1 files changed, 78 insertions, 0 deletions
diff --git a/src/utils/geometry.cpp b/src/utils/geometry.cpp
new file mode 100644
index 0000000..733190f
--- /dev/null
+++ b/src/utils/geometry.cpp
@@ -0,0 +1,78 @@
+////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 Leo Tenenbaum
+// This file is part of GraphColoring.
+//
+// GraphColoring is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GraphColoring is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GraphColoring.  If not, see <https://www.gnu.org/licenses/>.
+////////////////////////////////////////////////////////////////////////////////
+
+#include "geometry.hpp"
+
+#define _USE_MATH_DEFINES
+#include <cmath>
+#include <iostream>
+
+#include "errors.hpp"
+
+namespace utils {
+namespace geometry {
+
+bool InRectangle(int x, int y, int rx, int ry, int rw, int rh)
+{
+	return x >= rx && x <= rx+rw && y >= ry && y <= ry+rh;
+}
+
+bool InCircle(int x, int y, int cx, int cy, int r)
+{
+	return (x-cx)*(x-cx) + (y-cy)*(y-cy) <= r*r;
+}
+
+double LineAngle(int x1, int y1, int x2, int y2)
+{
+	if (x1 == x2)
+	{
+		if (y1 == y2)
+			return 0; // Give up
+		if (y1 < y2)
+			return M_PI / 2; // Slope = Positive infinity
+		if (y1 > y2)
+			return 3 * M_PI / 2; // Negative infinity
+	}
+	double slope = (double)(y2-y1)/(x2-x1);
+	return x2 > x1 ? atan(slope) : M_PI + atan(slope);
+
+}
+
+int PointToLineSegmentDistance(int x, int y, int x1, int y1, int x2, int y2,
+		int tolerance)
+{
+	// See https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line#Line_defined_by_two_points
+	// Check if point is inside rectangle bounded by endpoints.
+	int min_x = std::min(x1, x2);
+	int min_y = std::min(y1, y2);
+	int max_x = std::max(x1, x2);
+	int max_y = std::max(y1, y2);
+	if (x < min_x-tolerance || x > max_x+tolerance || y < min_y-tolerance
+	 || y > max_y+tolerance)
+		return -1;
+	// Check if the two points are the same.
+	if (x1 == x2 && y1 == y2)
+		return sqrt((x1-x)*(x1-x)+(y1-y)*(y1-y));
+	// Find distance to line.
+	int dx = x2-x1, dy = y2-y1;
+	double length = sqrt(dx*dx+dy*dy);
+	return abs(dy*x - dx*y + x2*y1 - y2*x1)/length;
+}
+
+} // namespace geometry
+} // namespace utils