Added concept of a texture's Pad Region

panda/src/gobj/texture.I

@@ -502,6 +502,62 @@ get_z_size() const {
   return _z_size;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: Texture::get_pad_x_size
+//       Access: Published
+//  Description: Returns size of the pad region.  See set_pad_size.
+////////////////////////////////////////////////////////////////////
+INLINE int Texture::
+get_pad_x_size() const {
+  return _pad_x_size;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: Texture::get_pad_y_size
+//       Access: Published
+//  Description: Returns size of the pad region.  See set_pad_size.
+////////////////////////////////////////////////////////////////////
+INLINE int Texture::
+get_pad_y_size() const {
+  return _pad_y_size;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: Texture::get_pad_z_size
+//       Access: Published
+//  Description: Returns size of the pad region.  See set_pad_size.
+////////////////////////////////////////////////////////////////////
+INLINE int Texture::
+get_pad_z_size() const {
+  return _pad_z_size;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: Texture::set_pad_size
+//       Access: Published
+//  Description: Sets the size of the pad region.
+//
+//               Sometimes, when a video card demands power-of-two
+//               textures, it is necessary to create a big texture
+//               and then only use a portion of it.  The pad region
+//               indicates which portion of the texture is not
+//               really in use.  All operations use the texture
+//               as a whole, including the pad region, unless they
+//               explicitly state that they use only the non-pad
+//               region.
+//
+//               Changing the texture's size clears the pad region.
+////////////////////////////////////////////////////////////////////
+INLINE void Texture::
+set_pad_size(int x, int y, int z) {
+  if (x > _x_size) x = _x_size;
+  if (y > _y_size) y = _y_size;
+  if (z > _z_size) z = _z_size;
+  _pad_x_size = x;
+  _pad_y_size = y;
+  _pad_z_size = z;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: Texture::get_num_components
 //       Access: Published
@@ -1087,6 +1143,7 @@ set_x_size(int x_size) {
     _x_size = x_size;
     ++_image_modified;
     clear_ram_image();
+    set_pad_size();
   }
 }
 
@@ -1104,6 +1161,7 @@ set_y_size(int y_size) {
     _y_size = y_size;
     ++_image_modified;
     clear_ram_image();
+    set_pad_size();
   }
 }
 
@@ -1123,6 +1181,7 @@ set_z_size(int z_size) {
     _z_size = z_size;
     ++_image_modified;
     clear_ram_image();
+    set_pad_size();
   }
 }
 

panda/src/gobj/texture.cxx

@@ -79,6 +79,10 @@ Texture(const string &name) :
   set_format(F_rgb);
   set_component_type(T_unsigned_byte);
 
+  _pad_x_size = 0;
+  _pad_y_size = 0;
+  _pad_z_size = 0;
+
   _loaded_from_image = false;
   _loaded_from_txo = false;
   _has_read_pages = false;
@@ -104,6 +108,9 @@ Texture(const Texture &copy) :
   _x_size(copy._x_size),
   _y_size(copy._y_size),
   _z_size(copy._z_size),
+  _pad_x_size(copy._pad_x_size),
+  _pad_y_size(copy._pad_y_size),
+  _pad_z_size(copy._pad_z_size),
   _num_components(copy._num_components),
   _component_width(copy._component_width),
   _texture_type(copy._texture_type),
@@ -151,6 +158,9 @@ operator = (const Texture &copy) {
   _x_size = copy._x_size;
   _y_size = copy._y_size;
   _z_size = copy._z_size;
+  _pad_x_size = copy._pad_x_size;
+  _pad_y_size = copy._pad_y_size;
+  _pad_z_size = copy._pad_z_size;
   _num_components = copy._num_components;
   _component_width = copy._component_width;
   _texture_type = copy._texture_type;
@@ -245,6 +255,7 @@ setup_texture(Texture::TextureType texture_type, int x_size, int y_size,
   set_format(format);
 
   clear_ram_image();
+  set_pad_size();
   _loaded_from_image = false;
   _loaded_from_txo = false;
   _has_read_pages = false;
@@ -2643,6 +2654,9 @@ reconsider_image_properties(int x_size, int y_size, int num_components,
       nassertr(x_size == y_size, false);
     }
 #endif
+    if ((_x_size != x_size)||(_y_size != y_size)) {
+      set_pad_size();
+    }
     _x_size = x_size;
     _y_size = y_size;
     _num_components = num_components;
@@ -3541,6 +3555,7 @@ fillin(DatagramIterator &scan, BamReader *manager, bool has_rawdata) {
       _ram_images[n]._image = image;
     }
     _loaded_from_image = true;
+    set_pad_size();
     ++_image_modified;
     ++_properties_modified;
   }

panda/src/gobj/texture.h

@@ -340,6 +340,13 @@ PUBLISHED:
   INLINE void set_x_size(int x_size);
   INLINE void set_y_size(int y_size);
   INLINE void set_z_size(int z_size);
+
+  INLINE int get_pad_x_size() const;
+  INLINE int get_pad_y_size() const;
+  INLINE int get_pad_z_size() const;
+  
+  INLINE void set_pad_size(int x=0, int y=0, int z=0);
+  
   void set_format(Format format);
   void set_component_type(ComponentType component_type);
   INLINE void set_loaded_from_image();
@@ -504,6 +511,10 @@ protected:
   bool _render_to_texture;
   bool _match_framebuffer_format;
 
+  int _pad_x_size;
+  int _pad_y_size;
+  int _pad_z_size;
+  
   // A Texture keeps a list (actually, a map) of all the
   // PreparedGraphicsObjects tables that it has been prepared into.
   // Each PGO conversely keeps a list (a set) of all the Textures that