diff options
Diffstat (limited to 'Project/glm/gtx/matrix_decompose.inl')
| -rw-r--r-- | Project/glm/gtx/matrix_decompose.inl | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/Project/glm/gtx/matrix_decompose.inl b/Project/glm/gtx/matrix_decompose.inl new file mode 100644 index 0000000..694f5ec --- /dev/null +++ b/Project/glm/gtx/matrix_decompose.inl @@ -0,0 +1,186 @@ +/// @ref gtx_matrix_decompose + +#include "../gtc/constants.hpp" +#include "../gtc/epsilon.hpp" + +namespace glm{ +namespace detail +{ + /// Make a linear combination of two vectors and return the result. + // result = (a * ascl) + (b * bscl) + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<3, T, Q> combine( + vec<3, T, Q> const& a, + vec<3, T, Q> const& b, + T ascl, T bscl) + { + return (a * ascl) + (b * bscl); + } + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER vec<3, T, Q> scale(vec<3, T, Q> const& v, T desiredLength) + { + return v * desiredLength / length(v); + } +}//namespace detail + + // Matrix decompose + // http://www.opensource.apple.com/source/WebCore/WebCore-514/platform/graphics/transforms/TransformationMatrix.cpp + // Decomposes the mode matrix to translations,rotation scale components + + template<typename T, qualifier Q> + GLM_FUNC_QUALIFIER bool decompose(mat<4, 4, T, Q> const& ModelMatrix, vec<3, T, Q> & Scale, qua<T, Q> & Orientation, vec<3, T, Q> & Translation, vec<3, T, Q> & Skew, vec<4, T, Q> & Perspective) + { + mat<4, 4, T, Q> LocalMatrix(ModelMatrix); + + // Normalize the matrix. + if(epsilonEqual(LocalMatrix[3][3], static_cast<T>(0), epsilon<T>())) + return false; + + for(length_t i = 0; i < 4; ++i) + for(length_t j = 0; j < 4; ++j) + LocalMatrix[i][j] /= LocalMatrix[3][3]; + + // perspectiveMatrix is used to solve for perspective, but it also provides + // an easy way to test for singularity of the upper 3x3 component. + mat<4, 4, T, Q> PerspectiveMatrix(LocalMatrix); + + for(length_t i = 0; i < 3; i++) + PerspectiveMatrix[i][3] = static_cast<T>(0); + PerspectiveMatrix[3][3] = static_cast<T>(1); + + /// TODO: Fixme! + if(epsilonEqual(determinant(PerspectiveMatrix), static_cast<T>(0), epsilon<T>())) + return false; + + // First, isolate perspective. This is the messiest. + if( + epsilonNotEqual(LocalMatrix[0][3], static_cast<T>(0), epsilon<T>()) || + epsilonNotEqual(LocalMatrix[1][3], static_cast<T>(0), epsilon<T>()) || + epsilonNotEqual(LocalMatrix[2][3], static_cast<T>(0), epsilon<T>())) + { + // rightHandSide is the right hand side of the equation. + vec<4, T, Q> RightHandSide; + RightHandSide[0] = LocalMatrix[0][3]; + RightHandSide[1] = LocalMatrix[1][3]; + RightHandSide[2] = LocalMatrix[2][3]; + RightHandSide[3] = LocalMatrix[3][3]; + + // Solve the equation by inverting PerspectiveMatrix and multiplying + // rightHandSide by the inverse. (This is the easiest way, not + // necessarily the best.) + mat<4, 4, T, Q> InversePerspectiveMatrix = glm::inverse(PerspectiveMatrix);// inverse(PerspectiveMatrix, inversePerspectiveMatrix); + mat<4, 4, T, Q> TransposedInversePerspectiveMatrix = glm::transpose(InversePerspectiveMatrix);// transposeMatrix4(inversePerspectiveMatrix, transposedInversePerspectiveMatrix); + + Perspective = TransposedInversePerspectiveMatrix * RightHandSide; + // v4MulPointByMatrix(rightHandSide, transposedInversePerspectiveMatrix, perspectivePoint); + + // Clear the perspective partition + LocalMatrix[0][3] = LocalMatrix[1][3] = LocalMatrix[2][3] = static_cast<T>(0); + LocalMatrix[3][3] = static_cast<T>(1); + } + else + { + // No perspective. + Perspective = vec<4, T, Q>(0, 0, 0, 1); + } + + // Next take care of translation (easy). + Translation = vec<3, T, Q>(LocalMatrix[3]); + LocalMatrix[3] = vec<4, T, Q>(0, 0, 0, LocalMatrix[3].w); + + vec<3, T, Q> Row[3], Pdum3; + + // Now get scale and shear. + for(length_t i = 0; i < 3; ++i) + for(length_t j = 0; j < 3; ++j) + Row[i][j] = LocalMatrix[i][j]; + + // Compute X scale factor and normalize first row. + Scale.x = length(Row[0]);// v3Length(Row[0]); + + Row[0] = detail::scale(Row[0], static_cast<T>(1)); + + // Compute XY shear factor and make 2nd row orthogonal to 1st. + Skew.z = dot(Row[0], Row[1]); + Row[1] = detail::combine(Row[1], Row[0], static_cast<T>(1), -Skew.z); + + // Now, compute Y scale and normalize 2nd row. + Scale.y = length(Row[1]); + Row[1] = detail::scale(Row[1], static_cast<T>(1)); + Skew.z /= Scale.y; + + // Compute XZ and YZ shears, orthogonalize 3rd row. + Skew.y = glm::dot(Row[0], Row[2]); + Row[2] = detail::combine(Row[2], Row[0], static_cast<T>(1), -Skew.y); + Skew.x = glm::dot(Row[1], Row[2]); + Row[2] = detail::combine(Row[2], Row[1], static_cast<T>(1), -Skew.x); + + // Next, get Z scale and normalize 3rd row. + Scale.z = length(Row[2]); + Row[2] = detail::scale(Row[2], static_cast<T>(1)); + Skew.y /= Scale.z; + Skew.x /= Scale.z; + + // At this point, the matrix (in rows[]) is orthonormal. + // Check for a coordinate system flip. If the determinant + // is -1, then negate the matrix and the scaling factors. + Pdum3 = cross(Row[1], Row[2]); // v3Cross(row[1], row[2], Pdum3); + if(dot(Row[0], Pdum3) < 0) + { + for(length_t i = 0; i < 3; i++) + { + Scale[i] *= static_cast<T>(-1); + Row[i] *= static_cast<T>(-1); + } + } + + // Now, get the rotations out, as described in the gem. + + // FIXME - Add the ability to return either quaternions (which are + // easier to recompose with) or Euler angles (rx, ry, rz), which + // are easier for authors to deal with. The latter will only be useful + // when we fix https://bugs.webkit.org/show_bug.cgi?id=23799, so I + // will leave the Euler angle code here for now. + + // ret.rotateY = asin(-Row[0][2]); + // if (cos(ret.rotateY) != 0) { + // ret.rotateX = atan2(Row[1][2], Row[2][2]); + // ret.rotateZ = atan2(Row[0][1], Row[0][0]); + // } else { + // ret.rotateX = atan2(-Row[2][0], Row[1][1]); + // ret.rotateZ = 0; + // } + + int i, j, k = 0; + T root, trace = Row[0].x + Row[1].y + Row[2].z; + if(trace > static_cast<T>(0)) + { + root = sqrt(trace + static_cast<T>(1.0)); + Orientation.w = static_cast<T>(0.5) * root; + root = static_cast<T>(0.5) / root; + Orientation.x = root * (Row[1].z - Row[2].y); + Orientation.y = root * (Row[2].x - Row[0].z); + Orientation.z = root * (Row[0].y - Row[1].x); + } // End if > 0 + else + { + static int Next[3] = {1, 2, 0}; + i = 0; + if(Row[1].y > Row[0].x) i = 1; + if(Row[2].z > Row[i][i]) i = 2; + j = Next[i]; + k = Next[j]; + + root = sqrt(Row[i][i] - Row[j][j] - Row[k][k] + static_cast<T>(1.0)); + + Orientation[i] = static_cast<T>(0.5) * root; + root = static_cast<T>(0.5) / root; + Orientation[j] = root * (Row[i][j] + Row[j][i]); + Orientation[k] = root * (Row[i][k] + Row[k][i]); + Orientation.w = root * (Row[j][k] - Row[k][j]); + } // End if <= 0 + + return true; + } +}//namespace glm |