fuckingtech/public/assets/glsl/lygia/geometry/triangle/contain.cuh
Elias Rhouzlane bf76c6b086 fix: code
2025-04-06 17:23:52 +02:00

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#include "triangle.cuh"
#include "../../math/operations.cuh"
#include "../../math/cross.cuh"
/*
contributors: Thomas Müller & Alex Evans
description: Does the position lie within the triangle
use: <float3> contain(<Triangle> tri, <float3> _pos)
*/
#ifndef FNC_TRIANGLE_CONTAIN
#define FNC_TRIANGLE_CONTAIN
inline __host__ __device__ bool contain(const Triangle& _tri, const float3& _pos) {
// Move the triangle so that the point becomes the
// triangles origin
float3 local_a = _tri.a - _pos;
float3 local_b = _tri.b - _pos;
float3 local_c = _tri.c - _pos;
// The point should be moved too, so they are both
// relative, but because we don't use p in the
// equation anymore, we don't need it!
// p -= p;
// Compute the normal vectors for triangles:
// u = normal of PBC
// v = normal of PCA
// w = normal of PAB
float3 u = cross(local_b, local_c);
float3 v = cross(local_c, local_a);
float3 w = cross(local_a, local_b);
// Test to see if the normals are facing the same direction.
// If yes, the point is inside, otherwise it isn't.
return dot(u, v) >= 0.0f && dot(u, w) >= 0.0f;
}
#endif