tiny.geometry.Triangle

1/// A triangle with counter-clockwise winding around its normal.2pub const Triangle = extern struct {3    a: Vec3,4    b: Vec3,5    c: Vec3,67    /// The unnormalized normal, twice the area in length.8    pub fn areaNormal(triangle: Triangle) Vec3 {9        return triangle.b.sub(triangle.a).cross(triangle.c.sub(triangle.a));10    }1112    /// Whether the corners are collinear, or so close to it that the area13    /// normal is rounding noise.14    pub fn isDegenerate(triangle: Triangle) bool {15        const edge1 = triangle.b.sub(triangle.a);16        const edge2 = triangle.c.sub(triangle.a);17        return tolerance.isParallel(edge1.cross(edge2).lengthSq(), edge1.lengthSq() * edge2.lengthSq());18    }1920    /// The unit normal, or null for a degenerate triangle.21    pub fn normal(triangle: Triangle) ?Vec3 {22        if (triangle.isDegenerate()) return null;23        return triangle.areaNormal().normalized(0);24    }2526    pub fn centroid(triangle: Triangle) Vec3 {27        return triangle.a.add(triangle.b).add(triangle.c).scale(1.0 / 3.0);28    }2930    pub fn bounds(triangle: Triangle) Aabb {31        return Aabb.fromPoint(triangle.a).joinPoint(triangle.b).joinPoint(triangle.c);32    }3334    pub fn vertex(triangle: Triangle, index: usize) Vec3 {35        assert(index < 3);36        return switch (index) {37            0 => triangle.a,38            1 => triangle.b,39            else => triangle.c,40        };41    }42};

1pub const Triangle = primitive.Triangle;