Related
I used the hexagon code in this tutorial and created a createHex class (Should I post the code?). The linked web page has used the following code to actually draw the hexagons using the math in createHex:
#Override
public void paint(Graphics g){
for(int j = 0; int j < BOARD_HEIGHT; j++){
for(int i = 0; i < BOARD_HEIGHT; I++){
mCellMetrics.setCellIndex(i, j);
if(mCells[j][i] != 0){
mCellMetrics.computeCorners(mCornersX, mCornersY);
g.setColor((mCells[j][i] == L_ON) ? COLOR.ORANGE):COLOR.GRAY;
g.fillPolygon(mCornersX, mCornersY, NUM_HEX_CORNERS);
g.setColor(COLOR.BLACK)
g.drawPolygon(mCornersX, mCornersY, NUM_HEX_CORNERS);
}
}
}
}
The problem I encountered is that Android does not have a Graphics class that contains all the required methods. I did about an hour and a half of fishing around the android documentation and the closest thing I found was the Path class but it doesn't have the methods I need. I want to use the hexagon code in the linked article at the top but I can't find the equivalent of the graphics class. If there isn't an equivalent, can someone show me how to get the results I want using the linked code?
My question: How can I port the code in the linked article to android?
EDIT:
I decided that it might be helpful to others (and potential answerers) if I included the hexagon code that calculates the sides and whatnot of a hexagon, so here is createHex.java:
package com.rush;
/**
* Uniform hexagonal grid cell's metrics utility class.
*/
public class HexGridCell {
private static final int[] NEIGHBORS_DI = { 0, 1, 1, 0, -1, -1 };
private static final int[][] NEIGHBORS_DJ = {
{ -1, -1, 0, 1, 0, -1 }, { -1, 0, 1, 1, 1, 0 } };
private final int[] CORNERS_DX; // array of horizontal offsets of the cell's corners
private final int[] CORNERS_DY; // array of
vertical offsets of the cell's corners
private final int SIDE;
private int mX = 0; // cell's left coordinate
private int mY = 0; // cell's top coordinate
private int mI = 0; // cell's horizontal grid coordinate
private int mJ = 0; // cell's vertical grid coordinate
/**
* Cell radius (distance from center to one of the corners)
*/
public final int RADIUS;
/**
* Cell height
*/
public final int HEIGHT;
/**
* Cell width
*/
public final int WIDTH;
public static final int NUM_NEIGHBORS = 6;
/**
* #param radius Cell radius (distance from the center to one of the corners)
*/
public HexGridCell(int radius) {
RADIUS = radius;
WIDTH = radius * 2;
HEIGHT = (int) (((float) radius) * Math.sqrt(3));
SIDE = radius * 3 / 2;
int cdx[] = { RADIUS / 2, SIDE, WIDTH, SIDE, RADIUS / 2, 0 };
CORNERS_DX = cdx;
int cdy[] = { 0, 0, HEIGHT / 2, HEIGHT, HEIGHT, HEIGHT / 2 };
CORNERS_DY = cdy;
}
/**
* #return X coordinate of the cell's top left corner.
*/
public int getLeft() {
return mX;
}
/**
* #return Y coordinate of the cell's top left corner.
*/
public int getTop() {
return mY;
}
/**
* #return X coordinate of the cell's center
*/
public int getCenterX() {
return mX + RADIUS;
}
/**
* #return Y coordinate of the cell's center
*/
public int getCenterY() {
return mY + HEIGHT / 2;
}
/**
* #return Horizontal grid coordinate for the cell.
*/
public int getIndexI() {
return mI;
}
/**
* #return Vertical grid coordinate for the cell.
*/
public int getIndexJ() {
return mJ;
}
/**
* #return Horizontal grid coordinate for the given neighbor.
*/
public int getNeighborI(int neighborIdx) {
return mI + NEIGHBORS_DI[neighborIdx];
}
/**
* #return Vertical grid coordinate for the given neighbor.
*/
public int getNeighborJ(int neighborIdx) {
return mJ + NEIGHBORS_DJ[mI % 2][neighborIdx];
}
/**
* Computes X and Y coordinates for all of the cell's 6 corners, clockwise,
* starting from the top left.
*
* #param cornersX Array to fill in with X coordinates of the cell's corners
* #param cornersX Array to fill in with Y coordinates of the cell's corners
*/
public void computeCorners(int[] cornersX, int[] cornersY) {
for (int k = 0; k < NUM_NEIGHBORS; k++) {
cornersX[k] = mX + CORNERS_DX[k];
cornersY[k] = mY + CORNERS_DY[k];
}
}
/**
* Sets the cell's horizontal and vertical grid coordinates.
*/
public void setCellIndex(int i, int j) {
mI = i;
mJ = j;
mX = i * SIDE;
mY = HEIGHT * (2 * j + (i % 2)) / 2;
}
/**
* Sets the cell as corresponding to some point inside it (can be used for
* e.g. mouse picking).
*/
public void setCellByPoint(int x, int y) {
int ci = (int)Math.floor((float)x/(float)SIDE);
int cx = x - SIDE*ci;
int ty = y - (ci % 2) * HEIGHT / 2;
int cj = (int)Math.floor((float)ty/(float)HEIGHT);
int cy = ty - HEIGHT*cj;
if (cx > Math.abs(RADIUS / 2 - RADIUS * cy / HEIGHT)) {
setCellIndex(ci, cj);
} else {
setCellIndex(ci - 1, cj + (ci % 2) - ((cy < HEIGHT / 2) ? 1 :
0));
}
}
}
For an explanation of how the code works please refer to the linked article.
Try this:
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Path;
import android.graphics.Region;
import android.util.AttributeSet;
import android.view.View;
public class HexagonMaskView extends View {
private Path hexagonPath;
private Path hexagonBorderPath;
private float radius;
private float width, height;
private int maskColor;
public HexagonMaskView(Context context) {
super(context);
init();
}
public HexagonMaskView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public HexagonMaskView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
hexagonPath = new Path();
hexagonBorderPath = new Path();
maskColor = 0xFF01FF77;
}
public void setRadius(float r) {
this.radius = r;
calculatePath();
}
public void setMaskColor(int color) {
this.maskColor = color;
invalidate();
}
private void calculatePath() {
float triangleHeight = (float) (Math.sqrt(3) * radius / 2);
float centerX = width/2;
float centerY = height/2;
hexagonPath.moveTo(centerX, centerY + radius);
hexagonPath.lineTo(centerX - triangleHeight, centerY + radius/2);
hexagonPath.lineTo(centerX - triangleHeight, centerY - radius/2);
hexagonPath.lineTo(centerX, centerY - radius);
hexagonPath.lineTo(centerX + triangleHeight, centerY - radius/2);
hexagonPath.lineTo(centerX + triangleHeight, centerY + radius/2);
hexagonPath.moveTo(centerX, centerY + radius);
float radiusBorder = radius - 5;
float triangleBorderHeight = (float) (Math.sqrt(3) * radiusBorder / 2);
hexagonBorderPath.moveTo(centerX, centerY + radiusBorder);
hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY + radiusBorder/2);
hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY - radiusBorder/2);
hexagonBorderPath.lineTo(centerX, centerY - radiusBorder);
hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY - radiusBorder/2);
hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY + radiusBorder/2);
hexagonBorderPath.moveTo(centerX, centerY + radiusBorder);
invalidate();
}
#Override
public void onDraw(Canvas c){
super.onDraw(c);
c.clipPath(hexagonBorderPath, Region.Op.DIFFERENCE);
c.drawColor(Color.WHITE);
c.save();
c.clipPath(hexagonPath, Region.Op.DIFFERENCE);
c.drawColor(maskColor);
c.save();
}
// getting the view size and default radius
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
width = MeasureSpec.getSize(widthMeasureSpec);
height = MeasureSpec.getSize(heightMeasureSpec);
radius = height / 2 - 10;
calculatePath();
}
}
Try this or download demo example.
public static Bitmap getHexagonalCroppedBitmap(Bitmap bitmap, int radius) {
Bitmap finalBitmap;
if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
false);
else
finalBitmap = bitmap;
Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
finalBitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
Paint paint = new Paint();
final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
finalBitmap.getHeight());
Point point1_draw = new Point(75, 0);
Point point2_draw = new Point(0, 50);
Point point3_draw = new Point(0, 100);
Point point4_draw = new Point(75, 150);
Point point5_draw = new Point(150, 100);
Point point6_draw = new Point(150, 50);
Path path = new Path();
path.moveTo(point1_draw.x, point1_draw.y);
path.lineTo(point2_draw.x, point2_draw.y);
path.lineTo(point3_draw.x, point3_draw.y);
path.lineTo(point4_draw.x, point4_draw.y);
path.lineTo(point5_draw.x, point5_draw.y);
path.lineTo(point6_draw.x, point6_draw.y);
path.close();
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawPath(path, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(finalBitmap, rect, rect, paint);
return output;
}
pass your image to be cropped to hexagon as bitmap to this function
Bitmap myhexagon = getHexagonalCroppedBitmap(Myimage, yourHexagonalRadius);
this is page-curl view , i want when nextView() is called my TextView get the next string
but I can't use TextView from xml layout it gives me null ,
how I can but buttons and TextView in customView ?
can any one help me to solve this with code ?
