使用大小为4的数组来表示一个单点
问题描述：
我与Wiimote的API工作，我碰到这个代码来了，使用大小为4的数组来表示一个单点
float[] srcX = new float[4];
float[] srcY = new float[4];
float[] dstX = new float[4];
float[] dstY = new float[4];
我无法理解为什么会有4辆彩车代表一个数组单点。请指导。谢谢。
这里是整个代码，
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Threading;
using System.Runtime.InteropServices;//for firing keyboard and mouse events (optional)
using System.IO;//for saving the reading the calibration data
using WiimoteLib;
namespace WiimoteWhiteboard
{
public partial class Form1 : Form
{
//instance of the wii remote
Wiimote wm = new Wiimote();
const int smoothingBufferSize = 50;
PointF[] smoothingBuffer = new PointF[smoothingBufferSize];
int smoothingBufferIndex = 0;
int smoothingAmount = 4;
bool enableSmoothing = true;
bool cursorControl = false;
int screenWidth = 1024;//defaults, gets replaced by actual screen size
int screenHeight = 768;
int calibrationState = 0;
float calibrationMargin = .1f;
CalibrationForm cf = null;
Warper warper = new Warper();
float[] srcX = new float[4];
float[] srcY = new float[4];
float[] dstX = new float[4];
float[] dstY = new float[4];
//declare consts for mouse messages
public const int INPUT_MOUSE = 0;
public const int INPUT_KEYBOARD = 1;
public const int INPUT_HARDWARE = 2;
public const int MOUSEEVENTF_MOVE = 0x01;
public const int MOUSEEVENTF_LEFTDOWN = 0x02;
public const int MOUSEEVENTF_LEFTUP = 0x04;
public const int MOUSEEVENTF_RIGHTDOWN = 0x08;
public const int MOUSEEVENTF_RIGHTUP = 0x10;
public const int MOUSEEVENTF_MIDDLEDOWN = 0x20;
public const int MOUSEEVENTF_MIDDLEUP = 0x40;
public const int MOUSEEVENTF_ABSOLUTE = 0x8000;
//declare consts for key scan codes
public const byte VK_TAB = 0x09;
public const byte VK_MENU = 0x12; // VK_MENU is Microsoft talk for the ALT key
public const byte VK_SPACE = 0x20;
public const byte VK_RETURN = 0x0D;
public const byte VK_LEFT =0x25;
public const byte VK_UP =0x26;
public const byte VK_RIGHT =0x27;
public const byte VK_DOWN =0x28;
public const int KEYEVENTF_EXTENDEDKEY = 0x01;
public const int KEYEVENTF_KEYUP = 0x02;
//for firing mouse and keyboard events
[DllImport("user32.dll", SetLastError = true)]
static extern uint SendInput(uint nInputs, INPUT[] pInputs, int cbSize);
[StructLayout(LayoutKind.Sequential)]
public struct MOUSEINPUT
{
public int dx;//4
public int dy;//4
public uint mouseData;//4
public uint dwFlags;//4
public uint time;//4
public IntPtr dwExtraInfo;//4
}
[StructLayout(LayoutKind.Sequential)]
public struct KEYBDINPUT
{
public ushort wVk;//2
public ushort wScan;//2
public uint dwFlags;//4
public uint time;//4
public IntPtr dwExtraInfo;//4
}
[StructLayout(LayoutKind.Sequential)]
public struct HARDWAREINPUT
{
public uint uMsg;
public ushort wParamL;
public ushort wParamH;
}
[StructLayout(LayoutKind.Explicit, Size = 28)]
public struct INPUT
{
[FieldOffset(0)]
public int type;
[FieldOffset(4)] //*
public MOUSEINPUT mi;
[FieldOffset(4)] //*
public KEYBDINPUT ki;
[FieldOffset(4)] //*
public HARDWAREINPUT hi;
}
//imports mouse_event function from user32.dll
[DllImport("user32.dll")]
private static extern void mouse_event(
