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git-svn-id: svn://svn.ijw.co.nz/svn/OpenRa@1140 993157c7-ee19-0410-b2c4-bb4e9862e678

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chrisf
2007-07-07 09:06:40 +00:00
parent 27c74b1ef1
commit 761b01a618
2 changed files with 68 additions and 76 deletions
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110
OpenRa.Game/Clock.cs
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@@ -1,109 +1,75 @@
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace OpenRa.Game
{
/// <summary>
/// Provides access to the current time, frame time, and frame rate.
/// </summary>
public static class Clock
{
/// <summary>
/// Performs one-time initialization for the clock service
/// </summary>
[DllImport("kernel32.dll")]
static extern bool QueryPerformanceCounter(out long value);
[DllImport("kernel32.dll")]
static extern bool QueryPerformanceFrequency(out long frequency);
static int frameCount = 0;
static long frequency;
static long lastTime;
static double frameTime = 0;
static double totalTime = 0;
const int FramerateUpdateFrequency = 10;
static int lastFrameRate = 0;
static int lastFrameCount = 0;
static double nextFrameRateUpdateTime = 0;
static Clock()
{
startTime = System.Environment.TickCount;
StartFrame();
QueryPerformanceFrequency(out frequency);
QueryPerformanceCounter(out lastTime);
}
public static void Reset()
{
frameCount = 0;
lastFrameCount = 0;
lastFrameRate = 0;
startTime = System.Environment.TickCount;
StartFrame();
totalTime = 0;
}
#region StartFrame
/// <summary>
/// Indicates to the clock that a new frame has begun. This should be called exactly once per frame.
/// </summary>
public static void StartFrame()
public static void StartFrame()
{
int ticks = System.Environment.TickCount - startTime;
frameStartTime = ticks / 1000.0;
long time;
QueryPerformanceCounter(out time);
frameTime = (double)(time - lastTime) / (double)frequency;
totalTime += frameTime;
lastTime = time;
frameCount++;
if( Time > nextFrameRateUpdateTime )
if (totalTime > nextFrameRateUpdateTime)
{
// set next update time
nextFrameRateUpdateTime += (1.0 / FramerateUpdateFrequency);
// average between last and current frame, to make spikes less severe
const int OldFramerateWeight = 10;
const int OldFramerateWeight = 20;
const int NewFramerateWeight = 1;
int newFrameRate = (frameCount - lastFrameCount) * FramerateUpdateFrequency;
lastFrameRate = (lastFrameRate * OldFramerateWeight + NewFramerateWeight * newFrameRate) / (OldFramerateWeight + NewFramerateWeight );
lastFrameRate = (lastFrameRate * OldFramerateWeight + NewFramerateWeight * newFrameRate)
/ (OldFramerateWeight + NewFramerateWeight);
lastFrameCount = frameCount;
}
}
#endregion
#region Private Implementation Details
// number of framerate updates per second
private const int FramerateUpdateFrequency = 10;
// the time at which the application started
private static int startTime;
// the time at which this frame began
private static double frameStartTime;
// total number of frames rendered
private static int frameCount = 0;
// next time to update fps count
private static double nextFrameRateUpdateTime = 0;
// frame count at most recent fps calculation
private static int lastFrameCount = 0;
// most recently calculated fps
private static int lastFrameRate = 0;
#endregion
#region Properties
/// <summary>
/// The time the current frame started
/// </summary>
public static double Time
public static double Time
{
get { return frameStartTime; }
get { return totalTime; }
}
/// <summary>
/// The number of frames rendered since the engine started
/// </summary>
public static int FrameCount
{
get { return frameCount; }
}
/// <summary>
/// The most recent frame-rate
/// </summary>
public static int FrameRate
{
get { return lastFrameRate; }
}
/// <summary>
/// The frame time corresponding to the most recent frame-rate
/// </summary>
public static double FrameTime
{
get { return 1.0 / lastFrameRate; }
get { return frameTime; }
}
#endregion
}
}