Android Bitmap is black

Android Bitmap is black - android

I'm trying to draw a map from a textfile onto a Bitmap, but the Bitmap is all black
First i load a textfile that looks like this (shortened):
0000000000 (200 width)
0111111110
0111100010
0000111110
0000111000
0000000000
(120 height)
Where "1" is ground and "0" is a wall, 1 should be white and 0 should be black.
Code:
public Map(String map) {
this.map = map;
init();
}
public void init() {
mapArray = new int[WIDTH*HEIGHT];
String[] splitMap = map.split("\n");
int width = splitMap[0].length();
int height = splitMap.length;
int[] colors = new int[WIDTH * HEIGHT];
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
int type = Integer.valueOf(splitMap[y].charAt(x));
setType(x, y, type);
if(type == WALL) {
setColor(x, y, Color.rgb(0, 0, 0), colors);
} else if(type == GROUND) {
setColor(x, y, Color.rgb(255, 255, 255), colors);
} else if(type == GOAL) {
setColor(x, y, Color.rgb(255, 255, 255), colors);
}
}
}
bitmap = Bitmap.createBitmap(colors, WIDTH, HEIGHT, Config.ARGB_8888);
}
public void setColor(int x, int y, int color, int[] colors) {
for(int y1 = 0; y1 < 4; y1++) {
for(int x1 = 0; x1 < 4; x1++) {
colors[(x + x1) + (y + y1) * WIDTH] = color;
}
}
}
public void setPixel(int x, int y, int color) {
for(int y1 = 0; y1 < 4; y1++) {
for(int x1 = 0; x1 < 4; x1++) {
bitmap.setPixel(x + x1, y + y1, color);
}
}
}
public void setType(int x, int y, int type) {
for(int y1 = 0; y1 < 4; y1++) {
for(int x1 = 0; x1 < 4; x1++) {
mapArray[(x + x1) + (y + y1) * WIDTH] = type;
}
}
}
public int getType(int x, int y) {
return mapArray[x + y * WIDTH];
}
public void doDraw(Canvas canvas) {
canvas.drawBitmap(bitmap, 0, 0, null);
}
private final static int WALL = 0;
private final static int GROUND = 1;
private final static int GOAL = 2;
private final static int WIDTH = 800;
private final static int HEIGHT = 480;
private int[] mapArray = null;
private String map = null;
public Bitmap bitmap;

int type = Integer.valueOf(splitMap[y].charAt(x));
That's the line that's causing the problem.
scala> Integer.valueOf('1')
res3: java.lang.Integer = 49
scala> Integer.valueOf('0')
res4: java.lang.Integer = 48
The problem is that charAt gives you a char, which you then convert into an integer. What you really want to do is Integer.parseInt(splitMap[y].substring(x,x+1)
Integer.valueOf("0".substring(0,1))
res7: java.lang.Integer = 0
This illustrates a lesson though - never leave a switch statement without providing a default; similarly never leave an if/else if/... without leaving an else. Even if you're expecting never to hit it, you should put some noticeable error message if you do; it will help you debug.

Related

How to fit the Ringdroid waveform in full width according to width of mobile screen

I want to implement the Ringdroid waveform in my android app.But for some songs,the waveform created after choosing the song is larger than the screen size and for songs the waveform width is smaller than the mobile screen width .
Plz suggest me the change in code of Ringdroid ,so that every time the waveform of song totally covers the width of screen.
This is the link of Ringdroid project
https://github.com/google/ringdroid

After a whole lot of searching and surfing about it. I tried it myself and got the desired output with it
This is the WaveformView class of Ringdroid
package com.ringdroid;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import com.ringdroid.soundfile.SoundFile;
/**
* WaveformView is an Android view that displays a visual representation
* of an audio waveform. It retrieves the frame gains from a CheapSoundFile
* object and recomputes the shape contour at several zoom levels.
*
* This class doesn't handle selection or any of the touch interactions
* directly, so it exposes a listener interface. The class that embeds
* this view should add itself as a listener and make the view scroll
* and respond to other events appropriately.
