diff --git a/cmake_support/FindMesa.cmake b/cmake_support/FindMesa.cmake
new file mode 100644
index 0000000000000000000000000000000000000000..6b1c33d79271caa0ba33bec3f1fafe011c2267d8
--- /dev/null
+++ b/cmake_support/FindMesa.cmake
@@ -0,0 +1,37 @@
+set(OPENGL_FOUND FALSE)
+
+if (OPENGL_INCLUDE_DIR)
+
+ # in cache already
+ set(OPENGL_FOUND TRUE)
+
+else (OPENGL_INCLUDE_DIR)
+
+ if(DEFINED MESA_PREFIX)
+ set(_MESA_PREFIX ${MESA_PREFIX})
+ elseif(DEFINED ENV{MESA_PREFIX})
+ set(_MESA_PREFIX $ENV{MESA_PREFIX})
+ else()
+ message(FATAL_ERROR "no MESA_PREFIX given or found in environment")
+ endif()
+
+ if(DEFINED _MESA_PREFIX)
+ set(OPENGL_INCLUDE_DIR "${_MESA_PREFIX}/include" CACHE PATH "Mesa include")
+ set(OPENGL_LIBRARY_DIR "${_MESA_PREFIX}/lib" CACHE PATH "Mesa lib")
+ set(OPENGL_gl_LIBRARY "${_MESA_PREFIX}/lib/libGL.so" CACHE PATH "Mesa gl lib")
+ set(OPENGL_glu_LIBRARY "${_MESA_PREFIX}/lib/libGLU.so" CACHE PATH "Mesa glu lib")
+
+ set(OPENGL_LIBRARIES ${_MESA_PREFIX}/lib/libGL.so ${_MESA_PREFIX}/lib/libGLU.so ${_MESA_PREFIX}/lib/libOSMesa.so CACHE PATH "Mesa libs")
+ set(OPENGL_FOUND TRUE)
+ message(STATUS "Found Mesa include dir: ${OPENGL_INCLUDE_DIR}")
+ message(STATUS "Found Mesa lib dir: ${OPENGL_LIBRARY_DIR}")
+ message(STATUS "Using Mesa libs: ${OPENGL_LIBRARIES}")
+ endif()
+
+endif()
+
+if(NOT OPENGL_FOUND)
+ message(FATAL_ERROR "no Mesa found, please provide the correct location with MESA_PREFIX")
+endif()
+
+mark_as_advanced (OPENGL_INCLUDE_DIR)
diff --git a/modules/gfx/src/impl/mesa_offscreen_buffer.cc b/modules/gfx/src/impl/mesa_offscreen_buffer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..39ed73b5cfd090c4f451e0881364e9ba5778e05b
--- /dev/null
+++ b/modules/gfx/src/impl/mesa_offscreen_buffer.cc
@@ -0,0 +1,214 @@
+//------------------------------------------------------------------------------
+// This file is part of the OpenStructure project <www.openstructure.org>
+//
+// Copyright (C) 2008-2011 by the OpenStructure authors
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License as published by the Free
+// Software Foundation; either version 3.0 of the License, or (at your option)
+// any later version.