I have searched with many tutorials but I get this understanding
activity class :
public class StandaloneExample extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.standalone_example);
}
#Override
public void onDestroy(){
super.onDestroy();
System.gc();
finish();
}
/**
* Set the current orientation to landscape. This will prevent the OS from changing
* the app's orientation.
*/
public void lockOrientationLandscape() {
lockOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
}
/**
* Set the current orientation to portrait. This will prevent the OS from changing
* the app's orientation.
*/
public void lockOrientationPortrait() {
lockOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}
public void lockOrientation( int orientation ) {
setRequestedOrientation(orientation);
}
}
pageCurlView :
public class PageCurlView extends View {
private class Vector2D {
public float x, y;
public Vector2D(float x, float y) {
this.x = x;
this.y = y;
}
#Override
public String toString() {
// TODO Auto-generated method stub
return "(" + this.x + "," + this.y + ")";
}
public float length() {
return (float) Math.sqrt(x * x + y * y);
}
public float lengthSquared() {
return (x * x) + (y * y);
}
public boolean equals(Object o) {
if (o instanceof Vector2D) {
Vector2D p = (Vector2D) o;
return p.x == x && p.y == y;
}
return false;
}
public Vector2D reverse() {
return new Vector2D(-x, -y);
}
public Vector2D sum(Vector2D b) {
return new Vector2D(x + b.x, y + b.y);
}
public Vector2D sub(Vector2D b) {
return new Vector2D(x - b.x, y - b.y);
}
public float dot(Vector2D vec) {
return (x * vec.x) + (y * vec.y);
}
public float cross(Vector2D a, Vector2D b) {
return a.cross(b);
}
public float cross(Vector2D vec) {
return x * vec.y - y * vec.x;
}
public float distanceSquared(Vector2D other) {
float dx = other.x - x;
float dy = other.y - y;
return (dx * dx) + (dy * dy);
}
public float distance(Vector2D other) {
return (float) Math.sqrt(distanceSquared(other));
}
public float dotProduct(Vector2D other) {
return other.x * x + other.y * y;
}
public Vector2D normalize() {
float magnitude = (float) Math.sqrt(dotProduct(this));
return new Vector2D(x / magnitude, y / magnitude);
}
public Vector2D mult(float scalar) {
return new Vector2D(x * scalar, y * scalar);
}
}
/**
* Inner class used to make a fixed timed animation of the curl effect.
*/
class FlipAnimationHandler extends Handler {
#Override
public void handleMessage(Message msg) {
PageCurlView.this.FlipAnimationStep();
}
public void sleep(long millis) {
this.removeMessages(0);
sendMessageDelayed(obtainMessage(0), millis);
}
}
/**
* Base
*
* #param context
*/
public PageCurlView(Context context) {
super(context);
init(context);
ResetClipEdge();
}
/**
* Construct the object from an XML file. Valid Attributes:
*
* #see android.view.View#View(android.content.Context,
* android.util.AttributeSet)
*/
public PageCurlView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
// Get the data from the XML AttributeSet
{
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.PageCurlView);
// Get data
bEnableDebugMode = a.getBoolean(
R.styleable.PageCurlView_enableDebugMode, bEnableDebugMode);
mCurlSpeed = a.getInt(R.styleable.PageCurlView_curlSpeed,
mCurlSpeed);
mUpdateRate = a.getInt(R.styleable.PageCurlView_updateRate,
mUpdateRate);
mInitialEdgeOffset = a.getInt(
R.styleable.PageCurlView_initialEdgeOffset,
mInitialEdgeOffset);
mCurlMode = a.getInt(R.styleable.PageCurlView_curlMode, mCurlMode);
Log.i(TAG, "mCurlSpeed: " + mCurlSpeed);
Log.i(TAG, "mUpdateRate: " + mUpdateRate);
Log.i(TAG, "mInitialEdgeOffset: " + mInitialEdgeOffset);
Log.i(TAG, "mCurlMode: " + mCurlMode);
// recycle object (so it can be used by others)
a.recycle();
}
ResetClipEdge();
}
/**
* Initialize the view
*/
private final void init(Context context) {
LayoutInflater.from(context).inflate(R.layout.standalone_example, null,
true);
// left text view
textViewContent = (TextView) this.findViewById(R.id.textView);
// Foreground text paint
mTextPaint = new Paint();
mTextPaint.setAntiAlias(true);
mTextPaint.setTextSize(16);
mTextPaint.setColor(0xFF000000);
// The shadow
mTextPaintShadow = new TextPaint();
mTextPaintShadow.setAntiAlias(true);
mTextPaintShadow.setTextSize(16);
mTextPaintShadow.setColor(0x00000000);
// Cache the context
mContext = new WeakReference<Context>(context);
hesham = context;
// Base padding
setPadding(3, 3, 3, 3);
// The focus flags are needed
setFocusable(true);
setFocusableInTouchMode(true);
mMovement = new Vector2D(0, 0);
mFinger = new Vector2D(0, 0);
mOldMovement = new Vector2D(0, 0);
// Create our curl animation handler
mAnimationHandler = new FlipAnimationHandler();
// Create our edge paint
mCurlEdgePaint = new Paint();
mCurlEdgePaint.setColor(Color.WHITE);
mCurlEdgePaint.setAntiAlias(true);
mCurlEdgePaint.setStyle(Paint.Style.FILL);
mCurlEdgePaint.setShadowLayer(10, -5, 5, 0x99000000);
// Set the default props, those come from an XML :D
mCurlSpeed = 120;
mUpdateRate = 66;
mInitialEdgeOffset = 30;
mCurlMode = 2;
// LEGACY PAGE HANDLING!
// Create pages
mPages = new ArrayList<Bitmap>();
mPages.add(BitmapFactory.decodeResource(getResources(),
R.drawable.page1));
mPages.add(BitmapFactory.decodeResource(getResources(),
R.drawable.page2));
// Create some sample images
mForeground = mPages.get(0);
mBackground = mPages.get(1);
}
/**
* Reset points to it's initial clip edge state
*/
public void ResetClipEdge() {
// Set our base movement
mMovement.x = mInitialEdgeOffset;
mMovement.y = mInitialEdgeOffset;
mOldMovement.x = 0;
mOldMovement.y = 0;
// Now set the points
// TODO: OK, those points MUST come from our measures and
// the actual bounds of the view!
mA = new Vector2D(mInitialEdgeOffset, 0);
mB = new Vector2D(this.getWidth(), this.getHeight());
mC = new Vector2D(this.getWidth(), 0);
mD = new Vector2D(0, 0);
mE = new Vector2D(0, 0);
mF = new Vector2D(0, 0);
mOldF = new Vector2D(0, 0);
// The movement origin point
mOrigin = new Vector2D(this.getWidth(), 0);
}
/**
* Return the context which created use. Can return null if the context has
* been erased.
*/
private Context GetContext() {
return mContext.get();
}
/**
* See if the current curl mode is dynamic
*
* #return TRUE if the mode is CURLMODE_DYNAMIC, FALSE otherwise
*/
public boolean IsCurlModeDynamic() {
return mCurlMode == CURLMODE_DYNAMIC;
}
/**
* Set the curl speed.
*
* #param curlSpeed
* - New speed in px/frame
* #throws IllegalArgumentException
* if curlspeed < 1
*/
public void SetCurlSpeed(int curlSpeed) {
if (curlSpeed < 1)
throw new IllegalArgumentException(
"curlSpeed must be greated than 0");
mCurlSpeed = curlSpeed;
}
/**
* Get the current curl speed
*
* #return int - Curl speed in px/frame
*/
public int GetCurlSpeed() {
return mCurlSpeed;
}
/**
* Set the update rate for the curl animation
*
* #param updateRate
* - Fixed animation update rate in fps
* #throws IllegalArgumentException
* if updateRate < 1
*/
public void SetUpdateRate(int updateRate) {
if (updateRate < 1)
throw new IllegalArgumentException(
"updateRate must be greated than 0");
mUpdateRate = updateRate;
}
/**
* Get the current animation update rate
*
* #return int - Fixed animation update rate in fps
*/
public int GetUpdateRate() {
return mUpdateRate;
}
/**
* Set the initial pixel offset for the curl edge
*
* #param initialEdgeOffset
* - px offset for curl edge
* #throws IllegalArgumentException
* if initialEdgeOffset < 0
*/
public void SetInitialEdgeOffset(int initialEdgeOffset) {
if (initialEdgeOffset < 0)
throw new IllegalArgumentException(
"initialEdgeOffset can not negative");
mInitialEdgeOffset = initialEdgeOffset;
}
/**
* Get the initial pixel offset for the curl edge
*
* #return int - px
*/
public int GetInitialEdgeOffset() {
return mInitialEdgeOffset;
}
/**
* Set the curl mode.
