1 /*
2 * Copyright (C) 2009 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "config.h"
27 #include "PerspectiveTransformOperation.h"
28
29 #include <algorithm>
30
31 using namespace std;
32
33 namespace WebCore {
34
blend(const TransformOperation * from,double progress,bool blendToIdentity)35 PassRefPtr<TransformOperation> PerspectiveTransformOperation::blend(const TransformOperation* from, double progress, bool blendToIdentity)
36 {
37 if (from && !from->isSameType(*this))
38 return this;
39
40 if (blendToIdentity)
41 return PerspectiveTransformOperation::create(m_p + (1. - m_p) * progress);
42
43 const PerspectiveTransformOperation* fromOp = static_cast<const PerspectiveTransformOperation*>(from);
44 double fromP = fromOp ? fromOp->m_p : 0;
45 double toP = m_p;
46
47 TransformationMatrix fromT;
48 TransformationMatrix toT;
49 fromT.applyPerspective(fromP);
50 toT.applyPerspective(toP);
51 toT.blend(fromT, progress);
52 TransformationMatrix::DecomposedType decomp;
53 toT.decompose(decomp);
54
55 return PerspectiveTransformOperation::create(decomp.perspectiveZ ? -1.0 / decomp.perspectiveZ : 0.0);
56 }
57
58 } // namespace WebCore
59