1 // Copyright 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "cc/base/math_util.h" 6 7 #include <cmath> 8 9 #include "cc/test/geometry_test_utils.h" 10 #include "testing/gmock/include/gmock/gmock.h" 11 #include "testing/gtest/include/gtest/gtest.h" 12 #include "ui/gfx/rect.h" 13 #include "ui/gfx/rect_f.h" 14 #include "ui/gfx/transform.h" 15 16 namespace cc { 17 namespace { 18 19 TEST(MathUtilTest, ProjectionOfPerpendicularPlane) { 20 // In this case, the m33() element of the transform becomes zero, which could 21 // cause a divide-by-zero when projecting points/quads. 22 23 gfx::Transform transform; 24 transform.MakeIdentity(); 25 transform.matrix().set(2, 2, 0); 26 27 gfx::RectF rect = gfx::RectF(0, 0, 1, 1); 28 gfx::RectF projected_rect = MathUtil::ProjectClippedRect(transform, rect); 29 30 EXPECT_EQ(0, projected_rect.x()); 31 EXPECT_EQ(0, projected_rect.y()); 32 EXPECT_TRUE(projected_rect.IsEmpty()); 33 } 34 35 TEST(MathUtilTest, EnclosingClippedRectUsesCorrectInitialBounds) { 36 HomogeneousCoordinate h1(-100, -100, 0, 1); 37 HomogeneousCoordinate h2(-10, -10, 0, 1); 38 HomogeneousCoordinate h3(10, 10, 0, -1); 39 HomogeneousCoordinate h4(100, 100, 0, -1); 40 41 // The bounds of the enclosing clipped rect should be -100 to -10 for both x 42 // and y. However, if there is a bug where the initial xmin/xmax/ymin/ymax are 43 // initialized to numeric_limits<float>::min() (which is zero, not -flt_max) 44 // then the enclosing clipped rect will be computed incorrectly. 45 gfx::RectF result = MathUtil::ComputeEnclosingClippedRect(h1, h2, h3, h4); 46 47 // Due to floating point math in ComputeClippedPointForEdge this result 48 // is fairly imprecise. 0.15f was empirically determined. 49 EXPECT_RECT_NEAR( 50 gfx::RectF(gfx::PointF(-100, -100), gfx::SizeF(90, 90)), result, 0.15f); 51 } 52 53 TEST(MathUtilTest, EnclosingRectOfVerticesUsesCorrectInitialBounds) { 54 gfx::PointF vertices[3]; 55 int num_vertices = 3; 56 57 vertices[0] = gfx::PointF(-10, -100); 58 vertices[1] = gfx::PointF(-100, -10); 59 vertices[2] = gfx::PointF(-30, -30); 60 61 // The bounds of the enclosing rect should be -100 to -10 for both x and y. 62 // However, if there is a bug where the initial xmin/xmax/ymin/ymax are 63 // initialized to numeric_limits<float>::min() (which is zero, not -flt_max) 64 // then the enclosing clipped rect will be computed incorrectly. 65 gfx::RectF result = 66 MathUtil::ComputeEnclosingRectOfVertices(vertices, num_vertices); 67 68 EXPECT_FLOAT_RECT_EQ(gfx::RectF(gfx::PointF(-100, -100), gfx::SizeF(90, 90)), 69 result); 70 } 71 72 TEST(MathUtilTest, SmallestAngleBetweenVectors) { 73 gfx::Vector2dF x(1, 0); 74 gfx::Vector2dF y(0, 1); 75 gfx::Vector2dF test_vector(0.5, 0.5); 76 77 // Orthogonal vectors are at an angle of 90 degress. 78 EXPECT_EQ(90, MathUtil::SmallestAngleBetweenVectors(x, y)); 79 80 // A vector makes a zero angle with itself. 81 EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(x, x)); 82 EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(y, y)); 83 EXPECT_EQ(0, MathUtil::SmallestAngleBetweenVectors(test_vector, test_vector)); 84 85 // Parallel but reversed vectors are at 180 degrees. 86 EXPECT_FLOAT_EQ(180, MathUtil::SmallestAngleBetweenVectors(x, -x)); 87 EXPECT_FLOAT_EQ(180, MathUtil::SmallestAngleBetweenVectors(y, -y)); 88 EXPECT_FLOAT_EQ( 89 180, MathUtil::SmallestAngleBetweenVectors(test_vector, -test_vector)); 90 91 // The test vector is at a known angle. 92 EXPECT_FLOAT_EQ( 93 45, std::floor(MathUtil::SmallestAngleBetweenVectors(test_vector, x))); 94 EXPECT_FLOAT_EQ( 95 45, std::floor(MathUtil::SmallestAngleBetweenVectors(test_vector, y))); 96 } 97 98 TEST(MathUtilTest, VectorProjection) { 99 gfx::Vector2dF x(1, 0); 100 gfx::Vector2dF y(0, 1); 101 gfx::Vector2dF test_vector(0.3f, 0.7f); 102 103 // Orthogonal vectors project to a zero vector. 104 EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), MathUtil::ProjectVector(x, y)); 105 EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), MathUtil::ProjectVector(y, x)); 106 107 // Projecting a vector onto the orthonormal basis gives the corresponding 108 // component of the vector. 109 EXPECT_VECTOR_EQ(gfx::Vector2dF(test_vector.x(), 0), 110 MathUtil::ProjectVector(test_vector, x)); 111 EXPECT_VECTOR_EQ(gfx::Vector2dF(0, test_vector.y()), 112 MathUtil::ProjectVector(test_vector, y)); 113 114 // Finally check than an arbitrary vector projected to another one gives a 115 // vector parallel to the second vector. 116 gfx::Vector2dF target_vector(0.5, 0.2f); 117 gfx::Vector2dF projected_vector = 118 MathUtil::ProjectVector(test_vector, target_vector); 119 EXPECT_EQ(projected_vector.x() / target_vector.x(), 120 projected_vector.y() / target_vector.y()); 121 } 122 123 } // namespace 124 } // namespace cc 125
