Add initial prototype.

3-mid/opengl/source/lean/renderer/opengl-impostor-terrain.ads

@@ -0,0 +1,46 @@
+package openGL.Impostor.terrain
+--
+-- Handles impostoring of terrain 'visuals', which has greater image precision needs, to help avoid border cracks.
+--
+is
+   type Item is new Impostor.item with private;
+   type View is access all Item'Class;
+
+
+   overriding
+   procedure set_Target      (Self : in out Item;   Target       : in     openGL.Visual.view);
+
+   overriding
+   function current_Camera_look_at_Rotation
+                             (Self : in Item) return Matrix_3x3;
+
+   overriding
+   function  update_Required (Self : access Item;   the_Camera   : access Camera.item'Class) return Boolean;
+
+   overriding
+   procedure update          (Self : in out Item;   the_Camera   : access Camera.item'Class;
+                                                    texture_Pool : in     Texture.Pool_view);
+   overriding
+   procedure pre_update      (Self : in out Item;   the_Camera   : access Camera.item'Class);
+
+   overriding
+   procedure post_update     (Self : in out Item;   the_Camera   : access Camera.item'Class);
+
+   procedure free            (Self : in out View);
+
+
+
+private
+
+   type Item is new Impostor.item with
+      record
+         current_Complete  : Boolean;
+
+         prior_copy_Width  : gl.glSizeI := 0;
+         prior_copy_Height : gl.glSizeI := 0;
+         prior_Complete    : Boolean    := False;
+
+         current_Camera_look_at_Rotation : Matrix_3x3 := Identity_3x3;
+      end record;
+
+end openGL.Impostor.terrain;