Android :: OpenGL Coding - Emulator Doesn't Work

After spending the better half of this day getting my HTC Magic to work in developer mode, I've now found that some of my frist openGL coding attempts that appeared to work fine in the emulator doesn't work as expected on the device. I've narrowed this down to glColorf(r, g, b, a) not working as expected on the device itself. The provided OpenGL samples do work though. So for example, after modifying Cube.java from the samples to the below code I find that I get the expected grey square on the emulator but a blank white screen (background fill colour) on the device.

class Cube { public Cube() { int one = 0x10000; int vertices[] = { -one, -one, -one, one, one, -one, one, one, };
// Buffers to be passed to gl*Pointer() functions // must be direct, i.e., they must be placed on the // native heap where the garbage collector cannot // move them. // // Buffers with multi-byte datatypes (e.g., short, int, float) // must have their byte order set to native order
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4); vbb.order(ByteOrder.nativeOrder()); mVertexBuffer = vbb.asIntBuffer(); mVertexBuffer.put(vertices); mVertexBuffer.position(0); }
public void draw(GL10 gl) { gl.glFrontFace(GL10.GL_CW); gl.glVertexPointer(2, gl.GL_FIXED, 0, mVertexBuffer); gl.glColor4f(0.5f, 0.5f, 0.5f, 0.5f); gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4); }
private IntBuffer mVertexBuffer;