public float Sample(Vector2D coord)
{
if (coord.X > 1)
coord.X = 1;
else if (coord.X < 0)
coord.X = 0;
if (coord.Y > 1)
coord.Y = 1;
else if (coord.Y < 0)
coord.Y = 0;
return SampleActual((int)(coord.X * (width - 1)), (int)(coord.Y * (height - 1)));
}
public HeightFieldObject(Vector3D origin, MaterialShader shader, Vector2D size, Bitmap bitmapSrc)
: base(origin, shader, -1)
{
this.bitmapSrc = bitmapSrc;
// calculate bounds
areaExtent = size;
Vector2D halfSize = size * 0.5;
areaStart = origin - halfSize;
areaEnd = origin + halfSize;
double szLen = size.Length();
radius = Math.Sqrt((szLen * szLen) + (1.1 * 1.1)) / 2;
hField = HeightField.FromBitmap(bitmapSrc);
onePx = new Vector2D(areaExtent.X / hField.Width, areaExtent.Y / hField.Height);
this.origin.Y = 0.5;
zMin = 0;
zTop = 1;
rectangles = new Rectangle3D[]
{
new Rectangle3D(new Vector3D(areaStart.X, zTop, areaStart.Y), new Vector3D(areaEnd.X, zTop, areaEnd.Y),
new PlaneD(new Vector3D(0, 1, 0), -zTop)), // top
new Rectangle3D(new Vector3D(areaStart.X, zMin, areaStart.Y), new Vector3D(areaEnd.X, zMin, areaEnd.Y),
new PlaneD(new Vector3D(0, -1, 0), zMin)), // bottom
new Rectangle3D(new Vector3D(areaStart.X, zMin, areaStart.Y), new Vector3D(areaStart.X, zTop, areaEnd.Y),
new PlaneD(new Vector3D(-1, 0, 0), halfSize.X)), // left
new Rectangle3D(new Vector3D(areaEnd.X, zMin, areaStart.Y), new Vector3D(areaEnd.X, zTop, areaEnd.Y),
new PlaneD(new Vector3D(1, 0, 0), -halfSize.X)), // right
new Rectangle3D(new Vector3D(areaStart.X, zMin, areaStart.Y), new Vector3D(areaEnd.X, zTop, areaStart.Y),
new PlaneD(new Vector3D(0, 0, -1), halfSize.Y)), // front
new Rectangle3D(new Vector3D(areaStart.X, zMin, areaEnd.Y), new Vector3D(areaEnd.X, zTop, areaEnd.Y),
new PlaneD(new Vector3D(0, 0, 1), -halfSize.Y)), // back
};
}
public override Vector2D GetTexCoord(Vector3D p, uint subIdx)
{
Vector2D coord = new Vector2D(p.X - areaStart.X, p.Z - areaStart.Y);
coord.X /= areaExtent.X;
coord.Y /= areaExtent.Y;
return coord;
}
public override Vector3D GetNormal(Vector3D pos, uint subIdx)
{
Vector2D coord = new Vector2D(pos.X - areaStart.X, pos.Z - areaStart.Y);
coord.X /= areaExtent.X;
coord.Y /= areaExtent.Y;
// calc normal from surrounding pixels
float val = hField.Sample(coord);
float valxmin = hField.SampleShiftX(coord.X, coord.Y, -1);
float valxmax = hField.SampleShiftX(coord.X, coord.Y, 1);
Vector3D rightAngle = new Vector3D(0, 0, -1);
Vector3D p1 = new Vector3D(onePx.X, valxmax - val, 0).Cross(rightAngle);
Vector3D p2 = new Vector3D(-onePx.X, valxmin - val, 0).Cross(rightAngle);
Vector3D xDir = Vector3D.Normalize(p1 - p2);
float valymin = hField.SampleShiftY(coord.X, coord.Y, -1);
float valymax = hField.SampleShiftY(coord.X, coord.Y, 1);
rightAngle = new Vector3D(1, 0, 0);
p1 = new Vector3D(0, valymax - val, onePx.Y).Cross(rightAngle);
p2 = new Vector3D(0, valymin - val, -onePx.Y).Cross(rightAngle);
Vector3D yDir = Vector3D.Normalize(p1 - p2);
return Vector3D.Normalize(xDir + yDir);
}
