func (s *Sim) Paint(p *qml.Painter) {
diffuseColor := []gl.Float{0.5, 1, 1, 0}
diffusePos := []gl.Float{0, 0, 1, 0}
gl.Rotated(-45, 1, 0, 0)
gl.Lightfv(gl.LIGHT0, gl.DIFFUSE, diffuseColor)
gl.Lightfv(gl.LIGHT0, gl.POSITION, diffusePos)
gl.Enable(gl.LIGHT0)
gl.Enable(gl.LIGHTING)
gl.Enable(gl.DEPTH_TEST)
gl.Enable(gl.NORMALIZE)
gl.ClearColor(0, 0, 0, 0)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
width := gl.Double(s.Int("width"))
height := gl.Double(s.Int("height"))
gl.PushMatrix()
scale := width / 5
gl.Translated(0.5*width, 0.5*height, 0)
gl.Scaled(scale, scale, scale)
for i := range body {
pos := body[i].Position()
gl.PushMatrix()
gl.Translated(gl.Double(pos[0]), gl.Double(pos[1]), gl.Double(pos[2]))
gl.Scaled(sphereRadius, sphereRadius, sphereRadius)
drawSphere(16, 16)
gl.PopMatrix()
}
gl.PopMatrix()
}
func drawSphere(latSegs, lonSegs int) {
for i := 0; i < latSegs; i++ {
latFrac0, latFrac1 := float64(i)/float64(latSegs), float64(i+1)/float64(latSegs)
latAngle0, latAngle1 := math.Pi*(latFrac0-0.5), math.Pi*(latFrac1-0.5)
z0, z1 := math.Sin(latAngle0), math.Sin(latAngle1)
r0, r1 := math.Cos(latAngle0), math.Cos(latAngle1)
gl.Begin(gl.QUAD_STRIP)
for j := 0; j <= lonSegs; j++ {
lonFrac := float64(j) / float64(lonSegs)
lonAngle := 2 * math.Pi * lonFrac
x0, x1 := r0*math.Cos(lonAngle), r1*math.Cos(lonAngle)
y0, y1 := r0*math.Sin(lonAngle), r1*math.Sin(lonAngle)
gl.Normal3d(gl.Double(x0), gl.Double(y0), gl.Double(z0))
gl.Vertex3d(gl.Double(x0), gl.Double(y0), gl.Double(z0))
gl.Normal3d(gl.Double(x1), gl.Double(y1), gl.Double(z1))
gl.Vertex3d(gl.Double(x1), gl.Double(y1), gl.Double(z1))
}
gl.End()
}
}