Skip to content

Commit

Permalink
Cleaned up the code a bit and fixed comments
Browse files Browse the repository at this point in the history 
Some suggestions have been honored and the code now uses more declare
blocks. Also some comments contained copy-paste errors.
  • Loading branch information
David Bouchain committed Dec 6, 2011
1 parent c1c6a3b commit 5a429f8
Showing 1 changed file with 50 additions and 44 deletions.
94 changes: 50 additions & 44 deletions demo/fire.adb
View file
Expand Up @@ -22,12 +22,8 @@
-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

with Ada.Numerics.Elementary_Functions;
use Ada.Numerics.Elementary_Functions;

with Ada.Real_Time; use Ada.Real_Time;

with Ada.Real_Time;
with Ada.Numerics.Float_Random;
use Ada.Numerics.Float_Random;

with Lumen.Window;
with Lumen.Events;
Expand All @@ -40,25 +36,25 @@ procedure Fire is
-- These are the system parameters.
--
-- The maximum age of a particle:
Particle_Lifetime : constant Duration := 2.0;
Particle_Lifetime : constant := 2.0;
--
-- The number of particles in the particle system:
Particle_Count : constant Positive := 1000;
Particle_Count : constant := 1000;
--
-- The amount of scatter around the emitter when spawning:
Particle_Spread : constant Float := 0.4;
Particle_Spread : constant := 0.4;
--
-- The amount upward acceleration:
Particle_Lift : constant Float := 0.5;
Particle_Lift : constant := 0.5;
--
-- The red component of the particle color:
Particle_Red : constant Float := 1.0;
Particle_Red : constant := 1.0;
--
-- The red component of the particle color:
Particle_Green : constant Float := 0.25;
-- The green component of the particle color:
Particle_Green : constant := 0.25;
--
-- The red component of the particle color:
Particle_Blue : constant Float := 0.1;
-- The blue component of the particle color:
Particle_Blue : constant := 0.1;

------------------------------------------------------------------------
--
Expand Down Expand Up @@ -103,17 +99,18 @@ procedure Fire is
-- The random number generator is needed for the system noise,
-- which is added to the particles velocity on respawn.
--
RNG : Generator;
RNG : Ada.Numerics.Float_Random.Generator;

------------------------------------------------------------------------
--
-- This sets the age of the particles to that the global particle
-- This sets the age of the particles so that the global particle
-- lifetime is uniformly filled. The spawning interval is
-- therefore Particle_Lifetime / Particle_Count.
--
-- This also jitters the particles' velocities.
--
procedure Initialize_Particles is
use Ada.Numerics.Float_Random;
Spawn_Period : Duration := Particle_Lifetime / Duration (Particle_Count);
begin
for I in 1 .. Particle_Count loop
Expand All @@ -138,6 +135,7 @@ procedure Fire is
-- particular machine shouldn't even run OpenGL.
--
procedure Update_Particles (DT : Duration) is
use Ada.Numerics.Float_Random;
begin
for I in 1 .. Particle_Count loop
Particles (I).Age := Particles (I).Age + DT;
Expand Down Expand Up @@ -188,16 +186,16 @@ procedure Fire is
--
-- This is for real-time rendering.
--
Start_Time : Time := Clock;
End_Time : Time;
Delta_Time : Duration;
Start_Time : Ada.Real_Time.Time := Ada.Real_Time.Clock;
End_Time : Ada.Real_Time.Time;
Delta_Time : Duration;

------------------------------------------------------------------------
--
-- This is for computing the frame rate every second.
--
FPS_Base_Time : Time := Start_Time;
FPS_Counter : Integer := 0;
FPS_Base_Time : Ada.Real_Time.Time := Start_Time;
FPS_Counter : Integer := 0;

begin

Expand Down Expand Up @@ -236,6 +234,7 @@ begin
for X in 1 .. 32 loop
for Y in 1 .. 32 loop
declare
use Ada.Numerics.Elementary_Functions;
X_Dist : Float := abs (Float (X - 17) - 0.5) / 16.0;
Y_Dist : Float := abs (Float (Y - 17) - 0.5) / 16.0;
Alpha : Float := 1.0 - Sqrt (X_Dist**2.0 + Y_Dist**2.0);
Expand Down Expand Up @@ -310,30 +309,37 @@ Outer:
end;
end loop;

---------------------------------------------------------------------
--
-- This computes the delta time, i.e. the time the last frame
-- took to complete.
--
End_Time := Clock;
Delta_Time := To_Duration (End_Time - Start_Time);
Start_Time := End_Time;
declare
use Ada.Real_Time;
begin

------------------------------------------------------------------
--
-- This computes the delta time, i.e. the time the last frame
-- took to complete.
--
End_Time := Clock;
Delta_Time := To_Duration (End_Time - Start_Time);
Start_Time := End_Time;

------------------------------------------------------------------
--
-- This counts how many frames are rendered in one
-- second. When one second is over the frames-per-second
-- value is displayed as the window name (usually in the
-- title bar) and the counter is reset.
--
if To_Duration (Start_Time - FPS_Base_Time) >= 1.0 then
Lumen.Window.Set_Names (Window,
Name => "FPS: "
& Integer'Image (FPS_Counter));
FPS_Base_Time := Start_Time;
FPS_Counter := 0;
else
FPS_Counter := FPS_Counter + 1;
end if;
end;

---------------------------------------------------------------------
--
-- This counts how many frames are rendered in one second. When
-- one second is over the frames-per-second value is displayed
-- as the window name (usually in the title bar) and the
-- counter is reset.
--
if To_Duration (Start_Time - FPS_Base_Time) >= 1.0 then
Lumen.Window.Set_Names (Window, Name => "FPS: " & Integer'Image (FPS_Counter));
FPS_Base_Time := Start_Time;
FPS_Counter := 0;
else
FPS_Counter := FPS_Counter + 1;
end if;

---------------------------------------------------------------------
--
-- This is our 'physics update'.
Expand Down

0 comments on commit 5a429f8

Please sign in to comment.