 {
  54         NO_BUFFER      = GL_NONE,
  55         FRONT_LEFT     = GL_FRONT_LEFT,
  56         FRONT_RIGHT    = GL_FRONT_RIGHT,
  57         BACK_LEFT      = GL_BACK_LEFT,
  58         BACK_RIGHT     = GL_BACK_RIGHT,
  59         FRONT          = GL_FRONT,
  60         BACK           = GL_BACK,
  61         LEFT           = GL_LEFT,
  62         RIGHT          = GL_RIGHT,
  63         FRONT_AND_BACK = GL_FRONT_AND_BACK
  64 };
  65
  66 /**
  67 Framebuffer objects can be used to perform offscreen rendering.  The most
  68 common application is rendering to a texture, which can then be used for
  69 fullscreen shader effects.
  70
  71 A framebuffer consist of a number of logical buffers, such as color and depth
  72 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  73 least one image must be attached for the framebuffer to be usable.
  74
  75 Requires the GL_EXT_framebuffer_object extension.
  76 */
  77 class Framebuffer: public Bindable<Framebuffer>
  78 {
  79 private:
  80         struct Attachment
  81         {
  82                 FramebufferAttachment attachment;
  83                 GLenum type;
  84                 union
  85                 {
  86                         Renderbuffer *rbuf;
  87                         Texture *tex;
  88                 };
  89                 unsigned level;
  90
  91                 Attachment(FramebufferAttachment);
  92                 void set(Renderbuffer &);
  93                 void set(Texture &, unsigned);
  94                 void clear();
  95         };
  96
  97         unsigned id;
  98         std::vector<Attachment> attachments;
  99         unsigned width;
 100         unsigned height;
 101         mutable unsigned dirty;
 102
 103         Framebuffer(unsigned);
 104 public:
 105         Framebuffer();
 106         ~Framebuffer();
 107
 108 private:
 109         void update_attachment(unsigned) const;
 110         void check_size();
 111 public:
 112         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 113         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level);
 114         void detach(FramebufferAttachment attch);
 115
 116         /**
 117         Checks the completeness status of the framebuffer.  Returns
 118         FRAMEBUFFER_COMPLETE if the framebuffer is complate and can be rendered to,
 119         or one of the error status codes otherwise.
 120         */
 121         FramebufferStatus check_status() const;
 122
 123         void clear(BufferBits);
 124
 125         void bind() const;
 126
 127         static const Framebuffer *current();
 128         static void unbind();
 129
 130         static Framebuffer &system();
 131 private:
 132         unsigned get_attachment_index(FramebufferAttachment);
 133 };
 134
 135 inline BufferBits operator|(BufferBits a, BufferBits b)
 136 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 137
 138 } // namespace GL
 139 } // namespace Msp
 140
 141 #endif