A 'YawToEntity' function. Seems to work well enough. Another possible use for this is in turning bots to face a waypoint entity in a 3D (or 2D in 3D) game.
Open in online IDEGlobal timer = CreateTimer( 25 ) Graphics3D 800, 600, 0, 2 SetBuffer BackBuffer() Global cam = CreateCamera() CameraZoom cam, 1.6 MoveEntity cam, 0.0, 60.0, 0.0 TurnEntity cam, 90.0, 0.0, 0.0 Global light = CreateLight() Global cone = CreateCone() RotateMesh cone, 90.0, 0.0, 0.0 UpdateNormals cone PositionEntity cone, 0.0, 0.0, -20.0 Global cube = CreateCube() UpdateNormals cube PositionEntity cube, 40.0, 0.0, 20.0 While Not KeyHit( 1 ) MoveEntity cube, -0.22, 0.0, 0.0 YawToEntity( cone, cube, 0.5 ) ;PointEntity( cone, cube ) ;MoveEntity cone, 0.0, 0.0, 0.3 UpdateWorld RenderWorld Text 10, 10, DeltaYaw( cone, cube ) Flip WaitTimer( timer ) Wend End Function YawToEntity( src_entity, dest_entity, rate# ) ; Turns 'src_entity' to point at 'dest_entity' at the rotation rate specified by 'rate#'. Local target_yaw# = DeltaYaw( src_entity, dest_entity ) ; If the required correction amount is less than the correction amount to be applied... If Abs( target_yaw# ) < rate# ; Point 'src_entity' directly at 'dest_entity' to prevent jittering. TurnEntity src_entity, 0.0, target_yaw#, 0.0 Else ; Turn 'src_entity' gradually towards 'dest_entity'. TurnEntity src_entity, 0.0, rate# * Sgn( target_yaw# ), 0.0 EndIf End Function