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                 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                                 {
  66                                         static_cast<Texture2D *>(attch.tex)->allocate(attch.level);
  67                                         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, attch.attachment, attch.type, attch.tex->get_id(), attch.level);
  68                                 }
  69                                 else
  70                                         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch.attachment, 0, 0);
  71                         }
  72
  73                         if(attch.attachment>=COLOR_ATTACHMENT0 && attch.attachment<=COLOR_ATTACHMENT3)
  74                                 color_buf = attch.attachment;
  75                         if(attch.attachment==DEPTH_ATTACHMENT)
  76                                 has_depth = true;
  77                 }
  78
  79                 glDrawBuffer(color_buf);
  80                 glDepthMask(has_depth);
  81         }
  82         else
  83                 dirty |= mask;
  84 }
  85
  86 void Framebuffer::check_size()
  87 {
  88         for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
  89                 if(i->type)
  90                 {
  91                         if(i->type==GL_RENDERBUFFER_EXT)
  92                         {
  93                                 width = i->rbuf->get_width();
  94                                 height = i->rbuf->get_height();
  95                         }
  96                         else if(i->type==GL_TEXTURE_2D)
  97                         {
  98                                 Texture2D *tex = static_cast<Texture2D *>(i->tex);
  99                                 width = tex->get_width();
 100                                 height = tex->get_height();
 101                         }
 102                         if(current()==this)
 103                                 glViewport(0, 0, width, height);
 104                         break;
 105                 }
 106 }
 107
 108 void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
 109 {
 110         if(!id)
 111                 throw InvalidState("Can't attach to system framebuffer");
 112
 113         unsigned i = get_attachment_index(attch);
 114         attachments[i].set(rbuf);
 115         update_attachment(1<<i);
 116         check_size();
 117 }
 118
 119 void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, unsigned level)
 120 {
 121         if(!id)
 122                 throw InvalidState("Can't attach to system framebuffer");
 123
 124         unsigned i = get_attachment_index(attch);
 125         attachments[i].set(tex, level);
 126         update_attachment(1<<i);
 127         check_size();
 128 }
 129
 130 void Framebuffer::detach(FramebufferAttachment attch)
 131 {
 132         if(!id)
 133                 throw InvalidState("Can't detach from system framebuffer");
 134
 135         unsigned i = get_attachment_index(attch);
 136         attachments[i].clear();
 137         update_attachment(1<<i);
 138         check_size();
 139 }
 140
 141 FramebufferStatus Framebuffer::check_status() const
 142 {
 143         Bind _bind(this, true);
 144         return static_cast<FramebufferStatus>(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
 145 }
 146
 147 void Framebuffer::clear(BufferBits bits)
 148 {
 149         Bind _bind(this, true);
 150         glClear(bits);
 151 }
 152
 153 void Framebuffer::bind() const
 154 {
 155         if(set_current(this))
 156         {
 157                 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, id);
 158                 if(dirty)
 159                 {
 160                         update_attachment(dirty);
 161                         dirty = 0;
 162                 }
 163                 if(width && height)
 164                         glViewport(0, 0, width, height);
 165         }
 166 }
 167
 168 const Framebuffer *Framebuffer::current()
 169 {
 170         if(!cur_obj)
 171                 cur_obj = &system();
 172         return cur_obj;
 173 }
 174
 175 void Framebuffer::unbind()
 176 {
 177         system().bind();
 178 }
 179
 180 Framebuffer &Framebuffer::system()
 181 {
 182         static Framebuffer sys_framebuf(0);
 183         return sys_framebuf;
 184 }
 185
 186 unsigned Framebuffer::get_attachment_index(FramebufferAttachment attch)
 187 {
 188         for(unsigned i=0; i<attachments.size(); ++i)
 189                 if(attachments[i].attachment==attch)
 190                         return i;
 191         attachments.push_back(Attachment(attch));
 192         return attachments.size()-1;
 193 }
 194
 195
 196 Framebuffer::Attachment::Attachment(FramebufferAttachment a):
 197         attachment(a),
 198         type(0),
 199         level(0)
 200 { }
 201
 202 void Framebuffer::Attachment::set(Renderbuffer &r)
 203 {
 204         type = GL_RENDERBUFFER_EXT;
 205         rbuf = &r;
 206         level = 0;
 207 }
 208
 209 void Framebuffer::Attachment::set(Texture &t, unsigned l)
 210 {
 211         type = t.get_target();
 212         tex = &t;
 213         level = l;
 214 }
 215
 216 void Framebuffer::Attachment::clear()
 217 {
 218         type = 0;
 219 }
 220
 221 } // namespace GL
 222 } // namespace Msp