source/framebuffer.h

   1 #ifndef MSP_GL_FRAMEBUFFER_H_
   2 #define MSP_GL_FRAMEBUFFER_H_
   3
   4 #include <vector>
   5 #include "bindable.h"
   6 #include "gl.h"
   7 #include "texturecube.h"
   8
   9 namespace Msp {
  10 namespace GL {
  11
  12 class Renderbuffer;
  13 class Texture;
  14 class Texture2D;
  15
  16 enum FramebufferAttachment
  17 {
  18         COLOR_ATTACHMENT0  = GL_COLOR_ATTACHMENT0_EXT,
  19         COLOR_ATTACHMENT1  = GL_COLOR_ATTACHMENT1_EXT,
  20         COLOR_ATTACHMENT2  = GL_COLOR_ATTACHMENT2_EXT,
  21         COLOR_ATTACHMENT3  = GL_COLOR_ATTACHMENT3_EXT,
  22         DEPTH_ATTACHMENT   = GL_DEPTH_ATTACHMENT_EXT,
  23         STENCIL_ATTACHMENT = GL_STENCIL_ATTACHMENT_EXT
  24 };
  25
  26 enum FramebufferStatus
  27 {
  28         FRAMEBUFFER_INCOMPLETE_ATTACHMENT         = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT,
  29         FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT,
  30         FRAMEBUFFER_INCOMPLETE_DIMENSIONS         = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT,
  31         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT,
  32         FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT,
  33         FRAMEBUFFER_INCOMPLETE_READ_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT,
  34         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED_EXT,
  35         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE_EXT
  36 };
  37
  38 enum BufferBits
  39 {
  40         COLOR_BUFFER_BIT   = GL_COLOR_BUFFER_BIT,
  41         DEPTH_BUFFER_BIT   = GL_DEPTH_BUFFER_BIT,
  42         STENCIL_BUFFER_BIT = GL_STENCIL_BUFFER_BIT,
  43         ACCUM_BUFFER_BIT   = GL_ACCUM_BUFFER_BIT
  44 };
  45
  46 enum RWBuffer
  47 {
  48         NO_BUFFER      = GL_NONE,
  49         FRONT_LEFT     = GL_FRONT_LEFT,
  50         FRONT_RIGHT    = GL_FRONT_RIGHT,
  51         BACK_LEFT      = GL_BACK_LEFT,
  52         BACK_RIGHT     = GL_BACK_RIGHT,
  53         FRONT          = GL_FRONT,
  54         BACK           = GL_BACK,
  55         LEFT           = GL_LEFT,
  56         RIGHT          = GL_RIGHT,
  57         FRONT_AND_BACK = GL_FRONT_AND_BACK
  58 };
  59
  60 /**
  61 Framebuffer objects can be used to perform offscreen rendering.  The most
  62 common application is rendering to a texture, which can then be used for
  63 fullscreen shader effects.
  64
  65 A framebuffer consist of a number of logical buffers, such as color and depth
  66 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  67 least one image must be attached for the framebuffer to be usable.
  68
  69 Requires the GL_EXT_framebuffer_object extension.  The blit functions require
  70 the GL_EXT_framebuffer_blit extension.
  71 */
  72 class Framebuffer: public Bindable<Framebuffer>
  73 {
  74 private:
  75         struct Attachment
  76         {
  77                 FramebufferAttachment attachment;
  78                 GLenum type;
  79                 union
  80                 {
  81                         Renderbuffer *rbuf;
  82                         Texture *tex;
  83                 };
  84                 unsigned level;
  85                 GLenum cube_face;
  86
  87                 Attachment(FramebufferAttachment);
  88                 void set(Renderbuffer &);
  89                 void set(Texture &, GLenum, unsigned);
  90                 void clear();
  91         };
  92
  93         unsigned id;
  94         std::vector<Attachment> attachments;
  95         unsigned width;
  96         unsigned height;
  97         mutable unsigned dirty;
  98
  99         Framebuffer(unsigned);
 100 public:
 101         Framebuffer();
 102         ~Framebuffer();
 103
 104         unsigned get_width() const { return width; }
 105         unsigned get_height() const { return height; }
 106
 107 private:
 108         void update_attachment(unsigned) const;
 109         void check_size();
 110 public:
 111         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 112         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 113         void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0);
 114         void detach(FramebufferAttachment attch);
 115
 116         /** Checks the completeness of the framebuffer.  Returns
 117         FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to,
 118         or one of the error status codes otherwise. */
 119         FramebufferStatus check_status() const;
 120
 121         void clear(BufferBits);
 122
 123         /** Blits a region from another framebuffer into this one.  If the source
 124         and destination regions have different dimensions, the contents will be
 125         stretched.  If filter is true, linear interpolation will be used, otherwise
 126         no interpolation is done. */
 127         void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1,
 128                 int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter);
 129
 130         /** Blits a region from another framebuffer into this one, retaining its
 131         dimensions. */
 132         void blit_from(const Framebuffer & other, int sx, int sy,
 133                 unsigned wd, unsigned ht, int dx, int dy, BufferBits bits);
 134
 135         /** Blits the entire contents of another framebuffer into this one. */
 136         void blit_from(const Framebuffer &other, BufferBits bits, bool filter);
 137
 138         void bind() const;
 139
 140         static const Framebuffer *current();
 141         static void unbind();
 142
 143         static Framebuffer &system();
 144 private:
 145         unsigned get_attachment_index(FramebufferAttachment);
 146 };
 147
 148 inline BufferBits operator|(BufferBits a, BufferBits b)
 149 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 150
 151 } // namespace GL
 152 } // namespace Msp
 153
 154 #endif