fix movement vector magnitude

src/renderer.h

@@ -391,31 +391,31 @@ moveCamera(bool up, bool left, bool down, bool right, bool forward, bool backwar
 	if (!up && !left && !down && !right && !forward && !backward)
 		return;
 
-	// TODO: fix vector addition bug doubling move speed vector magnitude when
-	// 	moving in 2 directions
-
 	float d = 5.f; // units per frame
 
 	glm::vec3 f = g_camera.forward;
 	glm::vec3 u = g_camera.up;
 	glm::vec3 old = g_camera.position;
 	glm::vec3 &p = g_camera.position;
+	glm::vec3 v(0.f); // normalized direction
 	
-	if (forward) p += f * d;
-	if (backward) p -= f * d;
-	if (up) p += u * d;
-	if (down) p -= u * d;
+	if (forward) v += f;
+	if (backward) v -= f;
+	if (up) v += u;
+	if (down) v -= u;
 	if (left)
 	{
 		glm::vec3 l = glm::cross(f, u);
-		p -= l * d;
+		v -= l;
 	}
 	if (right)
 	{
 		glm::vec3 r = glm::cross(u, f);
-		p -= r * d;
+		v -= r;
 	}
 
+	glm::normalize(v);
+	p += (v * d);
 	glm::vec3 diff = old - p;
 	g_scene_matrices.view = glm::translate(g_scene_matrices.view, diff);
 	g_scene_matrices.MVP = g_scene_matrices.projection * g_scene_matrices.view * g_scene_matrices.model;