add pressure control flag on size and flow, change data directory in OSX to Documents

engine/brush.h

@@ -17,6 +17,8 @@ public:
     float m_tip_opacity;
     float m_tip_angle;
     bool  m_tip_angle_follow = false;
+    bool  m_tip_flow_pressure = false;
+    bool  m_tip_size_pressure = false;
     float m_jitter_scale;
     float m_jitter_angle;
     float m_jitter_spread;
@@ -62,6 +64,7 @@ public:
         float fov;
     };
     int m_layer;
+    float m_curve;
     float m_dist;
     float m_step;
     Camera m_camera;