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():
  21         width(0),
  22         height(0)
  23 {
  24         static RequireExtension _ext("GL_EXT_framebuffer_object");
  25
  26         glGenFramebuffersEXT(1, &id);
  27         bind();
  28 }
  29
  30 Framebuffer::~Framebuffer()
  31 {
  32         glDeleteFramebuffersEXT(1, &id);
  33 }
  34
  35 void Framebuffer::bind() const
  36 {
  37         if(!cur_fbo)
  38                 get(GL_VIEWPORT, sys_viewport);
  39         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, id);
  40         cur_fbo=this;
  41         if(width && height)
  42                 viewport(0, 0, width, height);
  43 }
  44
  45 void Framebuffer::attach(FramebufferAttachment attch, Renderbuffer &rbuf)
  46 {
  47         maybe_bind();
  48         glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch, GL_RENDERBUFFER_EXT, rbuf.get_id());
  49         get_or_create_attachment(attch)=rbuf;
  50         check_size();
  51 }
  52
  53 void Framebuffer::attach(FramebufferAttachment attch, Texture2D &tex, int level)
  54 {
  55         maybe_bind();
  56         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, attch, tex.get_target(), tex.get_id(), level);
  57         get_or_create_attachment(attch)=tex;
  58         check_size();
  59 }
  60
  61 void Framebuffer::detach(FramebufferAttachment attch)
  62 {
  63         maybe_bind();
  64         for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
  65                 if(i->attachment==attch)
  66                 {
  67                         if(i->type==GL_RENDERBUFFER_EXT)
  68                                 glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, attch, GL_RENDERBUFFER_EXT, 0);
  69                         else if(i->type==GL_TEXTURE_2D)
  70                                 glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, attch, GL_TEXTURE_2D, 0, 0);
  71                         attachments.erase(i);
  72                         check_size();
  73                         return;
  74                 }
  75 }
  76
  77 FramebufferStatus Framebuffer::check_status() const
  78 {
  79         maybe_bind();
  80         return static_cast<FramebufferStatus>(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT));
  81 }
  82
  83 const Framebuffer *Framebuffer::current()
  84 {
  85         return cur_fbo;
  86 }
  87
  88 void Framebuffer::unbind()
  89 {
  90         if(cur_fbo)
  91         {
  92                 glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
  93                 cur_fbo=0;
  94                 viewport(sys_viewport[0], sys_viewport[1], sys_viewport[2], sys_viewport[3]);
  95         }
  96 }
  97
  98 void Framebuffer::maybe_bind() const
  99 {
 100         if(cur_fbo!=this)
 101                 bind();
 102 }
 103
 104 Framebuffer::Attachment &Framebuffer::get_or_create_attachment(FramebufferAttachment attch)
 105 {
 106         for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
 107                 if(i->attachment==attch)
 108                         return *i;
 109         attachments.push_back(Attachment(attch));
 110         return attachments.back();
 111 }
 112
 113 void Framebuffer::check_size()
 114 {
 115         if(!attachments.empty())
 116         {
 117                 const Attachment &attch=attachments.front();
 118                 if(attch.type==GL_RENDERBUFFER_EXT)
 119                 {
 120                         width=attch.rbuf->get_width();
 121                         height=attch.rbuf->get_height();
 122                 }
 123                 else if(attch.type==GL_TEXTURE_2D)
 124                 {
 125                         Texture2D *tex=static_cast<Texture2D *>(attch.tex);
 126                         width=tex->get_width();
 127                         height=tex->get_height();
 128                 }
 129                 if(cur_fbo==this)
 130                         viewport(0, 0, width, height);
 131         }
 132 }
 133
 134 const Framebuffer *Framebuffer::cur_fbo=0;
 135 int Framebuffer::sys_viewport[4]={ 0, 0, 1, 1 };
 136
 137
 138 Framebuffer::Attachment::Attachment(FramebufferAttachment a):
 139         attachment(a),
 140         type(0)
 141 { }
 142
 143 Framebuffer::Attachment &Framebuffer::Attachment::operator=(Renderbuffer &r)
 144 {
 145         type=GL_RENDERBUFFER_EXT;
 146         rbuf=&r;
 147         return *this;
 148 }
 149
 150 Framebuffer::Attachment &Framebuffer::Attachment::operator=(Texture &t)
 151 {
 152         type=t.get_target();
 153         tex=&t;
 154         return *this;
 155 }
 156
 157
 158 void viewport(int x, int y, unsigned w, unsigned h)
 159 {
 160         glViewport(x, y, w, h);
 161 }
 162
 163 void clear(BufferBits bits)
 164 {
 165         glClear(bits);
 166 }
 167
 168 void draw_buffer(RWBuffer buf)
 169 {
 170         glDrawBuffer(buf);
 171 }
 172
 173 void read_buffer(RWBuffer buf)
 174 {
 175         glReadBuffer(buf);
 176 }
 177
 178 } // namespace GL
 179 } // namespace Msp