long dwFlags, // motion and click options
long dx, // horizontal position or change
long dy, // vertical position or change
long dwData, // wheel movement
long dwExtraInfo // application-defined information
);
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetCursorPos(int X, int Y);
//imports keybd_event function from user32.dll
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void keybd_event(byte bVk, byte bScan, long dwFlags, long dwExtraInfo);
WiimoteState lastWiiState = new WiimoteState();//helps with event firing
//end keyboard and mouse input emulation variables----------------------------------------
Mutex mut = new Mutex();
public Form1()
{
screenWidth = Screen.GetBounds(this).Width;
screenHeight = Screen.GetBounds(this).Height;
InitializeComponent();
for (int i = 0; i < smoothingBufferSize; i++)
smoothingBuffer[i] = new PointF();
setSmoothing(smoothingAmount);
}
private void Form1_Load(object sender, EventArgs e)
{
//add event listeners to changes in the wiiremote
//fired for every input report - usually 100 times per second if acclerometer is enabled
wm.WiimoteChanged += new WiimoteChangedEventHandler(wm_OnWiimoteChanged);
//fired when the extension is attached on unplugged
wm.WiimoteExtensionChanged += new WiimoteExtensionChangedEventHandler(wm_OnWiimoteExtensionChanged);
try
{
//connect to wii remote
wm.Connect();
//set what features you want to enable for the remote, look at Wiimote.InputReport for options
wm.SetReportType(Wiimote.InputReport.IRAccel, true);
//set wiiremote LEDs with this enumerated ID
wm.SetLEDs(true, false, false, false);
}
catch (Exception x)
{
MessageBox.Show("Exception: " + x.Message);
this.Close();
}
loadCalibrationData();
}
void wm_OnWiimoteExtensionChanged(object sender, WiimoteExtensionChangedEventArgs args)
{
//if extension attached, enable it
if(args.Inserted)
wm.SetReportType(Wiimote.InputReport.IRExtensionAccel, true);
else
wm.SetReportType(Wiimote.InputReport.IRAccel, true);
}
float UpdateTrackingUtilization()
{
//area of ideal calibration coordinates (to match the screen)
float idealArea = (1 - 2*calibrationMargin) * 1024 * (1 - 2*calibrationMargin) * 768;
//area of quadrliatera
float actualArea = 0.5f * Math.Abs((srcX[1] - srcX[2]) * (srcY[0] - srcY[3]) - (srcX[0] - srcX[3]) * (srcY[1] - srcY[2]));
float util = (actualArea/idealArea)*100;
BeginInvoke((MethodInvoker)delegate() { lblTrackingUtil.Text = util.ToString("f0"); });
BeginInvoke((MethodInvoker)delegate() { pbTrackingUtil.Value = (int)util; });
return util;
}
PointF getSmoothedCursor(int amount)
{
int start = smoothingBufferIndex - amount;
if (start < 0)
start = 0;
PointF smoothed = new PointF(0,0);
int count = smoothingBufferIndex - start;
for (int i = start; i < smoothingBufferIndex; i++)
{
smoothed.X += smoothingBuffer[i%smoothingBufferSize].X;
smoothed.Y += smoothingBuffer[i % smoothingBufferSize].Y;
}
smoothed.X /= count;
smoothed.Y /= count;
return smoothed;
}
void wm_OnWiimoteChanged(object sender, WiimoteChangedEventArgs args)
{
mut.WaitOne();
//extract the wiimote state
WiimoteState ws = args.WiimoteState;
if (ws.IRState.Found1)
{
