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_INCOMPLETE_MULTISAMPLE        = GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE,
  38         FRAMEBUFFER_INCOMPLETE_LAYER_COUNT        = GL_FRAMEBUFFER_INCOMPLETE_LAYER_COUNT_ARB,
  39         FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS      = GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS,
  40         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED,
  41         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE
  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 };
  50
  51 class framebuffer_incomplete: public std::runtime_error
  52 {
  53 public:
  54         framebuffer_incomplete(FramebufferStatus);
  55         virtual ~framebuffer_incomplete() throw() { }
  56 };
  57
  58 /**
  59 Framebuffer objects can be used to perform offscreen rendering.  The most
  60 common application is rendering to a texture, which can then be used for
  61 fullscreen shader effects.
  62
  63 A framebuffer consist of a number of logical buffers, such as color and depth
  64 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  65 least one image must be attached for the framebuffer to be usable.
  66
  67 Requires the GL_EXT_framebuffer_object extension.  The blit functions require
  68 the GL_EXT_framebuffer_blit extension.
  69 */
  70 class Framebuffer: public Bindable<Framebuffer>
  71 {
  72 private:
  73         struct Attachment
  74         {
  75                 FramebufferAttachment attachment;
  76                 GLenum type;
  77                 union
  78                 {
  79                         Renderbuffer *rbuf;
  80                         Texture *tex;
  81                 };
  82                 unsigned level;
  83                 unsigned layer;
  84
  85                 Attachment(FramebufferAttachment);
  86                 void set(Renderbuffer &);
  87                 void set(Texture &, unsigned, unsigned);
  88                 void clear();
  89         };
  90
  91         struct Viewport
  92         {
  93                 int left;
  94                 int bottom;
  95                 unsigned width;
  96                 unsigned height;
  97
  98                 Viewport();
  99         };
 100
 101         unsigned id;
 102         std::vector<Attachment> attachments;
 103         unsigned width;
 104         unsigned height;
 105         Viewport view;
 106         mutable unsigned dirty;
 107
 108         Framebuffer(unsigned);
 109 public:
 110         Framebuffer();
 111         ~Framebuffer();
 112
 113         unsigned get_width() const { return width; }
 114         unsigned get_height() const { return height; }
 115
 116 private:
 117         void update_attachment(unsigned) const;
 118         void check_size();
 119         unsigned get_attachment_index(FramebufferAttachment);
 120 public:
 121         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 122         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 123         void attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level = 0);
 124         void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0);
 125         void detach(FramebufferAttachment attch);
 126
 127         /** Checks the completeness of the framebuffer.  Returns
 128         FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to,
 129         or one of the error status codes otherwise. */
 130         FramebufferStatus check_status() const;
 131
 132         /** Ensures that the framebuffer is complete, throwing an exception if it
 133         isn't. */
 134         void require_complete() const;
 135
 136         void viewport(int, int, unsigned, unsigned);
 137         void reset_viewport();
 138
 139         void clear(BufferBits);
 140
 141         /** Blits a region from another framebuffer into this one.  If the source
 142         and destination regions have different dimensions, the contents will be
 143         stretched.  If filter is true, linear interpolation will be used, otherwise
 144         no interpolation is done. */
 145         void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1,
 146                 int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter);
 147
 148         /** Blits a region from another framebuffer into this one, retaining its
 149         dimensions. */
 150         void blit_from(const Framebuffer & other, int sx, int sy,
 151                 unsigned wd, unsigned ht, int dx, int dy, BufferBits bits);
 152
 153         /** Blits the entire contents of another framebuffer into this one. */
 154         void blit_from(const Framebuffer &other, BufferBits bits, bool filter);
 155
 156         void bind() const;
 157
 158         static const Framebuffer *current();
 159         static void unbind();
 160
 161         static Framebuffer &system();
 162 };
 163
 164 inline BufferBits operator|(BufferBits a, BufferBits b)
 165 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 166
 167 } // namespace GL
 168 } // namespace Msp
 169
 170 #endif