*
* WaveformView doesn't actually handle selection, but it will just display
* the selected part of the waveform in a different color.
*/
public class WaveformView extends View {
public interface WaveformListener {
public void waveformTouchStart(float x);
public void waveformTouchMove(float x);
public void waveformTouchEnd();
public void waveformFling(float x);
public void waveformDraw();
public void waveformZoomIn();
public void waveformZoomOut();
};
// Colors
private Paint mGridPaint;
private Paint mSelectedLinePaint;
private Paint mUnselectedLinePaint;
private Paint mUnselectedBkgndLinePaint;
private Paint mBorderLinePaint;
private Paint mPlaybackLinePaint;
private Paint mTimecodePaint;
private SoundFile mSoundFile;
private int[] mLenByZoomLevel;
private double[][] mValuesByZoomLevel;
private double[] mZoomFactorByZoomLevel;
private int[] mHeightsAtThisZoomLevel;
private int mZoomLevel;
private int mNumZoomLevels;
private int mSampleRate;
private int mSamplesPerFrame;
private int mOffset;
private int mSelectionStart;
private int mSelectionEnd;
private int mPlaybackPos;
private float mDensity;
private float mInitialScaleSpan;
private WaveformListener mListener;
private GestureDetector mGestureDetector;
private ScaleGestureDetector mScaleGestureDetector;
private boolean mInitialized;
public WaveformView(Context context, AttributeSet attrs) {
super(context, attrs);
// We don't want keys, the markers get these
setFocusable(false);
Resources res = getResources();
mGridPaint = new Paint();
mGridPaint.setAntiAlias(false);
mGridPaint.setColor(res.getColor(R.color.grid_line));
mSelectedLinePaint = new Paint();
mSelectedLinePaint.setAntiAlias(false);
mSelectedLinePaint.setColor(res.getColor(R.color.waveform_selected));
mUnselectedLinePaint = new Paint();
mUnselectedLinePaint.setAntiAlias(false);
mUnselectedLinePaint.setColor(res.getColor(R.color.waveform_unselected));
mUnselectedBkgndLinePaint = new Paint();
mUnselectedBkgndLinePaint.setAntiAlias(false);
mUnselectedBkgndLinePaint.setColor(res.getColor(R.color.waveform_unselected_bkgnd_overlay));
mBorderLinePaint = new Paint();
mBorderLinePaint.setAntiAlias(true);
mBorderLinePaint.setStrokeWidth(1.5f);
mBorderLinePaint.setPathEffect(new DashPathEffect(new float[] { 3.0f, 2.0f }, 0.0f));
mBorderLinePaint.setColor(res.getColor(R.color.selection_border));
mPlaybackLinePaint = new Paint();
mPlaybackLinePaint.setAntiAlias(false);
mPlaybackLinePaint.setColor(res.getColor(R.color.playback_indicator));
mTimecodePaint = new Paint();
mTimecodePaint.setTextSize(12);
mTimecodePaint.setAntiAlias(true);
mTimecodePaint.setColor(res.getColor(R.color.timecode));
mTimecodePaint.setShadowLayer(2, 1, 1, res.getColor(R.color.timecode_shadow));
mGestureDetector = new GestureDetector(
context,
new GestureDetector.SimpleOnGestureListener() {
public boolean onFling(MotionEvent e1, MotionEvent e2, float vx, float vy) {
mListener.waveformFling(vx);
return true;
}
}
);
mScaleGestureDetector = new ScaleGestureDetector(
context,
new ScaleGestureDetector.SimpleOnScaleGestureListener() {
public boolean onScaleBegin(ScaleGestureDetector d) {
Log.v("Ringdroid", "ScaleBegin " + d.getCurrentSpanX());
mInitialScaleSpan = Math.abs(d.getCurrentSpanX());
return true;
}
