private double[][] getShadowSmoothKernel(int radius) {
double res[][] = shadowSmoothKernelMap.get(Integer.valueOf(radius));
if (res == null) {
FilterKernel shadowSmoothKernel = new GaussianFilterKernel();
double shadowKernelScale = 1.0;
double shadowScaledInvRadius =
1.0 / shadowSmoothRadius * shadowKernelScale * shadowSmoothKernel.getSpatialSupport();
int size = 2 * radius + 1;
res = new double[size][size];
for (int k = -radius; k <= radius; k++) {
int x = radius + k;
double k_square = MathLib.sqr(k * shadowScaledInvRadius);
for (int l = -radius; l <= radius; l++) {
int y = radius + l;
double r = MathLib.sqrt(k_square + MathLib.sqr(l * shadowScaledInvRadius));
res[x][y] = shadowSmoothKernel.getFilterCoeff(r);
}
}
synchronized (shadowSmoothKernelMap) {
shadowSmoothKernelMap.put(Integer.valueOf(radius), res);
}
}
return res;
}
private void computeNextTimeStep(float t, float dt) {
for (Particle particle : particles) {
Vector force = getForce(t);
particle.incSpeed(VectorMath.multiply(dt, force));
float radialAccel = particle.getRadialAcceleration() * dt;
float tangentAccel = particle.getTangentialAcceleration() * dt;
if (MathLib.fabs(radialAccel) > MathLib.EPSILON
|| MathLib.fabs(tangentAccel) > MathLib.EPSILON) {
Vector centre = getForceCentre(t);
Vector normal = VectorMath.normalize(VectorMath.normal(particle.getPosition(), centre));
if (MathLib.fabs(radialAccel) > MathLib.EPSILON) {
particle.incSpeed(VectorMath.multiply(radialAccel, normal));
}
if (MathLib.fabs(tangentAccel) > MathLib.EPSILON) {
Vector tangent = VectorMath.normalize(VectorMath.tangent(particle.getPosition(), centre));
particle.incSpeed(VectorMath.multiply(tangentAccel, tangent));
}
}
particle.incPosition(VectorMath.multiply(dt, particle.getSpeed()));
particle.incRotation(VectorMath.multiply(dt, particle.getRotationSpeed()));
particle.decLife(dt);
}
storeMotion(t, dt);
}
protected int selectNearestPointFromTriangle(
TriangleControlShape pTriangle, int viewX, int viewY) {
double dx, dy;
dx = pTriangle.viewX[0] - viewX;
dy = pTriangle.viewY[0] - viewY;
double dr0 = MathLib.sqrt(dx * dx + dy * dy);
dx = pTriangle.viewX[1] - viewX;
dy = pTriangle.viewY[1] - viewY;
double dr1 = MathLib.sqrt(dx * dx + dy * dy);
dx = pTriangle.viewX[2] - viewX;
dy = pTriangle.viewY[2] - viewY;
double dr2 = MathLib.sqrt(dx * dx + dy * dy);
return dr0 < dr1 ? (dr0 < dr2 ? 0 : 2) : (dr1 < dr2 ? 1 : 2);
}