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
   8 namespace Msp {
   9 namespace GL {
  10
  11 class Renderbuffer;
  12 class Texture;
  13 class Texture2D;
  14
  15 enum FramebufferAttachment
  16 {
  17         COLOR_ATTACHMENT0  = GL_COLOR_ATTACHMENT0_EXT,
  18         COLOR_ATTACHMENT1  = GL_COLOR_ATTACHMENT1_EXT,
  19         COLOR_ATTACHMENT2  = GL_COLOR_ATTACHMENT2_EXT,
  20         COLOR_ATTACHMENT3  = GL_COLOR_ATTACHMENT3_EXT,
  21         DEPTH_ATTACHMENT   = GL_DEPTH_ATTACHMENT_EXT,
  22         STENCIL_ATTACHMENT = GL_STENCIL_ATTACHMENT_EXT
  23 };
  24
  25 enum FramebufferStatus
  26 {
  27         FRAMEBUFFER_INCOMPLETE_ATTACHMENT         = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT,
  28         FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT,
  29         FRAMEBUFFER_INCOMPLETE_DIMENSIONS         = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT,
  30         FRAMEBUFFER_INCOMPLETE_FORMATS            = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT,
  31         FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT,
  32         FRAMEBUFFER_INCOMPLETE_READ_BUFFER        = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT,
  33         FRAMEBUFFER_UNSUPPORTED                   = GL_FRAMEBUFFER_UNSUPPORTED_EXT,
  34         FRAMEBUFFER_COMPLETE                      = GL_FRAMEBUFFER_COMPLETE_EXT
  35 };
  36
  37 enum BufferBits
  38 {
  39         COLOR_BUFFER_BIT   = GL_COLOR_BUFFER_BIT,
  40         DEPTH_BUFFER_BIT   = GL_DEPTH_BUFFER_BIT,
  41         STENCIL_BUFFER_BIT = GL_STENCIL_BUFFER_BIT,
  42         ACCUM_BUFFER_BIT   = GL_ACCUM_BUFFER_BIT
  43 };
  44
  45 enum RWBuffer
  46 {
  47         NO_BUFFER      = GL_NONE,
  48         FRONT_LEFT     = GL_FRONT_LEFT,
  49         FRONT_RIGHT    = GL_FRONT_RIGHT,
  50         BACK_LEFT      = GL_BACK_LEFT,
  51         BACK_RIGHT     = GL_BACK_RIGHT,
  52         FRONT          = GL_FRONT,
  53         BACK           = GL_BACK,
  54         LEFT           = GL_LEFT,
  55         RIGHT          = GL_RIGHT,
  56         FRONT_AND_BACK = GL_FRONT_AND_BACK
  57 };
  58
  59 /**
  60 Framebuffer objects can be used to perform offscreen rendering.  The most
  61 common application is rendering to a texture, which can then be used for
  62 fullscreen shader effects.
  63
  64 A framebuffer consist of a number of logical buffers, such as color and depth
  65 buffers.  Renderbuffers and Textures can be attached to the logical buffers.  At
  66 least one image must be attached for the framebuffer to be usable.
  67
  68 Requires the GL_EXT_framebuffer_object 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
  84                 Attachment(FramebufferAttachment);
  85                 void set(Renderbuffer &);
  86                 void set(Texture &, unsigned);
  87                 void clear();
  88         };
  89
  90         unsigned id;
  91         std::vector<Attachment> attachments;
  92         unsigned width;
  93         unsigned height;
  94         mutable unsigned dirty;
  95
  96         Framebuffer(unsigned);
  97 public:
  98         Framebuffer();
  99         ~Framebuffer();
 100
 101         unsigned get_width() const { return width; }
 102         unsigned get_height() const { return height; }
 103
 104 private:
 105         void update_attachment(unsigned) const;
 106         void check_size();
 107 public:
 108         void attach(FramebufferAttachment attch, Renderbuffer &rbuf);
 109         void attach(FramebufferAttachment attch, Texture2D &tex, unsigned level = 0);
 110         void detach(FramebufferAttachment attch);
 111
 112         /**
 113         Checks the completeness status of the framebuffer.  Returns
 114         FRAMEBUFFER_COMPLETE if the framebuffer is complate and can be rendered to,
 115         or one of the error status codes otherwise.
 116         */
 117         FramebufferStatus check_status() const;
 118
 119         void clear(BufferBits);
 120         void blit_from(const Framebuffer &, int, int, int, int, int, int, int, int, BufferBits, bool);
 121         void blit_from(const Framebuffer &, int, int, unsigned, unsigned, int, int, BufferBits);
 122         void blit_from(const Framebuffer &, BufferBits, bool);
 123
 124         void bind() const;
 125
 126         static const Framebuffer *current();
 127         static void unbind();
 128
 129         static Framebuffer &system();
 130 private:
 131         unsigned get_attachment_index(FramebufferAttachment);
 132 };
 133
 134 inline BufferBits operator|(BufferBits a, BufferBits b)
 135 { return static_cast<BufferBits>(static_cast<int>(a)|static_cast<int>(b)); }
 136
 137 } // namespace GL
 138 } // namespace Msp
 139
 140 #endif