* <p>
* Can be one of the following values:
* </p>
* <table>
* <colgroup align="left" /> <colgroup align="left" />
* <tr>
* <th>Value</th>
* <th>Description</th>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_SIMPLE com.dcg.pagecurl:CURLMODE_SIMPLE}</code></td>
* <td>Curl target will move only in one axis.</td>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_DYNAMIC com.dcg.pagecurl:CURLMODE_DYNAMIC}</code></td>
* <td>Curl target will move on both X and Y axis.</td>
* </tr>
* </table>
*
* #see #CURLMODE_SIMPLE
* #see #CURLMODE_DYNAMIC
* #param curlMode
* #throws IllegalArgumentException
* if curlMode is invalid
*/
public void SetCurlMode(int curlMode) {
if (curlMode != CURLMODE_SIMPLE && curlMode != CURLMODE_DYNAMIC)
throw new IllegalArgumentException("Invalid curlMode");
mCurlMode = curlMode;
}
/**
* Return an integer that represents the current curl mode.
* <p>
* Can be one of the following values:
* </p>
* <table>
* <colgroup align="left" /> <colgroup align="left" />
* <tr>
* <th>Value</th>
* <th>Description</th>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_SIMPLE com.dcg.pagecurl:CURLMODE_SIMPLE}</code></td>
* <td>Curl target will move only in one axis.</td>
* </tr>
* <tr>
* <td>
* <code>{#link #CURLMODE_DYNAMIC com.dcg.pagecurl:CURLMODE_DYNAMIC}</code></td>
* <td>Curl target will move on both X and Y axis.</td>
* </tr>
* </table>
*
* #see #CURLMODE_SIMPLE
* #see #CURLMODE_DYNAMIC
* #return int - current curl mode
*/
public int GetCurlMode() {
return mCurlMode;
}
/**
* Enable debug mode. This will draw a lot of data in the view so you can
* track what is happening
*
* #param bFlag
* - boolean flag
*/
public void SetEnableDebugMode(boolean bFlag) {
bEnableDebugMode = bFlag;
}
/**
* Check if we are currently in debug mode.
*
* #return boolean - If TRUE debug mode is on, FALSE otherwise.
*/
public boolean IsDebugModeEnabled() {
return bEnableDebugMode;
}
/**
* #see android.view.View#measure(int, int)
*/
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int finalWidth, finalHeight;
finalWidth = measureWidth(widthMeasureSpec);
finalHeight = measureHeight(heightMeasureSpec);
setMeasuredDimension(finalWidth, finalHeight);
}
/**
* Determines the width of this view
*
* #param measureSpec
* A measureSpec packed into an int
* #return The width of the view, honoring constraints from measureSpec
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text
result = specSize;
}
return result;
}
/**
* Determines the height of this view
*
* #param measureSpec
* A measureSpec packed into an int
* #return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
// Measure the text (beware: ascent is a negative number)
result = specSize;
}
return result;
}
/**
* Render the text
*
* #see android.view.View#onDraw(android.graphics.Canvas)
*/
// #Override
// protected void onDraw(Canvas canvas) {
// super.onDraw(canvas);
// canvas.drawText(mText, getPaddingLeft(), getPaddingTop() - mAscent,
// mTextPaint);
// }
// ---------------------------------------------------------------
// Curling. This handles touch events, the actual curling
// implementations and so on.
// ---------------------------------------------------------------
#Override
public boolean onTouchEvent(MotionEvent event) {
if (!bBlockTouchInput) {
// Get our finger position
mFinger.x = event.getX();
mFinger.y = event.getY();
int width = getWidth();
// Depending on the action do what we need to
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mOldMovement.x = mFinger.x;
mOldMovement.y = mFinger.y;
// If we moved over the half of the display flip to next
if (mOldMovement.x > (width >> 1)) {
mMovement.x = mInitialEdgeOffset;
mMovement.y = mInitialEdgeOffset;
// Set the right movement flag
bFlipRight = true;
} else {
// Set the left movement flag
bFlipRight = false;
// go to next previous page
previousView();
// Set new movement
mMovement.x = IsCurlModeDynamic() ? width << 1 : width;
mMovement.y = mInitialEdgeOffset;
}
break;
case MotionEvent.ACTION_UP:
bUserMoves = false;
bFlipping = true;
FlipAnimationStep();
break;
case MotionEvent.ACTION_MOVE:
bUserMoves = true;
// Get movement
mMovement.x -= mFinger.x - mOldMovement.x;
mMovement.y -= mFinger.y - mOldMovement.y;
mMovement = CapMovement(mMovement, true);
// Make sure the y value get's locked at a nice level
if (mMovement.y <= 1)
mMovement.y = 1;
// Get movement direction
if (mFinger.x < mOldMovement.x) {
bFlipRight = true;
} else {
bFlipRight = false;
}
// Save old movement values
mOldMovement.x = mFinger.x;
mOldMovement.y = mFinger.y;
// Force a new draw call
DoPageCurl();
this.invalidate();
break;
}
}
// TODO: Only consume event if we need to.
return true;
}
/**
* Make sure we never move too much, and make sure that if we move too much
* to add a displacement so that the movement will be still in our radius.
*
* #paramradius - radius form the flip origin
* #param bMaintainMoveDir
* - Cap movement but do not change the current movement
* direction
* #return Corrected point
*/
private Vector2D CapMovement(Vector2D point, boolean bMaintainMoveDir) {
// Make sure we never ever move too much
if (point.distance(mOrigin) > mFlipRadius) {
if (bMaintainMoveDir) {
// Maintain the direction
point = mOrigin.sum(point.sub(mOrigin).normalize()
.mult(mFlipRadius));
} else {
// Change direction
if (point.x > (mOrigin.x + mFlipRadius))
point.x = (mOrigin.x + mFlipRadius);
else if (point.x < (mOrigin.x - mFlipRadius))
point.x = (mOrigin.x - mFlipRadius);
point.y = (float) (Math.sin(Math.acos(Math.abs(point.x
- mOrigin.x)
/ mFlipRadius)) * mFlipRadius);
}
}
return point;
}
/**
* Execute a step of the flip animation
*/
public void FlipAnimationStep() {
if (!bFlipping)
return;
int width = getWidth();
// No input when flipping
bBlockTouchInput = true;
// Handle speed
float curlSpeed = mCurlSpeed;
if (!bFlipRight)
curlSpeed *= -1;
// Move us
mMovement.x += curlSpeed;
mMovement = CapMovement(mMovement, false);
// Create values
DoPageCurl();
// Check for endings :D
if (mA.x < 1 || mA.x > width - 1) {
bFlipping = false;
if (bFlipRight) {
// SwapViews();
nextView();
}
ResetClipEdge();
// Create values
DoPageCurl();
// Enable touch input after the next draw event
bEnableInputAfterDraw = true;
} else {
mAnimationHandler.sleep(mUpdateRate);
}
// Force a new draw call
this.invalidate();
}
/**
* Do the page curl depending on the methods we are using
*/
private void DoPageCurl() {
if (bFlipping) {
if (IsCurlModeDynamic())
doDynamicCurl();
else
doSimpleCurl();
} else {
if (IsCurlModeDynamic())
doDynamicCurl();
else
doSimpleCurl();
}
}
/**
* Do a simple page curl effect
*/
private void doSimpleCurl() {
int width = getWidth();
int height = getHeight();
// Calculate point A
mA.x = width - mMovement.x;
mA.y = height;
// Calculate point D
mD.x = 0;
mD.y = 0;
if (mA.x > width / 2) {
mD.x = width;
mD.y = height - (width - mA.x) * height / mA.x;
} else {
mD.x = 2 * mA.x;
mD.y = 0;
}
// Now calculate E and F taking into account that the line
// AD is perpendicular to FB and EC. B and C are fixed points.
double angle = Math
.atan((height - mD.y) / (mD.x + mMovement.x - width));
double _cos = Math.cos(2 * angle);
double _sin = Math.sin(2 * angle);
// And get F
mF.x = (float) (width - mMovement.x + _cos * mMovement.x);
mF.y = (float) (height - _sin * mMovement.x);
// If the x position of A is above half of the page we are still not
// folding the upper-right edge and so E and D are equal.
if (mA.x > width / 2) {
mE.x = mD.x;
mE.y = mD.y;
} else {
// So get E
mE.x = (float) (mD.x + _cos * (width - mD.x));
mE.y = (float) -(_sin * (width - mD.x));
}
}
/**
* Calculate the dynamic effect, that one that follows the users finger
*/
private void doDynamicCurl() {
int width = getWidth();
int height = getHeight();
// F will follow the finger, we add a small displacement
// So that we can see the edge
mF.x = width - mMovement.x + 0.1f;
mF.y = height - mMovement.y + 0.1f;
// Set min points
if (mA.x == 0) {
mF.x = Math.min(mF.x, mOldF.x);
mF.y = Math.max(mF.y, mOldF.y);
}
// Get diffs
float deltaX = width - mF.x;
float deltaY = height - mF.y;
float BH = (float) (Math.sqrt(deltaX * deltaX + deltaY * deltaY) / 2);
double tangAlpha = deltaY / deltaX;
double alpha = Math.atan(deltaY / deltaX);
double _cos = Math.cos(alpha);
double _sin = Math.sin(alpha);
mA.x = (float) (width - (BH / _cos));
mA.y = height;
mD.y = (float) (height - (BH / _sin));
mD.x = width;
mA.x = Math.max(0, mA.x);
if (mA.x == 0) {
mOldF.x = mF.x;
mOldF.y = mF.y;
}
// Get W
mE.x = mD.x;
mE.y = mD.y;
// Correct
if (mD.y < 0) {
mD.x = width + (float) (tangAlpha * mD.y);
mE.y = 0;
mE.x = width + (float) (Math.tan(2 * alpha) * mD.y);
}
}
/**
* Swap between the fore and back-ground.
