gistfile1.adb

with Ada.Text_IO;       use Ada.Text_IO;
with Ada.Float_Text_IO; use Ada.Float_Text_IO;
with Ada.Real_Time;   use Ada.Real_Time;
with Interfaces;        use Interfaces;

procedure Main is
   package Duration_IO is new Ada.Text_IO.Fixed_IO(Duration); use Duration_IO;

   width     : constant integer :=  640;
   height    : constant integer :=  480;
   N         : constant integer :=   13;
   frames    : constant integer := 1000;

   type Color is (Red, Green, Blue);
   type Frame is array (0 .. (width*height*3-1)) of Unsigned_8;

   function Index(x, y: Integer; c : Color) return Integer is
   begin
      return width*y*3+x*3+Color'Pos(c);
   end index;

   procedure Blur(a : in Frame; b : out Frame) is
   begin
      for y in 1..height-2 loop
         for x in 1..width-2 loop
            for c in Color'Range loop
               b(index(x,y,c)) := Unsigned_8((Integer(a(index(x,y-1,c))) +
                                              Integer(a(index(x,y+1,c))) +
                                              Integer(a(index(x-1,y,c))) +
                                              Integer(a(index(x+1,y,c)))   )/4);
            end loop;
         end loop;
      end loop;
   end Blur;

   a1 : Frame;
   a2 : Frame;

   time_begin   : Time;
   time_elapsed : Duration;

begin
   time_begin := Clock;

   for nn in 1..frames loop --
      for i in 1..N loop
         Blur(a1, a2);
         Blur(a2, a1);
      end loop;
   end loop;

   time_elapsed := To_Duration(Clock - time_begin);

   Put("BlurGNAT: fps = "); Put(Float(frames)/Float(time_elapsed));
   Put(" time = "); Put(time_elapsed);
   Put_Line(" sec");
end Main;