- add ray_vs_cylinder + tests, point_sphere_distance + tests

Author: polymonster

src/lib.rs

@@ -433,6 +433,11 @@ pub fn point_aabb_distance<T: Float, V: VecN<T> + NumberOps<T> + VecFloatOps<T>>
     dist(closest_point_on_aabb(p, aabb_min, aabb_max), p)
 }
 
+// returns the unsigned distance from point p0 to the sphere (or 2d circle) centred at s0 with radius r
+pub fn point_sphere_distance<T: Float, V: VecN<T> + NumberOps<T> + VecFloatOps<T>>(p0: V, s0: V, r: T) -> T {
+    dist(p0, closest_point_on_sphere(p0, s0, r))
+}
+
 /// returns the distance point p is from a triangle defined by t1-t2-t3
 pub fn point_triangle_distance<T: Float + FloatOps<T> + NumberOps<T>, V: VecN<T> + NumberOps<T> + VecFloatOps<T>>(p: V, t1: V, t2: V, t3: V) -> T {
     let (w23, w31, w12) = barycentric(p, t1, t2, t3);
@@ -1061,6 +1066,79 @@ pub fn ray_vs_capsule<T: Float + FloatOps<T> + NumberOps<T> + SignedNumberOps<T>
     }
 }
 
+// returns true if there is an intersection between ray wih origin r0 and direction rv against the cylinder with line c0 - c1 and radius cr
+// the intersection point is stored in ip if one exists
+pub fn ray_vs_cylinder<T: Float + FloatOps<T> + NumberOps<T> + SignedNumberOps<T>>(r0: Vec3<T>, rv: Vec3<T>, c0: Vec3<T>, c1: Vec3<T>, cr: T) -> Option<Vec3<T>> {
+    // intesection of ray and infinite cylinder about axis
+    // https://stackoverflow.com/questions/4078401/trying-to-optimize-line-vs-cylinder-intersection
+    let a = c0;
+    let b = c1;
+    let v = rv;
+    let r = cr;
+    
+    let ab = b - a;
+    let ao = r0 - a;
+    let aoxab = cross(ao, ab);
+    let vxab = cross(v, ab);
+    let ab2 = dot(ab, ab);
+    
+    let aa = dot(vxab, vxab);
+    let bb = T::two() * dot(vxab, aoxab);
+    let cc = dot(aoxab, aoxab) - (r*r * ab2);
+    let dd = bb * bb - T::four() * aa * cc;
+    
+    if dd >= T::zero() {
+        let t = (-bb - sqrt(dd)) / (T::two() * aa);
+        if t >= T::zero() {
+            // intersection point
+            let ipc = r0 + rv * t;
+            // clamps to finite cylinder extents
+            let ipd = distance_on_line(ipc, a, b);
+            if ipd >= T::zero() && ipd <= dist(a, b) {
+                return Some(ipc);
+            }
+        }
+    }
+    
+    // intersect with the top and bottom circles
+    let ip_top = ray_vs_plane(r0, rv, c0, normalize(c0 - c1));
+    let ip_bottom = ray_vs_plane(r0, rv, c1, normalize(c1 - c0));
+    let r2 = r*r;
+
+    let mut btop = false;
+    if let Some(ip_top) = ip_top {
+        if dist2(ip_top, c0) < r2 {
+            btop = true;
+        }
+    }
+
+    if let Some(ip_bottom) = ip_bottom {
+        if dist2(ip_bottom, c1) < r2 {
+            if btop {
+                if let Some(ip_top) = ip_top {
+                    let d1 = distance_on_line(ip_top, r0, r0 + rv);
+                    let d2 = distance_on_line(ip_bottom, r0, r0 + rv);
+                    if d2 < d1 {
+                        return Some(ip_bottom);
+                    }
+                }
+            }
+            else {
+                return Some(ip_bottom);
+            }
+        }
+    }
+    
+    if btop {
+        if let Some(ip_top) = ip_top {
+            return Some(ip_top);
+        }
+    }
+
+
+    None
+}
+
 /// returns true if the sphere with centre s and radius r is inside the frustum defined by 6 planes packed as vec4's .xyz = normal, .w = plane distance
 pub fn sphere_vs_frustum<T: Number>(s: Vec3<T>, r: T, planes: &[Vec4<T>; 6]) -> bool {
     for p in planes.iter().take(6) {
@@ -1562,17 +1640,18 @@ pub fn map_to_range<T: Float, X: Base<T>>(v: X, in_start: X, in_end: X, out_star
     out_start + slope * (v - in_start)
 }
 
