Added screen to world coordinates conversion (broken)

include/camera_arcball.hpp

@@ -4,6 +4,7 @@
 #include <glm/gtc/matrix_transform.hpp>
 #define _USE_MATH_DEFINES
 #include <math.h>
+#include <screendefs.hpp>
 
 class Camera {
 public:
@@ -25,6 +26,30 @@ public:
 	glm::vec3 GetViewDir() const { return normalize(m_lookAt-m_eye); }
 	glm::vec3 GetRightVector() const { return glm::normalize(glm::cross(m_lookAt - m_eye, m_upVector)); }
 
+	glm::vec2 GetWorldXyFromMouse(float mx, float my) const {
+		//calculate point in center of screen
+		glm::vec3 p_eye = m_eye;
+		glm::vec3 p_sCenter = m_eye + 0.1f * GetViewDir();
+		glm::vec3 curr_up = normalize(glm::cross(GetRightVector(), GetViewDir()));
+		//extent of screen in width and height
+		//0.1 away from eye, spans 45 (see call to glm::perspective in main.cpp)
+		//float s_extent_h = 0.2 * std::tan(3.14159265 * 45 / 180.);
+		float s_extent_h = 0.2f * std::tan(3.14159265 * 45 / 180. / 2.);
+		float s_extent_w = WIDTH / static_cast<float>(HEIGHT) * s_extent_h;
+		glm::vec3 p_mouse = p_sCenter + (mx - 0.5f) * s_extent_w * 0.5f * GetRightVector() + (my - 0.5f) * s_extent_h * 0.5f * curr_up; //TODO: Potentially needs (1-my) instead of my
+		glm::vec3 r = glm::normalize(p_mouse - p_eye);
+		if (std::abs(r.z) > 0.00001) {
+			float t = -p_mouse.z / r.z;
+			glm::vec3 res_p = p_mouse + t * r;
+			return glm::vec2(res_p.x, res_p.y);
+		}
+		else {
+			return glm::vec2(std::copysign(r.x, 999999.), std::copysign(r.y, 999999.));
+		}
+	
+	
+	}
+
 	void SetCameraView(glm::vec3 eye, glm::vec3 lookat, glm::vec3 up) {
 		m_eye = std::move(eye);
 		m_lookAt = std::move(lookat);