Android屏幕校准

 

android原始版本里是没有屏幕校准功能的，tp坐标到lcd坐标是完全按照线性关系来转换的。例如，tp坐标是(X_t ,Y_t )分辨率是（W_t x H_t ），lcd坐标是(X,Y)，分辨率是(W x H)，则 X=(X_t *W)/W_t， Y=(Y_t *H)/H_t 。但是一般触摸屏不是完全线性的，自然转换关系也就不一样了，好在有tslib，能帮我们解决这个问题。但是android里没有tslib，我们也不需 要完全将tslib移植过来，只需要其中根据采样点生成转换矩阵的部分，这部分是由ts_calibrate.c文件中的 perform_calibration()函数来实现的。所以只需要将该函数移植过来就可以。这里将该函数及用到的数据结构代码贴出来如下：

typedef struct{

       int x[5], xfb[5];      //x[5],y[5]是分别是tp五个点的x,y坐标，xfb[5],yfb[5]是lcd五个点的x,y坐标。

       int y[5], yfb[5];

       int a[7];                //a[7]是生成的7个转换参数，tp到lcd坐标转换方程是： X_lcd = (X_tp *a[1] + Y_tp *a[2] + a[0])/a[6]

}calibration;               //  Y_lcd = (X_tp *a[4] + Y_tp *a[5] + a[3])/a[6]

int perform_calibration(calibration *cal) {
          int j;
         float n, x, y, x2, y2, xy, z, zx, zy;
         float det, a, b, c, e, f, i;
         float scaling = 65536.0;
 
 // Get sums for matrix
         n = x = y = x2 = y2 = xy = 0;
         for(j=0;j<5;j++) {
                 n += 1.0;
                 x += (float)cal->x[j];
                 y += (float)cal->y[j];
                 x2 += (float)(cal->x[j]*cal->x[j]);
                 y2 += (float)(cal->y[j]*cal->y[j]);
                 xy += (float)(cal->x[j]*cal->y[j]);
         }
 
 // Get determinant of matrix -- check if determinant is too small
         det = n*(x2*y2 - xy*xy) + x*(xy*y - x*y2) + y*(x*xy - y*x2);
         if(det < 0.1 && det > -0.1) {
                 printf("ts_calibrate: determinant is too small -- %f/n",det);
                 return 0;
         }
 
 // Get elements of inverse matrix
         a = (x2*y2 - xy*xy)/det;
         b = (xy*y - x*y2)/det;
         c = (x*xy - y*x2)/det;
         e = (n*y2 - y*y)/det;
         f = (x*y - n*xy)/det;
         i = (n*x2 - x*x)/det;
 
 // Get sums for x calibration
         z = zx = zy = 0;
         for(j=0;j<5;j++) {
                 z += (float)cal->xfb[j];
                 zx += (float)(cal->xfb[j]*cal->x[j]);
                 zy += (float)(cal->xfb[j]*cal->y[j]);
         }
 // Now multiply out to get the calibration for framebuffer x coord
         cal->a[0] = (int)((a*z + b*zx + c*zy)*(scaling));
         cal->a[1] = (int)((b*z + e*zx + f*zy)*(scaling));
         cal->a[2] = (int)((c*z + f*zx + i*zy)*(scaling));

         printf("%f %f %f/n",(a*z + b*zx + c*zy),
                                 (b*z + e*zx + f*zy),
                                 (c*z + f*zx + i*zy));

 // Get sums for y calibration
         z = zx = zy = 0;
         for(j=0;j<5;j++) {
                 z += (float)cal->yfb[j];
                 zx += (float)(cal->yfb[j]*cal->x[j]);
                 zy += (float)(cal->yfb[j]*cal->y[j]);
         }
 
 // Now multiply out to get the calibration for framebuffer y coord
         cal->a[3] = (int)((a*z + b*zx + c*zy)*(scaling));
         cal->a[4] = (int)((b*z + e*zx + f*zy)*(scaling));
         cal->a[5] = (int)((c*z + f*zx + i*zy)*(scaling));

         printf("%f %f %f/n",(a*z + b*zx + c*zy),
                                 (b*z + e*zx + f*zy),
                                 (c*z + f*zx + i*zy));
 
 // If we got here, we're OK, so assign scaling to a[6] and return
         cal->a[6] = (int)scaling;
         return 1;
｝