public boolean onScale(ScaleGestureDetector d) {
float scale = Math.abs(d.getCurrentSpanX());
Log.v("Ringdroid", "Scale " + (scale - mInitialScaleSpan));
if (scale - mInitialScaleSpan > 40) {
mListener.waveformZoomIn();
mInitialScaleSpan = scale;
}
if (scale - mInitialScaleSpan < -40) {
mListener.waveformZoomOut();
mInitialScaleSpan = scale;
}
return true;
}
public void onScaleEnd(ScaleGestureDetector d) {
Log.v("Ringdroid", "ScaleEnd " + d.getCurrentSpanX());
}
}
);
mSoundFile = null;
mLenByZoomLevel = null;
mValuesByZoomLevel = null;
mHeightsAtThisZoomLevel = null;
mOffset = 0;
mPlaybackPos = -1;
mSelectionStart = 0;
mSelectionEnd = 0;
mDensity = 1.0f;
mInitialized = false;
}
#Override
public boolean onTouchEvent(MotionEvent event) {
mScaleGestureDetector.onTouchEvent(event);
if (mGestureDetector.onTouchEvent(event)) {
return true;
}
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
mListener.waveformTouchStart(event.getX());
break;
case MotionEvent.ACTION_MOVE:
mListener.waveformTouchMove(event.getX());
break;
case MotionEvent.ACTION_UP:
mListener.waveformTouchEnd();
break;
}
return true;
}
public boolean hasSoundFile() {
return mSoundFile != null;
}
public void setSoundFile(SoundFile soundFile) {
mSoundFile = soundFile;
mSampleRate = mSoundFile.getSampleRate();
mSamplesPerFrame = mSoundFile.getSamplesPerFrame();
computeDoublesForAllZoomLevels();
mHeightsAtThisZoomLevel = null;
}
public boolean isInitialized() {
return mInitialized;
}
public int getZoomLevel() {
return mZoomLevel;
}
public void setZoomLevel(int zoomLevel) {
while (mZoomLevel > zoomLevel) {
zoomIn();
}
while (mZoomLevel < zoomLevel) {
zoomOut();
}
}
public boolean canZoomIn() {
return (mZoomLevel > 0);
}
public void zoomIn() {
if (canZoomIn()) {
mZoomLevel--;
mSelectionStart *= 2;
mSelectionEnd *= 2;
mHeightsAtThisZoomLevel = null;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter *= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
invalidate();
}
}
public boolean canZoomOut() {
return (mZoomLevel < mNumZoomLevels - 1);
}
public void zoomOut() {
if (canZoomOut()) {
mZoomLevel++;
mSelectionStart /= 2;
mSelectionEnd /= 2;
int offsetCenter = mOffset + getMeasuredWidth() / 2;
offsetCenter /= 2;
mOffset = offsetCenter - getMeasuredWidth() / 2;
if (mOffset < 0)
mOffset = 0;
mHeightsAtThisZoomLevel = null;
invalidate();
}
}
public int maxPos() {
return mLenByZoomLevel[mZoomLevel];
}
public int secondsToFrames(double seconds) {
return (int)(1.0 * seconds * mSampleRate / mSamplesPerFrame + 0.5);
}
public int secondsToPixels(double seconds) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)(z * seconds * mSampleRate / mSamplesPerFrame + 0.5);
}
public double pixelsToSeconds(int pixels) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (pixels * (double)mSamplesPerFrame / (mSampleRate * z));
}
public int millisecsToPixels(int msecs) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)((msecs * 1.0 * mSampleRate * z) /
(1000.0 * mSamplesPerFrame) + 0.5);
}
public int pixelsToMillisecs(int pixels) {
double z = mZoomFactorByZoomLevel[mZoomLevel];
return (int)(pixels * (1000.0 * mSamplesPerFrame) /
(mSampleRate * z) + 0.5);
}
public void setParameters(int start, int end, int offset) {
mSelectionStart = start;
mSelectionEnd = end;