int x = ws.IRState.RawX1;
int y = ws.IRState.RawY1;
float warpedX = x;
float warpedY = y;
warper.warp(x, y, ref warpedX, ref warpedY);
smoothingBuffer[smoothingBufferIndex % smoothingBufferSize].X = warpedX;
smoothingBuffer[smoothingBufferIndex % smoothingBufferSize].Y = warpedY;
smoothingBufferIndex++;
if (!lastWiiState.IRState.Found1)//mouse down
{
lastWiiState.IRState.Found1 = ws.IRState.Found1;
smoothingBufferIndex = 0;//resets the count
if (cursorControl)
{
INPUT[] buffer = new INPUT[2];
buffer[0].type = INPUT_MOUSE;
buffer[0].mi.dx = (int)(warpedX *65535.0f/screenWidth);
buffer[0].mi.dy = (int)(warpedY * 65535.0f/screenHeight);
buffer[0].mi.mouseData = 0;
buffer[0].mi.dwFlags = MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_MOVE;
buffer[0].mi.time = 0;
buffer[0].mi.dwExtraInfo = (IntPtr)0;
buffer[1].type = INPUT_MOUSE;
buffer[1].mi.dx = 0;
buffer[1].mi.dy = 0;
buffer[1].mi.mouseData = 0;
buffer[1].mi.dwFlags = MOUSEEVENTF_LEFTDOWN;
buffer[1].mi.time = 1;
buffer[1].mi.dwExtraInfo = (IntPtr)0;
SendInput(2, buffer, Marshal.SizeOf(buffer[0]));
}//cusor control
switch (calibrationState)
{
case 1:
srcX[calibrationState - 1] = x;
srcY[calibrationState - 1] = y;
calibrationState = 2;
doCalibration();
break;
case 2:
srcX[calibrationState - 1] = x;
srcY[calibrationState - 1] = y;
calibrationState = 3;
doCalibration();
break;
case 3:
srcX[calibrationState - 1] = x;
srcY[calibrationState - 1] = y;
calibrationState = 4;
doCalibration();
break;
case 4:
srcX[calibrationState - 1] = x;
srcY[calibrationState - 1] = y;
calibrationState = 5;
doCalibration();
break;
default:
break;
}//calibtation state
}//mouse down
else
{
if (cursorControl)//dragging
{
INPUT[] buffer = new INPUT[1];
buffer[0].type = INPUT_MOUSE;
if (enableSmoothing)
{
PointF s = getSmoothedCursor(smoothingAmount);
buffer[0].mi.dx = (int)(s.X * 65535.0f/screenWidth);
buffer[0].mi.dy = (int)(s.Y * 65535.0f/screenHeight);
}
else
{
buffer[0].mi.dx = (int)(warpedX * 65535.0f/screenWidth);
buffer[0].mi.dy = (int)(warpedY * 65535.0f/screenHeight);
}
buffer[0].mi.mouseData = 0;
buffer[0].mi.dwFlags = MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_MOVE;
buffer[0].mi.time = 0;
buffer[0].mi.dwExtraInfo = (IntPtr)0;
SendInput(1, buffer, Marshal.SizeOf(buffer[0]));
}
}
}//ir visible
else
{
if (lastWiiState.IRState.Found1)//mouse up
{
lastWiiState.IRState.Found1 = ws.IRState.Found1;
if (cursorControl)
{
INPUT[] buffer = new INPUT[2];
buffer[0].type = INPUT_MOUSE;
buffer[0].mi.dx = 0;
buffer[0].mi.dy = 0;
buffer[0].mi.mouseData = 0;
buffer[0].mi.dwFlags = MOUSEEVENTF_LEFTUP;
buffer[0].mi.time = 0;
buffer[0].mi.dwExtraInfo = (IntPtr)0;
buffer[1].type = INPUT_MOUSE;
buffer[1].mi.dx = 0;
buffer[1].mi.dy = 0;
buffer[1].mi.mouseData = 0;
buffer[1].mi.dwFlags = MOUSEEVENTF_MOVE;
buffer[1].mi.time = 0;
buffer[1].mi.dwExtraInfo = (IntPtr)0;
SendInput(2, buffer, Marshal.SizeOf(buffer[0]));
}
}//ir lost
}
if (!lastWiiState.ButtonState.A && ws.ButtonState.A)
{
BeginInvoke((MethodInvoker)delegate() { btnCalibrate.PerformClick(); });
}
lastWiiState.ButtonState.A = ws.ButtonState.A;
if (!lastWiiState.ButtonState.B && ws.ButtonState.B)
