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 <wtf/MathExtras.h>
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 double p = m_p.calcFloatValue(1);
42 p = p + (1. - p) * progress; // FIXME: this seems wrong. https://bugs.webkit.org/show_bug.cgi?id=52700
43 return PerspectiveTransformOperation::create(Length(clampToPositiveInteger(p), Fixed));
44 }
45
46 const PerspectiveTransformOperation* fromOp = static_cast<const PerspectiveTransformOperation*>(from);
47 Length fromP = fromOp ? fromOp->m_p : Length(m_p.type());
48 Length toP = m_p;
49
50 TransformationMatrix fromT;
51 TransformationMatrix toT;
52 fromT.applyPerspective(fromP.calcFloatValue(1));
53 toT.applyPerspective(toP.calcFloatValue(1));
54 toT.blend(fromT, progress);
55 TransformationMatrix::DecomposedType decomp;
56 toT.decompose(decomp);
57
58 if (decomp.perspectiveZ) {
59 double val = -1.0 / decomp.perspectiveZ;
60 return PerspectiveTransformOperation::create(Length(clampToPositiveInteger(val), Fixed));
61 }
62 return PerspectiveTransformOperation::create(Length(0, Fixed));
63 }
64
65 } // namespace WebCore
66