mOffset = offset;
}
public int getStart() {
return mSelectionStart;
}
public int getEnd() {
return mSelectionEnd;
}
public int getOffset() {
return mOffset;
}
public void setPlayback(int pos) {
mPlaybackPos = pos;
}
public void setListener(WaveformListener listener) {
mListener = listener;
}
public void recomputeHeights(float density) {
mHeightsAtThisZoomLevel = null;
mDensity = density;
mTimecodePaint.setTextSize((int)(12 * density));
invalidate();
}
protected void drawWaveformLine(Canvas canvas,
int x, int y0, int y1,
Paint paint) {
canvas.drawLine(x, y0, x, y1, paint);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mSoundFile == null)
return;
if (mHeightsAtThisZoomLevel == null)
computeIntsForThisZoomLevel();
// Draw waveform
int measuredWidth = getMeasuredWidth();
int measuredHeight = getMeasuredHeight();
int start = mOffset;
int width = mHeightsAtThisZoomLevel.length - start;
int ctr = measuredHeight / 2;
if (width > measuredWidth)
width = measuredWidth;
// Draw grid
double onePixelInSecs = pixelsToSeconds(1);
boolean onlyEveryFiveSecs = (onePixelInSecs > 1.0 / 50.0);
double fractionalSecs = mOffset * onePixelInSecs;
int integerSecs = (int) fractionalSecs;
int i = 0;
while (i < width) {
i++;
fractionalSecs += onePixelInSecs;
int integerSecsNew = (int) fractionalSecs;
if (integerSecsNew != integerSecs) {
integerSecs = integerSecsNew;
if (!onlyEveryFiveSecs || 0 == (integerSecs % 5)) {
canvas.drawLine(i, 0, i, measuredHeight, mGridPaint);
}
}
}
// Draw waveform
for (i = 0; i < width; i++) {
Paint paint;
if (i + start >= mSelectionStart &&
i + start < mSelectionEnd) {
paint = mSelectedLinePaint;
} else {
drawWaveformLine(canvas, i, 0, measuredHeight,
mUnselectedBkgndLinePaint);
paint = mUnselectedLinePaint;
}
drawWaveformLine(
canvas, i,
ctr - mHeightsAtThisZoomLevel[start + i],
ctr + 1 + mHeightsAtThisZoomLevel[start + i],
paint);
if (i + start == mPlaybackPos) {
canvas.drawLine(i, 0, i, measuredHeight, mPlaybackLinePaint);
}
}
// If we can see the right edge of the waveform, draw the
// non-waveform area to the right as unselected
for (i = width; i < measuredWidth; i++) {
drawWaveformLine(canvas, i, 0, measuredHeight,
mUnselectedBkgndLinePaint);
}
// Draw borders
canvas.drawLine(
mSelectionStart - mOffset + 0.5f, 30,
mSelectionStart - mOffset + 0.5f, measuredHeight,
mBorderLinePaint);
canvas.drawLine(
mSelectionEnd - mOffset + 0.5f, 0,
mSelectionEnd - mOffset + 0.5f, measuredHeight - 30,
mBorderLinePaint);
// Draw timecode
double timecodeIntervalSecs = 1.0;
if (timecodeIntervalSecs / onePixelInSecs < 50) {
timecodeIntervalSecs = 5.0;
}
if (timecodeIntervalSecs / onePixelInSecs < 50) {
timecodeIntervalSecs = 15.0;
}
// Draw grid
fractionalSecs = mOffset * onePixelInSecs;
int integerTimecode = (int) (fractionalSecs / timecodeIntervalSecs);
i = 0;
while (i < width) {
i++;
fractionalSecs += onePixelInSecs;
integerSecs = (int) fractionalSecs;
int integerTimecodeNew = (int) (fractionalSecs /
timecodeIntervalSecs);
if (integerTimecodeNew != integerTimecode) {
integerTimecode = integerTimecodeNew;
// Turn, e.g. 67 seconds into "1:07"
String timecodeMinutes = "" + (integerSecs / 60);
String timecodeSeconds = "" + (integerSecs % 60);
if ((integerSecs % 60) < 10) {
timecodeSeconds = "0" + timecodeSeconds;