keybd_event(VK_SPACE, 0x45, 0, 0);
if (lastWiiState.ButtonState.B && !ws.ButtonState.B)
keybd_event(VK_SPACE, 0x45, KEYEVENTF_KEYUP, 0);
lastWiiState.ButtonState.B = ws.ButtonState.B;
if (!lastWiiState.ButtonState.Up && ws.ButtonState.Up)
keybd_event(VK_UP, 0x45, 0, 0);
if (lastWiiState.ButtonState.Up && !ws.ButtonState.Up)
keybd_event(VK_UP, 0x45, KEYEVENTF_KEYUP, 0);
lastWiiState.ButtonState.Up = ws.ButtonState.Up;
if (!lastWiiState.ButtonState.Down && ws.ButtonState.Down)
keybd_event(VK_DOWN, 0x45, 0, 0);
if (lastWiiState.ButtonState.Down && !ws.ButtonState.Down)
keybd_event(VK_DOWN, 0x45, KEYEVENTF_KEYUP, 0);
lastWiiState.ButtonState.Down = ws.ButtonState.Down;
if (!lastWiiState.ButtonState.Left && ws.ButtonState.Left)
keybd_event(VK_LEFT, 0x45, 0, 0);
if (lastWiiState.ButtonState.Left && !ws.ButtonState.Left)
keybd_event(VK_LEFT, 0x45, KEYEVENTF_KEYUP, 0);
lastWiiState.ButtonState.Left = ws.ButtonState.Left;
if (!lastWiiState.ButtonState.Right && ws.ButtonState.Right)
keybd_event(VK_RIGHT, 0x45, 0, 0);
if (lastWiiState.ButtonState.Right && !ws.ButtonState.Right)
keybd_event(VK_RIGHT, 0x45, KEYEVENTF_KEYUP, 0);
lastWiiState.ButtonState.Right = ws.ButtonState.Right;
lastWiiState.IRState.Found1 = ws.IRState.Found1;
lastWiiState.IRState.RawX1 = ws.IRState.RawX1;
lastWiiState.IRState.RawY1 = ws.IRState.RawY1;
lastWiiState.IRState.Found2 = ws.IRState.Found2;
lastWiiState.IRState.RawX2 = ws.IRState.RawX2;
lastWiiState.IRState.RawY2 = ws.IRState.RawY2;
lastWiiState.IRState.Found3 = ws.IRState.Found3;
lastWiiState.IRState.RawX3 = ws.IRState.RawX3;
lastWiiState.IRState.RawY3 = ws.IRState.RawY3;
lastWiiState.IRState.Found4 = ws.IRState.Found4;
lastWiiState.IRState.RawX4 = ws.IRState.RawX4;
lastWiiState.IRState.RawY4 = ws.IRState.RawY4;
//draw battery value on GUI
//BeginInvoke((MethodInvoker)delegate() { pbBattery.Value = (ws.Battery > 0xc8 ? 0xc8 : (int)ws.Battery); });
//float f = (((100.0f * 48.0f * (float)(ws.Battery/48.0f)))/192.0f);
//BeginInvoke((MethodInvoker)delegate() { lblBattery.Text = f.ToString("f0") + "%"; });
//check the GUI check boxes if the IR dots are visible
//String irstatus = "Visible IR dots: ";
//if (ws.IRState.Found1)
// irstatus += "1 ";
//if (ws.IRState.Found2)
// irstatus += "2 ";
//if (ws.IRState.Found3)
// irstatus += "3 ";
//if (ws.IRState.Found4)
// irstatus += "4 ";
//BeginInvoke((MethodInvoker)delegate() { lblIRvisible.Text = irstatus; });
mut.ReleaseMutex();
}
public void loadCalibrationData()
{
// create reader & open file
try
{
TextReader tr = new StreamReader("calibration.dat");
for (int i = 0; i < 4; i++)
{
srcX[i] = float.Parse(tr.ReadLine());
srcY[i] = float.Parse(tr.ReadLine());
}
smoothingAmount = int.Parse(tr.ReadLine());
// close the stream
tr.Close();
}
catch (Exception x)
{
//no prexsting calibration
return;
}
warper.setDestination( screenWidth * calibrationMargin,
screenHeight * calibrationMargin,
screenWidth * (1.0f-calibrationMargin),
screenHeight * calibrationMargin,
screenWidth * calibrationMargin,
screenHeight * (1.0f - calibrationMargin),
screenWidth * (1.0f - calibrationMargin),