+// This library is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this library; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+//------------------------------------------------------------------------------
+
+/*
+ Author: Ansgar Philippsen
+*/
+
+#include <ost/log.hh>
+#include <ost/gfx/offscreen_buffer.hh>
+#include <ost/gfx/scene.hh>
+
+namespace ost { namespace gfx {
+
+static XVisualInfo* get_visinfo(Display* dpy, bool use_accum)
+{
+ int buf[64];
+ unsigned int bufc=0;
+ int d[]={16,12,8,6,4,1};
+ int c[]={16,12,8,6,5,4,2,1};
+ int a[]={8,4};
+ XVisualInfo *vis=NULL;
+
+ buf[bufc++]=GLX_RGBA;
+ buf[bufc++]=GLX_DEPTH_SIZE;
+ unsigned int depthi=bufc++;
+ buf[bufc++]=GLX_RED_SIZE;
+ unsigned int redi=bufc++;
+ buf[bufc++]=GLX_BLUE_SIZE;
+ unsigned int bluei=bufc++;
+ buf[bufc++]=GLX_GREEN_SIZE;
+ unsigned int greeni=bufc++;
+ unsigned int accumi=0;
+ if(use_accum) {
+ buf[bufc++]=GLX_ACCUM_RED_SIZE;
+ accumi=bufc++;
+ buf[bufc++]=GLX_ACCUM_BLUE_SIZE;
+ bufc++;
+ buf[bufc++]=GLX_ACCUM_GREEN_SIZE;
+ bufc++;
+ }
+ buf[bufc++]=None;
+
+ for(unsigned int j=0;j<sizeof(c)/sizeof(int);j++) {
+ for(unsigned int i=0;i<sizeof(d)/sizeof(int);i++) {
+ buf[depthi]=d[i];
+ buf[redi]=c[j];
+ buf[bluei]=c[j];
+ buf[greeni]=c[j];
+ if(use_accum) {
+ for(unsigned int k=0;k<sizeof(a)/sizeof(int);k++) {
+ buf[accumi+0]=a[k];
+ buf[accumi+2]=a[k];
+ buf[accumi+4]=a[k];
+ vis=glXChooseVisual(dpy,DefaultScreen(dpy),buf);
+ if(vis) return vis;
+ }
+ } else {
+ vis=glXChooseVisual(dpy,DefaultScreen(dpy),buf);
+ if(vis) return vis;
+ }
+ }
+ }
+ return NULL;
+}
+
+static void create_error(const std::string& m)
+{
+ LOG_ERROR("error creating offscreen rendering context: " << m);
+}
+
+OffscreenBuffer::OffscreenBuffer(unsigned int width, unsigned int height, const OffscreenBufferFormat& f, bool shared):
+ width_(width), height_(height), valid_(false), active_(false)
+{
+ LOG_DEBUG("offscreen buffer: checking for DISPLAY");
+ if(getenv("DISPLAY")==NULL) {
+ create_error("missing DISPLAY environment variable");
+ return;
+ }
+
+ LOG_DEBUG("offscreen buffer: XOpenDisplay");
+ dpy_ = XOpenDisplay(getenv("DISPLAY"));
+ if(dpy_==NULL) {
+ create_error("XOpenDisplay() failed");
+ return;
+ }
+
+#if 0
+ std::vector<int> attrib_list;
+ attrib_list.push_back(GLX_RENDER_TYPE);
+ attrib_list.push_back(GLX_RGBA_BIT);
+ attrib_list.push_back(GLX_DRAWABLE_TYPE);
+ attrib_list.push_back(GLX_PIXMAP_BIT);
+ attrib_list.push_back(GLX_DOUBLEBUFFER);
+ attrib_list.push_back(False);
+ attrib_list.push_back(GLX_DEPTH_SIZE);
+ attrib_list.push_back(f.dbits);
+ attrib_list.push_back(GLX_RED_SIZE);
+ attrib_list.push_back(f.cbits);
+ attrib_list.push_back(GLX_GREEN_SIZE);
+ attrib_list.push_back(f.cbits);
+ attrib_list.push_back(GLX_BLUE_SIZE);
+ attrib_list.push_back(f.cbits);
+ attrib_list.push_back(GLX_ALPHA_SIZE);
+ attrib_list.push_back(f.abits);
+ attrib_list.push_back(0);
+
+ int nelem=0;
+ LOG_DEBUG("offscreen buffer: glXChooseFBConfig");
+ fbconfig_ =glXChooseFBConfig(dpy_,0,&attrib_list[0],&nelem);
+ if(fbconfig_==0 || nelem==0) {
+ create_error("glXChooseFBConfig failed");
+ return;
+ }
+
+#else
+
+ visinfo_ = get_visinfo(dpy_,true);
+ if(!visinfo_) {
+ create_error("get_visinfo() failed");
