/**
* Adds a series of polygons by rotating the points list (ps) steps times, and colouring them as
* defined by the color array (stripes!).
*/
public void lathePolygons(float[][] ps, Color[] color, int steps) {
float _ps[][] = new float[ps.length][3];
float stepAngle = (float) Math.PI * 2 / steps; // the angle of each step in radians
int currColor = 0;
float m[][];
for (int step = 0; step < steps; step++) {
// translate each point to it next step round
m = Tools3d.rotateAboutZ(stepAngle);
for (int i = 0; i < ps.length; i++) {
Tools3d.applyTo(m, ps[i], _ps[i]);
}
// build the polygons
for (int point = 0; point < ps.length - 1; point++) {
this.addPolygon(
new float[][] {_ps[point], ps[point], ps[point + 1], _ps[point + 1]}, color[currColor]);
}
// copy the translated array to the starting array read for the next iteration
for (int i = 0; i < ps.length; i++) {
ps[i][0] = _ps[i][0];
ps[i][1] = _ps[i][1];
ps[i][2] = _ps[i][2];
}
currColor++;
if (currColor == color.length) {
currColor = 0;
}
}
}
/**
* Uses the camera to map all points from model space, (x, y, z) to screen space (x_, y_, z_).
* Remember that x_ represents the depth of the point and (y_, z_) maps to the screen (x, y)
* co-ords of the point.
*
* @see CameraMan
*/
public void transform() {
final float[] f = modelViewer.cameraMan.getFocus();
final float[][] m = modelViewer.cameraMan.getMatrix();
final float d = modelViewer.cameraMan.getDistance();
float[] a = new float[3];
visible = false; // set true if any points are visble to the camera
for (int i = 0; i < npoints * 3; i += 3) {
a[0] = ps[i] - f[0];
a[1] = ps[i + 1] - f[1];
a[2] = ps[i + 2] - f[2];
Tools3d.applyTo(m, a, a);
visibles[i / 3] = Tools3d.projectYZ(a, a, d);
ps_[i] = a[0];
if (visibles[i / 3]) {
modelViewer.cameraMan.scaleToScreen(a);
ps_[i + 1] = a[1];
ps_[i + 2] = a[2];
visible = true;
}
// depth bounding box
if (i == 0) {
x_min = x_max = ps_[i];
} else {
if (ps_[i] < x_min) x_min = ps_[i];
if (ps_[i] > x_max) x_max = ps_[i];
}
}
}
