Add initial prototype.

3-mid/opengl/source/lean/text/opengl-font-texture.ads

@@ -0,0 +1,68 @@
+with
+     openGL.Texture,
+     openGL.GlyphImpl.texture;
+
+package openGL.Font.texture
+--
+--  A texture font is a specialisation of the font class for handling texture mapped fonts.
+--
+is
+   type Item is new Font.item with private;
+   type View is access all Item'Class;
+
+
+   ---------
+   --  Forge
+   --
+
+   function to_Font_texture  (fontFilePath : in String) return Font.texture.item;
+   --
+   --
+   --  Open and read a font file. Sets Error flag.
+
+
+   function new_Font_texture (fontFilePath : in String) return Font.texture.view;
+
+
+   function to_Font_texture (pBufferBytes      : in FontImpl.unsigned_char_Pointer;
+                             bufferSizeInBytes : in Natural) return Font.texture.item;
+   --
+   --  Open and read a font from a buffer in memory. Sets Error flag.
+   --
+   --  The buffer is owned by the client and is NOT copied by FTGL. The
+   --  pointer must be valid while using FTGL.
+   --
+   --  pBufferBytes:      The in-memory buffer.
+   --  bufferSizeInBytes: The length of the buffer in bytes.
+
+   overriding
+   procedure destruct (Self : in out Item);
+
+   procedure free     (Self : in out View);
+
+
+   --------------
+   --  Attributes
+   --
+
+   function gl_Texture (Self : in Item)                                 return openGL.Texture.texture_Name;
+   function Quad       (Self : in Item;   for_Character : in Character) return GlyphImpl.Texture.Quad_t;
+
+
+
+private
+
+   type Item is new Font.item with null record;
+
+
+   overriding
+   function MakeGlyph (Self : access Item;   Slot : in freetype_c.FT_GlyphSlot.item) return glyph.Container.Glyph_view;
+   --
+   --  Construct a glyph of the correct type.
+   --
+   --  Clients must override the function and return their specialised FTGlyph.
+   --  Returns an FTGlyph or null on failure.
+   --
+   --  Slot: A FreeType glyph slot.
+
+end openGL.Font.texture;