}
String timecodeStr = timecodeMinutes + ":" + timecodeSeconds;
float offset = (float) (
0.5 * mTimecodePaint.measureText(timecodeStr));
canvas.drawText(timecodeStr,
i - offset,
(int)(12 * mDensity),
mTimecodePaint);
}
}
if (mListener != null) {
mListener.waveformDraw();
}
}
/**
* Called once when a new sound file is added
*/
private void computeDoublesForAllZoomLevels() {
int numFrames = mSoundFile.getNumFrames();
int[] frameGains = mSoundFile.getFrameGains();
double[] smoothedGains = new double[numFrames];
if (numFrames == 1) {
smoothedGains[0] = frameGains[0];
} else if (numFrames == 2) {
smoothedGains[0] = frameGains[0];
smoothedGains[1] = frameGains[1];
} else if (numFrames > 2) {
smoothedGains[0] = (double)(
(frameGains[0] / 2.0) +
(frameGains[1] / 2.0));
for (int i = 1; i < numFrames - 1; i++) {
smoothedGains[i] = (double)(
(frameGains[i - 1] / 3.0) +
(frameGains[i ] / 3.0) +
(frameGains[i + 1] / 3.0));
}
smoothedGains[numFrames - 1] = (double)(
(frameGains[numFrames - 2] / 2.0) +
(frameGains[numFrames - 1] / 2.0));
}
// Make sure the range is no more than 0 - 255
double maxGain = 1.0;
for (int i = 0; i < numFrames; i++) {
if (smoothedGains[i] > maxGain) {
maxGain = smoothedGains[i];
}
}
double scaleFactor = 1.0;
if (maxGain > 255.0) {
scaleFactor = 255 / maxGain;
}
// Build histogram of 256 bins and figure out the new scaled max
maxGain = 0;
int gainHist[] = new int[256];
for (int i = 0; i < numFrames; i++) {
int smoothedGain = (int)(smoothedGains[i] * scaleFactor);
if (smoothedGain < 0)
smoothedGain = 0;
if (smoothedGain > 255)
smoothedGain = 255;
if (smoothedGain > maxGain)
maxGain = smoothedGain;
gainHist[smoothedGain]++;
}
// Re-calibrate the min to be 5%
double minGain = 0;
int sum = 0;
while (minGain < 255 && sum < numFrames / 20) {
sum += gainHist[(int)minGain];
minGain++;
}
// Re-calibrate the max to be 99%
sum = 0;
while (maxGain > 2 && sum < numFrames / 100) {
sum += gainHist[(int)maxGain];
maxGain--;
}
// Compute the heights
double[] heights = new double[numFrames];
double range = maxGain - minGain;
for (int i = 0; i < numFrames; i++) {
double value = (smoothedGains[i] * scaleFactor - minGain) / range;
if (value < 0.0)
value = 0.0;
if (value > 1.0)
value = 1.0;
heights[i] = value * value;
}
mNumZoomLevels = 5;
mLenByZoomLevel = new int[5];
mZoomFactorByZoomLevel = new double[5];
mValuesByZoomLevel = new double[5][];
// Level 0 is doubled, with interpolated values
mLenByZoomLevel[0] = numFrames * 2;
mZoomFactorByZoomLevel[0] = 2.0;
mValuesByZoomLevel[0] = new double[mLenByZoomLevel[0]];
if (numFrames > 0) {
mValuesByZoomLevel[0][0] = 0.5 * heights[0];
mValuesByZoomLevel[0][1] = heights[0];
}
for (int i = 1; i < numFrames; i++) {
mValuesByZoomLevel[0][2 * i] = 0.5 * (heights[i - 1] + heights[i]);
mValuesByZoomLevel[0][2 * i + 1] = heights[i];
}
// Level 1 is normal
mLenByZoomLevel[1] = numFrames;
mValuesByZoomLevel[1] = new double[mLenByZoomLevel[1]];
mZoomFactorByZoomLevel[1] = 1.0;
for (int i = 0; i < mLenByZoomLevel[1]; i++) {
mValuesByZoomLevel[1][i] = heights[i];
}
// 3 more levels are each halved
for (int j = 2; j < 5; j++) {
mLenByZoomLevel[j] = mLenByZoomLevel[j - 1] / 2;
mValuesByZoomLevel[j] = new double[mLenByZoomLevel[j]];
mZoomFactorByZoomLevel[j] = mZoomFactorByZoomLevel[j - 1] / 2.0;
