1 files changed, 28 insertions, 52 deletions

diff --git a/src/spatial.c b/src/spatial.c
index 74a0cad..791c6f9 100644
--- a/src/spatial.c
+++ b/src/spatial.c
@@ -12,29 +12,37 @@ static inline float dist(xas_spatial_coord a, xas_spatial_coord b) {
               + powf(b.z - a.z, 2.0f), 0.5f);
 }
 
-static float dotf(float *sets, size_t count, size_t len) {
-    float ret = 0.0f;
-
-    size_t x, y;
+static float dotf(xas_spatial_coord a, xas_spatial_coord b) {
+    return a.x * b.x
+         + a.y * b.y
+         + a.z * b.z;
+}
 
-    if (count == 0 || len == 0) {
-        return 0.0f;
-    }
+static void diff(xas_spatial_coord *ret,
+                 xas_spatial_coord a,
+                 xas_spatial_coord b) {
+    ret->x = a.x - b.x;
+    ret->y = a.y - b.y;
+    ret->z = a.z - b.z;
+}
 
-    for (x=0; x<count; x++) {
-        float num = sets[x*len+0];
+static float magnf(xas_spatial_coord coord) {
+    return sqrtf(coord.x * coord.x
+               + coord.y * coord.y
+               + coord.z * coord.z);
+}
 
-        for (y=1; y<len; y++) {
-            num *= sets[x*len+y];
-        }
+static inline float degf(float rad) {
+    float ret = (rad / M_PI) * 180.0f;
 
-        ret += num;
+    while (ret >= 360.0f) {
+        ret -= 360.0f;
     }
 
     return ret;
 }
 
-static void rotate(xas_spatial_rotation rotation,
+static void rotate(xas_spatial_coord rotation,
                    xas_spatial_coord *coord) {
     double cosY = cos(rotation.y),
            sinY = sin(rotation.y),
@@ -68,48 +76,16 @@ static void rotate(xas_spatial_rotation rotation,
     coord->z = Yz;
 }
 
-static inline float degf(float rad) {
-    float ret = (rad / M_PI) * 180.0f;
-
-    while (ret >= 360.0f) {
-        ret -= 360.0f;
-    }
-
-    return ret;
-}
-
 static int within_cone(xas_spatial_coord coord,
                        xas_spatial_cone cone) {
-    xas_spatial_rotation rotation = {
-        .x = (M_PI * 2.0f) - cone.rotation.x,
-        .y = (M_PI * 2.0f) - cone.rotation.y,
-        .z = (M_PI * 2.0f) - cone.rotation.z
-    };
-
-    float radius;
+    xas_spatial_coord apex_to_x;
 
-    coord.x -= cone.coord.x;
-    coord.y -= cone.coord.y;
-    coord.z -= cone.coord.z;
+    float cosf_angle = cosf(cone.angle / 2.0f);
 
-    cone.coord.x = 0.0f;
-    cone.coord.y = 0.0f;
-    cone.coord.z = 0.0f;
-
-    rotate(rotation, &coord);
-
-
-    radius = tanf(cone.angle / 2.0f) * coord.x;
-
-    /*
-     * If the given point is outside the cone radius at its X coordinate, then
-     * it is outside of the cone.
-     */
-    if (fabs(coord.y) > radius || fabs(coord.z) > radius) {
-        return 0;
-    }
+    diff(&apex_to_x, cone.coord, coord);
 
-    return 1;
+    return dotf(apex_to_x, cone.rotation) / magnf(apex_to_x) / magnf(cone.rotation)
+      > cosf_angle;
 }
 
 static int buffer_realloc(xas_spatial_scene *scene,
@@ -347,7 +323,7 @@ void xas_spatial_scene_destroy(xas_spatial_scene *scene) {
 
 void xas_spatial_scene_set_observer(xas_spatial_scene *scene,
                                       xas_spatial_coord coord,
-                                      xas_spatial_rotation rotation,
+                                      xas_spatial_coord rotation,
                                       float width) {
     scene->observer.coord    = coord;
     scene->observer.rotation = rotation;