blob: f7b82670a7f85f0245cc7f9d25ef696d23eacea6 [file] [log] [blame]
 // Copyright 2014 The Cobalt Authors. All Rights Reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include "cobalt/math/transform_2d.h" #include #include namespace cobalt { namespace math { Matrix3F TranslateMatrix(float x, float y) { return Matrix3F::FromValues(1.0f, 0, x, 0, 1.0f, y, 0, 0, 1.0f); } Matrix3F ScaleMatrix(float x_scale, float y_scale) { return Matrix3F::FromValues(x_scale, 0, 0, 0, y_scale, 0, 0, 0, 1.0f); } Matrix3F ScaleMatrix(float scale) { return ScaleMatrix(scale, scale); } Matrix3F RotateMatrix(float counter_clockwise_angle_in_radians) { float sin_theta = sin(counter_clockwise_angle_in_radians); float cos_theta = cos(counter_clockwise_angle_in_radians); // Rotation matrix for a space where up is represented by negative y. return Matrix3F::FromValues(cos_theta, sin_theta, 0, -sin_theta, cos_theta, 0, 0, 0, 1.0f); } Vector2dF GetScale2d(const Matrix3F& transform) { float m00 = transform(0, 0); float m01 = transform(0, 1); float m10 = transform(1, 0); float m11 = transform(1, 1); return Vector2dF(std::sqrt(m00 * m00 + m10 * m10), std::sqrt(m01 * m01 + m11 * m11)); } bool IsOnlyScaleAndTranslate(const Matrix3F& transform) { const float kEpsilon = 0.0001f; return std::abs(transform(0, 1)) < kEpsilon && std::abs(transform(1, 0)) < kEpsilon && std::abs(transform(2, 0)) < kEpsilon && std::abs(transform(2, 1)) < kEpsilon && std::abs(transform(2, 2) - 1.0f) < kEpsilon; } } // namespace math } // namespace cobalt