*/
#Deprecated
private void SwapViews() {
Bitmap temp = mForeground;
mForeground = mBackground;
mBackground = temp;
}
/**
* Swap to next view
*/
private void nextView() {
MySQLiteHelper SqlLiteInstance = new MySQLiteHelper(hesham);
SqlLiteInstance.insertForTest("تايتل", "لبلب", "ثثث");
SqlLiteInstance.insertForTest("تايتل التاني", "5555", "5555");
SqlLiteInstance.insertForTest("التالت", "66666", "66666");
int foreIndex = mIndex + 1;
Cursor myDataBase = SqlLiteInstance.getCurrentPageData(1);
if (myDataBase.moveToFirst() && myDataBase.getCount() >= 1) {
do {
textViewContent.setText(myDataBase.getString(0));
} while (myDataBase.moveToNext());
}
if (foreIndex >= mPages.size()) {
foreIndex = 0;
}
int backIndex = foreIndex + 1;
if (backIndex >= mPages.size()) {
backIndex = 0;
}
mIndex = foreIndex;
setViews(foreIndex, backIndex);
}
/**
* Swap to previous view
*/
private void previousView() {
int backIndex = mIndex;
int foreIndex = backIndex - 1;
if (foreIndex < 0) {
foreIndex = mPages.size() - 1;
}
mIndex = foreIndex;
setViews(foreIndex, backIndex);
}
/**
* Set current fore and background
*
* #param foreground
* - Foreground view index
* #param background
* - Background view index
*/
private void setViews(int foreground, int background) {
mForeground = mPages.get(foreground);
mBackground = mPages.get(background);
}
// ---------------------------------------------------------------
// Drawing methods
// ---------------------------------------------------------------
#Override
protected void onDraw(Canvas canvas) {
// Always refresh offsets
mCurrentLeft = getLeft();
mCurrentTop = getTop();
// Translate the whole canvas
// canvas.translate(mCurrentLeft, mCurrentTop);
// We need to initialize all size data when we first draw the view
if (!bViewDrawn) {
bViewDrawn = true;
onFirstDrawEvent(canvas);
}
canvas.drawColor(Color.WHITE);
// Curl pages
// DoPageCurl();
// TODO: This just scales the views to the current
// width and height. We should add some logic for:
// 1) Maintain aspect ratio
// 2) Uniform scale
// 3) ...
Rect rect = new Rect();
rect.left = 0;
rect.top = 0;
rect.bottom = getHeight();
rect.right = getWidth();
// First Page render
Paint paint = new Paint();
// Draw our elements
drawForeground(canvas, rect, paint);
drawBackground(canvas, rect, paint);
drawCurlEdge(canvas);
// Draw any debug info once we are done
if (bEnableDebugMode)
drawDebug(canvas);
// Check if we can re-enable input
if (bEnableInputAfterDraw) {
bBlockTouchInput = false;
bEnableInputAfterDraw = false;
}
// Restore canvas
// canvas.restore();
}
/**
* Called on the first draw event of the view
*
* #param canvas
*/
protected void onFirstDrawEvent(Canvas canvas) {
mFlipRadius = getWidth();
ResetClipEdge();
DoPageCurl();
}
/**
* Draw the foreground
*
* #param canvas
* #param rect
* #param paint
*/
private void drawForeground(Canvas canvas, Rect rect, Paint paint) {
canvas.drawBitmap(mForeground, null, rect, paint);
// Draw the page number (first page is 1 in real life :D
// there is no page number 0 hehe)
drawPageNum(canvas, mIndex);
}
/**
* Create a Path used as a mask to draw the background page
*
* #return
*/
private Path createBackgroundPath() {
Path path = new Path();
path.moveTo(mA.x, mA.y);
path.lineTo(mB.x, mB.y);
path.lineTo(mC.x, mC.y);
path.lineTo(mD.x, mD.y);
path.lineTo(mA.x, mA.y);
return path;
}
/**
* Draw the background image.
*
* #param canvas
* #param rect
* #param paint
*/
private void drawBackground(Canvas canvas, Rect rect, Paint paint) {
Path mask = createBackgroundPath();
// Save current canvas so we do not mess it up
canvas.save();
canvas.clipPath(mask);
canvas.drawBitmap(mBackground, null, rect, paint);
// Draw the page number (first page is 1 in real life :D
// there is no page number 0 hehe)
drawPageNum(canvas, mIndex);
canvas.restore();
}
/**
* Creates a path used to draw the curl edge in.
*
* #return
*/
private Path createCurlEdgePath() {
Path path = new Path();
path.moveTo(mA.x, mA.y);
path.lineTo(mD.x, mD.y);
path.lineTo(mE.x, mE.y);
path.lineTo(mF.x, mF.y);
path.lineTo(mA.x, mA.y);
return path;
}
/**
* Draw the curl page edge
*
* #param canvas
*/
private void drawCurlEdge(Canvas canvas) {
Path path = createCurlEdgePath();
canvas.drawPath(path, mCurlEdgePaint);
}
/**
* Draw page num (let this be a bit more custom)
*
* #param canvas
* #param pageNum
*/
private void drawPageNum(Canvas canvas, int pageNum) {
mTextPaint.setColor(Color.WHITE);
String pageNumText = "- " + pageNum + " -";
drawCentered(canvas, pageNumText,
canvas.getHeight() - mTextPaint.getTextSize() - 5, mTextPaint,
mTextPaintShadow);
}
// ---------------------------------------------------------------
// Debug draw methods
// ---------------------------------------------------------------
/**
* Draw a text with a nice shadow
*/
public static void drawTextShadowed(Canvas canvas, String text, float x,
float y, Paint textPain, Paint shadowPaint) {
canvas.drawText(text, x - 1, y, shadowPaint);
canvas.drawText(text, x, y + 1, shadowPaint);
canvas.drawText(text, x + 1, y, shadowPaint);
canvas.drawText(text, x, y - 1, shadowPaint);
canvas.drawText(text, x, y, textPain);
}
/**
* Draw a text with a nice shadow centered in the X axis
*
* #param canvas
* #param text
* #param y
* #param textPain
* #param shadowPaint
*/
public static void drawCentered(Canvas canvas, String text, float y,
Paint textPain, Paint shadowPaint) {
float posx = (canvas.getWidth() - textPain.measureText(text)) / 2;
drawTextShadowed(canvas, text, posx, y, textPain, shadowPaint);
}
/**
* Draw debug info
*
* #param canvas
*/
private void drawDebug(Canvas canvas) {
float posX = 10;
float posY = 20;
Paint paint = new Paint();
paint.setStrokeWidth(5);
paint.setStyle(Style.STROKE);
paint.setColor(Color.BLACK);
canvas.drawCircle(mOrigin.x, mOrigin.y, getWidth(), paint);
paint.setStrokeWidth(3);
paint.setColor(Color.RED);
canvas.drawCircle(mOrigin.x, mOrigin.y, getWidth(), paint);
paint.setStrokeWidth(5);
paint.setColor(Color.BLACK);
canvas.drawLine(mOrigin.x, mOrigin.y, mMovement.x, mMovement.y, paint);
paint.setStrokeWidth(3);
paint.setColor(Color.RED);
canvas.drawLine(mOrigin.x, mOrigin.y, mMovement.x, mMovement.y, paint);
posY = debugDrawPoint(canvas, "A", mA, Color.RED, posX, posY);
posY = debugDrawPoint(canvas, "B", mB, Color.GREEN, posX, posY);
posY = debugDrawPoint(canvas, "C", mC, Color.BLUE, posX, posY);
posY = debugDrawPoint(canvas, "D", mD, Color.CYAN, posX, posY);
posY = debugDrawPoint(canvas, "E", mE, Color.YELLOW, posX, posY);
posY = debugDrawPoint(canvas, "F", mF, Color.LTGRAY, posX, posY);
posY = debugDrawPoint(canvas, "Mov", mMovement, Color.DKGRAY, posX,
posY);
posY = debugDrawPoint(canvas, "Origin", mOrigin, Color.MAGENTA, posX,
posY);
posY = debugDrawPoint(canvas, "Finger", mFinger, Color.GREEN, posX,
posY);
// Draw some curl stuff (Just some test)
/*
* canvas.save(); Vector2D center = new
* Vector2D(getWidth()/2,getHeight()/2);
* //canvas.rotate(315,center.x,center.y);
*
* // Test each lines //float radius = mA.distance(mD)/2.f; //float
* radius = mA.distance(mE)/2.f; float radius = mA.distance(mF)/2.f;
* //float radius = 10; float reduction = 4.f; RectF oval = new RectF();
* oval.top = center.y-radius/reduction; oval.bottom =
* center.y+radius/reduction; oval.left = center.x-radius; oval.right =
* center.x+radius; canvas.drawArc(oval, 0, 360, false, paint);
* canvas.restore(); /*
*/
}
private float debugDrawPoint(Canvas canvas, String name, Vector2D point,
int color, float posX, float posY) {
return debugDrawPoint(canvas, name + " " + point.toString(), point.x,
point.y, color, posX, posY);
}
private float debugDrawPoint(Canvas canvas, String name, float X, float Y,
int color, float posX, float posY) {
mTextPaint.setColor(color);
drawTextShadowed(canvas, name, posX, posY, mTextPaint, mTextPaintShadow);
Paint paint = new Paint();
paint.setStrokeWidth(5);
paint.setColor(color);
canvas.drawPoint(X, Y, paint);
return posY + 15;
}
}
xml code :
<RelativeLayout
android:id="#+id/game_layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.mystictreegames.pagecurl.PageCurlView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/dcgpagecurlPageCurlView1"
android:background="#drawable/facebook">
</com.mystictreegames.pagecurl.PageCurlView>
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_centerVertical="true"
android:text="جوهر كون المرء انه انسان لا يسعى الى الكمال"/>
log error:
FATAL EXCEPTION: main
E/AndroidRuntime(2497): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mystictreegames.pagecurl/com.mystictreegames.pagecurl.StandaloneExample}: android.view.InflateException: Binary XML file line #13: Error inflating class com.mystictreegames.pagecurl.PageCurlView
In the init() of the PageCurlView class, you are inflating R.layout.standalone_example. Objects are added in a circular manner (R.layout.standalone_example has PageCurlView which has R.layout.standalone_example which has ...).
