source/core/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/arb_geometry_shader4.h>
   9 #include <msp/gl/extensions/ext_framebuffer_multisample.h>
  10 #include <msp/gl/extensions/ext_framebuffer_object.h>
  11 #include <msp/gl/extensions/nv_fbo_color_attachments.h>
  12
  13 namespace Msp {
  14 namespace GL {
  15
  16 class Renderbuffer;
  17 class Texture;
  18 class Texture2D;
  19 class Texture3D;
  20
  21 enum FramebufferAttachment
  22 {
  23         COLOR_ATTACHMENT0  = GL_COLOR_ATTACHMENT0,
  24         COLOR_ATTACHMENT1  = GL_COLOR_ATTACHMENT1,
  25         COLOR_ATTACHMENT2  = GL_COLOR_ATTACHMENT2,
  26         COLOR_ATTACHMENT3  = GL_COLOR_ATTACHMENT3,
  27         DEPTH_ATTACHMENT   = GL_DEPTH_ATTACHMENT,
  28         STENCIL_ATTACHMENT = GL_STENCIL_ATTACHMENT
  29 };
  30
  31 enum FramebufferStatus
  32 {
  33         FRAMEBUFFER_INCOMPLETE_ATTACHMENT         = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT,
  34         FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT,
  35         FRAMEBUFFER_INCOMPLETE_DIMENSIONS         = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT,
  36         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT,
  37         FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER,
  38         FRAMEBUFFER_INCOMPLETE_READ_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER,
  39         FRAMEBUFFER_INCOMPLETE_MULTISAMPLE        = GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE,
  40         FRAMEBUFFER_INCOMPLETE_LAYER_COUNT        = GL_FRAMEBUFFER_INCOMPLETE_LAYER_COUNT_ARB,
  41         FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS      = GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS,
  42         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED,
  43         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE
  44 };
  45
  46 enum BufferBits
  47 {
  48         COLOR_BUFFER_BIT   = GL_COLOR_BUFFER_BIT,
  49         DEPTH_BUFFER_BIT   = GL_DEPTH_BUFFER_BIT,
  50         STENCIL_BUFFER_BIT = GL_STENCIL_BUFFER_BIT
  51 };
  52
  53 class framebuffer_incomplete: public std::runtime_error
  54 {
  55 public:
  56         framebuffer_incomplete(FramebufferStatus);
  57         virtual ~framebuffer_incomplete() throw() { }
  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                 unsigned layer;
  86
  87                 Attachment(FramebufferAttachment);
  88                 void set(Renderbuffer &);
  89                 void set(Texture &, unsigned, unsigned);
  90                 void clear();
  91         };
  92
  93         struct Viewport
  94         {
  95                 int left;
  96                 int bottom;
  97                 unsigned width;
  98                 unsigned height;
  99
 100                 Viewport();
 101         };
 102
 103         unsigned id;
 104         std::vector<Attachment> attachments;
 105         unsigned width;
 106         unsigned height;
 107         Viewport view;
 108         mutable unsigned dirty;
 109
 110         Framebuffer(unsigned);
 111 public:
 112         Framebuffer();
 113         ~Framebuffer();
 114
 115         unsigned get_width() const { return width; }
 116         unsigned get_height() const { return height; }
 117
 118 private:
 119         void update_attachment(unsigned) const;
 120         void check_size();
 121         unsigned get_attachment_index(FramebufferAttachment);
 122         void set_texture_attachment(FramebufferAttachment, Texture &, unsigned, int);
 123 public:
 124         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 125         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 126         void attach(FramebufferAttachment attch, Texture3D &tex, unsigned layer, unsigned level = 0);
 127         void attach(FramebufferAttachment attch, TextureCube &tex, TextureCubeFace face, unsigned level = 0);
 128         void detach(FramebufferAttachment attch);
 129
 130         /** Checks the completeness of the framebuffer.  Returns
 131         FRAMEBUFFER_COMPLETE if the framebuffer is complete and can be rendered to,
 132         or one of the error status codes otherwise. */
 133         FramebufferStatus check_status() const;
 134
 135         /** Ensures that the framebuffer is complete, throwing an exception if it
 136         isn't. */
 137         void require_complete() const;
 138
 139         void viewport(int, int, unsigned, unsigned);
 140         void reset_viewport();
 141
 142         void clear();
 143         void clear(BufferBits);
 144
 145         /** Blits a region from another framebuffer into this one.  If the source
 146         and destination regions have different dimensions, the contents will be
 147         stretched.  If filter is true, linear interpolation will be used, otherwise
 148         no interpolation is done. */
 149         void blit_from(const Framebuffer &other, int sx0, int sy0, int sx1, int sy1,
 150                 int dx0, int dy0, int dx1, int dy1, BufferBits bits, bool filter);
 151
 152         /** Blits a region from another framebuffer into this one, retaining its
 153         dimensions. */
 154         void blit_from(const Framebuffer & other, int sx, int sy,
 155                 unsigned wd, unsigned ht, int dx, int dy, BufferBits bits);
 156
 157         /** Blits the entire contents of another framebuffer into this one. */
 158         void blit_from(const Framebuffer &other, BufferBits bits, bool filter);
 159
 160         void bind() const;
 161
 162         static const Framebuffer *current();
 163         static void unbind();
 164
 165         static Framebuffer &system();
 166 };
 167
 168 inline BufferBits operator|(BufferBits a, BufferBits b)
 169 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 170
 171 } // namespace GL
 172 } // namespace Msp
 173
 174 #endif