source/framebuffer.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2007  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include "extension.h"
   9 #include "ext_framebuffer_object.h"
  10 #include "framebuffer.h"
  11 #include "misc.h"
  12 #include "renderbuffer.h"
  13 #include "texture2d.h"
  14
  15 using namespace std;
  16
  17 namespace Msp {
  18 namespace GL {
  19
  20 Framebuffer::Framebuffer(unsigned i):
  21         id(i),
  22         dirty(0)
  23 {
  24         if(id)
  25                 throw InvalidParameterValue("System framebuffer must have id 0");
  26
  27         int viewport[4];
  28         glGetIntegerv(GL_VIEWPORT, viewport);
  29         width = viewport[2];
  30         height = viewport[3];
  31 }
  32
  33 Framebuffer::Framebuffer():
  34         width(0),
  35         height(0),
  36         dirty(0)
  37 {
  38         static RequireExtension _ext("GL_EXT_framebuffer_object");
  39
  40         glGenFramebuffersEXT(1, &id);
  41 }
  42
  43 Framebuffer::~Framebuffer()
  44 {
  45         if(id)
  46                 glDeleteFramebuffersEXT(1, &id);
  47         if(current()==this)
  48                 unbind();
  49 }
  50
  51 void Framebuffer::update_attachment(unsigned mask) const
  52 {
  53         if(current()==this)
  54         {
  55                 GLenum color_buf = GL_NONE;
  56                 for(unsigned i=0; i<attachments.size(); ++i)
  57                 {
  58                         const Attachment &attch = attachments[i];
  59                         if(mask&(1<<i))
  60                         {
  61                                 if(attch.type==GL_RENDERBUFFER_EXT)
  62                                         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch.attachment, GL_RENDERBUFFER_EXT, attch.rbuf->get_id());
  63                                 else if(attch.type==GL_TEXTURE_2D)
  64                                 {
  65                                         static_cast<Texture2D *>(attch.tex)->allocate(attch.level);
  66                                         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, attch.attachment, attch.type, attch.tex->get_id(), attch.level);
  67                                 }
  68                                 else
  69                                         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch.attachment, 0, 0);
  70                         }
  71
  72                         if(attch.attachment>=COLOR_ATTACHMENT0 && attch.attachment<=COLOR_ATTACHMENT3)
  73                                 color_buf = attch.attachment;
  74                 }
  75
  76                 glDrawBuffer(color_buf);
  77         }
  78         else
  79                 dirty |= mask;
  80 }
  81
  82 void Framebuffer::check_size()
  83 {
  84         for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
  85                 if(i->type)
  86                 {
  87                         if(i->type==GL_RENDERBUFFER_EXT)
  88                         {
  89                                 width = i->rbuf->get_width();
  90                                 height = i->rbuf->get_height();
  91                         }
  92                         else if(i->type==GL_TEXTURE_2D)
  93                         {
  94                                 Texture2D *tex = static_cast<Texture2D *>(i->tex);
  95                                 width = tex->get_width();
  96                                 height = tex->get_height();
  97                         }
  98                         if(current()==this)
  99                                 glViewport(0, 0, width, height);
 100                         break;
 101                 }
 102 }
 103
 104 void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
 105 {
 106         if(!id)
 107                 throw InvalidState("Can't attach to system framebuffer");
 108
 109         unsigned i = get_attachment_index(attch);
 110         attachments[i].set(rbuf);
 111         update_attachment(1<<i);
 112         check_size();
 113 }
 114
 115 void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, unsigned level)
 116 {
 117         if(!id)
 118                 throw InvalidState("Can't attach to system framebuffer");
 119
 120         unsigned i = get_attachment_index(attch);
 121         attachments[i].set(tex, level);
 122         update_attachment(1<<i);
 123         check_size();
 124 }
 125
 126 void Framebuffer::detach(FramebufferAttachment attch)
 127 {
 128         if(!id)
 129                 throw InvalidState("Can't detach from system framebuffer");
 130
 131         unsigned i = get_attachment_index(attch);
 132         attachments[i].clear();
 133         update_attachment(1<<i);
 134         check_size();
 135 }
 136
 137 FramebufferStatus Framebuffer::check_status() const
 138 {
 139         Bind _bind(this, true);
 140         return static_cast<FramebufferStatus>(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
 141 }
 142
 143 void Framebuffer::clear(BufferBits bits)
 144 {
 145         Bind _bind(this, true);
 146         glClear(bits);
 147 }
 148
 149 void Framebuffer::bind() const
 150 {
 151         if(set_current(this))
 152         {
 153                 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, id);
 154                 if(dirty)
 155                 {
 156                         update_attachment(dirty);
 157                         dirty = 0;
 158                 }
 159                 if(width && height)
 160                         glViewport(0, 0, width, height);
 161         }
 162 }
 163
 164 const Framebuffer *Framebuffer::current()
 165 {
 166         if(!cur_obj)
 167                 cur_obj = &system();
 168         return cur_obj;
 169 }
 170
 171 void Framebuffer::unbind()
 172 {
 173         system().bind();
 174 }
 175
 176 Framebuffer &Framebuffer::system()
 177 {
 178         static Framebuffer sys_framebuf(0);
 179         return sys_framebuf;
 180 }
 181
 182 unsigned Framebuffer::get_attachment_index(FramebufferAttachment attch)
 183 {
 184         for(unsigned i=0; i<attachments.size(); ++i)
 185                 if(attachments[i].attachment==attch)
 186                         return i;
 187         attachments.push_back(Attachment(attch));
 188         return attachments.size()-1;
 189 }
 190
 191
 192 Framebuffer::Attachment::Attachment(FramebufferAttachment a):
 193         attachment(a),
 194         type(0),
 195         level(0)
 196 { }
 197
 198 void Framebuffer::Attachment::set(Renderbuffer &r)
 199 {
 200         type = GL_RENDERBUFFER_EXT;
 201         rbuf = &r;
 202         level = 0;
 203 }
 204
 205 void Framebuffer::Attachment::set(Texture &t, unsigned l)
 206 {
 207         type = t.get_target();
 208         tex = &t;
 209         level = l;
 210 }
 211
 212 void Framebuffer::Attachment::clear()
 213 {
 214         type = 0;
 215 }
 216
 217 } // namespace GL
 218 } // namespace Msp