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 // Copyright 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "cc/base/math_util.h" #include #include "cc/test/geometry_test_utils.h" #include "testing/gmock/include/gmock/gmock.h" #include "testing/gtest/include/gtest/gtest.h" #include "ui/gfx/rect.h" #include "ui/gfx/rect_f.h" #include "ui/gfx/transform.h" namespace cc { namespace { TEST(MathUtilTest, ProjectionOfPerpendicularPlane) { // In this case, the m33() element of the transform becomes zero, which could // cause a divide-by-zero when projecting points/quads. gfx::Transform transform; transform.MakeIdentity(); transform.matrix().set(2, 2, 0); gfx::RectF rect = gfx::RectF(0, 0, 1, 1); gfx::RectF projected_rect = MathUtil::ProjectClippedRect(transform, rect); EXPECT_EQ(0, projected_rect.x()); EXPECT_EQ(0, projected_rect.y()); EXPECT_TRUE(projected_rect.IsEmpty()); } TEST(MathUtilTest, EnclosingClippedRectUsesCorrectInitialBounds) { 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::min() (which is zero, not -flt_max) // then the enclosing clipped rect will be computed incorrectly. gfx::RectF result = MathUtil::ComputeEnclosingClippedRect(h1, h2, h3, h4); // Due to floating point math in ComputeClippedPointForEdge this result // is fairly imprecise. 0.15f was empirically determined. EXPECT_RECT_NEAR( gfx::RectF(gfx::PointF(-100, -100), gfx::SizeF(90, 90)), result, 0.15f); } TEST(MathUtilTest, EnclosingRectOfVerticesUsesCorrectInitialBounds) { gfx::PointF vertices[3]; int num_vertices = 3; vertices[0] = gfx::PointF(-10, -100); vertices[1] = gfx::PointF(-100, -10); vertices[2] = gfx::PointF(-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::min() (which is zero, not -flt_max) // then the enclosing clipped rect will be computed incorrectly. gfx::RectF result = MathUtil::ComputeEnclosingRectOfVertices(vertices, num_vertices); EXPECT_FLOAT_RECT_EQ(gfx::RectF(gfx::PointF(-100, -100), gfx::SizeF(90, 90)), result); } TEST(MathUtilTest, SmallestAngleBetweenVectors) { gfx::Vector2dF x(1, 0); gfx::Vector2dF y(0, 1); gfx::Vector2dF test_vector(0.5, 0.5); // Orthogonal vectors are at an angle of 90 degress. EXPECT_EQ(90, MathUtil::SmallestAngleBetweenVectors(x, y)); // A vector makes a zero angle with itself. EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(x, x)); EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(y, y)); EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(test_vector, test_vector)); // Parallel but reversed vectors are at 180 degrees. EXPECT_FLOAT_EQ(180, MathUtil::SmallestAngleBetweenVectors(x, -x)); EXPECT_FLOAT_EQ(180, MathUtil::SmallestAngleBetweenVectors(y, -y)); EXPECT_FLOAT_EQ( 180, MathUtil::SmallestAngleBetweenVectors(test_vector, -test_vector)); // The test vector is at a known angle. EXPECT_FLOAT_EQ( 45, std::floor(MathUtil::SmallestAngleBetweenVectors(test_vector, x))); EXPECT_FLOAT_EQ( 45, std::floor(MathUtil::SmallestAngleBetweenVectors(test_vector, y))); } TEST(MathUtilTest, VectorProjection) { gfx::Vector2dF x(1, 0); gfx::Vector2dF y(0, 1); gfx::Vector2dF test_vector(0.3f, 0.7f); // Orthogonal vectors project to a zero vector. EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), MathUtil::ProjectVector(x, y)); EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), MathUtil::ProjectVector(y, x)); // Projecting a vector onto the orthonormal basis gives the corresponding // component of the vector. EXPECT_VECTOR_EQ(gfx::Vector2dF(test_vector.x(), 0), MathUtil::ProjectVector(test_vector, x)); EXPECT_VECTOR_EQ(gfx::Vector2dF(0, test_vector.y()), MathUtil::ProjectVector(test_vector, y)); // Finally check than an arbitrary vector projected to another one gives a // vector parallel to the second vector. gfx::Vector2dF target_vector(0.5, 0.2f); gfx::Vector2dF projected_vector = MathUtil::ProjectVector(test_vector, target_vector); EXPECT_EQ(projected_vector.x() / target_vector.x(), projected_vector.y() / target_vector.y()); } } // namespace } // namespace cc