public Color getColor(Vec2D v)
{
// simple interpolation
// int col = (int)(v.u * this.image.width);
// int row = (int)(v.v * this.image.height);
// if (col >= this.image.width) col = this.image.width - 1;
// if (row >= this.image.height) row = this.image.height - 1;
// return image.getPixel(col, row);
// elegant bilinear interpolation
float x = v.u * (this.image.width - 1);
int x1 = (int)Math.Floor(v.u * (this.image.width - 1));
if (x1 >= this.image.width - 1) x1 = (int)v.u * (this.image.width - 2);
int x2 = x1 + 1;
float y = v.v * (this.image.height - 1);
int y1 = (int)Math.Floor(v.v * (this.image.height - 1));
if (y1 >= this.image.height - 1) y1 = (int)v.v * (this.image.height - 2);
int y2 = y1 + 1;
Color c11 = this.image.getPixel(x1, y1);
Color c12 = this.image.getPixel(x1, y2);
Color c21 = this.image.getPixel(x2, y1);
Color c22 = this.image.getPixel(x2, y2);
float den = 1.0f / ((x2 - x1) * (y2 - y1));
return (x2 - x) * (c11 * (y2 - y) + c12 * (y - y1)) + (x - x1) * (c21 * (y2 - y) + c22 * (y - y1)) * den;
}
public Color getColor(Vec2D uv)
{
int u = (int)Math.Floor(uv.u * this.nSteps);
int v = (int)Math.Floor(uv.v * this.nSteps);
return (u + v) % 2 == 0 ? this.color1 : this.color2;
}
public HitRecord(Point wp, Normal nm, Vec2D sp, float tt, Ray r, Shape? shape = null)
{
this.worldPoint = wp;
this.normal = nm;
this.surfacePoint = sp;
this.t = tt;
this.ray = r;
this.shape = shape;
}
public override Color Eval(Normal normal, Vec inDir, Vec outDir, Vec2D uv)
{
float thetaIn = MathF.Acos(Utility.NormalizedDot(normal.ToVec(), inDir));
float thetaOut = MathF.Acos(Utility.NormalizedDot(normal.ToVec(), outDir));
if (MathF.Abs(thetaIn - thetaOut) < this.thresholdAngleRad)
return this.pigment.getColor(uv);
else
return new Color(0f, 0f, 0f);
}
/// <summary>
/// Method that checks if two <see cref="Vec2D"/> objects
/// are approximately equal.
/// </summary>
/// <param name="vector"> The Vec2D to be compared to</param>
/// <returns> True if the two vecs are equal</returns>
public bool isClose(Vec2D vector)
=> Utility.areClose(this.u, vector.u) && Utility.areClose(this.v, vector.v);
public Color getColor(Vec2D vec)
{
return this.c;
}
public override Color Eval(Normal normal, Vec inDir, Vec outDir, Vec2D uv)
{
return this.pigment.getColor(uv) * (this.reflectance / Constant.PI);
}
public abstract Color Eval(Normal normal, Vec inDir, Vec outDir, Vec2D uv);
