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