{curl 7.0 applet}

{import * from CURL.GRAPHICS.SCENE}

{define-proc public
    {sphere-vertices-normals hres:int, vres:int}:
    ({Array-of FloatDistance3d}, {Array-of FloatDirection3d})
    let vertices:{Array-of FloatDistance3d} =
        {{Array-of FloatDistance3d}.from-size
            (hres + 1) * (vres + 1),
            {FloatDistance3d 0f(m), 0f(m), 0f(m)}
        }
    let normals:{Array-of FloatDirection3d} =
        {{Array-of FloatDirection3d}.from-size
            (hres + 1) * (vres + 1),
            {FloatDirection3d 0, 0, 0}
        }
    let n:int = 0
    {for i:int = 0 to hres do
        {for j:int = 0 to vres do
            let azimuth:FloatAngle = -180f(deg) + i * 360f(deg)/hres
            let elevation:FloatAngle =  -90f(deg) + j * 180f(deg)/vres
            set vertices[n] =
                {FloatDistance3d
                    ({cos azimuth} * {cos elevation}) * 1f(in),
                    ({sin azimuth} * {cos elevation}) * 1f(in),
                    ({sin elevation}) * 1f(in)
                }
            set normals[n] = vertices[n]/1f(in)
            {inc n}
        }
    }
    {return vertices, normals}
}
{define-proc public
    {mesh-faces hres:int, vres:int}:#{Array-of #{Array-of int}}
    let faces:#{Array-of #{Array-of int}} =
        {{Array-of #{Array-of int}}.from-size hres * vres, null}
    let n:int = 0
    {for i:int = 0 to hres - 1 do
        {for j:int = 0 to vres - 1 do
            set faces[n] =
                {new {Array-of int},
                    i       * (vres + 1) + j,
                    (i + 1) * (vres + 1) + j,
                    (i + 1) * (vres + 1) + j + 1,
                    i       * (vres + 1) + j + 1
                }
            {inc n}
        }
    }
    {return faces}
}
{define-class public Sphere {inherits PolygonSet}

  field hres:int
  field vres:int
  {constructor public {default
                          hres:int = 20,
                          vres:int = 10,
                          ...}
    {construct-super ... }
    set self.hres = hres
    set self.vres = vres
    set (self.vertices, self.normals) =
        {sphere-vertices-normals hres, vres}
    set self.faces = {mesh-faces hres, vres}
  }
  {method open public
    {paint renderer:Renderer3d,
        viewport-width:Distance, viewport-height:Distance}:void
    {with
        renderer.cull-face-enabled? = true
     do
        {super.paint renderer, viewport-width, viewport-height}
    }

  }
  {method open public
    {get-local-bounding-box
        check-visibility?:bool = false
    }:(min-xyz:Distance3d,
       max-xyz:Distance3d,
       valid-bounds?:bool)
    {return
        {Distance3d -1in, -1in, -1in},
        {Distance3d 1in, 1in, 1in},
        not check-visibility? or self.bounding-box-or-object-visible?
    }
  }
}
{value
    let scene:Scene = {Scene}
    let camera:Camera = scene.camera
    let camera-target:Distance3d = {Distance3d 0ft, 0ft, 0ft}
    let camera-position:Distance3d = {Distance3d 2in, -1in, 2in}
    let camera-direction:Direction3d =
        {(camera-target - camera-position).direction}
    let up:Direction3d = {Direction3d 0, 0, 1}
    {camera.set-orientation-and-position
        camera-direction, up, position = camera-position}
    set camera.projection = Projection.perspective
    set camera.near-clipping-plane = 1in
    set camera.far-clipping-plane = 20ft
    set camera.field-of-view = 90degrees
    let dir-light-color:Color = {Palette.get-magenta} ||magenta
    let dir-light:DirectionalLight =
        {DirectionalLight
            direction =  {Direction3d -1, 0, 0},
            diffuse-color = dir-light-color,
            specular-color = dir-light-color
        }
    {scene.add-object dir-light}
    let sphere:Sphere =
        {Sphere
            lighting-enabled? = true,
            hres = 50, vres = 25,
            fill-pattern = {FillPattern.get-white}
        }
    {scene.add-object sphere}
    let scene-graphic:SceneGraphic =
        {SceneGraphic
            scene,
            width=2in,
            height=2in,
            background = {FillPattern.get-black}
        }
    scene-graphic
}