1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
/*
* Copyright (C) 2012 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "cc/CCMathUtil.h"
#include "TransformationMatrix.h"
#include <gmock/gmock.h>
#include <gtest/gtest.h>
using namespace WebCore;
namespace {
TEST(CCMathUtilTest, verifyBackfaceVisibilityBasicCases)
{
TransformationMatrix transform;
transform.makeIdentity();
EXPECT_FALSE(transform.isBackFaceVisible());
transform.makeIdentity();
transform.rotate3d(0, 80, 0);
EXPECT_FALSE(transform.isBackFaceVisible());
transform.makeIdentity();
transform.rotate3d(0, 100, 0);
EXPECT_TRUE(transform.isBackFaceVisible());
// Edge case, 90 degree rotation should return false.
transform.makeIdentity();
transform.rotate3d(0, 90, 0);
EXPECT_FALSE(transform.isBackFaceVisible());
}
TEST(CCMathUtilTest, verifyBackfaceVisibilityForPerspective)
{
TransformationMatrix layerSpaceToProjectionPlane;
// This tests if isBackFaceVisible works properly under perspective transforms.
// Specifically, layers that may have their back face visible in orthographic
// projection, may not actually have back face visible under perspective projection.
// Case 1: Layer is rotated by slightly more than 90 degrees, at the center of the
// prespective projection. In this case, the layer's back-side is visible to
// the camera.
layerSpaceToProjectionPlane.makeIdentity();
layerSpaceToProjectionPlane.applyPerspective(1);
layerSpaceToProjectionPlane.translate3d(0, 0, 0);
layerSpaceToProjectionPlane.rotate3d(0, 100, 0);
EXPECT_TRUE(layerSpaceToProjectionPlane.isBackFaceVisible());
// Case 2: Layer is rotated by slightly more than 90 degrees, but shifted off to the
// side of the camera. Because of the wide field-of-view, the layer's front
// side is still visible.
//
// |<-- front side of layer is visible to perspective camera
// \ | /
// \ | /
// \| /
// | /
// |\ /<-- camera field of view
// | \ /
// back side of layer -->| \ /
// \./ <-- camera origin
//
layerSpaceToProjectionPlane.makeIdentity();
layerSpaceToProjectionPlane.applyPerspective(1);
layerSpaceToProjectionPlane.translate3d(-10, 0, 0);
layerSpaceToProjectionPlane.rotate3d(0, 100, 0);
EXPECT_FALSE(layerSpaceToProjectionPlane.isBackFaceVisible());
// Case 3: Additionally rotating the layer by 180 degrees should of course show the
// opposite result of case 2.
layerSpaceToProjectionPlane.rotate3d(0, 180, 0);
EXPECT_TRUE(layerSpaceToProjectionPlane.isBackFaceVisible());
}
} // namespace
|
