1 /*
2 * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
3 * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 *
20 */
21
22 #include "config.h"
23 #include "RotateTransformOperation.h"
24
25 #include <algorithm>
26 #include <wtf/MathExtras.h>
27
28 using namespace std;
29
30 namespace WebCore {
31
blend(const TransformOperation * from,double progress,bool blendToIdentity)32 PassRefPtr<TransformOperation> RotateTransformOperation::blend(const TransformOperation* from, double progress, bool blendToIdentity)
33 {
34 if (from && !from->isSameType(*this))
35 return this;
36
37 if (blendToIdentity)
38 return RotateTransformOperation::create(m_x, m_y, m_z, m_angle - m_angle * progress, m_type);
39
40 const RotateTransformOperation* fromOp = static_cast<const RotateTransformOperation*>(from);
41
42 // Optimize for single axis rotation
43 if (!fromOp || (fromOp->m_x == 0 && fromOp->m_y == 0 && fromOp->m_z == 1) ||
44 (fromOp->m_x == 0 && fromOp->m_y == 1 && fromOp->m_z == 0) ||
45 (fromOp->m_x == 1 && fromOp->m_y == 0 && fromOp->m_z == 0)) {
46 double fromAngle = fromOp ? fromOp->m_angle : 0;
47 return RotateTransformOperation::create(fromOp ? fromOp->m_x : m_x,
48 fromOp ? fromOp->m_y : m_y,
49 fromOp ? fromOp->m_z : m_z,
50 fromAngle + (m_angle - fromAngle) * progress, m_type);
51 }
52
53 const RotateTransformOperation* toOp = this;
54
55 // Create the 2 rotation matrices
56 TransformationMatrix fromT;
57 TransformationMatrix toT;
58 fromT.rotate3d((float)(fromOp ? fromOp->m_x : 0),
59 (float)(fromOp ? fromOp->m_y : 0),
60 (float)(fromOp ? fromOp->m_z : 1),
61 (float)(fromOp ? fromOp->m_angle : 0));
62
63 toT.rotate3d((float)(toOp ? toOp->m_x : 0),
64 (float)(toOp ? toOp->m_y : 0),
65 (float)(toOp ? toOp->m_z : 1),
66 (float)(toOp ? toOp->m_angle : 0));
67
68 // Blend them
69 toT.blend(fromT, progress);
70
71 // Extract the result as a quaternion
72 TransformationMatrix::DecomposedType decomp;
73 toT.decompose(decomp);
74
75 // Convert that to Axis/Angle form
76 double x = -decomp.quaternionX;
77 double y = -decomp.quaternionY;
78 double z = -decomp.quaternionZ;
79 double length = sqrt(x * x + y * y + z * z);
80 double angle = 0;
81
82 if (length > 0.00001) {
83 x /= length;
84 y /= length;
85 z /= length;
86 angle = rad2deg(acos(decomp.quaternionW) * 2);
87 } else {
88 x = 0;
89 y = 0;
90 z = 1;
91 }
92 return RotateTransformOperation::create(x, y, z, angle, ROTATE_3D);
93 }
94
95 } // namespace WebCore
96