+ return;
+ }
+
+ context_=glXCreateContext(dpy_, visinfo_, 0, False);
+ if(!context_) {
+ create_error("glxCreateContext() failed");
+ return;
+ }
+
+ pm_=XCreatePixmap(dpy_,RootWindow(dpy_,DefaultScreen(dpy_)),
+ width_,height_,visinfo_->depth);
+ if(!pm_) {
+ create_error("XCreatePixmap() failed");
+ return;
+ }
+
+ glxpm_=glXCreateGLXPixmap(dpy_, visinfo_, pm_);
+ if(!glxpm_) {
+ create_error("glXCreateGLXPixmap() failed");
+ return;
+ }
+
+#endif
+
+ valid_=true;
+}
+
+OffscreenBuffer::~OffscreenBuffer()
+{
+ if(valid_) {
+ glXDestroyGLXPixmap(dpy_,glxpm_);
+ XFreePixmap(dpy_,pm_);
+ glXDestroyContext(dpy_,context_);
+ valid_=false;
+ }
+}
+
+bool OffscreenBuffer::Resize(unsigned int width, unsigned int height)
+{
+ width_=width;
+ height_=height;
+
+ if(pm_) {
+ XFreePixmap(dpy_,pm_);
+ }
+ pm_=XCreatePixmap(dpy_,RootWindow(dpy_,DefaultScreen(dpy_)),
+ width_,height_,visinfo_->depth);
+ if(!pm_) {
+ create_error("XCreatePixmap() failed");
+ return false;
+ }
+
+ if(glxpm_) {
+ glXDestroyGLXPixmap(dpy_,glxpm_);
+ }
+ glxpm_=glXCreateGLXPixmap(dpy_, visinfo_, pm_);
+ if(!glxpm_) {
+ create_error("glXCreateGLXPixmap() failed");
+ return false;
+ }
+
+ if(active_) {
+ MakeActive();
+ }
+
+ return true;
+}
+
+bool OffscreenBuffer::MakeActive()
+{
+ if(glXMakeCurrent(dpy_,glxpm_,context_)==False) {
+ LOG_ERROR("error activating offscreen rendering: glXMakeCurrent() failed");
+ return false;
+ }
+ active_=true;
+ return true;
+}
+
+}} // ns
diff --git a/modules/gfx/src/impl/mesa_offscreen_buffer.hh b/modules/gfx/src/impl/mesa_offscreen_buffer.hh
new file mode 100644
index 0000000000000000000000000000000000000000..5ed38b942e7ab7a8b5c41924d1f3f2fcb7a44e24
--- /dev/null
+++ b/modules/gfx/src/impl/mesa_offscreen_buffer.hh
@@ -0,0 +1,64 @@
+//------------------------------------------------------------------------------
+// This file is part of the OpenStructure project <www.openstructure.org>
+//
+// Copyright (C) 2008-2011 by the OpenStructure authors
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License as published by the Free
+// Software Foundation; either version 3.0 of the License, or (at your option)
+// any later version.
+// This library is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this library; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+//------------------------------------------------------------------------------
+#ifndef OST_GFX_MESA_OFFSCREEN_BUFFER_HH
+#define OST_GFX_MESA_OFFSCREEN_BUFFER_HH
+
+#include <stack>
+#include <ost/gfx/glext_include.hh>
+#include <GL/glx.h>
+
+namespace ost { namespace gfx {
+
+/*
+ mesa implementation for offscreen buffers
+
+ Author: Ansgar Philippsen
+*/
+
+class OffscreenBuffer
+{
+public:
+ OffscreenBuffer(unsigned int width, unsigned int height, const OffscreenBufferFormat& f, bool shared=true);
+ ~OffscreenBuffer();
+
+ bool Resize(unsigned int w, unsigned int h);
+
+ bool MakeActive();
+
+ bool IsActive() {return active_;}
+
+ bool IsValid() {return valid_;}
+
+private:
+ int width_;
+ int height_;
+ bool valid_;
+ bool active_;
+
+ Display* dpy_;
+ XVisualInfo* visinfo_;
+ Pixmap pm_;
+ GLXPixmap glxpm_;
+ GLXContext context_;
+ GLXFBConfig* fbconfig_;
+};
+
+}} // ns
+
+#endif