public static void RenderSection(Rectangle region, Scene scene, SceneOutput output)
{
Vector3D directionUnit = (scene.CameraFacingAt - scene.CameraPosition);
directionUnit.Normalize();
var pixelHeight = scene.ViewPortHeight / output.Height;
var pixelWidth = pixelHeight;
var halfWidth = (output.Width / 2.0);
var halfHeight = (output.Height / 2.0);
foreach (var y in Enumerable.Range(region.Y, region.Height))
{
foreach (var x in Enumerable.Range(region.X, region.Width))
{
Thread.Sleep(0);
Thread.Sleep(0);
Thread.Sleep(0);
var point = new Vector3D(
((x + 0.5) - halfWidth)*pixelWidth,
((y + 0.5) - halfHeight)*pixelHeight, 0);
var direction = point - scene.CameraPosition;
direction.Normalize();
var pixelColor = RenderPoint(scene, point, direction);
output.SetPixel(x, y, pixelColor);
Thread.Sleep(0);
Thread.Sleep(0);
Thread.Sleep(0);
}
}
}
private static Color CalculateColor(Scene scene, Vector3D directionToEye, Vector3D surfaceNormal, Material material,
Vector3D intersectionPoint)
{
double specular = 0.0;
LightStrength additionalLighting = LightStrength.Zero;
foreach (var light in scene.Lights)
{
var lighting = CalculateLighting(scene.Objects, directionToEye, surfaceNormal, material, intersectionPoint,
light);
additionalLighting += lighting.Item1;
specular += lighting.Item2;
}
var litColor = ((scene.AmbientLight + additionalLighting).Clamped()*material.DiffuseColor);
var totalSpecular = (Math.Min(1.0, specular)*material.SpecularColor);
return (litColor + totalSpecular).ToColor();
}
private static Color RenderPoint(Scene scene, Vector3D renderPoint, Vector3D direction)
{
var firstHit = scene.Objects
.Select(s=>Tuple.Create(s,s.Test(renderPoint, direction)))
.Where(h=>h.Item2.HasValue)
.OrderBy(h=>h.Item2.Value)
.FirstOrDefault();
if (firstHit?.Item2 != null)
{
var sphere = firstHit.Item1;
var t = firstHit.Item2.Value;
var intersectionPoint = renderPoint + direction * t;
var directionToEye = -direction;
directionToEye.Normalize(); //should be anyway?
var material = sphere.Material;
var surfaceNormal = sphere.NormalAt(intersectionPoint);
return CalculateColor(scene, directionToEye, surfaceNormal, material, intersectionPoint);
}
return scene.DefaultColor;
}