screenHeight * (1.0f - calibrationMargin));
warper.setSource(srcX[0], srcY[0], srcX[1], srcY[1], srcX[2], srcY[2], srcX[3], srcY[3]);
warper.computeWarp();
setSmoothing(smoothingAmount);
cursorControl = true;
// BeginInvoke((MethodInvoker)delegate() { cbCursorControl.Checked = cursorControl; });
UpdateTrackingUtilization();
}
public void saveCalibrationData()
{
TextWriter tw = new StreamWriter("calibration.dat");
// write a line of text to the file
for (int i = 0; i < 4; i++)
{
tw.WriteLine(srcX[i]);
tw.WriteLine(srcY[i]);
}
tw.WriteLine(smoothingAmount);
// close the stream
tw.Close();
}
public void doCalibration(){
if (cf == null)
return;
int x = 0;
int y = 0;
int size = 25;
Pen p = new Pen(Color.Red);
switch (calibrationState)
{
case 1:
x = (int)(screenWidth * calibrationMargin);
y = (int)(screenHeight * calibrationMargin);
cf.showCalibration(x, y, size, p);
dstX[calibrationState - 1] = x;
dstY[calibrationState - 1] = y;
break;
case 2:
x = screenWidth - (int)(screenWidth * calibrationMargin);
y = (int)(screenHeight * calibrationMargin);
cf.showCalibration(x, y, size, p);
dstX[calibrationState - 1] = x;
dstY[calibrationState - 1] = y;
break;
case 3:
x = (int)(screenWidth * calibrationMargin);
y = screenHeight -(int)(screenHeight * calibrationMargin);
cf.showCalibration(x, y, size, p);
dstX[calibrationState - 1] = x;
dstY[calibrationState - 1] = y;
break;
case 4:
x = screenWidth - (int)(screenWidth * calibrationMargin);
y = screenHeight -(int)(screenHeight * calibrationMargin);
cf.showCalibration(x, y, size, p);
dstX[calibrationState - 1] = x;
dstY[calibrationState - 1] = y;
break;
case 5:
//compute warp
warper.setDestination(dstX[0], dstY[0], dstX[1], dstY[1], dstX[2], dstY[2], dstX[3], dstY[3]);
warper.setSource(srcX[0], srcY[0], srcX[1], srcY[1], srcX[2], srcY[2], srcX[3], srcY[3]);
warper.computeWarp();
cf.Close();
cf = null;
calibrationState = 0;
cursorControl = true;
// BeginInvoke((MethodInvoker)delegate() { cbCursorControl.Checked = cursorControl; });
// saveCalibrationData();
UpdateTrackingUtilization();
break;
default:
break;
}
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
//disconnect the wiimote
wm.Disconnect();
saveCalibrationData();
}
private void btnCalibrate_Click(object sender, EventArgs e)
{
if (cf == null)
{
cf = new CalibrationForm();
cf.Show();
}
if (cf.IsDisposed)
{
cf = new CalibrationForm();
cf.Show();
}
cursorControl = false;
calibrationState = 1;
doCalibration();
}
private void cbCursorControl_CheckedChanged(object sender, EventArgs e)
{
//cursorControl = cbCursorControl.Checked;
}
private void label1_Click(object sender, EventArgs e)
{
}
private void setSmoothing(int smoothing)
{
smoothingAmount = smoothing;
//trackBar1.Value = smoothing;
enableSmoothing = (smoothingAmount != 0);
// lblSmoothing.Text = "Smoothing: " + smoothingAmount;
}
//private void trackBar1_Scroll(object sender, EventArgs e)
//{
// smoothingAmount = trackBar1.Value;
// enableSmoothing = (smoothingAmount != 0);
// lblSmoothing.Text = "Smoothing: " + smoothingAmount;
//}
private void lblIRvisible_Click(object sender, EventArgs e)
{
}
}
}