Pentagram: Difference between revisions
Ada version
(Ada version) |
|||
Line 12:
* [http://proofsfromthebook.com/2013/08/04/angle-sum-of-a-pentagram/ Angle sum of a pentagram]
<br><br>
=={{header|Ada}}==
{{libheader|SDLAda}}
<lang Ada>with Ada.Numerics.Elementary_Functions;
with SDL.Video.Windows.Makers;
with SDL.Video.Renderers.Makers;
with SDL.Video.Rectangles;
with SDL.Events.Events;
procedure Pentagram is
Width : constant := 600;
Height : constant := 600;
Offset : constant := 300.0;
Radius : constant := 250.0;
use SDL.Video.Rectangles;
use SDL.C;
Window : SDL.Video.Windows.Window;
Renderer : SDL.Video.Renderers.Renderer;
Event : SDL.Events.Events.Events;
type Node_Id is mod 5;
Nodes : array (Node_Id) of Point;
procedure Calculate is
use Ada.Numerics.Elementary_Functions;
begin
for I in Nodes'Range loop
Nodes (I) := (X => int (Offset + Radius * Sin (Float (I), Cycle => 5.0)),
Y => int (Offset - Radius * Cos (Float (I), Cycle => 5.0)));
end loop;
end Calculate;
function Orient_2D (A, B, C : Point) return int is
((B.X - A.X) * (C.Y - A.Y) - (B.Y - A.Y) * (C.X - A.X));
procedure Fill is
Count : Natural;
begin
for Y in int (Offset - Radius) .. int (Offset + Radius) loop
for X in int (Offset - Radius) .. int (Offset + Radius) loop
Count := 0;
for Node in Nodes'Range loop
Count := Count +
(if Orient_2D (Nodes (Node), Nodes (Node + 2), (X, Y)) > 0 then 1 else 0);
end loop;
if Count in 4 .. 5 then
Renderer.Draw (Point => (X, Y));
end if;
end loop;
end loop;
end Fill;
procedure Draw_Outline is
begin
for Node in Nodes'Range loop
Renderer.Draw (Line => (Nodes (Node), Nodes (Node + 2)));
end loop;
end Draw_Outline;
procedure Wait is
use type SDL.Events.Event_Types;
begin
loop
SDL.Events.Events.Wait (Event);
exit when Event.Common.Event_Type = SDL.Events.Quit;
end loop;
end Wait;
begin
if not SDL.Initialise (Flags => SDL.Enable_Screen) then
return;
end if;
SDL.Video.Windows.Makers.Create (Win => Window,
Title => "Pentagram",
Position => SDL.Natural_Coordinates'(X => 10, Y => 10),
Size => SDL.Positive_Sizes'(Width, Height),
Flags => 0);
SDL.Video.Renderers.Makers.Create (Renderer, Window.Get_Surface);
Renderer.Set_Draw_Colour ((0, 0, 0, 255));
Renderer.Fill (Rectangle => (0, 0, Width, Height));
Calculate;
Renderer.Set_Draw_Colour ((50, 50, 150, 255));
Fill;
Renderer.Set_Draw_Colour ((0, 220, 0, 255));
Draw_Outline;
Window.Update_Surface;
Wait;
Window.Finalize;
SDL.Finalise;
end Pentagram;</lang>
=={{header|AutoHotkey}}==
| |||