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Added intersectLineQuad and fastIntersectLineQuad
This commit is contained in:
Tormod Haugland
parent
31fef4819b
commit
ed98125fc0
@ -103,7 +103,7 @@ namespace glm
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genType & intersectionPosition1, genType & intersectionNormal1,
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genType & intersectionPosition2 = genType(), genType & intersectionNormal2 = genType());
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//! Compute the intersection of a line and a non-degenerate quadrilateral.
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//! Compute the intersection of a ray and a non-degenerate quadrilateral.
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//! From the GLM_GTX_intersect extension
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template <typename genType>
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GLM_FUNC_DECL bool intersectRayQuad(
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@ -112,13 +112,32 @@ namespace glm
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genType & bilinearCoordinates
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);
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//! Compute the intersection of a ray and a non-degenerate quadrilateral.
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//! Does not compute the bilinear coordinates of the intersection.
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//! From the GLM_GTX_intersect extension
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template<typename genType>
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GLM_FUNC_DECL bool fastIntersectRayQuad(
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genType const & orig, genType const & dir,
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genType const & v00, genType const & v10, genType const & v11, genType const & v01
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);
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//! Compute the intersection of a line and a non-degenerate quadrilateral.
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//! From the GLM_GTX_intersect extension
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template<typename genType>
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GLM_FUNC_DECL bool intersectLineQuad(
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genType const & orig, genType const & dir,
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genType const & v00, genType const & v10, genType const & v11, genType const & v01,
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genType & bilinearCoordinates
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);
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//! Compute the intersection of a line and a non-degenerate quadrilateral.
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//! Does not compute the bilinear coordinates of the intersection.
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//! From the GLM_GTX_intersect extension
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template<typename genType>
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GLM_FUNC_DECL bool fastIntersectRayQuad(
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GLM_FUNC_DECL bool fastIntersectLineQuad(
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genType const & orig, genType const & dir,
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genType const & v00, genType const & v10, genType const & v11, genType const & v01
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);
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/// @}
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@ -449,6 +449,232 @@ namespace glm
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return true;
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}
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template<typename genType>
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GLM_FUNC_QUALIFIER bool intersectLineQuad
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(
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genType const & orig, genType const & dir,
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genType const & v00, genType const & v10, genType const & v11, genType const & v01,
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genType & bilinearCoordinates
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)
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{
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// Epsilon to reject parallell lines
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typename genType::value_type epsilon = std::numeric_limits<typename genType::value_type>::epsilon();
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// Calculate edges and normal of first triangle
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genType e01 = v10 - v00;
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genType e03 = v01 - v00;
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genType p = glm::cross(dir, e03);
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typename genType::value_type det = glm::dot(e01, p);
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// Reject rays orthagonal to the normal vector. I.e. rays parallell to the plane.
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if(det < epsilon && det > -epsilon)
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return false;
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typename genType::value_type inv_det = typename genType::value_type(1.0f)/det;
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genType s = orig - v00;
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// Calculate the barycentric alpha coordinate of the first triangle
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typename genType::value_type alpha = inv_det * glm::dot(s, p);
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// It lies outside the triangle
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if(alpha > typename genType::value_type(1.0f))
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return false;
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if(alpha < typename genType::value_type(0.0f))
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return false;
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// Vector perpendicular to T and e01
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genType q = glm::cross(s, e01);
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// Calculate barycentric beta coordinate of the first triangle
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typename genType::value_type beta = inv_det * glm::dot(dir, q);
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if(beta > typename genType::value_type(1.0f))
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return false;
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if(beta < typename genType::value_type(0.0f))
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return false;
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bilinearCoordinates.z = inv_det * glm::dot(e03, q);
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if(alpha + beta > typename genType::value_type(1.0f)){
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// Do exactly the same for the second triangle
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genType e23 = v01 - v11;
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genType e21 = v10 - v11;
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p = glm::cross(dir, e21);
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det = glm::dot(e23, p);
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if(det < epsilon && det > -epsilon)
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return false;
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inv_det = typename genType::value_type(1.0f)/det;
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s = orig - v11;
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alpha = inv_det * glm::dot(s, p);
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if(alpha < typename genType::value_type(0.0f))
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return false;
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q = glm::cross(s, e23);
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beta = inv_det * glm::dot(dir, q);
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if(beta < typename genType::value_type(0.0f))
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return false;
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// This to support degenerate squares
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if(beta + alpha > typename genType::value_type(1.0f))
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return false;
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bilinearCoordinates.z = inv_det * glm::dot(e21, q);
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}
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// Compute barycentric coordinates of v11
