Add a Texturing class to encapsulate the state of multiple texturing units

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

diff --git a/source/texturing.cpp b/source/texturing.cpp
new file mode 100644 (file)
index 0000000..69c2b3c
--- /dev/null
+++ b/source/texturing.cpp
@@ -0,0 +1,105 @@
+/* $Id$
+
+This file is part of libmspgl
+Copyright © 2010  Mikko Rasa, Mikkosoft Productions
+Distributed under the LGPL
+*/
+
+#include "texenv.h"
+#include "texture.h"
+#include "texturing.h"
+#include "texunit.h"
+
+namespace Msp {
+namespace GL {
+
+Texturing::~Texturing()
+{
+       if(current()==this)
+               unbind();
+}
+
+void Texturing::attach(unsigned attch, const Texture &tex)
+{
+       set_attachment(attch, &tex, 0);
+}
+
+void Texturing::attach(unsigned attch, const Texture &tex, const TexEnv &env)
+{
+       set_attachment(attch, &tex, &env);
+}
+
+void Texturing::detach(unsigned attch)
+{
+       set_attachment(attch, 0, 0);
+}
+
+void Texturing::set_attachment(unsigned attch, const Texture *tex, const TexEnv *env)
+{
+       if(attch>=TexUnit::get_n_units())
+               throw InvalidParameterValue("Invalid texture attachment");
+
+       if(attachments.size()<=attch)
+               attachments.resize(attch+1);
+
+       attachments[attch].tex = tex;
+       attachments[attch].env = env;
+
+       if(current()==this)
+               bind_attachment(attch);
+}
+
+void Texturing::bind_attachment(unsigned i) const
+{
+       const Attachment &attch = attachments[i];
+       TexUnit::activate(i);
+       if(attch.tex)
+               attch.tex->bind();
+       else
+               Texture::unbind();
+       if(attch.env)
+               attch.env->bind();
+       else
+               TexEnv::unbind();
+}
+
+void Texturing::unbind_attachment(unsigned i)
+{
+       TexUnit::activate(i);
+       Texture::unbind();
+       TexEnv::unbind();
+}
+
+void Texturing::bind() const
+{
+       const Texturing *old = current();
+       if(set_current(this))
+       {
+               for(unsigned i=0; i<attachments.size(); ++i)
+                       bind_attachment(i);
+               if(old)
+               {
+                       for(unsigned i=attachments.size(); i<old->attachments.size(); ++i)
+                               unbind_attachment(i);
+               }
+       }
+}
+
+void Texturing::unbind()
+{
+       const Texturing *old = current();
+       if(set_current(0))
+       {
+               for(unsigned i=old->attachments.size(); i--;)
+                       unbind_attachment(i);
+       }
+}
+
+
+Texturing::Attachment::Attachment():
+       tex(0),
+       env(0)
+{ }
+
+} // namespace GL
+} // namespace Msp;