I wrote this camera last week everything works fine, accept for the fact that I don't how to use the look position as Z-position.
If you try it you'll see for youself.
import static java.lang.Math.cos;
import static java.lang.Math.sin;
import static java.lang.Math.toRadians;
import static org.lwjgl.opengl.GL11.*;
import org.lwjgl.Sys;
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import org.lwjgl.util.vector.Vector3f;
public class Camera{
private Vector3f position = null; //X, Y, Z position of the PandaCam
private float yaw = 0.0f; //Yaw of the PandaCam
private float pitch = 0.0f; //Pitch of the PandaCam
private float dx = 0.0f, dy = 0.0f;
private float multi = 0.005f;
private float moveSpeed = 0.25f;
private float mouseSensitivity = 0.02f;
private float tDelta = getDelta();
private long lastFrame, time;
/**
* Create a new PandaCam
* default:
* x = 0
* y = 0
* z = 0
*/
public Camera(){
position = new Vector3f(0, 0, 0);
}
/**
* Create a new PandaCam
* default:
* z = 0
*
* #param x Set the Starting X position of the camera
* #param y Set the Starting Y position of the camera
*/
public Camera(float x, float y){
position = new Vector3f(x, y, 0);
}
/**
* Create a new PandaCam
*
* #param x Set the Starting X position of the camera
* #param y Set the Starting Y position of the camera
* #param z Set the Starting Z position of the camera
*/
public Camera(float x, float y, float z){
position = new Vector3f(x, y, z);
}
/**
* Call this function every frame to update the PandaCam
*/
public void update(){
glLoadIdentity();
mouseInput();
keyboardInput();
setPosition();
}
/**
* #return Returns the delta time.
*/
public int getDelta(){
time = (Sys.getTime() * 1000) / Sys.getTimerResolution();
int delta = (int) (time - lastFrame);
lastFrame = time;
return delta;
}
/**
* Updates the PandaCam yaw
* #param amount The amount the yaw moves. takes numbers below and above zero
*/
public void yaw(float amount){
yaw -= amount;
}
/**
* Updates the PandaCam pitch
* #param amount The amount the pitch moves. takes numbers below and above zero
*/
public void pitch(float amount){
pitch += amount;
}
/**
* Moves the PandaCam forward.
* #param distance The distance the camera move's forward
*/
public void walkForward(float distance){
calculatePosition(0, 0, multi * distance * 0.003f);
}
/**
* Moves the PandaCam backward.
* #param distance The distance the camera move's backward
*/
public void walkBackwards(float distance){
calculatePosition(0, 0, -multi * distance * 0.003f);
}
/**
* Moves the PandaCam left.
* #param distance The distance the camera move's left
*/
public void strafeLeft(float distance){
calculatePosition(multi * distance * 0.003f, 0, 0);
}
/**
* Moves the PandaCam right.
* #param distance The distance the camera move's right
*/
public void strafeRight(float distance){
calculatePosition(-multi * distance * 0.003f, 0, 0);
}
/**
* Sets the PandaCam position
* #param dx Is an amount that the PandaCam add's or subtracts from the current X
* #param dy Is an amount that the PandaCam add's or subtracts from the current Y
* #param dz Is an amount that the PandaCam add's or subtracts from the current Z
*/
private void calculatePosition(float dx, float dy, float dz){
position.x -= dx * (float) sin(toRadians(yaw - 90)) + dz * sin(toRadians(yaw));
position.y += dy * (float) sin(toRadians(pitch - 90)) + dz * sin(toRadians(pitch));
position.z += dx * (float) cos(toRadians(yaw - 90)) + dz * cos(toRadians(yaw));
}
/**
* Handles the keyboard input
*/
public void keyboardInput(){
//Move forward
if (Keyboard.isKeyDown(Keyboard.KEY_W) || Keyboard.isKeyDown(Keyboard.KEY_UP)){
walkForward(moveSpeed * (tDelta/10));
}
//Move backwards
if (Keyboard.isKeyDown(Keyboard.KEY_S) || Keyboard.isKeyDown(Keyboard.KEY_DOWN)){
walkBackwards(moveSpeed * (tDelta/10));
}
//Strafe left
if (Keyboard.isKeyDown(Keyboard.KEY_A) || Keyboard.isKeyDown(Keyboard.KEY_LEFT)){
strafeLeft(moveSpeed * (tDelta/10));
}
//Strafe right
if (Keyboard.isKeyDown(Keyboard.KEY_D) || Keyboard.isKeyDown(Keyboard.KEY_RIGHT)){
strafeRight(moveSpeed * (tDelta/10));
}
}
/**
* Handles mouse Input
*/
public void mouseInput(){
dx = Mouse.getDX();
dy = Mouse.getDY();
yaw(dx * mouseSensitivity);
pitch(dy * mouseSensitivity);
}
/**
* Sets the position of the PandaCam
*/
public void setPosition(){
//Rotate the pitch around the X axis
glRotatef(-pitch, 1.0f, 0.0f, 0.0f);
//Rotate the yaw around the Y axis
glRotatef(-yaw, 0.0f, 1.0f, 0.0f);
//translate to the position vector's location
glTranslatef(position.x, position.y, position.z);
}
public float getMX(){
return Mouse.getX();
}
public float getMY(){
return Mouse.getY();
}
/**
* #return The Pitch position of the PandaCam
*/
public float getPitch(){
return -pitch;
}
/**
* #return The Yaw position of the PandaCam
*/
public float getYaw(){
return -yaw;
}
/**
* #return The X position of the PandaCam
*/
public float getX(){
return position.x;
}
/**
* #return The Y position of the PandaCam
*/
public float getY(){
return position.y;
}
/**
* #return The Z position of the PandaCam
*/
public float getZ(){
return position.z;
}
}
In OpenGL Camera (view) matrix is usually built using lookAt method which defines the view direction of camera.Here is a source where you can find lookAt method implementation.
Or here is my answer to someone with camera problem ,with LWJGL lookat example code included :)
Btw , if you are using fixed pipeline (which seems to be the case ) ,take a look at :
gluLookAt ()
I would like to know if its possible to draw a Arc on a graphics Panel using a gradient and how I would go about it.
My end goal would be to rotate the arc in a full circle so it would be similar to a rotating loading circle. However it is not a loading bar. It would be a background of a custom JButton.
Any suggestions to alternatives that would create a similar effect would be appreciated.
This is similar to what oi want to draw. Keep in mind that it will be "rotating"
public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
RadialGradientPaint rgp = new RadialGradientPaint(
new Point(getWidth() / 2, getHeight() / 2),
radius,
new float[]{0f, 1f},
new Color[]{Color.RED, Color.YELLOW}
);
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, 0, 45, Arc2D.PIE));
g2d.dispose();
}
}
}
You might like to have a look at 2D Graphics for more info
Updated after additional input
So you want a conical fill effect then...
