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/nv_fbo_color_attachments.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_EXT,
  34         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT,
  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 class framebuffer_incomplete: public std::runtime_error
  49 {
  50 public:
  51         framebuffer_incomplete(FramebufferStatus);
  52         virtual ~framebuffer_incomplete() throw() { }
  53 };
  54
  55 /**
  56 Framebuffer objects can be used to perform offscreen rendering.  The most
  57 common application is rendering to a texture, which can then be used for
  58 fullscreen shader effects.
  59
  60 A framebuffer consist of a number of logical buffers, such as color and depth
  61 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  62 least one image must be attached for the framebuffer to be usable.
  63
  64 Requires the GL_EXT_framebuffer_object extension.  The blit functions require
  65 the GL_EXT_framebuffer_blit extension.
  66 */
  67 class Framebuffer: public Bindable<Framebuffer>
  68 {
  69 private:
  70         struct Attachment
  71         {
  72                 FramebufferAttachment attachment;
  73                 GLenum type;
  74                 union
  75                 {
  76                         Renderbuffer *rbuf;
  77                         Texture *tex;
  78                 };
  79                 unsigned level;
  80                 unsigned layer;
  81
  82                 Attachment(FramebufferAttachment);
  83                 void set(Renderbuffer &);
  84                 void set(Texture &, unsigned, unsigned);
  85                 void clear();
  86         };
  87
  88         struct Viewport
  89         {
  90                 int left;
  91                 int bottom;
  92                 unsigned width;
  93                 unsigned height;
  94
  95                 Viewport();
  96         };
  97
  98         unsigned id;
  99         std::vector<Attachment> attachments;
 100         unsigned width;
 101         unsigned height;
 102         Viewport view;
 103         mutable unsigned dirty;
 104
 105         Framebuffer(unsigned);
 106 public:
 107         Framebuffer();
 108         ~Framebuffer();
 109
 110         unsigned get_width() const { return width; }
 111         unsigned get_height() const { return height; }
 112
 113 private:
 114         void update_attachment(unsigned) const;
 115         void check_size();
 116         unsigned get_attachment_index(FramebufferAttachment);
 117 public:
 118         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 119         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 120         void attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level = 0);
 121         void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0);
 122         void detach(FramebufferAttachment attch);
 123
 124         /** Checks the completeness of the framebuffer.  Returns
 125         FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to,
 126         or one of the error status codes otherwise. */
 127         FramebufferStatus check_status() const;
 128
 129         /** Ensures that the framebuffer is complete, throwing an exception if it
 130         isn't. */
 131         void require_complete() const;
 132
 133         void viewport(int, int, unsigned, unsigned);
 134         void reset_viewport();
 135
 136         void clear(BufferBits);
 137
 138         /** Blits a region from another framebuffer into this one.  If the source
 139         and destination regions have different dimensions, the contents will be
 140         stretched.  If filter is true, linear interpolation will be used, otherwise
 141         no interpolation is done. */
 142         void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1,
 143                 int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter);
 144
 145         /** Blits a region from another framebuffer into this one, retaining its
 146         dimensions. */
 147         void blit_from(const Framebuffer & other, int sx, int sy,
 148                 unsigned wd, unsigned ht, int dx, int dy, BufferBits bits);
 149
 150         /** Blits the entire contents of another framebuffer into this one. */
 151         void blit_from(const Framebuffer &other, BufferBits bits, bool filter);
 152
 153         void bind() const;
 154
 155         static const Framebuffer *current();
 156         static void unbind();
 157
 158         static Framebuffer &system();
 159 };
 160
 161 inline BufferBits operator|(BufferBits a, BufferBits b)
 162 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 163
 164 } // namespace GL
 165 } // namespace Msp
 166
 167 #endif