-// TODO:
-// fix ray vs capsule intersection based the c++ lib
+// TODO: tests
 // line_segment_between_line_segment (test)
 // sphere_vs_capsule (test)
-// ray_vs_capsule (test)
-// missing fail cases
+// ray_vs_line_segment (test)
+// shortest_line_segment_between_line_segments (test)
+// shortest_line_segment_between_lines (test)
+
 // projection, ndc
 // projection, sc
 // unprojection, ndc,
 // unprojection sc
-// projection matrices
+// projection matrices ;D
 // quilez functions
 // quat tests
 // mat from quat

tests/tests.rs

@@ -3397,10 +3397,186 @@ fn ray_vs_capsule_test() {
     }
 }
 
-// TODO: 
-// ray_vs_cylinder
-// sphere_vs_capsule
-// point_sphere_distance
-// ray_vs_line_segment
-// shortest_line_segment_between_line_segments
-// shortest_line_segment_between_lines
+#[test]
+fn ray_vs_cylinder_test() {
+    {
+        let r0 = vec3f(-15.203737, 6.055606, -4.583255);
+        let rv = vec3f(0.554472, -0.831708, -0.028680);
+        let cy0 = vec3f(-3.880000, -14.260001, 1.690000);
+        let cy1 = vec3f(-3.880000, 0.320001, 1.690000);
+        let cyr = 6.730000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), false);
+    }
+    {
+        let r0 = vec3f(21.496956, 1.133426, -4.004637);
+        let rv = vec3f(-0.831786, 0.025206, 0.554524);
+        let cy0 = vec3f(8.260000, -3.040000, 2.670000);
+        let cy1 = vec3f(8.260000, 13.280000, 2.670000);
+        let cyr = 8.160000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(15.876670, 1.303737, -0.257780), 0.001), true);
+    }
+    {
+        let r0 = vec3f(15.056831, 17.546116, -11.426116);
+        let rv = vec3f(-0.401653, -0.647563, 0.647563);
+        let cy0 = vec3f(3.360000, -4.820000, 7.450001);
+        let cy1 = vec3f(3.360000, 14.520000, 7.450001);
+        let cyr = 9.670000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(8.448961, 6.892612, -0.772611), 0.001), true);
+    }
+    {
+        let r0 = vec3f(10.119667, -22.706263, -0.770485);
+        let rv = vec3f(-0.452623, 0.786135, -0.420860);
+        let cy0 = vec3f(4.900000, -18.200001, -8.040000);
+        let cy1 = vec3f(4.900000, 0.680000, -8.040000);
+        let cyr = 2.920000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(5.396209, -14.502363, -5.162472), 0.001), true);
+    }
+    {
+        let r0 = vec3f(-0.795774, 7.815088, -6.405851);
+        let rv = vec3f(0.351940, -0.507207, 0.786689);
+        let cy0 = vec3f(4.080000, -15.730000, -0.670000);
+        let cy1 = vec3f(4.080000, 0.290000, -0.670000);
+        let cyr = 8.010000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(4.425715, 0.290000, 5.265714), 0.001), true);
+    }
+    {
+        let r0 = vec3f(6.690001, -23.490000, -9.060000);
+        let rv = vec3f(0.000000, 1.000000, 0.000000);
+        let cy0 = vec3f(6.690001, -13.490000, -9.060000);
+        let cy1 = vec3f(6.690001, -4.210001, -9.060000);
+        let cyr = 0.630000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(6.690001, -13.490000, -9.060000), 0.001), true);
+    }
+    {
+        let r0 = vec3f(18.464821, -4.349220, -17.132975);
+        let rv = vec3f(-0.702914, -0.036995, 0.710313);
+        let cy0 = vec3f(1.230000, -1.970000, -1.180000);
+        let cy1 = vec3f(1.230000, 12.070000, -1.180000);
+        let cyr = 4.510000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), false);
+    }
+    {
+        let r0 = vec3f(5.099485, -7.040759, 6.173443);
+        let rv = vec3f(-0.437602, 0.733279, -0.520391);
+        let cy0 = vec3f(8.280001, -3.640000, 3.580000);
+        let cy1 = vec3f(8.280001, 6.380000, 3.580000);