The implementation I have comes from Harmonic Code, but I can't find a direct reference to it (I think it's part of his (excellent) series), but you can see the source code here
Now. I had issues with the angles as it appears that 0 starts at the top point (not the left) and it doesn't like negative angles...you might have better luck, but what I did was create a basic buffer at a position I could easily get working and then rotate the graphics context using an AffineTransformation...
public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private float angle = 0;
private float extent = 270;
private BufferedImage buffer;
public TestPane() {
Timer timer = new Timer(125, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
angle -= 5;
if (angle > 360) {
angle = 0;
}
repaint();
}
});
timer.setRepeats(true);
timer.setCoalesce(false);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected BufferedImage getBuffer() {
if (buffer == null) {
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
buffer = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = buffer.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
float startAngle = 0;
Color start = new Color(0, 128, 0, 128);
Color end = new Color(0, 128, 0, 0);
ConicalGradientPaint rgp = new ConicalGradientPaint(
true,
new Point(getWidth() / 2, getHeight() / 2),
0.5f,
new float[]{startAngle, extent},
new Color[]{start, end});
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, startAngle + 90, -extent, Arc2D.PIE));
// g2d.fill(new Ellipse2D.Float(0, 0, radius, radius));
g2d.dispose();
g2d.dispose();
}
return buffer;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth()) / 2;
int y = (getHeight()) / 2;
BufferedImage buffer = getBuffer();
g2d.setTransform(AffineTransform.getRotateInstance(Math.toRadians(angle), x, y));
x = (getWidth() - buffer.getWidth()) / 2;
y = (getHeight() - buffer.getHeight()) / 2;
g2d.drawImage(buffer, x, y, this);
g2d.dispose();
}
}
public final class ConicalGradientPaint implements java.awt.Paint {
private final java.awt.geom.Point2D CENTER;
private final double[] FRACTION_ANGLES;
private final double[] RED_STEP_LOOKUP;
private final double[] GREEN_STEP_LOOKUP;
private final double[] BLUE_STEP_LOOKUP;
private final double[] ALPHA_STEP_LOOKUP;
private final java.awt.Color[] COLORS;
private static final float INT_TO_FLOAT_CONST = 1f / 255f;
/**
* Standard constructor which takes the FRACTIONS in values from 0.0f to
* 1.0f
*
* #param CENTER
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final java.awt.geom.Point2D CENTER, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
this(false, CENTER, 0.0f, GIVEN_FRACTIONS, GIVEN_COLORS);
}
/**
* Enhanced constructor which takes the FRACTIONS in degress from 0.0f to
* 360.0f and also an GIVEN_OFFSET in degrees around the rotation CENTER
*
* #param USE_DEGREES
* #param CENTER
* #param GIVEN_OFFSET
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final boolean USE_DEGREES, final java.awt.geom.Point2D CENTER, final float GIVEN_OFFSET, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
// Check that fractions and colors are of the same size
if (GIVEN_FRACTIONS.length != GIVEN_COLORS.length) {
throw new IllegalArgumentException("Fractions and colors must be equal in size");
}
final java.util.ArrayList<Float> FRACTION_LIST = new java.util.ArrayList<Float>(GIVEN_FRACTIONS.length);
final float OFFSET;
if (USE_DEGREES) {
final double DEG_FRACTION = 1f / 360f;
if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), -0.5) == 0) {
OFFSET = -0.5f;
} else if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), 0.5) == 0) {
OFFSET = 0.5f;
} else {
OFFSET = (float) (GIVEN_OFFSET * DEG_FRACTION);
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add((float) (fraction * DEG_FRACTION));
}
} else {
// Now it seems to work with rotation of 0.5f, below is the old code to correct the problem
// if (GIVEN_OFFSET == -0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly -0.5
// OFFSET = -0.49999f;
// }
// else if (GIVEN_OFFSET == 0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly +0.5
// OFFSET = 0.499999f;
// }
// else
{
OFFSET = GIVEN_OFFSET;
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add(fraction);
}
}
// Check for valid offset
if (OFFSET > 0.5f || OFFSET < -0.5f) {
throw new IllegalArgumentException("Offset has to be in the range of -0.5 to 0.5");
}
// Adjust fractions and colors array in the case where startvalue != 0.0f and/or endvalue != 1.0f
final java.util.List<java.awt.Color> COLOR_LIST = new java.util.ArrayList<java.awt.Color>(GIVEN_COLORS.length);
COLOR_LIST.addAll(java.util.Arrays.asList(GIVEN_COLORS));
// Assure that fractions start with 0.0f
if (FRACTION_LIST.get(0) != 0.0f) {
FRACTION_LIST.add(0, 0.0f);
final java.awt.Color TMP_COLOR = COLOR_LIST.get(0);
COLOR_LIST.add(0, TMP_COLOR);
}
// Assure that fractions end with 1.0f
if (FRACTION_LIST.get(FRACTION_LIST.size() - 1) != 1.0f) {
FRACTION_LIST.add(1.0f);
COLOR_LIST.add(GIVEN_COLORS[0]);
}
// Recalculate the fractions and colors with the given offset
final java.util.Map<Float, java.awt.Color> FRACTION_COLORS = recalculate(FRACTION_LIST, COLOR_LIST, OFFSET);
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
// Sort the hashmap by fraction and add the values to the FRACION_LIST and COLOR_LIST
final java.util.SortedSet<Float> SORTED_FRACTIONS = new java.util.TreeSet<Float>(FRACTION_COLORS.keySet());
final java.util.Iterator<Float> ITERATOR = SORTED_FRACTIONS.iterator();
while (ITERATOR.hasNext()) {
final float CURRENT_FRACTION = ITERATOR.next();
FRACTION_LIST.add(CURRENT_FRACTION);
COLOR_LIST.add(FRACTION_COLORS.get(CURRENT_FRACTION));
}
// Set the values
this.CENTER = CENTER;
COLORS = COLOR_LIST.toArray(new java.awt.Color[]{});
// Prepare lookup table for the angles of each fraction
final int MAX_FRACTIONS = FRACTION_LIST.size();
this.FRACTION_ANGLES = new double[MAX_FRACTIONS];
for (int i = 0; i < MAX_FRACTIONS; i++) {
FRACTION_ANGLES[i] = FRACTION_LIST.get(i) * 360;
}
// Prepare lookup tables for the color stepsize of each color
RED_STEP_LOOKUP = new double[COLORS.length];
GREEN_STEP_LOOKUP = new double[COLORS.length];
BLUE_STEP_LOOKUP = new double[COLORS.length];
ALPHA_STEP_LOOKUP = new double[COLORS.length];
for (int i = 0; i < (COLORS.length - 1); i++) {
RED_STEP_LOOKUP[i] = ((COLORS[i + 1].getRed() - COLORS[i].getRed()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
GREEN_STEP_LOOKUP[i] = ((COLORS[i + 1].getGreen() - COLORS[i].getGreen()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
BLUE_STEP_LOOKUP[i] = ((COLORS[i + 1].getBlue() - COLORS[i].getBlue()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
ALPHA_STEP_LOOKUP[i] = ((COLORS[i + 1].getAlpha() - COLORS[i].getAlpha()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
}
}
/**
* Recalculates the fractions in the FRACTION_LIST and their associated
* colors in the COLOR_LIST with a given OFFSET. Because the conical
* gradients always starts with 0 at the top and clockwise direction you
* could rotate the defined conical gradient from -180 to 180 degrees which
* equals values from -0.5 to +0.5
*
* #param FRACTION_LIST
* #param COLOR_LIST
* #param OFFSET
* #return Hashmap that contains the recalculated fractions and colors after
* a given rotation
*/
private java.util.HashMap<Float, java.awt.Color> recalculate(final java.util.List<Float> FRACTION_LIST, final java.util.List<java.awt.Color> COLOR_LIST, final float OFFSET) {
// Recalculate the fractions and colors with the given offset
final int MAX_FRACTIONS = FRACTION_LIST.size();
final java.util.HashMap<Float, java.awt.Color> FRACTION_COLORS = new java.util.HashMap<Float, java.awt.Color>(MAX_FRACTIONS);
for (int i = 0; i < MAX_FRACTIONS; i++) {
// Add offset to fraction
final float TMP_FRACTION = FRACTION_LIST.get(i) + OFFSET;
// Color related to current fraction
final java.awt.Color TMP_COLOR = COLOR_LIST.get(i);
// Check each fraction for limits (0...1)
if (TMP_FRACTION <= 0) {
FRACTION_COLORS.put(1.0f + TMP_FRACTION + 0.0001f, TMP_COLOR);
final float NEXT_FRACTION;
final java.awt.Color NEXT_COLOR;
if (i < MAX_FRACTIONS - 1) {
NEXT_FRACTION = FRACTION_LIST.get(i + 1) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(i + 1);
} else {
NEXT_FRACTION = 1 - FRACTION_LIST.get(0) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(0);
}
if (NEXT_FRACTION > 0) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, NEXT_COLOR, (int) ((NEXT_FRACTION - TMP_FRACTION) * 10000), (int) ((-TMP_FRACTION) * 10000));
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
}
} else if (TMP_FRACTION >= 1) {
FRACTION_COLORS.put(TMP_FRACTION - 1.0f - 0.0001f, TMP_COLOR);
final float PREVIOUS_FRACTION;
final java.awt.Color PREVIOUS_COLOR;
if (i > 0) {
PREVIOUS_FRACTION = FRACTION_LIST.get(i - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(i - 1);
} else {
PREVIOUS_FRACTION = FRACTION_LIST.get(MAX_FRACTIONS - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(MAX_FRACTIONS - 1);
}
if (PREVIOUS_FRACTION < 1) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, PREVIOUS_COLOR, (int) ((TMP_FRACTION - PREVIOUS_FRACTION) * 10000), (int) (TMP_FRACTION - 1.0f) * 10000);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
}
} else {
FRACTION_COLORS.put(TMP_FRACTION, TMP_COLOR);
}
}
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
return FRACTION_COLORS;
}
/**
* With the START_COLOR at the beginning and the DESTINATION_COLOR at the
* end of the given RANGE the method will calculate and return the color
* that equals the given VALUE. e.g. a START_COLOR of BLACK (R:0, G:0, B:0,
* A:255) and a DESTINATION_COLOR of WHITE(R:255, G:255, B:255, A:255) with
* a given RANGE of 100 and a given VALUE of 50 will return the color that
* is exactly in the middle of the gradient between black and white which is
* gray(R:128, G:128, B:128, A:255) So this method is really useful to
* calculate colors in gradients between two given colors.
