Prefer glDrawBuffers over glDrawBuffer

[libs/gl.git] / source / framebuffer.cpp

diff --git a/source/framebuffer.cpp b/source/framebuffer.cpp
index 43b0f94b82e4c882327ef686491453a1bc7cf263..f4e5a9445e0bce678292c6da327995daef70cc0a 100644 (file)
--- a/source/framebuffer.cpp
+++ b/source/framebuffer.cpp
@@ -1,6 +1,7 @@
+#include <msp/gl/extensions/arb_draw_buffers.h>
+#include <msp/gl/extensions/ext_framebuffer_blit.h>
+#include <msp/gl/extensions/ext_framebuffer_object.h>
 #include "error.h"
-#include "ext_framebuffer_blit.h"
-#include "ext_framebuffer_object.h"
 #include "framebuffer.h"
 #include "misc.h"
 #include "renderbuffer.h"
@@ -11,6 +12,42 @@ using namespace std;
 namespace Msp {
 namespace GL {
 
+void operator<<(LexicalConverter &conv, FramebufferStatus status)
+{
+       switch(status)
+       {
+       case FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
+               conv.result("incomplete attachment");
+               break;
+       case FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
+               conv.result("missing attachment");
+               break;
+       case FRAMEBUFFER_INCOMPLETE_DIMENSIONS:
+               conv.result("mismatched attachment dimensions");
+               break;
+       case FRAMEBUFFER_INCOMPLETE_FORMATS:
+               conv.result("mismatched attachment formats");
+               break;
+       case FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
+               conv.result("missing draw buffer attachment");
+               break;
+       case FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
+               conv.result("missing read buffer attachment");
+               break;
+       case FRAMEBUFFER_UNSUPPORTED:
+               conv.result("unsupported");
+               break;
+       default:
+               conv.result(lexical_cast<string, unsigned>(status, "%#x"));
+               break;
+       }
+}
+
+framebuffer_incomplete::framebuffer_incomplete(FramebufferStatus status):
+       runtime_error(lexical_cast<string>(status))
+{ }
+
+
 Framebuffer::Framebuffer(unsigned i):
        id(i),
        dirty(0)
@@ -18,10 +55,9 @@ Framebuffer::Framebuffer(unsigned i):
        if(id)
                throw invalid_argument("System framebuffer must have id 0");
 
-       int viewport[4];
-       glGetIntegerv(GL_VIEWPORT, viewport);
-       width = viewport[2];
-       height = viewport[3];
+       glGetIntegerv(GL_VIEWPORT, &view.left);
+       width = view.width;
+       height = view.height;
 }
 
 Framebuffer::Framebuffer():
@@ -46,7 +82,8 @@ void Framebuffer::update_attachment(unsigned mask) const
 {
        if(current()==this)
        {
-               GLenum color_buf = GL_NONE;
+               std::vector<GLenum> color_bufs;
+               color_bufs.reserve(attachments.size());
                for(unsigned i=0; i<attachments.size(); ++i)
                {
                        const Attachment &attch = attachments[i];
@@ -69,10 +106,19 @@ void Framebuffer::update_attachment(unsigned mask) const
                        }
 
                        if(attch.attachment>=COLOR_ATTACHMENT0 && attch.attachment<=COLOR_ATTACHMENT3)
-                               color_buf = attch.attachment;
+                               color_bufs.push_back(attch.attachment);
                }
 
-               glDrawBuffer(color_buf);
+               if(color_bufs.size()>1)
+                       static Require _req(ARB_draw_buffers);
+
+               GLenum first_buffer = (color_bufs.empty() ? GL_NONE : color_bufs.front());
+               if(ARB_draw_buffers)
+                       glDrawBuffers(color_bufs.size(), &color_bufs[0]);
+               else
+                       glDrawBuffer(first_buffer);
+
+               glReadBuffer(first_buffer);
        }
        else
                dirty |= mask;
@@ -80,6 +126,7 @@ void Framebuffer::update_attachment(unsigned mask) const
 
 void Framebuffer::check_size()
 {
+       bool full_viewport = (view.left==0 && view.bottom==0 && view.width==width && view.height==height);
        for(vector<Attachment>::iterator i=attachments.begin(); i!=attachments.end(); ++i)
                if(i->type)
                {
@@ -99,8 +146,8 @@ void Framebuffer::check_size()
                                width = static_cast<TextureCube *>(i->tex)->get_size();
                                height = width;
                        }
-                       if(current()==this)
-                               glViewport(0, 0, width, height);
+                       if(full_viewport)
+                               reset_viewport();
                        break;
                }
 }
@@ -160,13 +207,36 @@ void Framebuffer::detach(FramebufferAttachment attch)
 
 FramebufferStatus Framebuffer::check_status() const
 {
-       Bind _bind(this, true);
+       BindRestore _bind(this);
        return static_cast<FramebufferStatus>(glCheckFramebufferStatus(GL_FRAMEBUFFER));
 }
 
+void Framebuffer::require_complete() const
+{
+       FramebufferStatus status = check_status();
+       if(status!=FRAMEBUFFER_COMPLETE)
+               throw framebuffer_incomplete(status);
+}
+
+void Framebuffer::viewport(int l, int b, unsigned w, unsigned h)
+{
+       view.left = l;
+       view.bottom = b;
+       view.width = w;
+       view.height = h;
+
+       if(current()==this)
+               glViewport(view.left, view.bottom, view.width, view.height);
+}
+
+void Framebuffer::reset_viewport()
+{
+       viewport(0, 0, width, height);
+}
+
 void Framebuffer::clear(BufferBits bits)
 {
-       Bind _bind(this, true);
+       BindRestore _bind(this);
        glClear(bits);
 }
 
@@ -213,13 +283,14 @@ void Framebuffer::bind() const
                        update_attachment(dirty);
                        dirty = 0;
                }
+
                if(width && height)
-                       glViewport(0, 0, width, height);
+                       glViewport(view.left, view.bottom, view.width, view.height);
        }
 }
 
 const Framebuffer *Framebuffer::current()
-{      
+{
        if(!cur_obj)
                cur_obj = &system();
        return cur_obj;
@@ -263,5 +334,13 @@ void Framebuffer::Attachment::clear()
        type = 0;
 }
 
+
+Framebuffer::Viewport::Viewport():
+       left(0),
+       bottom(0),
+       width(0),
+       height(0)
+{ }
+
 } // namespace GL
 } // namespace Msp