private static void OnClose()
{
star.Dispose();
starUV.Dispose();
starQuads.Dispose();
starTexture.Dispose();
program.DisposeChildren = true;
program.Dispose();
fontProgram.DisposeChildren = true;
fontProgram.Dispose();
font.FontTexture.Dispose();
information.Dispose();
}
private static void OnRenderFrame()
{
watch.Stop();
float deltaTime = (float)watch.ElapsedTicks / System.Diagnostics.Stopwatch.Frequency;
watch.Restart();
// perform rotation of the scene depending on keyboard input
if (right)
{
phi += deltaTime;
}
if (left)
{
phi -= deltaTime;
}
if (up)
{
theta += deltaTime;
}
if (down)
{
theta -= deltaTime;
}
if (theta < 0)
{
theta += (float)Math.PI * 2;
}
// set up the viewport and clear the previous depth and color buffers
Gl.Viewport(0, 0, width, height);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// make sure the shader program and texture are being used
Gl.UseProgram(program.ProgramID);
Gl.BindTexture(starTexture);
// calculate the camera position using some fancy polar co-ordinates
Vector3 position = 20 * new Vector3((float)(Math.Cos(phi) * Math.Sin(theta)), (float)Math.Cos(theta), (float)(Math.Sin(phi) * Math.Sin(theta)));
Vector3 upVector = ((theta % (Math.PI * 2)) > Math.PI) ? new Vector3(0, 1, 0) : new Vector3(0, -1, 0);
program["view_matrix"].SetValue(Matrix4.LookAt(position, Vector3.Zero, upVector));
// loop through the stars, drawing each one
for (int i = 0; i < stars.Count; i++)
{
// set the position and color of this star
program["model_matrix"].SetValue(Matrix4.CreateTranslation(new Vector3(stars[i].dist, 0, 0)) * Matrix4.CreateRotationZ(stars[i].angle));
program["color"].SetValue(stars[i].color);
Gl.BindBufferToShaderAttribute(star, program, "vertexPosition");
Gl.BindBufferToShaderAttribute(starUV, program, "vertexUV");
Gl.BindBuffer(starQuads);
Gl.DrawElements(BeginMode.Triangles, starQuads.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);
// update the position of the star
stars[i].angle += (float)i / stars.Count * deltaTime * 2;
stars[i].dist -= 0.2f * deltaTime;
// if we've reached the center then move this star outwards and give it a new color
if (stars[i].dist < 0f)
{
stars[i].dist += 5f;
stars[i].color = new Vector3((float)generator.NextDouble(), (float)generator.NextDouble(), (float)generator.NextDouble());
}
}
// bind the font program as well as the font texture
Gl.UseProgram(fontProgram.ProgramID);
Gl.BindTexture(font.FontTexture);
// build this string every frame, since theta and phi can change
FontVAO vao = font.CreateString(fontProgram, string.Format("Theta: {0:0.000}, Phi: {1:0.000}", theta, phi), BMFont.Justification.Right);
vao.Position = new Vector2(width / 2 - 10, height / 2 - font.Height - 10);
vao.Draw();
vao.Dispose();
// draw the tutorial information, which is static
information.Draw();
Glut.glutSwapBuffers();
}
