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-rw-r--r--core/math/basis.cpp37
1 files changed, 26 insertions, 11 deletions
diff --git a/core/math/basis.cpp b/core/math/basis.cpp
index 9796ac59c2..34ed1c2d85 100644
--- a/core/math/basis.cpp
+++ b/core/math/basis.cpp
@@ -89,13 +89,26 @@ Basis Basis::orthogonalized() const {
return c;
}
+// Returns true if the basis vectors are orthogonal (perpendicular), so it has no skew or shear, and can be decomposed into rotation and scale.
+// See https://en.wikipedia.org/wiki/Orthogonal_basis
bool Basis::is_orthogonal() const {
- Basis identity;
- Basis m = (*this) * transposed();
+ const Vector3 x = get_column(0);
+ const Vector3 y = get_column(1);
+ const Vector3 z = get_column(2);
+ return Math::is_zero_approx(x.dot(y)) && Math::is_zero_approx(x.dot(z)) && Math::is_zero_approx(y.dot(z));
+}
- return m.is_equal_approx(identity);
+// Returns true if the basis vectors are orthonormal (orthogonal and normalized), so it has no scale, skew, or shear.
+// See https://en.wikipedia.org/wiki/Orthonormal_basis
+bool Basis::is_orthonormal() const {
+ const Vector3 x = get_column(0);
+ const Vector3 y = get_column(1);
+ const Vector3 z = get_column(2);
+ return Math::is_equal_approx(x.length_squared(), 1) && Math::is_equal_approx(y.length_squared(), 1) && Math::is_equal_approx(z.length_squared(), 1) && Math::is_zero_approx(x.dot(y)) && Math::is_zero_approx(x.dot(z)) && Math::is_zero_approx(y.dot(z));
}
+// Returns true if the basis is conformal (orthogonal, uniform scale, preserves angles and distance ratios).
+// See https://en.wikipedia.org/wiki/Conformal_linear_transformation
bool Basis::is_conformal() const {
const Vector3 x = get_column(0);
const Vector3 y = get_column(1);
@@ -104,6 +117,7 @@ bool Basis::is_conformal() const {
return Math::is_equal_approx(x_len_sq, y.length_squared()) && Math::is_equal_approx(x_len_sq, z.length_squared()) && Math::is_zero_approx(x.dot(y)) && Math::is_zero_approx(x.dot(z)) && Math::is_zero_approx(y.dot(z));
}
+// Returns true if the basis only has diagonal elements, so it may only have scale or flip, but no rotation, skew, or shear.
bool Basis::is_diagonal() const {
return (
Math::is_zero_approx(rows[0][1]) && Math::is_zero_approx(rows[0][2]) &&
@@ -111,8 +125,9 @@ bool Basis::is_diagonal() const {
Math::is_zero_approx(rows[2][0]) && Math::is_zero_approx(rows[2][1]));
}
+// Returns true if the basis is a pure rotation matrix, so it has no scale, skew, shear, or flip.
bool Basis::is_rotation() const {
- return Math::is_equal_approx(determinant(), 1, (real_t)UNIT_EPSILON) && is_orthogonal();
+ return is_conformal() && Math::is_equal_approx(determinant(), 1, (real_t)UNIT_EPSILON);
}
#ifdef MATH_CHECKS
@@ -263,7 +278,7 @@ Basis Basis::scaled_orthogonal(const Vector3 &p_scale) const {
return m;
}
-float Basis::get_uniform_scale() const {
+real_t Basis::get_uniform_scale() const {
return (rows[0].length() + rows[1].length() + rows[2].length()) / 3.0f;
}
@@ -278,7 +293,7 @@ Vector3 Basis::get_scale_abs() const {
Vector3(rows[0][2], rows[1][2], rows[2][2]).length());
}
-Vector3 Basis::get_scale_local() const {
+Vector3 Basis::get_scale_global() const {
real_t det_sign = SIGN(determinant());
return det_sign * Vector3(rows[0].length(), rows[1].length(), rows[2].length());
}
@@ -670,7 +685,7 @@ void Basis::set_euler(const Vector3 &p_euler, EulerOrder p_order) {
*this = zmat * ymat * xmat;
} break;
default: {
- ERR_FAIL_MSG("Invalid order parameter for set_euler(vec3,order)");
+ ERR_FAIL_MSG("Invalid Euler order parameter.");
}
}
}
@@ -707,7 +722,7 @@ Basis::operator String() const {
Quaternion Basis::get_quaternion() const {
#ifdef MATH_CHECKS
- ERR_FAIL_COND_V_MSG(!is_rotation(), Quaternion(), "Basis must be normalized in order to be casted to a Quaternion. Use get_rotation_quaternion() or call orthonormalized() if the Basis contains linearly independent vectors.");
+ ERR_FAIL_COND_V_MSG(!is_rotation(), Quaternion(), "Basis " + operator String() + " must be normalized in order to be casted to a Quaternion. Use get_rotation_quaternion() or call orthonormalized() if the Basis contains linearly independent vectors.");
#endif
/* Allow getting a quaternion from an unnormalized transform */
Basis m = *this;
@@ -834,7 +849,7 @@ void Basis::set_quaternion(const Quaternion &p_quaternion) {
void Basis::set_axis_angle(const Vector3 &p_axis, real_t p_angle) {
// Rotation matrix from axis and angle, see https://en.wikipedia.org/wiki/Rotation_matrix#Rotation_matrix_from_axis_angle
#ifdef MATH_CHECKS
- ERR_FAIL_COND_MSG(!p_axis.is_normalized(), "The axis Vector3 must be normalized.");
+ ERR_FAIL_COND_MSG(!p_axis.is_normalized(), "The axis Vector3 " + p_axis.operator String() + " must be normalized.");
#endif
Vector3 axis_sq(p_axis.x * p_axis.x, p_axis.y * p_axis.y, p_axis.z * p_axis.z);
real_t cosine = Math::cos(p_angle);
@@ -892,7 +907,7 @@ void Basis::_set_diagonal(const Vector3 &p_diag) {
rows[2][2] = p_diag.z;
}
-Basis Basis::lerp(const Basis &p_to, const real_t &p_weight) const {
+Basis Basis::lerp(const Basis &p_to, real_t p_weight) const {
Basis b;
b.rows[0] = rows[0].lerp(p_to.rows[0], p_weight);
b.rows[1] = rows[1].lerp(p_to.rows[1], p_weight);
@@ -901,7 +916,7 @@ Basis Basis::lerp(const Basis &p_to, const real_t &p_weight) const {
return b;
}
-Basis Basis::slerp(const Basis &p_to, const real_t &p_weight) const {
+Basis Basis::slerp(const Basis &p_to, real_t p_weight) const {
//consider scale
Quaternion from(*this);
Quaternion to(p_to);