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 #include <msp/gl/extensions/ext_framebuffer_object.h>
   9 #include <msp/gl/extensions/msp_stereo_rendering.h>
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 class Renderbuffer;
  15 class Texture;
  16 class Texture2D;
  17 class Texture3D;
  18
  19 enum FramebufferAttachment
  20 {
  21         COLOR_ATTACHMENT0  = GL_COLOR_ATTACHMENT0,
  22         COLOR_ATTACHMENT1  = GL_COLOR_ATTACHMENT1,
  23         COLOR_ATTACHMENT2  = GL_COLOR_ATTACHMENT2,
  24         COLOR_ATTACHMENT3  = GL_COLOR_ATTACHMENT3,
  25         DEPTH_ATTACHMENT   = GL_DEPTH_ATTACHMENT,
  26         STENCIL_ATTACHMENT = GL_STENCIL_ATTACHMENT
  27 };
  28
  29 enum FramebufferStatus
  30 {
  31         FRAMEBUFFER_INCOMPLETE_ATTACHMENT         = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT,
  32         FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT,
  33         FRAMEBUFFER_INCOMPLETE_DIMENSIONS         = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS,
  34         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS,
  35         FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER,
  36         FRAMEBUFFER_INCOMPLETE_READ_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER,
  37         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED,
  38         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE
  39 };
  40
  41 enum BufferBits
  42 {
  43         COLOR_BUFFER_BIT   = GL_COLOR_BUFFER_BIT,
  44         DEPTH_BUFFER_BIT   = GL_DEPTH_BUFFER_BIT,
  45         STENCIL_BUFFER_BIT = GL_STENCIL_BUFFER_BIT
  46 };
  47
  48 enum RWBuffer
  49 {
  50         NO_BUFFER      = GL_NONE,
  51         FRONT_LEFT     = GL_FRONT_LEFT,
  52         FRONT_RIGHT    = GL_FRONT_RIGHT,
  53         BACK_LEFT      = GL_BACK_LEFT,
  54         BACK_RIGHT     = GL_BACK_RIGHT,
  55         FRONT          = GL_FRONT,
  56         BACK           = GL_BACK,
  57         LEFT           = GL_LEFT,
  58         RIGHT          = GL_RIGHT,
  59         FRONT_AND_BACK = GL_FRONT_AND_BACK
  60 };
  61
  62 class framebuffer_incomplete: public std::runtime_error
  63 {
  64 public:
  65         framebuffer_incomplete(FramebufferStatus);
  66         virtual ~framebuffer_incomplete() throw() { }
  67 };
  68
  69 /**
  70 Framebuffer objects can be used to perform offscreen rendering.  The most
  71 common application is rendering to a texture, which can then be used for
  72 fullscreen shader effects.
  73
  74 A framebuffer consist of a number of logical buffers, such as color and depth
  75 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  76 least one image must be attached for the framebuffer to be usable.
  77
  78 Requires the GL_EXT_framebuffer_object extension.  The blit functions require
  79 the GL_EXT_framebuffer_blit extension.
  80 */
  81 class Framebuffer: public Bindable<Framebuffer>
  82 {
  83 private:
  84         struct Attachment
  85         {
  86                 FramebufferAttachment attachment;
  87                 GLenum type;
  88                 union
  89                 {
  90                         Renderbuffer *rbuf;
  91                         Texture *tex;
  92                 };
  93                 unsigned level;
  94                 unsigned layer;
  95
  96                 Attachment(FramebufferAttachment);
  97                 void set(Renderbuffer &);
  98                 void set(Texture &, unsigned, unsigned);
  99                 void clear();
 100         };
 101
 102         struct Viewport
 103         {
 104                 int left;
 105                 int bottom;
 106                 unsigned width;
 107                 unsigned height;
 108
 109                 Viewport();
 110         };
 111
 112         unsigned id;
 113         std::vector<Attachment> attachments;
 114         unsigned width;
 115         unsigned height;
 116         Viewport view;
 117         mutable unsigned dirty;
 118
 119         Framebuffer(unsigned);
 120 public:
 121         Framebuffer();
 122         ~Framebuffer();
 123
 124         unsigned get_width() const { return width; }
 125         unsigned get_height() const { return height; }
 126
 127 private:
 128         void update_attachment(unsigned) const;
 129         void check_size();
 130         unsigned get_attachment_index(FramebufferAttachment);
 131 public:
 132         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 133         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 134         void attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level = 0);
 135         void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0);
 136         void detach(FramebufferAttachment attch);
 137
 138         /** Checks the completeness of the framebuffer.  Returns
 139         FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to,
 140         or one of the error status codes otherwise. */
 141         FramebufferStatus check_status() const;
 142
 143         /** Ensures that the framebuffer is complete, throwing an exception if it
 144         isn't. */
 145         void require_complete() const;
 146
 147         void viewport(int, int, unsigned, unsigned);
 148         void reset_viewport();
 149
 150         void clear(BufferBits);
 151
 152         /** Blits a region from another framebuffer into this one.  If the source
 153         and destination regions have different dimensions, the contents will be
 154         stretched.  If filter is true, linear interpolation will be used, otherwise
 155         no interpolation is done. */
 156         void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1,
 157                 int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter);
 158
 159         /** Blits a region from another framebuffer into this one, retaining its
 160         dimensions. */
 161         void blit_from(const Framebuffer & other, int sx, int sy,
 162                 unsigned wd, unsigned ht, int dx, int dy, BufferBits bits);
 163
 164         /** Blits the entire contents of another framebuffer into this one. */
 165         void blit_from(const Framebuffer &other, BufferBits bits, bool filter);
 166
 167         void bind() const;
 168
 169         static const Framebuffer *current();
 170         static void unbind();
 171
 172         static Framebuffer &system();
 173 };
 174
 175 inline BufferBits operator|(BufferBits a, BufferBits b)
 176 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 177
 178 } // namespace GL
 179 } // namespace Msp
 180
 181 #endif