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

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1.1 KiB
HLSL

#include "triangle.hlsl"
#include "../../lighting/ray.hlsl"
/*
contributors: Inigo Quiles
description: Based on https://www.iquilezles.org/www/articles/intersectors/intersectors.htm
use: <float> intersect(<Triangle> tri, <float3> rayOrigin, <float3> rayDir, out <float3> intersectionPoint)
*/
#ifndef FNC_TRIANGLE_INTERSECT
#define FNC_TRIANGLE_INTERSECT
float intersect(Triangle _tri, float3 _rayOrigin, float3 _rayDir, inout float3 _point) {
float3 v1v0 = _tri.b - _tri.a;
float3 v2v0 = _tri.c - _tri.a;
float3 rov0 = _rayOrigin - _tri.a;
_point = cross(v1v0, v2v0);
float3 q = cross(rov0, _rayDir);
float d = 1.0f / dot(_rayDir, _point);
float u = d * -dot(q, v2v0);
float v = d * dot(q, v1v0);
float t = d * -dot(_point, rov0);
if (u < 0.0f || u > 1.0f || v < 0.0f || (u+v) > 1.0f || t < 0.0f)
t = 9999999.9f; // No intersection
return t;
}
float intersect(Triangle _tri, Ray _ray, inout float3 _point) { return intersect(_tri, _ray.origin, _ray.direction, _point); }
float intersect(Triangle _tri, Ray _ray) {
float3 p;
return intersect(_tri, _ray, p);
}
#endif