有了上面的基础，接下来就是将上面的代码移植到android中并在setting里面添加屏幕校准入口，要完成这些，需要修改的文件有：

1. frameworks/base/services/java/com/android/server/InputDevice.java

2. packages/apps/Settings/AndroidManifest.xml

3. packages/apps/Settings/res/xml/settings.xml

另外在Setting源码目录里再添加一个Calibration.java文件。

frameworks/base/services/java/com/android/server/InputDevice.java修改的地方如下（红色 表示添加，蓝色 表示删除）：

public class InputDevice {
     static final boolean DEBUG_POINTERS = false;
     static final boolean DEBUG_HACKS = false;
 
     /** Amount that trackball needs to move in order to generate a key event. */
     static final int TRACKBALL_MOVEMENT_THRESHOLD = 6;
 
     /** Maximum number of pointers we will track and report. */
     static final int MAX_POINTERS = 10;
 
     static final String CALIBRATION_FILE="/data/pointercal"; 
 
     final int id;
     final int classes;
     final String name;
     final AbsoluteInfo absX;
     final AbsoluteInfo absY;
     final AbsoluteInfo absPressure;
     final AbsoluteInfo absSize;

     ....................

            final AbsoluteInfo absX = device.absX;
             final AbsoluteInfo absY = device.absY;
             final AbsoluteInfo absPressure = device.absPressure;
             final AbsoluteInfo absSize = device.absSize;
 
             float tmpX = 0;    
             float tmpY = 0;
             String prop = SystemProperties.get("sys.config.calibrate", "noset");
 
             if ( !prop.equalsIgnoreCase("loaded") )
             {
                     if ( prop.equalsIgnoreCase("start") )
                     {
                         TransformInfo.xs =  0;
                         TransformInfo.ys =  0;
                     }
                     else if ( prop.equalsIgnoreCase("done") )
                     {
                         readCalibrate();
                     }
 
                     if ( TransformInfo.xs == 0 && absX != null )
                     {
                         TransformInfo.x1 = w;
                         TransformInfo.y1 = 0;
                         TransformInfo.z1 = 0-absX.minValue*w;
                         TransformInfo.xs =  absX.range;
                     }
                     if ( TransformInfo.ys == 0 && absY != null )
                     {
                         TransformInfo.x2 = 0;
                         TransformInfo.y2 = h;
                         TransformInfo.z2 = 0-absY.minValue*h;
                         TransformInfo.ys =  absY.range;
                     }
                     SystemProperties.set("sys.config.calibrate", "loaded");
             }

            for (int i=0; i                 final int j = i * MotionEvent.NUM_SAMPLE_DATA;

                 tmpX = reportData[j + MotionEvent.SAMPLE_X];
                 tmpY = reportData[j + MotionEvent.SAMPLE_Y];
                 if (absX != null ) {
                    reportData[j + MotionEvent.SAMPLE_X] =
                             ((reportData[j + MotionEvent.SAMPLE_X]-absX.minValue)
                                 / absX.range) * w; 

                      reportData[j + MotionEvent.SAMPLE_X] = (TransformInfo.x1 * tmpX + TransformInfo.y1 * tmpY + TransformInfo.z1) / TransformInfo.xs;
                 }
                 if (absY != null ) {
                    reportData[j + MotionEvent.SAMPLE_Y] =
                             ((reportData[j + MotionEvent.SAMPLE_Y]-absY.minValue)
                                 / absY.range) * h;

                      reportData[j + MotionEvent.SAMPLE_Y] = (TransformInfo.x2 * tmpX + TransformInfo.y2 * tmpY + TransformInfo.z2) / TransformInfo.ys;
                 }
                 if (absPressure != null) {
                     reportData[j + MotionEvent.SAMPLE_PRESSURE] =
                             ((reportData[j + MotionEvent.SAMPLE_PRESSURE]-absPressure.minValue)
                                 / (float)absPressure.range);
                 }
                 if (absSize != null) {
                     reportData[j + MotionEvent.SAMPLE_SIZE] =
                             ((reportData[j + MotionEvent.SAMPLE_SIZE]-absSize.minValue)
                                 / (float)absSize.range);
                 }

　　　　..................................

