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                 bool has_color = false;
  56                 bool has_depth = false;
  57                 for(unsigned i=0; i<attachments.size(); ++i)
  58                 {
  59                         const Attachment &attch = attachments[i];
  60                         if(mask&(1<<i))
  61                         {
  62                                 if(attch.type==GL_RENDERBUFFER_EXT)
  63                                         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch.attachment, GL_RENDERBUFFER_EXT, attch.rbuf->get_id());
  64                                 else if(attch.type==GL_TEXTURE_2D)
  65                                         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, attch.attachment, attch.type, attch.tex->get_id(), attch.level);
  66                                 else
  67                                         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch.attachment, 0, 0);
  68                         }
  69
  70                         if(attch.attachment>=COLOR_ATTACHMENT0 && attch.attachment<=COLOR_ATTACHMENT3)
  71                                 has_color = true;
  72                         if(attch.attachment==DEPTH_ATTACHMENT)
  73                                 has_depth = true;
  74                 }
  75
  76                 glDrawBuffer(has_color ? GL_FRONT : GL_NONE);
  77                 glDepthMask(has_depth);
  78         }
  79         else
  80                 dirty |= mask;
  81 }
  82
  83 void Framebuffer::check_size()
  84 {
  85         for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
  86                 if(i->type)
  87                 {
  88                         if(i->type==GL_RENDERBUFFER_EXT)
  89                         {
  90                                 width = i->rbuf->get_width();
  91                                 height = i->rbuf->get_height();
  92                         }
  93                         else if(i->type==GL_TEXTURE_2D)
  94                         {
  95                                 Texture2D *tex = static_cast<Texture2D *>(i->tex);
  96                                 width = tex->get_width();
  97                                 height = tex->get_height();
  98                         }
  99                         if(current()==this)
 100                                 glViewport(0, 0, width, height);
 101                         break;
 102                 }
 103 }
 104
 105 void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
 106 {
 107         if(!id)
 108                 throw InvalidState("Can't attach to system framebuffer");
 109
 110         unsigned i = get_attachment_index(attch);
 111         attachments[i].set(rbuf);
 112         update_attachment(1<<i);
 113         check_size();
 114 }
 115
 116 void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, int level)
 117 {
 118         if(!id)
 119                 throw InvalidState("Can't attach to system framebuffer");
 120
 121         unsigned i = get_attachment_index(attch);
 122         attachments[i].set(tex, level);
 123         update_attachment(1<<i);
 124         check_size();
 125 }
 126
 127 void Framebuffer::detach(FramebufferAttachment attch)
 128 {
 129         if(!id)
 130                 throw InvalidState("Can't detach from system framebuffer");
 131
 132         unsigned i = get_attachment_index(attch);
 133         attachments[i].clear();
 134         update_attachment(1<<i);
 135         check_size();
 136 }
 137
 138 FramebufferStatus Framebuffer::check_status() const
 139 {
 140         Bind _bind(this, true);
 141         return static_cast<FramebufferStatus>(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
 142 }
 143
 144 void Framebuffer::clear(BufferBits bits)
 145 {
 146         Bind _bind(this, true);
 147         glClear(bits);
 148 }
 149
 150 void Framebuffer::bind() const
 151 {
 152         if(set_current(this))
 153         {
 154                 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, id);
 155                 if(dirty)
 156                 {
 157                         update_attachment(dirty);
 158                         dirty = 0;
 159                 }
 160                 if(width && height)
 161                         glViewport(0, 0, width, height);
 162         }
 163 }
 164
 165 const Framebuffer *Framebuffer::current()
 166 {
 167         if(!cur_obj)
 168                 cur_obj = &system();
 169         return cur_obj;
 170 }
 171
 172 void Framebuffer::unbind()
 173 {
 174         system().bind();
 175 }
 176
 177 Framebuffer &Framebuffer::system()
 178 {
 179         static Framebuffer sys_framebuf(0);
 180         return sys_framebuf;
 181 }
 182
 183 unsigned Framebuffer::get_attachment_index(FramebufferAttachment attch)
 184 {
 185         for(unsigned i=0; i<attachments.size(); ++i)
 186                 if(attachments[i].attachment==attch)
 187                         return i;
 188         attachments.push_back(Attachment(attch));
 189         return attachments.size()-1;
 190 }
 191
 192
 193 Framebuffer::Attachment::Attachment(FramebufferAttachment a):
 194         attachment(a),
 195         type(0),
 196         level(0)
 197 { }
 198
 199 void Framebuffer::Attachment::set(Renderbuffer &r)
 200 {
 201         type = GL_RENDERBUFFER_EXT;
 202         rbuf = &r;
 203         level = 0;
 204 }
 205
 206 void Framebuffer::Attachment::set(Texture &t, int l)
 207 {
 208         type = t.get_target();
 209         tex = &t;
 210         level = l;
 211 }
 212
 213 void Framebuffer::Attachment::clear()
 214 {
 215         type = 0;
 216 }
 217
 218 } // namespace GL
 219 } // namespace Msp