*
* #param START_COLOR
* #param DESTINATION_COLOR
* #param RANGE
* #param VALUE
* #return Color calculated from a range of values by given value
*/
public java.awt.Color getColorFromFraction(final java.awt.Color START_COLOR, final java.awt.Color DESTINATION_COLOR, final int RANGE, final int VALUE) {
final float SOURCE_RED = START_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float SOURCE_GREEN = START_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float SOURCE_BLUE = START_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float SOURCE_ALPHA = START_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float DESTINATION_RED = DESTINATION_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float DESTINATION_GREEN = DESTINATION_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float DESTINATION_BLUE = DESTINATION_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float DESTINATION_ALPHA = DESTINATION_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float RED_DELTA = DESTINATION_RED - SOURCE_RED;
final float GREEN_DELTA = DESTINATION_GREEN - SOURCE_GREEN;
final float BLUE_DELTA = DESTINATION_BLUE - SOURCE_BLUE;
final float ALPHA_DELTA = DESTINATION_ALPHA - SOURCE_ALPHA;
final float RED_FRACTION = RED_DELTA / RANGE;
final float GREEN_FRACTION = GREEN_DELTA / RANGE;
final float BLUE_FRACTION = BLUE_DELTA / RANGE;
final float ALPHA_FRACTION = ALPHA_DELTA / RANGE;
//System.out.println(DISTANCE + " " + CURRENT_FRACTION);
return new java.awt.Color(SOURCE_RED + RED_FRACTION * VALUE, SOURCE_GREEN + GREEN_FRACTION * VALUE, SOURCE_BLUE + BLUE_FRACTION * VALUE, SOURCE_ALPHA + ALPHA_FRACTION * VALUE);
}
#Override
public java.awt.PaintContext createContext(final java.awt.image.ColorModel COLOR_MODEL, final java.awt.Rectangle DEVICE_BOUNDS, final java.awt.geom.Rectangle2D USER_BOUNDS, final java.awt.geom.AffineTransform TRANSFORM, final java.awt.RenderingHints HINTS) {
final java.awt.geom.Point2D TRANSFORMED_CENTER = TRANSFORM.transform(CENTER, null);
return new ConicalGradientPaintContext(TRANSFORMED_CENTER);
}
#Override
public int getTransparency() {
return java.awt.Transparency.TRANSLUCENT;
}
private final class ConicalGradientPaintContext implements java.awt.PaintContext {
final private java.awt.geom.Point2D CENTER;
public ConicalGradientPaintContext(final java.awt.geom.Point2D CENTER) {
this.CENTER = new java.awt.geom.Point2D.Double(CENTER.getX(), CENTER.getY());
}
#Override
public void dispose() {
}
#Override
public java.awt.image.ColorModel getColorModel() {
return java.awt.image.ColorModel.getRGBdefault();
}
#Override
public java.awt.image.Raster getRaster(final int X, final int Y, final int TILE_WIDTH, final int TILE_HEIGHT) {
final double ROTATION_CENTER_X = -X + CENTER.getX();
final double ROTATION_CENTER_Y = -Y + CENTER.getY();
final int MAX = FRACTION_ANGLES.length;
// Create raster for given colormodel
final java.awt.image.WritableRaster RASTER = getColorModel().createCompatibleWritableRaster(TILE_WIDTH, TILE_HEIGHT);
// Create data array with place for red, green, blue and alpha values
int[] data = new int[(TILE_WIDTH * TILE_HEIGHT * 4)];
double dx;
double dy;
double distance;
double angle;
double currentRed = 0;
double currentGreen = 0;
double currentBlue = 0;
double currentAlpha = 0;
for (int py = 0; py < TILE_HEIGHT; py++) {
for (int px = 0; px < TILE_WIDTH; px++) {
// Calculate the distance between the current position and the rotation angle
dx = px - ROTATION_CENTER_X;
dy = py - ROTATION_CENTER_Y;
distance = Math.sqrt(dx * dx + dy * dy);
// Avoid division by zero
if (distance == 0) {
distance = 1;
}
// 0 degree on top
angle = Math.abs(Math.toDegrees(Math.acos(dx / distance)));
if (dx >= 0 && dy <= 0) {
angle = 90.0 - angle;
} else if (dx >= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy <= 0) {
angle = 450.0 - angle;
}
// Check for each angle in fractionAngles array
for (int i = 0; i < (MAX - 1); i++) {
if ((angle >= FRACTION_ANGLES[i])) {
currentRed = COLORS[i].getRed() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * RED_STEP_LOOKUP[i];
currentGreen = COLORS[i].getGreen() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * GREEN_STEP_LOOKUP[i];
currentBlue = COLORS[i].getBlue() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * BLUE_STEP_LOOKUP[i];
currentAlpha = COLORS[i].getAlpha() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * ALPHA_STEP_LOOKUP[i];
continue;
}
}
// Fill data array with calculated color values
final int BASE = (py * TILE_WIDTH + px) * 4;
data[BASE + 0] = (int) (currentRed * 255);
data[BASE + 1] = (int) (currentGreen * 255);
data[BASE + 2] = (int) (currentBlue * 255);
data[BASE + 3] = (int) (currentAlpha * 255);
}
}
// Fill the raster with the data
RASTER.setPixels(0, 0, TILE_WIDTH, TILE_HEIGHT, data);
return RASTER;
}
}
}
}
I have a native library which is invoked by the JNI function called from UI. It runs just for a one time, it execute one command and in second run it just exits. I get the following print.
D/Zygote ( 111): Process 921 terminated by signal (2)
What does signal (2) mean? Can I infer something out of this message as to why the process was terminated? The native library works completely fine with a first execute.
My second question is about the accelerometer:
package com.example.android.accelerometerplay;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.BitmapFactory.Options;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.Surface;
import android.view.View;
import android.view.WindowManager;
/**
* This is an example of using the accelerometer to integrate the device's
* acceleration to a position using the Verlet method. This is illustrated with
* a very simple particle system comprised of a few iron balls freely moving on
* an inclined wooden table. The inclination of the virtual table is controlled
* by the device's accelerometer.
*
* #see SensorManager
* #see SensorEvent
* #see Sensor
*/
public class AccelerometerPlayActivity extends Activity {
private SimulationView mSimulationView;
private SensorManager mSensorManager;
private PowerManager mPowerManager;
private WindowManager mWindowManager;
private Display mDisplay;
private WakeLock mWakeLock;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get an instance of the SensorManager
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
// Get an instance of the PowerManager
mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);
// Get an instance of the WindowManager
mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
mDisplay = mWindowManager.getDefaultDisplay();
// Create a bright wake lock
mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, getClass()
.getName());
// instantiate our simulation view and set it as the activity's content
mSimulationView = new SimulationView(this);
setContentView(mSimulationView);
}
#Override
protected void onResume() {
super.onResume();
/*
* when the activity is resumed, we acquire a wake-lock so that the
* screen stays on, since the user will likely not be fiddling with the
* screen or buttons.
*/
mWakeLock.acquire();
// Start the simulation
mSimulationView.startSimulation();
}
#Override
protected void onPause() {
super.onPause();
/*
* When the activity is paused, we make sure to stop the simulation,
* release our sensor resources and wake locks
*/
// Stop the simulation
mSimulationView.stopSimulation();
// and release our wake-lock
mWakeLock.release();
}
class SimulationView extends View implements SensorEventListener {
// diameter of the balls in meters
private static final float sBallDiameter = 0.004f;
private static final float sBallDiameter2 = sBallDiameter * sBallDiameter;
// friction of the virtual table and air
private static final float sFriction = 0.1f;
private Sensor mAccelerometer;
private long mLastT;
private float mLastDeltaT;
private float mXDpi;
private float mYDpi;
private float mMetersToPixelsX;
private float mMetersToPixelsY;
private Bitmap mBitmap;
private Bitmap mWood;
private float mXOrigin;
private float mYOrigin;
private float mSensorX;
private float mSensorY;
private long mSensorTimeStamp;
private long mCpuTimeStamp;
private float mHorizontalBound;
private float mVerticalBound;
private final ParticleSystem mParticleSystem = new ParticleSystem();
/*
* Each of our particle holds its previous and current position, its
* acceleration. for added realism each particle has its own friction
* coefficient.
