GLModel background is now transparent on off-screen screenshots. Typo

fix in editor.

fsl/fslview/editor/editor.py

@@ -257,7 +257,7 @@ class Editor(props.HasProperties):
         
     def _revertChange(self, change):
 
-        overlay = change.ovelay
+        overlay = change.overlay
         opts    = self._displayCtx.getOpts(overlay)
         
         self._displayCtx.selectOverlay(overlay)

fsl/fslview/gl/__init__.py

@@ -314,7 +314,8 @@ def getOSMesaContext():
         # We follow the same process as for the
         # wx.glcanvas.GLContext, described above 
         dummy = glarrays.GLubyteArray.zeros((640, 480, 43))
-        thismod._osmesaGLContext = osmesa.OSMesaCreateContext(gl.GL_RGBA, None)
+        thismod._osmesaGLContext = osmesa.OSMesaCreateContextExt(
+            gl.GL_RGBA, 8, 4, 0, None)
         osmesa.OSMesaMakeCurrent(thismod._osmesaGLContext,
                                  dummy,
                                  gl.GL_UNSIGNED_BYTE,

fsl/fslview/gl/glmodel.py

@@ -207,6 +207,8 @@ class GLModel(globject.GLObject):
         self._renderTexture.bindAsRenderTarget()
         self._renderTexture.setRenderViewport(xax, yax, lo, hi)
 
+        gl.glClearColor(0, 0, 0, 0)
+
         gl.glClear(gl.GL_COLOR_BUFFER_BIT)
         gl.glClear(gl.GL_DEPTH_BUFFER_BIT)
         gl.glClear(gl.GL_STENCIL_BUFFER_BIT)
@@ -249,8 +251,9 @@ class GLModel(globject.GLObject):
                               gl.GL_UNSIGNED_INT,
                               indices)
 
-        # third pass - render the intersection of the 
-        # front and back faces from the stencil buffer
+        # third pass - render the intersection
+        # of the front and back faces from the
+        # stencil buffer to the render texture
         gl.glColorMask(gl.GL_TRUE, gl.GL_TRUE, gl.GL_TRUE, gl.GL_TRUE)
 
         gl.glDisable(gl.GL_CLIP_PLANE0)