Add initial prototype.

3-mid/opengl/private/gl/source/glu.ads

@@ -0,0 +1,30 @@
+with
+     GL,
+     System;
+
+package GLU
+   with Obsolescent
+--
+--  Provides a subset of the functions in GLU, tailored to be suitable for use with the openGL 'Embedded' profile.
+--
+--  Currently only 'gluScaleImage' is ported.
+--
+is
+   use GL;
+
+   procedure gluScaleImage (Format    : in GLenum;
+                            WidthIn   : in GLsizei;
+                            HeightIn  : in GLsizei;
+                            TypeIn    : in GLenum;
+                            DataIn    : in System.Address;
+                            WidthOut  : in GLsizei;
+                            HeightOut : in GLsizei;
+                            TypeOut   : in GLenum;
+                            DataOut   : in System.Address);
+   GLU_INVALID_VALUE,
+   GLU_INVALID_ENUM,
+   GLU_INVALID_TYPE,
+   GLU_INVALID_OPERATION,
+   GLU_OUT_OF_MEMORY : exception;
+
+end GLU;