+ case 0:
+ {
+ // this is the baseline for the spread value!
+ // standard deviation: sqrt(2/5)
+ // density function: sqrt(1-r^2)
+ return forward + randomvec() * spread;
+ }
+ case 1:
+ {
+ // same thing, basically
+ return normalize(forward + cliptoplane(randomvec() * spread, forward));
+ }
+ case 2:
+ {
+ // circle spread... has at sigma=1 a standard deviation of sqrt(1/2)
+ sigma = spread * 0.89442719099991587855; // match baseline stddev
+ v1 = findperpendicular(forward);
+ v2 = cross(forward, v1);
+ // random point on unit circle
+ dx = random() * 2 * M_PI;
+ dy = sin(dx);
+ dx = cos(dx);
+ // radius in our dist function
+ r = random();
+ r = sqrt(r);
+ return normalize(forward + (v1 * dx + v2 * dy) * r * sigma);
+ }
+ case 3: // gauss 3d
+ {
+ sigma = spread * 0.44721359549996; // match baseline stddev
+ // note: 2D gaussian has sqrt(2) times the stddev of 1D, so this factor is right
+ v1 = forward;
+ v1_x += gsl_ran_gaussian(sigma);
+ v1_y += gsl_ran_gaussian(sigma);
+ v1_z += gsl_ran_gaussian(sigma);
+ return v1;
+ }
+ case 4: // gauss 2d
+ {
+ sigma = spread * 0.44721359549996; // match baseline stddev
+ // note: 2D gaussian has sqrt(2) times the stddev of 1D, so this factor is right
+ v1_x = gsl_ran_gaussian(sigma);
+ v1_y = gsl_ran_gaussian(sigma);
+ v1_z = gsl_ran_gaussian(sigma);
+ return normalize(forward + cliptoplane(v1, forward));
+ }
+ case 5: // 1-r
+ {
+ sigma = spread * 1.154700538379252; // match baseline stddev
+ v1 = findperpendicular(forward);
+ v2 = cross(forward, v1);
+ // random point on unit circle
+ dx = random() * 2 * M_PI;
+ dy = sin(dx);
+ dx = cos(dx);
+ // radius in our dist function
+ r = random();
+ r = solve_cubic_abcd(-2, 3, 0, -r) * '0 1 0';
+ return normalize(forward + (v1 * dx + v2 * dy) * r * sigma);
+ }
+ case 6: // 1-r^2
+ {
+ sigma = spread * 1.095445115010332; // match baseline stddev
+ v1 = findperpendicular(forward);
+ v2 = cross(forward, v1);
+ // random point on unit circle
+ dx = random() * 2 * M_PI;
+ dy = sin(dx);
+ dx = cos(dx);
+ // radius in our dist function
+ r = random();
+ r = sqrt(1 - r);
+ r = sqrt(1 - r);
+ return normalize(forward + (v1 * dx + v2 * dy) * r * sigma);
+ }
+ case 7: // (1-r) (2-r)
+ {
+ sigma = spread * 1.224744871391589; // match baseline stddev
+ v1 = findperpendicular(forward);
+ v2 = cross(forward, v1);
+ // random point on unit circle
+ dx = random() * 2 * M_PI;
+ dy = sin(dx);
+ dx = cos(dx);
+ // radius in our dist function
+ r = random();
+ r = 1 - sqrt(r);
+ r = 1 - sqrt(r);
+ return normalize(forward + (v1 * dx + v2 * dy) * r * sigma);
+ }
+ default:
+ error("g_projectiles_spread_style must be 0 (sphere), 1 (flattened sphere), 2 (circle), 3 (gauss 3D), 4 (gauss plane), 5 (linear falloff), 6 (quadratic falloff), 7 (stronger falloff)!");