Add stencil support.

panda/src/display/drawableRegion.I

@@ -28,7 +28,8 @@ DrawableRegion() :
   _draw_buffer_type(RenderBuffer::T_back),
   _flags(0),
   _clear_color(0.0f, 0.0f, 0.0f, 0.0f),
-  _clear_depth(1.0f)
+  _clear_depth(1.0f),
+  _clear_stencil(0)
 {
 }
 
@@ -43,7 +44,8 @@ DrawableRegion(const DrawableRegion &copy) :
   _draw_buffer_type(copy._draw_buffer_type),
   _flags(copy._flags),
   _clear_color(copy._clear_color),
-  _clear_depth(copy._clear_depth)
+  _clear_depth(copy._clear_depth),
+  _clear_stencil(copy._clear_stencil)
 {
 }
 
@@ -59,6 +61,7 @@ operator = (const DrawableRegion &copy) {
   _flags = copy._flags;
   _clear_color = copy._clear_color;
   _clear_depth = copy._clear_depth;
+  _clear_stencil = copy._clear_stencil;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -72,6 +75,7 @@ copy_clear_settings(const DrawableRegion &copy) {
   _flags = (_flags & ~F_clear_all) | (copy._flags & F_clear_all);
   _clear_color = copy._clear_color;
   _clear_depth = copy._clear_depth;
+  _clear_stencil = copy._clear_stencil;
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -134,6 +138,36 @@ get_clear_depth_active() const {
   return ((_flags & F_clear_depth_active) != 0);
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: DrawableRegion::set_clear_stencil_active
+//       Access: Published
+//  Description: Toggles the flag that indicates whether the stencil
+//               buffer should be cleared every frame.  If this is
+//               true, the stencil buffer will be cleared to the value
+//               indicated by set_clear_stencil(); otherwise, it will be
+//               left alone.
+////////////////////////////////////////////////////////////////////
+INLINE void DrawableRegion::
+set_clear_stencil_active(bool clear_stencil_active) {
+  if (clear_stencil_active) {
+    _flags |= F_clear_stencil_active;
+  } else {
+    _flags &= ~F_clear_stencil_active;
+  }
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DrawableRegion::get_clear_stencil_active
+//       Access: Published
+//  Description: Returns the current setting of the flag that
+//               indicates whether the color buffer should be cleared
+//               every frame.  See set_clear_stencil_active().
+////////////////////////////////////////////////////////////////////
+INLINE bool DrawableRegion::
+get_clear_stencil_active() const {
+  return ((_flags & F_clear_stencil_active) != 0);
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: DrawableRegion::set_clear_color
 //       Access: Published
@@ -189,6 +223,33 @@ INLINE float DrawableRegion::
 get_clear_depth() const {
   return _clear_depth;
 }
+////////////////////////////////////////////////////////////////////
+//     Function: DrawableRegion::set_clear_stencil
+//       Access: Published
+//  Description: Sets the clear stencil to the indicated value.  This is
+//               the value that will be used to clear the stencil buffer
+//               every frame, but only if get_clear_color_active()
+//               returns true.  If get_clear_stencil_active() returns
+//               false, this is meaningless.
+////////////////////////////////////////////////////////////////////
+INLINE void DrawableRegion::
+set_clear_stencil(const unsigned int stencil) {
+  _clear_stencil = stencil;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DrawableRegion::get_clear_stencil
+//       Access: Published
+//  Description: Returns the current clear stencil value.  This is
+//               the value that will be used to clear the stencil buffer
+//               every frame, but only if get_clear_stencil_active()
+//               returns true.  If get_clear_stencil_active() returns
+//               false, this is meaningless.
+////////////////////////////////////////////////////////////////////
+INLINE unsigned int DrawableRegion::
+get_clear_stencil() const {
+  return _clear_stencil;
+}
 
 ////////////////////////////////////////////////////////////////////
 //     Function: DrawableRegion::disable_clears
@@ -200,6 +261,7 @@ INLINE void DrawableRegion::
 disable_clears() {
   set_clear_color_active(false);
   set_clear_depth_active(false);
+  set_clear_stencil_active(false);
 }
 
 ////////////////////////////////////////////////////////////////////

panda/src/display/drawableRegion.h

@@ -49,12 +49,18 @@ PUBLISHED:
   INLINE void set_clear_depth_active(bool clear_depth_active);
   INLINE bool get_clear_depth_active() const;
 
+  INLINE void set_clear_stencil_active(bool clear_stencil_active);
+  INLINE bool get_clear_stencil_active() const;
+
   INLINE void set_clear_color(const Colorf &color);
   INLINE const Colorf &get_clear_color() const;
 
   INLINE void set_clear_depth(float depth);
   INLINE float get_clear_depth() const;
 
+  INLINE void set_clear_stencil(unsigned int stencil);
+  INLINE unsigned int get_clear_stencil() const;
+
   INLINE void disable_clears();
 
   INLINE bool is_any_clear_active() const;
@@ -72,12 +78,14 @@ private:
   enum Flags {
     F_clear_color_active   = 0x0001,
     F_clear_depth_active   = 0x0002,
-    F_clear_all          = 0x0003, // = all of the above
+    F_clear_stencil_active = 0x0004,
+    F_clear_all            = 0x0007, // = all of the above
   };
   int _flags;
 
   Colorf _clear_color;
   float _clear_depth;
+  unsigned int _clear_stencil;
 };
 
 #include "drawableRegion.I"

panda/src/display/graphicsOutput.cxx

@@ -127,6 +127,7 @@ GraphicsOutput(GraphicsPipe *pipe,
   // depth.
   set_clear_color_active(true);
   set_clear_depth_active(true);
+  set_clear_stencil_active(true);
 
   switch (background_color.get_num_words()) {
   case 1:
@@ -815,6 +816,7 @@ make_cube_map(const string &name, int size, NodePath &camera_rig,
   // each display region.
   buffer->set_clear_color_active(false);
   buffer->set_clear_depth_active(false);
+  buffer->set_clear_stencil_active(false);
 
   PT(Lens) lens = new PerspectiveLens;
   lens->set_fov(90.0f);

panda/src/display/graphicsStateGuardian.cxx

@@ -725,6 +725,10 @@ clear(DrawableRegion *clearable) {
     clear_buffer_type |= RenderBuffer::T_depth;
     set_depth_clear_value(clearable->get_clear_depth());
   }
+  if (clearable->get_clear_stencil_active()) {
+    clear_buffer_type |= RenderBuffer::T_stencil;
+    set_stencil_clear_value(clearable->get_clear_stencil());
+  }
 
   if (clear_buffer_type != 0) {
     do_clear(get_render_buffer(clear_buffer_type,