## intersect (`lygia`/`geometry`/`aabb`/`intersect`)

Compute the near and far intersections of the cube (stored in the x and y components) using the slab method no intersection means vec.x > vec.y (really tNear > tFar) https://gist.github.com/DomNomNom/46bb1ce47f68d255fd5d

Dependencies:

Use:

``````<vec2> intersect(<AABB> box, <vec3> rayOrigin, <vec3> rayDir)
``````

Check it on Github

``````

#ifndef FNC_AABB_INTERSECT
#define FNC_AABB_INTERSECT

vec2 intersect(const in AABB box, const in vec3 rayOrigin, const in vec3 rayDir) {
vec3 tMin = (box.min - rayOrigin) / rayDir;
vec3 tMax = (box.max - rayOrigin) / rayDir;
vec3 t1 = min(tMin, tMax);
vec3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return vec2(tNear, tFar);
}

vec2 intersect(const in AABB box, const in Ray ray) {
vec3 tMin = (box.min - ray.origin) / ray.direction;
vec3 tMax = (box.max - ray.origin) / ray.direction;
vec3 t1 = min(tMin, tMax);
vec3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return vec2(tNear, tFar);
}

#endif
``````

Dependencies:

Use:

``````<float2> intersect(<AABB> box, <float3> rayOrigin, <float3> rayDir)
``````

Check it on Github

``````

#ifndef FNC_AABB_INTERSECT
#define FNC_AABB_INTERSECT

float2 intersect(const in AABB box, const in float3 rayOrigin, const in float3 rayDir) {
float3 tMin = (box.min - rayOrigin) / rayDir;
float3 tMax = (box.max - rayOrigin) / rayDir;
float3 t1 = min(tMin, tMax);
float3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return float2(tNear, tFar);
}

float2 intersect(const in AABB box, const in Ray ray) {
float3 tMin = (box.min - ray.origin) / ray.direction;
float3 tMax = (box.max - ray.origin) / ray.direction;
float3 t1 = min(tMin, tMax);
float3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return float2(tNear, tFar);
}

#endif
``````

Dependencies:

Use:

``````<float2> intersect(<AABB> box, <float3> rayOrigin, <float3> rayDir)
``````

Check it on Github

``````

#ifndef FNC_AABB_INTERSECT
#define FNC_AABB_INTERSECT

inline __host__ __device__ float2 intersect(const AABB& _box, const float3& _rayOrigin, const float3& _rayDir) {
float3 tMin = (_box.min - _rayOrigin) / _rayDir;
float3 tMax = (_box.max - _rayOrigin) / _rayDir;
float3 t1 = min(tMin, tMax);
float3 t2 = max(tMin, tMax);
float tNear = max(max(t1.x, t1.y), t1.z);
float tFar = min(min(t2.x, t2.y), t2.z);
return make_float2(tNear, tFar);
}

inline __host__ __device__ float2 intersect(const AABB& _box, const Ray& _ray) { return intersect(_box, _ray.origin, _ray.direction); }

#endif
``````