diff options
Diffstat (limited to 'Game/Code/lib/JEDI-SDL/SDL/Pas/sdlticks.pas')
| -rw-r--r-- | Game/Code/lib/JEDI-SDL/SDL/Pas/sdlticks.pas | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/Game/Code/lib/JEDI-SDL/SDL/Pas/sdlticks.pas b/Game/Code/lib/JEDI-SDL/SDL/Pas/sdlticks.pas new file mode 100644 index 00000000..8e00dd6f --- /dev/null +++ b/Game/Code/lib/JEDI-SDL/SDL/Pas/sdlticks.pas @@ -0,0 +1,197 @@ +unit sdlticks;
+{
+ $Id: sdlticks.pas,v 1.2 2006/11/08 08:22:48 savage Exp $
+
+}
+{******************************************************************************}
+{ }
+{ JEDI-SDL : Pascal units for SDL - Simple DirectMedia Layer }
+{ SDL GetTicks Class Wrapper }
+{ }
+{ }
+{ The initial developer of this Pascal code was : }
+{ Dominique Louis <Dominique@SavageSoftware.com.au> }
+{ }
+{ Portions created by Dominique Louis are }
+{ Copyright (C) 2004 - 2100 Dominique Louis. }
+{ }
+{ }
+{ Contributor(s) }
+{ -------------- }
+{ Dominique Louis <Dominique@SavageSoftware.com.au> }
+{ }
+{ Obtained through: }
+{ Joint Endeavour of Delphi Innovators ( Project JEDI ) }
+{ }
+{ You may retrieve the latest version of this file at the Project }
+{ JEDI home page, located at http://delphi-jedi.org }
+{ }
+{ The contents of this file are used with permission, subject to }
+{ the Mozilla Public License Version 1.1 (the "License"); you may }
+{ not use this file except in compliance with the License. You may }
+{ obtain a copy of the License at }
+{ http://www.mozilla.org/MPL/MPL-1.1.html }
+{ }
+{ Software distributed under the License is distributed on an }
+{ "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or }
+{ implied. See the License for the specific language governing }
+{ rights and limitations under the License. }
+{ }
+{ Description }
+{ ----------- }
+{ SDL Window Wrapper }
+{ }
+{ }
+{ Requires }
+{ -------- }
+{ SDL.dll on Windows platforms }
+{ libSDL-1.1.so.0 on Linux platform }
+{ }
+{ Programming Notes }
+{ ----------------- }
+{ }
+{ }
+{ }
+{ }
+{ Revision History }
+{ ---------------- }
+{ }
+{ September 23 2004 - DL : Initial Creation }
+{
+ $Log: sdlticks.pas,v $
+ Revision 1.2 2006/11/08 08:22:48 savage
+ updates tp sdlgameinterface and sdlticks functions.
+
+ Revision 1.1 2004/09/30 22:35:47 savage
+ Changes, enhancements and additions as required to get SoAoS working.
+
+}
+{******************************************************************************}
+
+interface
+
+uses
+ sdl;
+
+type
+ TSDLTicks = class
+ private
+ FStartTime : UInt32;
+ FTicksPerSecond : UInt32;
+ FElapsedLastTime : UInt32;
+ FFPSLastTime : UInt32;
+ FLockFPSLastTime : UInt32;
+ public
+ constructor Create;
+ destructor Destroy; override; // destructor
+
+ {*****************************************************************************
+ Init
+ If the hi-res timer is present, the tick rate is stored and the function
+ returns true. Otherwise, the function returns false, and the timer should
+ not be used.
+ *****************************************************************************}
+ function Init : boolean;
+
+ {***************************************************************************
+ GetGetElapsedSeconds
+ Returns the Elapsed time, since the function was last called.
+ ***************************************************************************}
+ function GetElapsedSeconds : Single;
+
+ {***************************************************************************
+ GetFPS
+ Returns the average frames per second.
+ If this is not called every frame, the client should track the number
+ of frames itself, and reset the value after this is called.
+ ***************************************************************************}
+ function GetFPS : single;
+
+ {***************************************************************************
+ LockFPS
+ Used to lock the frame rate to a set amount. This will block until enough
+ time has passed to ensure that the fps won't go over the requested amount.
+ Note that this can only keep the fps from going above the specified level;
+ it can still drop below it. It is assumed that if used, this function will
+ be called every frame. The value returned is the instantaneous fps, which
+ will be less than or equal to the targetFPS.
+ ***************************************************************************}
+ procedure LockFPS( targetFPS : Byte );
+ end;
+
+implementation
+
+{ TSDLTicks }
+constructor TSDLTicks.Create;
+begin
+ inherited;
+ FTicksPerSecond := 1000;
+end;
+
+destructor TSDLTicks.Destroy;
+begin
+ inherited;
+end;
+
+function TSDLTicks.GetElapsedSeconds : Single;
+var
+ currentTime : Cardinal;
+begin
+ currentTime := SDL_GetTicks;
+
+ result := ( currentTime - FElapsedLastTime ) / FTicksPerSecond;
+
+ // reset the timer
+ FElapsedLastTime := currentTime;
+end;
+
+function TSDLTicks.GetFPS : Single;
+var
+ currentTime, FrameTime : UInt32;
+ fps : single;
+begin
+ currentTime := SDL_GetTicks;
+
+ FrameTime := ( currentTime - FFPSLastTime );
+
+ if FrameTime = 0 then
+ FrameTime := 1;
+
+ fps := FTicksPerSecond / FrameTime;
+
+ // reset the timer
+ FFPSLastTime := currentTime;
+ result := fps;
+end;
+
+function TSDLTicks.Init : boolean;
+begin
+ FStartTime := SDL_GetTicks;
+ FElapsedLastTime := FStartTime;
+ FFPSLastTime := FStartTime;
+ FLockFPSLastTime := FStartTime;
+ result := true;
+end;
+
+procedure TSDLTicks.LockFPS( targetFPS : Byte );
+var
+ currentTime : UInt32;
+ targetTime : single;
+begin
+ if ( targetFPS = 0 ) then
+ targetFPS := 1;
+
+ targetTime := FTicksPerSecond / targetFPS;
+
+ // delay to maintain a constant frame rate
+ repeat
+ currentTime := SDL_GetTicks;
+ until ( ( currentTime - FLockFPSLastTime ) > targetTime );
+
+ // reset the timer
+ FLockFPSLastTime := currentTime;
+end;
+
+end.
+
+
\ No newline at end of file |