зеркало из https://github.com/mozilla/gecko-dev.git
117 строки
4.3 KiB
C++
117 строки
4.3 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef GFX_QUATERNION_H
|
|
#define GFX_QUATERNION_H
|
|
|
|
#include "mozilla/gfx/BasePoint4D.h"
|
|
#include "mozilla/gfx/Matrix.h"
|
|
#include "nsAlgorithm.h"
|
|
#include <algorithm>
|
|
|
|
struct gfxQuaternion : public mozilla::gfx::BasePoint4D<gfxFloat, gfxQuaternion> {
|
|
typedef mozilla::gfx::BasePoint4D<gfxFloat, gfxQuaternion> Super;
|
|
|
|
gfxQuaternion() : Super() {}
|
|
gfxQuaternion(gfxFloat aX, gfxFloat aY, gfxFloat aZ, gfxFloat aW) : Super(aX, aY, aZ, aW) {}
|
|
|
|
explicit gfxQuaternion(const mozilla::gfx::Matrix4x4& aMatrix) {
|
|
w = 0.5 * sqrt(std::max(1 + aMatrix[0][0] + aMatrix[1][1] + aMatrix[2][2], 0.0f));
|
|
x = 0.5 * sqrt(std::max(1 + aMatrix[0][0] - aMatrix[1][1] - aMatrix[2][2], 0.0f));
|
|
y = 0.5 * sqrt(std::max(1 - aMatrix[0][0] + aMatrix[1][1] - aMatrix[2][2], 0.0f));
|
|
z = 0.5 * sqrt(std::max(1 - aMatrix[0][0] - aMatrix[1][1] + aMatrix[2][2], 0.0f));
|
|
|
|
if(aMatrix[2][1] > aMatrix[1][2])
|
|
x = -x;
|
|
if(aMatrix[0][2] > aMatrix[2][0])
|
|
y = -y;
|
|
if(aMatrix[1][0] > aMatrix[0][1])
|
|
z = -z;
|
|
}
|
|
|
|
// Convert from |direction axis, angle| pair to gfxQuaternion.
|
|
//
|
|
// Reference:
|
|
// https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation
|
|
//
|
|
// if the direction axis is (x, y, z) = xi + yj + zk,
|
|
// and the angle is |theta|, this formula can be done using
|
|
// an extension of Euler's formula:
|
|
// q = cos(theta/2) + (xi + yj + zk)(sin(theta/2))
|
|
// = cos(theta/2) +
|
|
// x*sin(theta/2)i + y*sin(theta/2)j + z*sin(theta/2)k
|
|
// Note: aDirection should be an unit vector and
|
|
// the unit of aAngle should be Radian.
|
|
gfxQuaternion(const mozilla::gfx::Point3D &aDirection, gfxFloat aAngle) {
|
|
MOZ_ASSERT(mozilla::gfx::FuzzyEqual(aDirection.Length(), 1.0f),
|
|
"aDirection should be an unit vector");
|
|
x = aDirection.x * sin(aAngle/2.0);
|
|
y = aDirection.y * sin(aAngle/2.0);
|
|
z = aDirection.z * sin(aAngle/2.0);
|
|
w = cos(aAngle/2.0);
|
|
}
|
|
|
|
gfxQuaternion Slerp(const gfxQuaternion &aOther, gfxFloat aCoeff) const {
|
|
gfxFloat dot = mozilla::clamped(DotProduct(aOther), -1.0, 1.0);
|
|
if (dot == 1.0) {
|
|
return *this;
|
|
}
|
|
|
|
gfxFloat theta = acos(dot);
|
|
gfxFloat rsintheta = 1/sqrt(1 - dot*dot);
|
|
gfxFloat rightWeight = sin(aCoeff*theta)*rsintheta;
|
|
|
|
gfxQuaternion left = *this;
|
|
gfxQuaternion right = aOther;
|
|
|
|
left *= cos(aCoeff*theta) - dot*rightWeight;
|
|
right *= rightWeight;
|
|
|
|
return left + right;
|
|
}
|
|
|
|
using Super::operator*=;
|
|
|
|
// Quaternion multiplication
|
|
// Reference:
|
|
// https://en.wikipedia.org/wiki/Quaternion#Ordered_list_form
|
|
//
|
|
// (w1, x1, y1, z1)(w2, x2, y2, z2) = (w1w2 - x1x2 - y1y2 - z1z2,
|
|
// w1x2 + x1w2 + y1z2 - z1y2,
|
|
// w1y2 - x1z2 + y1w2 + z1x2,
|
|
// w1z2 + x1y2 - y1x2 + z1w2)
|
|
gfxQuaternion operator*(const gfxQuaternion& aOther) const {
|
|
return gfxQuaternion(
|
|
w * aOther.x + x * aOther.w + y * aOther.z - z * aOther.y,
|
|
w * aOther.y - x * aOther.z + y * aOther.w + z * aOther.x,
|
|
w * aOther.z + x * aOther.y - y * aOther.x + z * aOther.w,
|
|
w * aOther.w - x * aOther.x - y * aOther.y - z * aOther.z
|
|
);
|
|
}
|
|
gfxQuaternion& operator*=(const gfxQuaternion& aOther) {
|
|
*this = *this * aOther;
|
|
return *this;
|
|
}
|
|
|
|
mozilla::gfx::Matrix4x4 ToMatrix() const {
|
|
mozilla::gfx::Matrix4x4 temp;
|
|
|
|
temp[0][0] = 1 - 2 * (y * y + z * z);
|
|
temp[0][1] = 2 * (x * y + w * z);
|
|
temp[0][2] = 2 * (x * z - w * y);
|
|
temp[1][0] = 2 * (x * y - w * z);
|
|
temp[1][1] = 1 - 2 * (x * x + z * z);
|
|
temp[1][2] = 2 * (y * z + w * x);
|
|
temp[2][0] = 2 * (x * z + w * y);
|
|
temp[2][1] = 2 * (y * z - w * x);
|
|
temp[2][2] = 1 - 2 * (x * x + y * y);
|
|
|
|
return temp;
|
|
}
|
|
|
|
};
|
|
|
|
#endif /* GFX_QUATERNION_H */
|