示例#1
0
func initStars() {
	// Create the first stars
	for loop, _ := range stars {
		stars[loop] = &Star{
			angle: 0.0,
			dist:  (gl.GLfloat(loop) / gl.GLfloat(num)) * 5.0,
			r:     gl.GLubyte(rand.Float32() * 255),
			g:     gl.GLubyte(rand.Float32() * 255),
			b:     gl.GLubyte(rand.Float32() * 255),
		}
	}
}
示例#2
0
// Here goes our drawing code
func drawGLScene() {
	// Clear the screen and depth buffer
	gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
	gl.BindTexture(gl.TEXTURE_2D, uint(texture))

	for loop, star := range stars {
		gl.LoadIdentity()
		gl.Translatef(0.0, 0.0, float32(zoom))
		gl.Rotatef(float32(tilt), 1.0, 0.0, 0.0)
		gl.Rotatef(float32(star.angle), 0.0, 1.0, 0.0)
		gl.Translatef(float32(star.dist), 0.0, 0.0)
		gl.Rotatef(float32(-star.angle), 0.0, 1.0, 0.0)
		gl.Rotatef(float32(-tilt), 1.0, 0.0, 0.0)

		if twinkle {
			other := stars[(num-loop)-1]
			gl.Color4ub(uint8(other.r), uint8(other.g), uint8(other.b), 255)
			gl.Begin(gl.QUADS)
			gl.TexCoord2f(0.0, 0.0)
			gl.Vertex3f(-1.0, -1.0, 0.0)
			gl.TexCoord2f(1.0, 0.0)
			gl.Vertex3f(1.0, -1.0, 0.0)
			gl.TexCoord2f(1.0, 1.0)
			gl.Vertex3f(1.0, 1.0, 0.0)
			gl.TexCoord2f(0.0, 1.0)
			gl.Vertex3f(-1.0, 1.0, 0.0)
			gl.End()
		}

		gl.Rotatef(float32(spin), 0.0, 0.0, 1.0)
		gl.Color4ub(uint8(star.r), uint8(star.g), uint8(star.b), 255)
		gl.Begin(gl.QUADS)
		gl.TexCoord2f(0.0, 0.0)
		gl.Vertex3f(-1.0, -1.0, 0.0)
		gl.TexCoord2f(1.0, 0.0)
		gl.Vertex3f(1.0, -1.0, 0.0)
		gl.TexCoord2f(1.0, 1.0)
		gl.Vertex3f(1.0, 1.0, 0.0)
		gl.TexCoord2f(0.0, 1.0)
		gl.Vertex3f(-1.0, 1.0, 0.0)
		gl.End()

		spin += 0.01
		star.angle += gl.GLfloat(loop) / gl.GLfloat(num)
		star.dist -= 0.01

		if star.dist < 0.0 {
			star.dist += 5.0
			star.r = gl.GLubyte(rand.Float32() * 255)
			star.g = gl.GLubyte(rand.Float32() * 255)
			star.b = gl.GLubyte(rand.Float32() * 255)
		}
	}

	// Draw to the screen
	sdl.GL_SwapBuffers()

	// Gather our frames per second
	frames++
	t := sdl.GetTicks()
	if t-t0 >= 5000 {
		seconds := (t - t0) / 1000.0
		fps := frames / seconds
		fmt.Println(frames, "frames in", seconds, "seconds =", fps, "FPS")
		t0 = t
		frames = 0
	}
}