Instead of using some complex functions, you should probably try to simply use simpler constructs to see if everything is correctly setup: glBegin gl_TRIANGLES glVertex3f 0.75 0.75 0.0 glVertex3f 0.75 (-0.75) 0.0 glVertex3f (-0.75) (-0.75) 0.0 glEnd or glBegin gl_TRIANGLES glVertex4f 0.75 0.75 0.0 1 glVertex4f 0.75 (-0.75) 0.0 1 glVertex4f (-0.75) (-0.75) 0.0 1 glEnd Your program shows something using this. I haven't looked at the tutorial you're following but you should stick to the OpenGL references as i've found that most tutorials are crap (there are still good ones like NeHe stuff i think). Back to your problem: you should use GLfloat and not Float in your vertex definition. Your buffer definition should be: withArray verticies $ \ary -> glBufferData gl_ARRAY_BUFFER -- (fromIntegral $ sizeOf ary) (fromIntegral (length verticies * sizeOf (0::GLfloat))) ary gl_STATIC_DRAW The C version may get away with (sizeof vertices) because it uses the actual array (may be false) size but you have to compute the size of the array that is the number of elements times the size of elements. You're trying to draw from a VBO so i think you should not use --glEnableVertexAttribArray 0 You use the VBO: You need to enable client state glEnableClientState gl_VERTEX_ARRAY Bind the buffer that holds the data glBindBuffer gl_ARRAY_BUFFER buffer Set the bound buffer to be the vertex coords glVertexPointer 4 gl_FLOAT 0 nullPtr Call the draw glDrawArrays gl_TRIANGLES 0 3 glDisableClientState gl_VERTEX_ARRAY This may be explained properly in: http://nehe.gamedev.net/tutorial/vertex_buffer_objects/22002/ On Mon, 2013-03-11 at 01:45 -0500, Michael Baker wrote:
I'm trying to follow this book on OpenGL: http://www.arcsynthesis.org/gltut/Basics/Tut01%20Following% 20the%20Data.html
I'm trying to follow the examples using the OpenGLRaw package as the OpenGL package doesn't map very neatly to any of the examples. For instance, it is not clear to me now to create and use the vertex array used in the example that I linked to.
However, I'm struggling a bit because I haven't used Haskell's foreign interface before. Here is an attempt which is expected to draw a triangle, but instead draws nothing: http://hpaste.org/83837
Does anyone know of a tutorial for OpenGLRaw or the foreign interface that might help me understand how to marshall data around? It seems like many people turn to OpenGLRaw when they're learning OpenGL so that they can follow the tutorials. I imagine it would be useful to have a guide out there that covers how to actually use it.
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners