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