Add initial prototype.

3-mid/opengl/source/lean/text/private/opengl-glyphimpl.adb

@@ -0,0 +1,94 @@
+with
+     freetype_c.Binding,
+     freetype_c.FT_BBox,
+     freetype_c.FT_Vector;
+
+package body openGL.GlyphImpl
+is
+   -----------
+   --  Utility
+   --
+
+   function Bounds_of (glyth_Slot : in freetype_c.FT_GlyphSlot.item) return Bounds
+   is
+      use freetype_c.Binding;
+
+      bBox       : aliased freetype_c.FT_BBox.item;
+      the_Bounds :         Bounds;
+
+   begin
+      FT_Outline_Get_CBox (FT_GlyphSlot_Get_Outline (glyth_Slot).all'unchecked_Access,
+                           bBox'unchecked_Access);
+
+      the_Bounds := (Ball => <>,
+                     Box  => (Lower => [1 => Real (bbox.xMin) / 64.0,
+                                        2 => Real (bbox.yMin) / 64.0,
+                                        3 => 0.0],
+                              Upper => [1 => Real (bbox.xMax) / 64.0,
+                                        2 => Real (bbox.yMax) / 64.0,
+                                        3 => 0.0]));
+      set_Ball_from_Box (the_Bounds);
+
+      return the_Bounds;
+   end Bounds_of;
+
+
+   ---------
+   --  Forge
+   --
+
+   procedure define (Self : in out Item;   glyth_Slot : in freetype_c.FT_GlyphSlot.item)
+   is
+      use type freetype_c.FT_GlyphSlot.item;
+   begin
+      Self.Err := no_Error;
+
+      if glyth_Slot /= null
+      then
+         Self.bBox := Bounds_of (glyth_Slot);
+
+         declare
+            use freetype_c.Binding;
+            the_Advance : constant freetype_c.FT_Vector.item := FT_GlyphSlot_Get_Advance (glyth_Slot);
+         begin
+            Self.Advance := [Real (the_Advance.x) / 64.0,
+                             Real (the_Advance.y) / 64.0,
+                             0.0];
+         end;
+      end if;
+   end define;
+
+
+   procedure destruct (Self : in out Item)
+   is
+   begin
+      null;
+   end destruct;
+
+
+   --------------
+   --  Attributes
+   --
+
+   function Advance (Self : in Item) return Real
+   is
+   begin
+      return Self.Advance (1);
+   end Advance;
+
+
+   function BBox (Self : in Item) return Bounds
+   is
+   begin
+      return Self.bBox;
+   end BBox;
+
+
+   function Error (Self : in Item) return error_Kind
+   is
+   begin
+      return Self.Err;
+   end Error;
+
+
+end openGL.GlyphImpl;