public static void DrawSphere(string outputBitmapFilePath, IMatrixTransformationBuilder transformation)
{
// Rough and ready. Fully following the pseudocode from the text.
// Basically:
// For each pixel on the canvas, figure out the ray (direction) from there
// back to the origin of the emitting ray (light source).
// Then calculate the hit (first intersection), if any. If it's a hit then
// that pixel on the canvas gets drawn.
// The rest of the code is just pixel conversion e.g. determining what "1"
// represents in terms of numbers of pixels and also converting the half above /
// half below of the sphere to a non-negative set of pixels for drawing.
// inputs: could encapsulate in class to cleanup the code.
var ray_origin = new Vector4(0F, 0F, -5F, 1F);
var wall_z = 10F;
var wall_size = 7.0F;
IBasicShape shape = Sphere.CreateDefaultInstance();
shape.Transformation = transformation;
#pragma warning disable CS0618 // Type or member is obsolete
var xs = new SceneIntersectionCalculator(new List <IBasicShape> {
shape
});
#pragma warning restore CS0618 // Type or member is obsolete
var canvas_pixels = 100;
var pixel_size = wall_size / canvas_pixels;
var half = wall_size / 2;
var color = Color.FromScRgb(1.0F, 0.0F, 0.0F, 1.0F).Simplify();
using var canvas = new System.Drawing.Bitmap(canvas_pixels, canvas_pixels);
for (int y = 0; y < canvas_pixels; y++)
{
var world_y = half - pixel_size * y;
for (int x = 0; x < canvas_pixels; x++)
{
var world_x = -half + pixel_size * x;
var position = new Vector4(world_x, world_y, wall_z, 1F);
var r = new Domain.Model.Ray(
ray_origin,
Vector4.Normalize(position - ray_origin));
if (xs.CalculateHit(r).HasValue)
{
canvas.SetPixel(x, y, color);
}
}
}
canvas.Save(outputBitmapFilePath);
}
private static void DrawProjectilePath(IMatrixTransformationBuilder builder, System.Drawing.Bitmap canvas)
{
var hourMark = builder.Execute(new Vector4(0F, 0F, 0F, 1F));
var roundX = Math.Round(hourMark.X + 25F, 0);
var roundY = Math.Round(hourMark.Z + 25F, 0);
// WPF color - see the Projectile game for more info.
var wpfColor = Color.FromScRgb(1.0F, 0.0F, 0.0F, 1.0F);
canvas.SetPixel((int)roundX, (int)roundY, wpfColor.Simplify());
}
public void SetViewTransformation(IMatrixTransformationBuilder transform)
{
Transform = transform.GetCompositeTransformation();
}