Add initial prototype.

3-mid/opengl/source/lean/text/opengl-glyph-container.ads

@@ -0,0 +1,127 @@
+with
+     freetype.Face,
+     freetype.charMap;
+
+private
+with
+     ada.Containers.Vectors;
+
+package openGL.Glyph.Container
+--
+--  Contains the post processed Glyph objects.
+--
+is
+   type Item       is tagged private;
+   type Glyph_view is access all Glyph.item'Class;
+
+
+   ---------
+   --  Forge
+   --
+
+   function  to_glyph_Container (parent_Face : in freetype.Face.view) return glyph.Container.item;
+   --
+   -- parent_Face: The Freetype face.
+
+
+   procedure destruct (Self : in out Item);
+
+
+   --------------
+   --  Attributes
+   --
+
+   function CharMap (Self : access Item;   Encoding : in freeType_c.FT_Encoding) return Boolean;
+   --
+   --  Sets the character map for the face.
+   --
+   -- Encoding: The Freetype encoding symbol.
+   --
+   --  Returns True if charmap was valid and set correctly.
+
+
+   function FontIndex (Self : in Item;   Character : in freetype.charMap.characterCode) return Natural;
+   --
+   --  Get the font index of the input character.
+   --
+   --  Character: The character code of the requested glyph in the current encoding (eg apple roman).
+   --
+   --  Returns the font index for the character.
+
+
+   procedure add (Self : in out Item;   Glyph     : in Glyph_view;
+                                        Character : in freetype.charMap.characterCode);
+   --
+   --  Adds a glyph to this glyph list.
+   --
+   --  Glyph:     The FTGlyph to be inserted into the container.
+   --  Character: The char code of the glyph NOT the glyph index.
+
+
+   function Glyph (Self : in Item;   Character : in freetype.charMap.characterCode) return Glyph_view;
+   --
+   --  Get a glyph from the glyph list.
+   --
+   --  Character: The char code of the glyph NOT the glyph index.
+   --
+   --  Returns a Glyph or null is it hasn't been loaded.
+
+
+   function BBox (Self : in Item;   Character : in freetype.charMap.characterCode) return Bounds;
+   --
+   --  Get the bounding box for a character.
+   --
+   --  Character: The char code of the glyph NOT the glyph index.
+
+
+   function Advance (Self : in Item;   Character         : in freetype.charMap.characterCode;
+                                       nextCharacterCode : in freetype.charMap.characterCode) return Real;
+   --
+   --  Character:         Glyph index of the character.
+   --  nextCharacterCode: The next glyph in a string.
+   --
+   --  Returns the kerned advance width for a glyph.
+
+
+   function Error (Self : in Item) return freetype_c.FT_Error;
+   --
+   --  Queries the glyph container for errors.
+   --
+   --  Returns the current error code.
+
+
+   --------------
+   --  Operations
+   --
+
+   function render (Self : access Item;   Character         : in freetype.charMap.characterCode;
+                                          nextCharacterCode : in freetype.charMap.characterCode;
+                                          penPosition       : in Vector_3;
+                                          renderMode        : in Integer) return Vector_3;
+   --
+   --  Renders a character.
+   --
+   --  Character:         The glyph to be Rendered.
+   --  nextCharacterCode: The next glyph in the string. Used for kerning.
+   --  penPosition:       The position to Render the glyph.
+   --  renderMode:        Render mode to display.
+   --
+   --  Returns the distance to advance the pen position after rendering,
+
+
+
+private
+
+   type    charMap_view  is access all freetype.charMap.item'class;
+   package glyph_Vectors is new ada.Containers.Vectors (Positive, Glyph_view);
+
+   type Item is tagged
+      record
+         Face    : freetype.Face.view;       -- The FTGL face.
+         charMap : charMap_view;             -- The character map object associated with the current face.
+
+         Glyphs  : glyph_Vectors.Vector;     -- A structure to hold the glyphs.
+         Err     : freeType_c.FT_Error;      -- Current error code. Zero means no error.
+      end record;
+
+end openGL.Glyph.Container;