+        let cyr = 5.010000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), false);
+    }
+    {
+        let r0 = vec3f(2.376292, -19.823158, -17.518549);
+        let rv = vec3f(-0.035004, 0.796348, 0.603825);
+        let cy0 = vec3f(-7.020000, -16.830000, -6.010000);
+        let cy1 = vec3f(-7.020000, -0.330000, -6.010000);
+        let cyr = 7.450001;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), false);
+    }
+    {
+        let r0 = vec3f(2.137793, 13.814747, -21.165298);
+        let rv = vec3f(0.420438, -0.586862, 0.691972);
+        let cy0 = vec3f(9.010000, -11.050001, -1.690000);
+        let cy1 = vec3f(9.010000, 2.850001, -1.690000);
+        let cyr = 6.950001;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(9.993134, 2.850000, -8.236716), 0.001), true);
+    }
+    {
+        let r0 = vec3f(-2.701339, -15.851871, 9.038837);
+        let rv = vec3f(0.010470, 0.952736, -0.303619);
+        let cy0 = vec3f(-3.930000, -7.100000, 3.220000);
+        let cy1 = vec3f(-3.930000, 2.560000, 3.220000);
+        let cyr = 4.470000;
+        let i = ray_vs_cylinder(r0, rv, cy0, cy1, cyr);
+        assert_eq!(i.is_some(), true);
+        assert_eq!(approx(i.unwrap(), vec3f(-2.605165, -7.100000, 6.249780), 0.001), true);
+    }
+}
+
+#[test]
+fn point_sphere_distance_test() {
+    {
+        let sp = vec3f(-1.600000, -3.880000, -6.970000);
+        let sr = 4.970000;
+        let p = vec3f(-5.080000, 0.420000, 9.870001);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 12.755294, 0.001), true);
+    }
+    {
+        let sp = vec3f(-7.220000, 8.160000, 3.350000);
+        let sr = 5.600000;
+        let p = vec3f(1.690000, 7.090000, 1.570000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 3.548846, 0.001), true);
+    }
+    {
+        let sp = vec3f(-0.210000, 1.490000, -4.210000);
+        let sr = 2.670000;
+        let p = vec3f(0.970000, 8.260000, 5.120000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 8.917675, 0.001), true);
+    }
+    {
+        let sp = vec3f(7.450001, 2.280000, -9.090000);
+        let sr = 3.930000;
+        let p = vec3f(-1.790000, 9.670000, -3.280000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 9.251267, 0.001), true);
+    }
+    {
+        let sp = vec3f(6.680000, 4.900000, -8.760000);
+        let sr = 1.530000;
+        let p = vec3f(-8.059999, -6.430000, 0.010000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 19.026007, 0.001), true);
+    }
+    {
+        let sp = vec3f(-9.760000, 8.010000, -1.470000);
+        let sr = 7.219999;
+        let p = vec3f(-8.040000, 5.300000, -0.970000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 3.971538, 0.001), true);
+    }
+    {
+        let sp = vec3f(-6.010000, 9.680000, -5.880000);
+        let sr = 6.350000;
+        let p = vec3f(-7.690000, 7.450001, -8.250000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 2.687733, 0.001), true);
+    }
+    {
+        let sp = vec3f(3.190000, 4.540000, 2.230000);
+        let sr = 9.719999;
+        let p = vec3f(-3.210000, 3.350000, 0.060000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 2.858149, 0.001), true);
+    }
+    {
+        let sp = vec3f(3.170000, 5.250000, -8.000000);
+        let sr = 7.400000;
+        let p = vec3f(9.290001, 2.230000, -9.460000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 0.421002, 0.001), true);
+    }
+    {
+        let sp = vec3f(3.220000, -6.950000, 1.760000);
+        let sr = 5.530000;
+        let p = vec3f(1.290000, -4.470000, 4.830000);
+        let dd = point_sphere_distance(p, sp, sr);
+        assert_eq!(approx(dd, 1.136801, 0.001), true);
+    }
+}