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Diffstat (limited to 'src/include/glm/gtx/matrix_decompose.inl')
| -rw-r--r-- | src/include/glm/gtx/matrix_decompose.inl | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/include/glm/gtx/matrix_decompose.inl b/src/include/glm/gtx/matrix_decompose.inl new file mode 100644 index 0000000..81ab844 --- /dev/null +++ b/src/include/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
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