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/*
* 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 "CCMathUtil.h"
#include "CCLayerTreeTestCommon.h"
#include "FloatRect.h"
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <public/WebTransformationMatrix.h>
using namespace WebCore;
using WebKit::WebTransformationMatrix;
namespace {
TEST(CCMathUtilTest, verifyBackfaceVisibilityBasicCases)
{
WebTransformationMatrix 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)
{
WebTransformationMatrix 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());
}
TEST(CCMathUtilTest, verifyProjectionOfPerpendicularPlane)
{
// In this case, the m33() element of the transform becomes zero, which could cause a
// divide-by-zero when projecting points/quads.
WebTransformationMatrix transform;
transform.makeIdentity();
transform.setM33(0);
FloatRect rect = FloatRect(0, 0, 1, 1);
FloatRect projectedRect = CCMathUtil::projectClippedRect(transform, rect);
EXPECT_EQ(0, projectedRect.x());
EXPECT_EQ(0, projectedRect.y());
EXPECT_TRUE(projectedRect.isEmpty());
}
TEST(CCMathUtilTest, verifyEnclosingClippedRectUsesCorrectInitialBounds)
{
HomogeneousCoordinate h1(-100, -100, 0, 1);
HomogeneousCoordinate h2(-10, -10, 0, 1);
HomogeneousCoordinate h3(10, 10, 0, -1);
HomogeneousCoordinate h4(100, 100, 0, -1);
// The bounds of the enclosing clipped rect should be -100 to -10 for both x and y.
// However, if there is a bug where the initial xmin/xmax/ymin/ymax are initialized to
// numeric_limits<float>::min() (which is zero, not -flt_max) then the enclosing
// clipped rect will be computed incorrectly.
FloatRect result = CCMathUtil::computeEnclosingClippedRect(h1, h2, h3, h4);
EXPECT_FLOAT_RECT_EQ(FloatRect(FloatPoint(-100, -100), FloatSize(90, 90)), result);
}
TEST(CCMathUtilTest, verifyEnclosingRectOfVerticesUsesCorrectInitialBounds)
{
FloatPoint vertices[3];
int numVertices = 3;
vertices[0] = FloatPoint(-10, -100);
vertices[1] = FloatPoint(-100, -10);
vertices[2] = FloatPoint(-30, -30);
// The bounds of the enclosing rect should be -100 to -10 for both x and y. However,
// if there is a bug where the initial xmin/xmax/ymin/ymax are initialized to
// numeric_limits<float>::min() (which is zero, not -flt_max) then the enclosing
// clipped rect will be computed incorrectly.
FloatRect result = CCMathUtil::computeEnclosingRectOfVertices(vertices, numVertices);
EXPECT_FLOAT_RECT_EQ(FloatRect(FloatPoint(-100, -100), FloatSize(90, 90)), result);
}
TEST(CCMathUtilTest, smallestAngleBetweenVectors)
{
FloatSize x(1, 0);
FloatSize y(0, 1);
FloatSize testVector(0.5, 0.5);
// Orthogonal vectors are at an angle of 90 degress.
EXPECT_EQ(90, CCMathUtil::smallestAngleBetweenVectors(x, y));
// A vector makes a zero angle with itself.
EXPECT_EQ(0, CCMathUtil::smallestAngleBetweenVectors(x, x));
EXPECT_EQ(0, CCMathUtil::smallestAngleBetweenVectors(y, y));
EXPECT_EQ(0, CCMathUtil::smallestAngleBetweenVectors(testVector, testVector));
// Parallel but reversed vectors are at 180 degrees.
EXPECT_FLOAT_EQ(180, CCMathUtil::smallestAngleBetweenVectors(x, -x));
EXPECT_FLOAT_EQ(180, CCMathUtil::smallestAngleBetweenVectors(y, -y));
EXPECT_FLOAT_EQ(180, CCMathUtil::smallestAngleBetweenVectors(testVector, -testVector));
// The test vector is at a known angle.
EXPECT_FLOAT_EQ(45, floor(CCMathUtil::smallestAngleBetweenVectors(testVector, x)));
EXPECT_FLOAT_EQ(45, floor(CCMathUtil::smallestAngleBetweenVectors(testVector, y)));
}
TEST(CCMathUtilTest, vectorProjection)
{
FloatSize x(1, 0);
FloatSize y(0, 1);
FloatSize testVector(0.3f, 0.7f);
// Orthogonal vectors project to a zero vector.
EXPECT_EQ(FloatSize(0, 0), CCMathUtil::projectVector(x, y));
EXPECT_EQ(FloatSize(0, 0), CCMathUtil::projectVector(y, x));
// Projecting a vector onto the orthonormal basis gives the corresponding component of the
// vector.
EXPECT_EQ(FloatSize(testVector.width(), 0), CCMathUtil::projectVector(testVector, x));
EXPECT_EQ(FloatSize(0, testVector.height()), CCMathUtil::projectVector(testVector, y));
// Finally check than an arbitrary vector projected to another one gives a vector parallel to
// the second vector.
FloatSize targetVector(0.5, 0.2f);
FloatSize projectedVector = CCMathUtil::projectVector(testVector, targetVector);
EXPECT_EQ(projectedVector.width() / targetVector.width(),
projectedVector.height() / targetVector.height());
}
} // namespace
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