--- C:\DOCUME~1\xxx\LOCALS~1\Temp\GeometryShader.cs-revBASE.svn000.tmp.cs	zo aug 23 17:01:54 2009
+++ N:\opentk\Source\Examples\OpenGL\EXT\GeometryShader.cs	zo aug 23 17:02:57 2009
@@ -57,9 +57,9 @@
                 Exit();
             }
 
-            // create a shader object.
+            // Create a program object.
             shaderProgram = GL.CreateProgram();
-            // create shader objects for all three types.
+            // Create shader objects for all three types.
             int vert = GL.CreateShader(ShaderType.VertexShader);
             int frag = GL.CreateShader(ShaderType.FragmentShader);
             int geom = GL.CreateShader(ShaderType.GeometryShaderExt);
@@ -122,31 +122,33 @@
             compileShader(vert, vertSource);
             compileShader(geom, geomSource);
 
-            // attach shaders and link the program.
+            // The next three program parameters must be set before the program is linked.
+
+            // Set the input type of the primitives we are going to feed the geometry shader, this should be the same as
+            // the primitive type given to GL.Begin. If the types do not match a GL error will occur (todo: verify GL_INVALID_ENUM, on glBegin)
+            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryInputTypeExt, (int)All.Lines);
+            // Set the output type of the geometry shader. Becasue we input Lines we will output LineStrip(s).
+            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryOutputTypeExt, (int)All.LineStrip);
+
+            // We must tell the shader program how much vertices the geometry shader will output (at most).
+            // The simple way is to query the maximum and use that.
+            int tmp;
+            // Get the maximum amount of vertices into tmp.
+            GL.GetInteger((GetPName)ExtGeometryShader4.MaxGeometryOutputVerticesExt, out tmp);
+            // And feed amount that to the shader program. (0x0400 on a HD3850, with catalyst 9.8)
+            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryVerticesOutExt, tmp);
+
+            // Attach shaders and link the program.
             GL.AttachShader(shaderProgram, frag);
             GL.AttachShader(shaderProgram, vert);
             GL.AttachShader(shaderProgram, geom);
             GL.LinkProgram(shaderProgram);
 
-            // output link info log.
+            // Output link info log.
             string info;
             GL.GetProgramInfoLog(shaderProgram, out info);
             Debug.WriteLine(info);
 
-            // Set the input type of the primitives we are going to feed the geometry shader, this should be the same as
-            // the primitive type given to GL.Begin. If the types do not match a GL error will occur (todo: verify GL_INVALID_ENUM, on glBegin)
-            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryInputTypeExt, (int)All.Lines);
-            // Set the output type of the geometry shader. Becasue we input Lines we will output LineStrip(s).
-            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryOutputTypeExt, (int)All.LineStrip);
-
-            // We must tell the shader program how much vertices the geometry shader will output (at most).
-            // The simple way is to query the maximum and use that.
-            int tmp;
-            // Get the maximum amount of vertices into tmp.
-            GL.GetInteger((GetPName)ExtGeometryShader4.MaxGeometryOutputVerticesExt, out tmp);
-            // And feed amount that to the shader program. (0x0400 on a HD3850, with catalyst 9.8)
-            GL.Ext.ProgramParameter(shaderProgram, ExtGeometryShader4.GeometryVerticesOutExt, tmp);
-
             // Set clearcolor and bind the shader program.
             GL.ClearColor(0.1f, 0.1f, 0.1f, 0.1f);
             GL.UseProgram(shaderProgram);
@@ -207,7 +209,7 @@
             OpenTK.Matrix4 ortho = OpenTK.Matrix4.CreateOrthographicOffCenter(-1, 1, -1, 1, 1, -1);
             GL.LoadMatrix(ref ortho);
 
-            // Set selector state back to matrix mode
+            // Set selector state back to modelview matrix mode
             GL.MatrixMode(MatrixMode.Modelview);
             base.OnResize(e);