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Diffstat (limited to 'external/include/glm/gtx/matrix_decompose.inl')
| -rw-r--r-- | external/include/glm/gtx/matrix_decompose.inl | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/external/include/glm/gtx/matrix_decompose.inl b/external/include/glm/gtx/matrix_decompose.inl new file mode 100644 index 0000000..7194e9d --- /dev/null +++ b/external/include/glm/gtx/matrix_decompose.inl @@ -0,0 +1,194 @@ +/// @ref gtx_matrix_decompose +/// @file glm/gtx/matrix_decompose.inl + +namespace glm{ +namespace detail +{ + /// Make a linear combination of two vectors and return the result. + // result = (a * ascl) + (b * bscl) + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec3<T, P> combine( + tvec3<T, P> const & a, + tvec3<T, P> const & b, + T ascl, T bscl) + { + return (a * ascl) + (b * bscl); + } + + template <typename T, precision P> + GLM_FUNC_QUALIFIER tvec3<T, P> scale(tvec3<T, P> 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, precision P> + GLM_FUNC_QUALIFIER bool decompose(tmat4x4<T, P> const & ModelMatrix, tvec3<T, P> & Scale, tquat<T, P> & Orientation, tvec3<T, P> & Translation, tvec3<T, P> & Skew, tvec4<T, P> & Perspective) + { + tmat4x4<T, P> LocalMatrix(ModelMatrix); + + // Normalize the matrix. + if(LocalMatrix[3][3] == static_cast<T>(0)) + 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. + tmat4x4<T, P> 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(determinant(PerspectiveMatrix) == static_cast<T>(0)) + return false; + + // First, isolate perspective. This is the messiest. + if(LocalMatrix[0][3] != static_cast<T>(0) || LocalMatrix[1][3] != static_cast<T>(0) || LocalMatrix[2][3] != static_cast<T>(0)) + { + // rightHandSide is the right hand side of the equation. + tvec4<T, P> 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.) + tmat4x4<T, P> InversePerspectiveMatrix = glm::inverse(PerspectiveMatrix);// inverse(PerspectiveMatrix, inversePerspectiveMatrix); + tmat4x4<T, P> 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 = tvec4<T, P>(0, 0, 0, 1); + } + + // Next take care of translation (easy). + Translation = tvec3<T, P>(LocalMatrix[3]); + LocalMatrix[3] = tvec4<T, P>(0, 0, 0, LocalMatrix[3].w); + + tvec3<T, P> Row[3], Pdum3; + + // Now get scale and shear. + for(length_t i = 0; i < 3; ++i) + for(int 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; + // } + + T s, t, x, y, z, w; + + t = Row[0][0] + Row[1][1] + Row[2][2] + static_cast<T>(1); + + if(t > static_cast<T>(1e-4)) + { + s = static_cast<T>(0.5) / sqrt(t); + w = static_cast<T>(0.25) / s; + x = (Row[2][1] - Row[1][2]) * s; + y = (Row[0][2] - Row[2][0]) * s; + z = (Row[1][0] - Row[0][1]) * s; + } + else if(Row[0][0] > Row[1][1] && Row[0][0] > Row[2][2]) + { + s = sqrt (static_cast<T>(1) + Row[0][0] - Row[1][1] - Row[2][2]) * static_cast<T>(2); // S=4*qx + x = static_cast<T>(0.25) * s; + y = (Row[0][1] + Row[1][0]) / s; + z = (Row[0][2] + Row[2][0]) / s; + w = (Row[2][1] - Row[1][2]) / s; + } + else if(Row[1][1] > Row[2][2]) + { + s = sqrt (static_cast<T>(1) + Row[1][1] - Row[0][0] - Row[2][2]) * static_cast<T>(2); // S=4*qy + x = (Row[0][1] + Row[1][0]) / s; + y = static_cast<T>(0.25) * s; + z = (Row[1][2] + Row[2][1]) / s; + w = (Row[0][2] - Row[2][0]) / s; + } + else + { + s = sqrt(static_cast<T>(1) + Row[2][2] - Row[0][0] - Row[1][1]) * static_cast<T>(2); // S=4*qz + x = (Row[0][2] + Row[2][0]) / s; + y = (Row[1][2] + Row[2][1]) / s; + z = static_cast<T>(0.25) * s; + w = (Row[1][0] - Row[0][1]) / s; + } + + Orientation.x = x; + Orientation.y = y; + Orientation.z = z; + Orientation.w = w; + + return true; + } +}//namespace glm |