Use const more in ray_triangle

include/intersections.h

@@ -4,7 +4,7 @@
 
 #include "ray.h"
 
-constexpr float epsilon = std::numeric_limits<float>().epsilon();
+constexpr float epsilon = std::numeric_limits<float>::epsilon();
 
 namespace intersections {
     inline bool ray_sphere(const Ray ray, const glm::vec4 sphere) {
@@ -30,20 +30,20 @@ namespace intersections {
         float& t,
         float& u,
         float& v) {
-        glm::vec3 e1 = v1 - v0;
+        const glm::vec3 e1 = v1 - v0;
-        glm::vec3 e2 = v2 - v0;
+        const glm::vec3 e2 = v2 - v0;
 
-        glm::vec3 pvec = glm::cross(ray.direction, e2);
+        const glm::vec3 pvec = glm::cross(ray.direction, e2);
-        float det = glm::dot(e1, pvec);
+        const float det = glm::dot(e1, pvec);
 
         // if determinant is zero then ray is
         // parallel with the triangle plane
         if (det > -epsilon && det < epsilon)
             return false;
-        float invdet = 1.0 / det;
+        const float invdet = 1.0 / det;
 
         // calculate distance from m[0] to origin
-        glm::vec3 tvec = ray.origin - v0;
+        const glm::vec3 tvec = ray.origin - v0;
 
         // u and v are the barycentric coordinates
         // in triangle if u >= 0, v >= 0 and u + v <= 1
@@ -53,7 +53,7 @@ namespace intersections {
         if (u < 0.0 || u > 1.0)
             return false;
 
-        glm::vec3 qvec = glm::cross(tvec, e1);
+        const glm::vec3 qvec = glm::cross(tvec, e1);
         v = glm::dot(ray.direction, qvec) * invdet;
 
         // check against other edges