worked on raytracing

geo/Line2.h

@@ -3,6 +3,7 @@
 
 //#include <KLib/geo/Line.h>
 #include "Point2.h"
+#include "Ray2.h"
 
 class Line2 {
 
@@ -141,6 +142,69 @@ public:
 
 	}
 
+
+	bool getSegmentIntersectionInt(const Line2& other, Point2& result) const {
+
+		int mul = 100;
+
+		const float p0_x = std::round(p1.x*mul), p1_x = std::round(p2.x*mul), p2_x = std::round(other.p1.x*mul), p3_x = std::round(other.p2.x*mul);
+		const float p0_y = std::round(p1.y*mul), p1_y = std::round(p2.y*mul), p2_y = std::round(other.p1.y*mul), p3_y = std::round(other.p2.y*mul);
+
+		const float s1_x = p1_x - p0_x;
+		const float s1_y = p1_y - p0_y;
+		const float s2_x = p3_x - p2_x;
+		const float s2_y = p3_y - p2_y;
+
+		const float s = (-s1_y * (p0_x - p2_x) + s1_x * (p0_y - p2_y)) / (-s2_x * s1_y + s1_x * s2_y);
+		const float t = ( s2_x * (p0_y - p2_y) - s2_y * (p0_x - p2_x)) / (-s2_x * s1_y + s1_x * s2_y);
+
+		if (s >= 0 && s <= 1 && t >= 0 && t <= 1) {
+			result.x = (p0_x + (t * s1_x)) / mul;
+			result.y = (p0_y + (t * s1_y)) / mul;
+			return true;
+		}
+
+		return false;
+
+	}
+
+	/** does the line intersect with the given ray? */
+	bool intersects(const Ray2& ray, Point2& result) const {
+
+		//https://stackoverflow.com/questions/563198/how-do-you-detect-where-two-line-segments-intersect/565282#565282
+
+		const float p0_x = p1.x, p1_x = p2.x;
+		const float p0_y = p1.y, p1_y = p2.y;
+
+		const float p2_x = ray.start.x;//, p3_x = other.p2.x;
+		const float p2_y = ray.start.y;//, p3_y = other.p2.y;
+
+		const float s1_x = p1_x - p0_x;
+		const float s1_y = p1_y - p0_y;
+
+		const float s2_x = ray.dir.x;		// p3_x - p2_x;
+		const float s2_y = ray.dir.y;		// p3_y - p2_y;
+
+		// ray_start + s * ray_dir
+		const float s = (-s1_y * (p0_x - p2_x) + s1_x * (p0_y - p2_y)) / (-s2_x * s1_y + s1_x * s2_y);
+
+		// before the ray's start?
+		if (s < 0) {return false;}
+
+		// line.p1 + t * (line.p2-line.p1)
+		const float t = ( s2_x * (p0_y - p2_y) - s2_y * (p0_x - p2_x)) / (-s2_x * s1_y + s1_x * s2_y);
+
+		// t must be between 0 and 1, otherwise we are before the line's start / after the line's end
+		if (t < 0 || t > 1) {return false;}
+
+		// intersection
+		result.x = (p0_x + (t * s1_x));
+		result.y = (p0_y + (t * s1_y));
+		return true;
+
+	}
+
+
 };
 
 #endif // LINE2D_H