fix camera translation

src/renderer.h

@@ -82,9 +82,10 @@ enum projection_type
 struct camera
 {
 	glm::vec3 position;
-	glm::vec3 forward;
 	glm::vec3 target;
+	glm::vec3 forward;
 	glm::vec3 up;
+	glm::vec3 left;
 };
 
 typedef struct gl_buffer
@@ -275,7 +276,9 @@ initMatrices(projection_type p)
 		g_camera.position = glm::vec3(640,0,100); 
 		g_camera.target = glm::vec3(640,500,0);
 		g_camera.up = glm::vec3(0,1,0);
-		g_camera.forward = glm::normalize(g_camera.target - g_camera.position);
+		g_camera.forward = glm::normalize(g_camera.position - g_camera.target);
+		g_camera.left = glm::normalize(glm::cross(g_camera.up, g_camera.forward));
+		g_camera.up = glm::cross(g_camera.forward, g_camera.left);
 
 		glm::vec3 P, T, U;
 		P = normalize(g_camera.position);
@@ -401,26 +404,20 @@ moveCamera(bool up, bool left, bool down, bool right)
 	glm::mat4 &m = g_scene_matrices.view;
 	float d = 5.f; // units per frame
 
-#if 0
-	if (up) m = glm::translate(m, glm::vec3(0, -1 * d, 0));
-	if (left) m = glm::translate(m, glm::vec3(d, 0, 0));
-	if (down) m = glm::translate(m, glm::vec3(0, d, 0));
-	if (right) m = glm::translate(m, glm::vec3(-1 * d, 0, 0));
-#endif
 	glm::vec3 f = g_camera.forward;
 	glm::vec3 u = g_camera.up;
 	glm::vec3 old = g_camera.position;
 	glm::vec3 &p = g_camera.position;
-	if (up) p += (f * d);
+	if (up) p -= (f * d);
-	if (down) p -= (f * d);
+	if (down) p += (f * d);
 	if (left)
 	{
-		glm::vec3 l = glm::cross(u, f);
+		glm::vec3 l = glm::cross(f, u);
 		p += l * d;
 	}
 	if (right)
 	{
-		glm::vec3 r = glm::cross(f, u);
+		glm::vec3 r = glm::cross(u, f);
 		p += r * d;
 	}