func display() {
gl.Clear(gl.COLOR_BUFFER_BIT)
bitmap_output(40, 35, "This is written in a GLUT bitmap font.", glut.BITMAP_TIMES_ROMAN_24)
bitmap_output(30, 210, "More bitmap text is a fixed 9 by 15 font.", glut.BITMAP_9_BY_15)
bitmap_output(70, 240, " Helvetica is yet another bitmap font.", glut.BITMAP_HELVETICA_18)
gl.MatrixMode(gl.PROJECTION)
gl.PushMatrix()
gl.LoadIdentity()
glu.Perspective(40.0, 1.0, 0.1, 20.0)
gl.MatrixMode(gl.MODELVIEW)
gl.PushMatrix()
glu.LookAt(0.0, 0.0, 4.0, /* eye is at (0,0,30) */
0.0, 0.0, 0.0, /* center is at (0,0,0) */
0.0, 1.0, 0.0) /* up is in postivie Y direction */
gl.PushMatrix()
gl.Translatef(0, 0, -4)
gl.Rotatef(50, 0, 1, 0)
stroke_output(-2.5, 1.1, " This is written in a", glut.STROKE_ROMAN)
stroke_output(-2.5, 0, " GLUT stroke font.", glut.STROKE_ROMAN)
stroke_output(-2.5, -1.1, "using 3D perspective.", glut.STROKE_ROMAN)
gl.PopMatrix()
gl.MatrixMode(gl.MODELVIEW)
gl.PopMatrix()
gl.MatrixMode(gl.PROJECTION)
gl.PopMatrix()
gl.MatrixMode(gl.MODELVIEW)
gl.Flush()
}
func drawShip(angle float32) {
gl.PushMatrix()
gl.Translatef(x, y, 0.0)
gl.Rotatef(angle, 0.0, 0.0, 1.0)
if thrust {
gl.Color3f(1.0, 0.0, 0.0)
gl.Begin(gl.LINE_STRIP)
gl.Vertex2f(-0.75, -0.5)
gl.Vertex2f(-1.75, 0)
gl.Vertex2f(-0.75, 0.5)
gl.End()
}
gl.Color3f(1.0, 1.0, 0.0)
gl.Begin(gl.LINE_LOOP)
gl.Vertex2f(2.0, 0.0)
gl.Vertex2f(-1.0, -1.0)
gl.Vertex2f(-0.5, 0.0)
gl.Vertex2f(-1.0, 1.0)
gl.Vertex2f(2.0, 0.0)
gl.End()
if shield {
gl.Color3f(0.1, 0.1, 1.0)
gl.Begin(gl.LINE_LOOP)
for rad := 0.0; rad < 12.0; rad += 1.0 {
gl.Vertex2f(
float32(2.3*math.Cos(2*float64(rad)/math.Pi)+0.2),
float32(2.0*math.Sin(2*float64(rad)/math.Pi)))
}
gl.End()
}
gl.PopMatrix()
}
func stroke_output(x, y float32, str string, font glut.StrokeFont) {
gl.PushMatrix()
gl.Translatef(x, y, 0)
gl.Scalef(0.005, 0.005, 0.005)
for _, ch := range str {
font.Character(ch)
}
gl.PopMatrix()
}