　    static class AbsoluteInfo {
         int minValue;
         int maxValue;
         int range;
　     int flat;
         int fuzz;
     　};
 
     　static class TransformInfo {
         static int x1;
         static int y1;
         static int z1;
         static int x2;
         static int y2;
         static int z2;
         static int xs;
         static int ys;
     };
 
     InputDevice(int _id, int _classes, String _name,
             AbsoluteInfo _absX, AbsoluteInfo _absY,
             AbsoluteInfo _absPressure, AbsoluteInfo _absSize) {
         id = _id;
         classes = _classes;
         name = _name;
         absX = _absX;
         absY = _absY;
         absPressure = _absPressure;
         absSize = _absSize;
 
         TransformInfo.xs =  0;
         TransformInfo.ys =  0;
         readCalibrate();

　} 
    static void readCalibrate(){
             try {
                 FileInputStream is = new FileInputStream(CALIBRATION_FILE);
                 byte[] mBuffer = new byte[64];
                 int len = is.read(mBuffer);
                 is.close();
                 if (len > 0) {
                     int i;
                     for (i = 0; i < len; i++) {
                         if (mBuffer[i] == '/n' || mBuffer[i] == 0) {
                             break;
                         }
                     }
                     len = i;
                 }
 
                 StringTokenizer st = new StringTokenizer(new String(mBuffer, 0, len));
 
                 TransformInfo.x1 = Integer.parseInt(st.nextToken());
                 TransformInfo.y1 = Integer.parseInt(st.nextToken());
                 TransformInfo.z1 = Integer.parseInt(st.nextToken());
                 TransformInfo.x2 = Integer.parseInt(st.nextToken());
                 TransformInfo.y2 = Integer.parseInt(st.nextToken());
                 TransformInfo.z2 = Integer.parseInt(st.nextToken());
                 TransformInfo.xs = Integer.parseInt(st.nextToken());
                 TransformInfo.ys = TransformInfo.xs;
                 SystemProperties.set("sys.config.calibrate", "loaded");
             } catch (java.io.FileNotFoundException e) {
                 Log.i("InputDevice", "calibration file not found exception");
             } catch (java.io.IOException e) {
                 Log.i("InputDevice", "io exception");
             } catch (java.lang.NumberFormatException e) {
                Log.i("InputDevice", "number format exception");
             }
   }

};

packages/apps/Settings/AndroidManifest.xml文件修改地方如下:

                          android:label="@string/details_title">
            
                
                
            
        
 
                          android:label="@string/screen_calibration_settings">
              
                  
                  
              
          
 
        
            
                

packages/apps/Settings/res/xml/settings.xml文件修改地方如下:

                     settings:icon="@drawable/ic_settings_date_time"
             android:title="@string/date_and_time_settings_title">
                              android:action="android.intent.action.MAIN"
                 android:targetPackage="com.android.settings"
                 android:targetClass="com.android.settings.DateTimeSettings" />
        
 
        
                       settings:icon="@drawable/ic_settings_privacy"
              android:title="@string/screen_calibration_settings">
                               android:action="android.intent.action.MAIN"
                 android:targetPackage="com.android.settings"
                 android:targetClass="com.android.settings.Calibration"/>
        
 
 
        
 
                      settings:icon="@drawable/ic_settings_about"
             android:title="@string/about_settings">
                              android:action="android.intent.action.MAIN"
                 android:targetPackage="com.android.settings"
                 android:targetClass="com.android.settings.DeviceInfoSettings" />
        

Calibration.java文件代码如下

 

package com.android.settings;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.util.Log;
import android.view.Display;
import android.view.IWindowManager;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;
import android.os.SystemProperties;
public class Calibration extends Activity {
static final int SAMPLE_COUNTS = 5;
static final int POINT_DEGREE = 2;
static final int FACTOR_COUNTS = 7;
static final int TOP_LEFT = 0;
static final int TOP_RIGHT = 1;
static final int BOTTOM_RIGHT = 2;
static final int BOTTOM_LEFT = 3;
static final int CENTER = 4;
static final int X_AXIS = 0;
static final int Y_AXIS = 1;
static final int EDGE_GAP = 50;

static final String CALIBRATION_FILE = "/data/pointercal";
static final String TAG = "Calibration";
static final boolean DEBUG = true;

private int X_RES;
private int Y_RES;
private Display dpy;

