add circle intersection unit tests

src/lib/mathlib/CMakeLists.txt

@@ -48,3 +48,4 @@ px4_add_unit_gtest(SRC math/FunctionsTest.cpp)
 px4_add_unit_gtest(SRC math/test/UtilitiesTest.cpp)
 px4_add_unit_gtest(SRC math/WelfordMeanTest.cpp)
 px4_add_unit_gtest(SRC math/WelfordMeanVectorTest.cpp)
+px4_add_unit_gtest(SRC math/MaxDistanceToCircleTest.cpp)

src/lib/mathlib/math/MaxDistanceToCircleTest.cpp

@@ -0,0 +1,122 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2023 PX4 Development Team. 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.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE
+ * COPYRIGHT OWNER OR 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 <gtest/gtest.h>
+#include <matrix/matrix/math.hpp>
+#include "Functions.hpp"
+
+#include "TrajMath.hpp"
+
+using namespace math;
+using matrix::Vector2f;
+
+TEST(MaxDistanceToCircle, noDirection)
+{
+	Vector2f pos;
+	Vector2f circle_center;
+	float radius = 3.f;
+	Vector2f direction;
+	float distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_TRUE(isnan(distance));
+}
+
+TEST(MaxDistanceToCircle, insideCircle)
+{
+	// North position, South direction
+	Vector2f pos(1.f, 0.f);
+	Vector2f circle_center;
+	float radius = 3.f;
+	Vector2f direction(-1.f, 0.f);
+	float distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, 4.f);
+
+	// North position, West direction (direction doesn't need to be unit length)
+	direction = Vector2f(0.f, -3.42f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, sqrtf(radius * radius - 1.f));
+
+	// SE position, directed towards the center
+	pos = Vector2f(-2.f, 1.f);
+	direction = Vector2f(2.f, -1.f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, pos.norm() + radius);
+}
+
+TEST(MaxDistanceToCircle, outsideCircle)
+{
+	// North position, South direction
+	Vector2f pos(4.f, 0.f);
+	Vector2f circle_center;
+	float radius = 3.f;
+	Vector2f direction(-1.f, 0.f);
+	float distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, pos(0) + radius);
+
+	// looking away from the circle
+	direction = Vector2f(0.f, -3.42f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_TRUE(isnan(distance));
+
+	// SE position, directed towards the center
+	pos = Vector2f(-4.f, 2.f);
+	direction = Vector2f(2.f, -1.f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, pos.norm() + radius);
+}
+
+TEST(MaxDistanceToCircle, onCircle)
+{
+	// South, looking North
+	Vector2f pos(-4.f, 1.f);
+	Vector2f circle_center(-1.f, 1.f);
+	float radius = 3.f;
+	Vector2f direction(1.f, 0.f);
+	float distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, 2.f * radius);
+
+	// looking tangent to the circle
+	direction = Vector2f(0.f, -3.42f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, 0.f);
+
+	// looking away from the circle
+	direction = Vector2f(-10.f, -3.42f);
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, 0.f);
+
+	// SE position, directed towards the center
+	pos = Vector2f(-sqrtf(2.f) / 2.f, sqrtf(2.f) / 2.f) * radius + circle_center;
+	direction = -pos;
+	distance = trajectory::getMaxDistanceToCircle(pos, circle_center, radius, direction);
+	EXPECT_FLOAT_EQ(distance, 2.f * radius);
+}