Hi i´m trying to move a cube with the freeglut mouse "glutMotionFunc(processMouseActiveMotion)" callback, my problem is that the movement is not proportional between the mouse speed movement and the cube movement. MouseButton function: #define MOVE_STEP 0.04 float g_x=0.0f; glutMouseFunc(MouseButton); glutMotionFunc(processMouseActiveMotion); void MouseButton(int button, int state, int x, int y){ if(button == GLUT_LEFT_BUTTON && state== GLUT_DOWN){ initial_x=x; } } When the left button gets clicked the x cordinate is stored in initial_x variable. void processMouseActiveMotion(int x,int y){ if(x>initial_x){ g_x-= MOVE_STEP; }else{ g_x+= MOVE_STEP; } initial_x=x; } When I move the mouse I look in which way it moves comparing the mouse new x coordinate with the initial_x variable, if xinitial_x the cube moves to the right, if not it moves to the left. Any idea how can i move the cube according to the mouse movement speed? Thanks EDIT 1 The idea is that when you click on any point of the screen and you drag to the left/right the cube moves proportionally of the mouse mouvement speed.