class calibration {
     int x[] = new int[5];
     int y[] = new int[5];
     int xfb[] = new int[5];
     int yfb[] = new int[5];
     int a[] = new int[7];
};
private calibration cal;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    SystemProperties.set("sys.config.calibrate", "start");
    cal = new calibration();

    dpy = ((WindowManager) getSystemService(WINDOW_SERVICE)).getDefaultDisplay();
    X_RES = dpy.getWidth();
    Y_RES = dpy.getHeight();

    this.initScreenPoints();

    setContentView(new MyView(this));
}

// TopLeft-->TopRight-->BottomRight-->BottomLeft-->Center
// For 240 * 320 resolution, we use 50 pixel as edge gap
 private boolean initScreenPoints() {
    cal.xfb[TOP_LEFT] = EDGE_GAP;               // TopLeft
    cal.yfb[TOP_LEFT] = EDGE_GAP;

    cal.xfb[TOP_RIGHT] = X_RES - EDGE_GAP;      // TopRight
    cal.yfb[TOP_RIGHT] = EDGE_GAP;

    cal.xfb[BOTTOM_RIGHT] = X_RES - EDGE_GAP;   // BottomRight
    cal.yfb[BOTTOM_RIGHT] = Y_RES - EDGE_GAP;

    cal.xfb[BOTTOM_LEFT] = EDGE_GAP;            // BottomLeft
    cal.yfb[BOTTOM_LEFT] = Y_RES - EDGE_GAP;

    cal.xfb[CENTER] = X_RES / 2;                // Center
    cal.yfb[CENTER] = Y_RES / 2;
    return true;
}

 private boolean perform_calibration() {
    float n, x, y, x2, y2, xy, z, zx, zy;
    float det, a, b, c, e, f, g;
    float scaling = (float)65536.0;

    n = x = y = x2 = y2 = xy = 0;
    for (int i = 0; i < SAMPLE_COUNTS; i++) {
        n += 1.0;
        x += (float)cal.x[i];
        y += (float)cal.y[i];
        x2 += (float)(cal.x[i] * cal.x[i]);
        y2 += (float)(cal.y[i] * cal.y[i]);
        xy += (float)(cal.x[i] * cal.y[i]);
    }

    det = n * (x2 * y2 - xy * xy) + x * (xy * y - x * y2) + y * (x * xy - y * x2);
    if (det < 0.1 && det > -0.1) {
        Log.w("bigcren", "determinant is too small, det =" + det);
        return false;
    }

    if (DEBUG) {
        Log.i("bigcren", "(n,x,y,x2,y2,xy,det)=("
            + n + ","
            + x + ","
            + y + ","
            + x2 + ","
            + y2 + ","
            + xy + ","
            + det + ")");
        }

    a = (x2 * y2 - xy * xy) / det;
    b = (xy * y - x * y2) / det;
    c = (x * xy - y * x2) / det;
    e = (n * y2 - y * y) / det;
    f = (x * y - n * xy) / det;
    g = (n * x2 - x * x) / det;

    Log.i("bigcren", "(a,b,c,e,f,g)=("
        + a + ","
        + b + ","
        + c + ","
        + e + ","
        + f + ","
        + g + ")");

    // Get sums for x calibration
    z = zx = zy = 0;
    for(int i = 0; i < SAMPLE_COUNTS; i++) {
        z += (float)cal.xfb[i];
        zx += (float)(cal.xfb[i] * cal.x[i]);
        zy += (float)(cal.xfb[i] * cal.y[i]);
    }

    // Now multiply out to get the calibration for X coordination
    cal.a[0] = (int)((a * z + b * zx + c * zy) * (scaling));
    cal.a[1] = (int)((b * z + e * zx + f * zy) * (scaling));
    cal.a[2] = (int)((c * z + f * zx + g * zy) * (scaling));
    // Get sums for y calibration
    z = zx = zy = 0;
    for(int i = 0;i < SAMPLE_COUNTS; i++) {
        z += (float)cal.yfb[i];
        zx += (float)(cal.yfb[i] * cal.x[i]);
        zy += (float)(cal.yfb[i] * cal.y[i]);
    }

    // Now multiply out to get the calibration for Y coordination
    cal.a[3] = (int)((a * z + b * zx + c * zy) * (scaling));
    cal.a[4] = (int)((b * z + e * zx + f * zy) * (scaling));
    cal.a[5] = (int)((c * z + f * zx + g * zy) * (scaling));

    cal.a[6] = (int)scaling;

    return true;
    }

    private boolean saveCalibrationResult() {
        FileOutputStream os;
        String res = "";