*/
class Particle {
private float mPosX;
private float mPosY;
private float mAccelX;
private float mAccelY;
private float mLastPosX;
private float mLastPosY;
private float mOneMinusFriction;
Particle() {
// make each particle a bit different by randomizing its
// coefficient of friction
final float r = ((float) Math.random() - 0.5f) * 0.2f;
mOneMinusFriction = 1.0f - sFriction + r;
}
public void computePhysics(float sx, float sy, float dT, float dTC) {
// Force of gravity applied to our virtual object
final float m = 1000.0f; // mass of our virtual object
final float gx = -sx * m;
final float gy = -sy * m;
/*
* ·F = mA <=> A = ·F / m We could simplify the code by
* completely eliminating "m" (the mass) from all the equations,
* but it would hide the concepts from this sample code.
*/
final float invm = 1.0f / m;
final float ax = gx * invm;
final float ay = gy * invm;
/*
* Time-corrected Verlet integration The position Verlet
* integrator is defined as x(t+Æt) = x(t) + x(t) - x(t-Æt) +
* a(t)Ætö2 However, the above equation doesn't handle variable
* Æt very well, a time-corrected version is needed: x(t+Æt) =
* x(t) + (x(t) - x(t-Æt)) * (Æt/Æt_prev) + a(t)Ætö2 We also add
* a simple friction term (f) to the equation: x(t+Æt) = x(t) +
* (1-f) * (x(t) - x(t-Æt)) * (Æt/Æt_prev) + a(t)Ætö2
*/
final float dTdT = dT * dT;
final float x = mPosX + mOneMinusFriction * dTC * (mPosX - mLastPosX) + mAccelX
* dTdT;
final float y = mPosY + mOneMinusFriction * dTC * (mPosY - mLastPosY) + mAccelY
* dTdT;
mLastPosX = mPosX;
mLastPosY = mPosY;
mPosX = x;
mPosY = y;
mAccelX = ax;
mAccelY = ay;
}
/*
* Resolving constraints and collisions with the Verlet integrator
* can be very simple, we simply need to move a colliding or
* constrained particle in such way that the constraint is
* satisfied.
*/
public void resolveCollisionWithBounds() {
final float xmax = mHorizontalBound;
final float ymax = mVerticalBound;
final float x = mPosX;
final float y = mPosY;
if (x > xmax) {
mPosX = xmax;
} else if (x < -xmax) {
mPosX = -xmax;
}
if (y > ymax) {
mPosY = ymax;
} else if (y < -ymax) {
mPosY = -ymax;
}
}
}
/*
* A particle system is just a collection of particles
*/
class ParticleSystem {
static final int NUM_PARTICLES = 15;
private Particle mBalls[] = new Particle[NUM_PARTICLES];
ParticleSystem() {
/*
* Initially our particles have no speed or acceleration
*/
for (int i = 0; i < mBalls.length; i++) {
mBalls[i] = new Particle();
}
}
/*
* Update the position of each particle in the system using the
* Verlet integrator.
*/
private void updatePositions(float sx, float sy, long timestamp) {
final long t = timestamp;
if (mLastT != 0) {
final float dT = (float) (t - mLastT) * (1.0f / 1000000000.0f);
if (mLastDeltaT != 0) {
final float dTC = dT / mLastDeltaT;
final int count = mBalls.length;
for (int i = 0; i < count; i++) {
Particle ball = mBalls[i];
ball.computePhysics(sx, sy, dT, dTC);
}
}
mLastDeltaT = dT;
}
mLastT = t;
}
/*
* Performs one iteration of the simulation. First updating the
* position of all the particles and resolving the constraints and
* collisions.
*/
public void update(float sx, float sy, long now) {
// update the system's positions
updatePositions(sx, sy, now);
// We do no more than a limited number of iterations
final int NUM_MAX_ITERATIONS = 10;
/*
* Resolve collisions, each particle is tested against every
* other particle for collision. If a collision is detected the
* particle is moved away using a virtual spring of infinite
* stiffness.
*/
boolean more = true;
final int count = mBalls.length;
for (int k = 0; k < NUM_MAX_ITERATIONS && more; k++) {
more = false;
for (int i = 0; i < count; i++) {
Particle curr = mBalls[i];
for (int j = i + 1; j < count; j++) {
Particle ball = mBalls[j];
float dx = ball.mPosX - curr.mPosX;
float dy = ball.mPosY - curr.mPosY;
float dd = dx * dx + dy * dy;
// Check for collisions
if (dd <= sBallDiameter2) {
/*
* add a little bit of entropy, after nothing is
* perfect in the universe.
*/
dx += ((float) Math.random() - 0.5f) * 0.0001f;
dy += ((float) Math.random() - 0.5f) * 0.0001f;
dd = dx * dx + dy * dy;
// simulate the spring
final float d = (float) Math.sqrt(dd);
final float c = (0.5f * (sBallDiameter - d)) / d;
curr.mPosX -= dx * c;
curr.mPosY -= dy * c;
ball.mPosX += dx * c;
ball.mPosY += dy * c;
more = true;
}
}
/*
* Finally make sure the particle doesn't intersects
* with the walls.
*/
curr.resolveCollisionWithBounds();
}
}
}
public int getParticleCount() {
return mBalls.length;
}
public float getPosX(int i) {
return mBalls[i].mPosX;
}
public float getPosY(int i) {
return mBalls[i].mPosY;
}
}
public void startSimulation() {
/*
* It is not necessary to get accelerometer events at a very high
* rate, by using a slower rate (SENSOR_DELAY_UI), we get an
* automatic low-pass filter, which "extracts" the gravity component
* of the acceleration. As an added benefit, we use less power and
* CPU resources.
*/
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_UI);
}
public void stopSimulation() {
mSensorManager.unregisterListener(this);
}
public SimulationView(Context context) {
super(context);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
mXDpi = metrics.xdpi;
mYDpi = metrics.ydpi;
mMetersToPixelsX = mXDpi / 0.0254f;
mMetersToPixelsY = mYDpi / 0.0254f;
// rescale the ball so it's about 0.5 cm on screen
Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.ball);
final int dstWidth = (int) (sBallDiameter * mMetersToPixelsX + 0.5f);
final int dstHeight = (int) (sBallDiameter * mMetersToPixelsY + 0.5f);
mBitmap = Bitmap.createScaledBitmap(ball, dstWidth, dstHeight, true);
Options opts = new Options();
opts.inDither = true;
opts.inPreferredConfig = Bitmap.Config.RGB_565;
mWood = BitmapFactory.decodeResource(getResources(), R.drawable.wood, opts);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// compute the origin of the screen relative to the origin of
// the bitmap
mXOrigin = (w - mBitmap.getWidth()) * 0.5f;
mYOrigin = (h - mBitmap.getHeight()) * 0.5f;
mHorizontalBound = ((w / mMetersToPixelsX - sBallDiameter) * 0.5f);
mVerticalBound = ((h / mMetersToPixelsY - sBallDiameter) * 0.5f);
}
#Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
return;
/*
* record the accelerometer data, the event's timestamp as well as
* the current time. The latter is needed so we can calculate the
* "present" time during rendering. In this application, we need to
* take into account how the screen is rotated with respect to the
* sensors (which always return data in a coordinate space aligned
* to with the screen in its native orientation).
*/
switch (mDisplay.getRotation()) {
case Surface.ROTATION_0:
mSensorX = event.values[0];
mSensorY = event.values[1];
break;
case Surface.ROTATION_90:
mSensorX = -event.values[1];
mSensorY = event.values[0];
break;
case Surface.ROTATION_180:
mSensorX = -event.values[0];
mSensorY = -event.values[1];
break;
case Surface.ROTATION_270:
mSensorX = event.values[1];
mSensorY = -event.values[0];
break;
}
mSensorTimeStamp = event.timestamp;
mCpuTimeStamp = System.nanoTime();
}
#Override
protected void onDraw(Canvas canvas) {
/*
* draw the background
*/
canvas.drawBitmap(mWood, 0, 0, null);
/*
* compute the new position of our object, based on accelerometer
* data and present time.
*/
final ParticleSystem particleSystem = mParticleSystem;
final long now = mSensorTimeStamp + (System.nanoTime() - mCpuTimeStamp);
final float sx = mSensorX;
final float sy = mSensorY;
particleSystem.update(sx, sy, now);
final float xc = mXOrigin;
final float yc = mYOrigin;
final float xs = mMetersToPixelsX;
final float ys = mMetersToPixelsY;
final Bitmap bitmap = mBitmap;
final int count = particleSystem.getParticleCount();
for (int i = 0; i < count; i++) {
/*
* We transform the canvas so that the coordinate system matches
* the sensors coordinate system with the origin in the center
* of the screen and the unit is the meter.
*/
final float x = xc + particleSystem.getPosX(i) * xs;
final float y = yc - particleSystem.getPosY(i) * ys;
canvas.drawBitmap(bitmap, x, y, null);
}
// and make sure to redraw asap
invalidate();
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
}
}
How to move ball?
2 is SIGINT (Interrupt), you can check it in header file within your ndk directory