summaryrefslogtreecommitdiffstats
path: root/gfx/thebes/gfxQuaternion.h
diff options
context:
space:
mode:
Diffstat (limited to 'gfx/thebes/gfxQuaternion.h')
-rw-r--r--gfx/thebes/gfxQuaternion.h117
1 files changed, 117 insertions, 0 deletions
diff --git a/gfx/thebes/gfxQuaternion.h b/gfx/thebes/gfxQuaternion.h
new file mode 100644
index 0000000000..4180f7a7b4
--- /dev/null
+++ b/gfx/thebes/gfxQuaternion.h
@@ -0,0 +1,117 @@
+/* -*- 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 */