    // save the calibration factor in file system for InputDevice
    try {
        os = new FileOutputStream(CALIBRATION_FILE);
        res = String.format("%d %d %d %d %d %d %d", cal.a[1], cal.a[2], cal.a[0], cal.a[4], cal.a[5], cal.a[3], cal.a[6]);

        if (DEBUG) {
            Log.i("bigcren", "calibration result=" + res);
        }

        os.write(res.getBytes());
        os.close();
    } catch (FileNotFoundException e1) {
    // TODO Auto-generated catch block
        e1.printStackTrace();
        Log.w(TAG, "open calibration file write error: " + CALIBRATION_FILE );
    } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
    }
    return true;
 }

public class MyView extends View {
    private Canvas cv;
    private Paint paint;
    private Bitmap bmp;
    private int screen_pos;
    private Context mContext;
    public MyView(Context c) {
    super(c);
    // set full screen and no title
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    mContext=c;
    paint = new Paint();
    paint.setDither(true);
    paint.setAntiAlias(true);
    paint.setStrokeWidth(2);
    paint.setColor(Color.WHITE);
    paint.setStyle(Paint.Style.STROKE);
    bmp = Bitmap.createBitmap(X_RES, Y_RES, Bitmap.Config.ARGB_8888);
    cv = new Canvas(bmp);
    screen_pos = 0;
    drawCalibrationCross(screen_pos);
}

protected void onDraw(Canvas canvas) {
        canvas.drawColor(Color.BLACK);
        canvas.drawBitmap(bmp, 0, 0, null);
}

private boolean drawCalibrationCross(int pos) {
    if (DEBUG) {
        Log.i("bigcren", "draw cross at pos " + pos);
    }

    cv.drawColor(Color.BLACK);

    // draw X line
    cv.drawLine(cal.xfb[pos] - 10, cal.yfb[pos],
        cal.xfb[pos] - 2, cal.yfb[pos], paint);
    cv.drawLine(cal.xfb[pos] + 2, cal.yfb[pos],
        cal.xfb[pos] + 10, cal.yfb[pos], paint);

    // draw Y line
    cv.drawLine(cal.xfb[pos], cal.yfb[pos] - 10,
        cal.xfb[pos], cal.yfb[pos] - 2, paint);
    cv.drawLine(cal.xfb[pos], cal.yfb[pos] + 2,
        cal.xfb[pos], cal.yfb[pos] + 10, paint);
    invalidate();
    return true;
}

public boolean onTouchEvent(MotionEvent event) {
    float tmpx, tmpy;
    boolean ret;
    if (screen_pos > SAMPLE_COUNTS - 1) {
        Log.i("bigcren", "get sample ok");
        return true;
    }

    if (event.getAction() == MotionEvent.ACTION_UP) {
        tmpx = event.getX();
        tmpy = event.getY();
        if(Math.abs(cal.xfb[screen_pos]-tmpx)>15&&
            Math.abs(cal.yfb[screen_pos]-tmpy)>15){
                Toast.makeText(mContext, R.string.calibration_error,Toast.LENGTH_SHORT).show();
        return false;
    }

    cal.x[screen_pos] = (int)(event.getX()*4096.0/(float)X_RES + 0.5);
    cal.y[screen_pos] = (int)(event.getY()*4096.0/(float)Y_RES + 0.5);

    if (screen_pos == 4) {
        ret = perform_calibration();
        if (ret) {
            saveCalibrationResult();
            SystemProperties.set("sys.config.calibrate", "done");
            finish();
            return true;
            } else {
            screen_pos = 0;
            Log.w(TAG, "Calibration failed");
            }
        } else {
            screen_pos++;
            drawCalibrationCross(screen_pos);
            }
        }
        return true;
        }
    }
}

 

转自：

http://blog.csdn.net/king_sundi/archive/2011/01/19/6152865.aspx

 

http://blogold.chinaunix.net/u3/90973/showart_2162315.html

 

 

http://blog.csdn.net/cpuwolf/archive/2011/01/11/6130010.aspx

http://blog.csdn.net/dafeifly/archive/2009/10/13/4662498.aspx