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genType e02 = v11 - v00;
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genType N = glm::cross(e01, e03);
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typename genType::value_type alpha_11, beta_11;
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if(abs(N.x) >= abs(N.y) && abs(N.x) >= abs(N.z)) {
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alpha_11 = (e02.y * e03.z - e02.z * e03.y) / N.x;
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beta_11 = (e01.y * e02.z - e01.z * e02.y) / N.x;
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} else if(abs(N.y) >= abs(N.x) && abs(N.y) >= abs(N.z)) {
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alpha_11 = (e02.z * e03.x - e02.x * e03.z) / N.x;
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beta_11 = (e01.z * e02.x - e01.x * e02.z) / N.x;
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} else {
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alpha_11 = (e02.x * e03.y - e02.y * e03.x) / N.z;
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beta_11 = (e01.x * e02.y - e01.y * e02.x) / N.z;
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}
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// Compute bilinear coordinates of the intersection point
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if(abs(alpha_11 - typename genType::value_type(1.0f)) < epsilon) {
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bilinearCoordinates.x = alpha;
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if(abs(beta_11 - typename genType::value_type(1.0f)) < epsilon){
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bilinearCoordinates.y = beta;
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} else {
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bilinearCoordinates.y = beta/(bilinearCoordinates.x * (beta_11 - typename genType::value_type(1.0f)) + typename genType::value_type(1.0f));
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}
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} else if(abs(beta_11 - typename genType::value_type(1.0f)) < epsilon) {
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bilinearCoordinates.y = alpha;
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bilinearCoordinates.x = alpha/(bilinearCoordinates.y*(alpha_11 - typename genType::value_type(1.0f)) + typename genType::value_type(1.0f));
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} else {
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typename genType::value_type a, b, c, discr, q;
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a = -(beta_11 - typename genType::value_type(1.0f));
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b = alpha*(beta_11 - 1) - beta*(alpha_11 - typename genType::value_type(1.0f)) - typename genType::value_type(1.0f);
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c = alpha;
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discr = b*b - typename genType::value_type(4.0f)*a*c;
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// Get sign of b
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typename genType::value_type sign = (typename genType::value_type(0) < b) - (b < typename genType::value_type(0));
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q = -(typename genType::value_type(0.5f)) * (b + sign*glm::fastSqrt(discr));
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bilinearCoordinates.x = q/a;
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if(bilinearCoordinates.x < 0 || bilinearCoordinates.y > 1){
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bilinearCoordinates.x = c/q;
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}
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bilinearCoordinates.y = beta/(bilinearCoordinates.x*(beta_11 - 1) + 1);
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}
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return true;
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}
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template<typename genType>
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GLM_FUNC_QUALIFIER bool fastIntersectLineQuad
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(
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genType const & orig, genType const & dir,
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genType const & v00, genType const & v10, genType const & v11, genType const & v01
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)
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{
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// Epsilon to reject parallell lines
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typename genType::value_type epsilon = std::numeric_limits<typename genType::value_type>::epsilon();
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// Calculate edges and normal of first triangle
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genType e01 = v10 - v00;
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genType e03 = v01 - v00;
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genType p = glm::cross(dir, e03);
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typename genType::value_type det = glm::dot(e01, p);
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// Reject rays orthagonal to the normal vector. I.e. rays parallell to the plane.
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if(det < epsilon && det > -epsilon)
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return false;
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typename genType::value_type inv_det = typename genType::value_type(1.0f)/det;
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genType s = orig - v00;
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// Calculate the barycentric alpha coordinate of the first triangle
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typename genType::value_type alpha = inv_det * glm::dot(s, p);
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// It lies outside the triangle
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if(alpha > typename genType::value_type(1.0f))
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return false;
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if(alpha < typename genType::value_type(0.0f))
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return false;
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// Vector perpendicular to T and e01
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genType q = glm::cross(s, e01);
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// Calculate barycentric beta coordinate of the first triangle
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typename genType::value_type beta = inv_det * glm::dot(dir, q);
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if(beta > typename genType::value_type(1.0f))
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return false;
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if(beta < typename genType::value_type(0.0f))
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return false;
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if(alpha + beta > typename genType::value_type(1.0f)){
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// Do exactly the same for the second triangle
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genType e23 = v01 - v11;
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genType e21 = v10 - v11;
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p = glm::cross(dir, e21);
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det = glm::dot(e23, p);
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if(det < epsilon && det > -epsilon)
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return false;
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inv_det = typename genType::value_type(1.0f)/det;
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s = orig - v11;
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alpha = inv_det * glm::dot(s, p);
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if(alpha < typename genType::value_type(0.0f))
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return false;
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q = glm::cross(s, e23);
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beta = inv_det * glm::dot(dir, q);
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if(beta < typename genType::value_type(0.0f))
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return false;
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// This to support degenerate squares
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if(beta + alpha > typename genType::value_type(1.0f))
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return false;
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}
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return true;
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}
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}//namespace glm
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