for (int i = 0; i < mLenByZoomLevel[j]; i++) {
mValuesByZoomLevel[j][i] =
0.5 * (mValuesByZoomLevel[j - 1][2 * i] +
mValuesByZoomLevel[j - 1][2 * i + 1]);
}
}
if (numFrames > 5000) {
mZoomLevel = 3;
} else if (numFrames > 1000) {
mZoomLevel = 2;
} else if (numFrames > 300) {
mZoomLevel = 1;
} else {
mZoomLevel = 0;
}
mInitialized = true;
}
/**
* Called the first time we need to draw when the zoom level has changed
* or the screen is resized
*/
private void computeIntsForThisZoomLevel() {
int halfHeight = (getMeasuredHeight() / 2) - 1;
mHeightsAtThisZoomLevel = new int[mLenByZoomLevel[mZoomLevel]];
for (int i = 0; i < mLenByZoomLevel[mZoomLevel]; i++) {
mHeightsAtThisZoomLevel[i] =
(int)(mValuesByZoomLevel[mZoomLevel][i] * halfHeight);
}
}
}
The change is here in this part of code
DisplayMetrics displaymetrics = getContext().getResources().getDisplayMetrics();
int ScreenWidth= displaymetrics.widthPixels;
// Draw waveform
for ( i = 0; i < width; i++) {
Paint paint;
if (i + start >= mSelectionStart &&
i + start < mSelectionEnd) {
paint = mSelectedLinePaint;
} else {
drawWaveformLine(canvas, ((ScreenWidth/width)*i), 0, measuredHeight,
mUnselectedBkgndLinePaint);
paint = mUnselectedLinePaint;
}
drawWaveformLine(
canvas, ((ScreenWidth/width)*i),
ctr - mHeightsAtThisZoomLevel[start + i],
ctr + 1 + mHeightsAtThisZoomLevel[start + i],
paint);
you have to change the x-axis of draw line method according to your screen size

import java.util.LinkedList;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.SurfaceView;
/**
* A view that displays audio data on the screen as a waveform.
*/
public class WaveformView extends SurfaceView {
// The number of buffer frames to keep around (for a nice fade-out
// visualization.
private static final int HISTORY_SIZE = 6;
// To make quieter sounds still show up well on the display, we use
// +/- 8192 as the amplitude that reaches the top/bottom of the view
// instead of +/- 32767. Any samples that have magnitude higher than this
// limit will simply be clipped during drawing.
private static final float MAX_AMPLITUDE_TO_DRAW = 8192.0f;
// The queue that will hold historical audio data.
private LinkedList<short[]> mAudioData;
private Paint mPaint;
public WaveformView(Context context) {
this(context, null, 0);
}
public WaveformView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public WaveformView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mAudioData = new LinkedList<short[]>();
mPaint = new Paint();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setColor(Color.WHITE);
mPaint.setStrokeWidth(0);
mPaint.setAntiAlias(true);
}
/**
* Updates the waveform view with a new "frame" of samples and renders it.
* The new frame gets added to the front of the rendering queue, pushing the
* previous frames back, causing them to be faded out visually.
*
* #param buffer the most recent buffer of audio samples.
*/
public synchronized void updateAudioData(short[] buffer) {
short[] newBuffer;
// We want to keep a small amount of history in the view to provide a nice
// fading effect. We use a linked list that we treat as a queue for this.
if (mAudioData.size() == HISTORY_SIZE) {
newBuffer = mAudioData.removeFirst();
System.arraycopy(buffer, 0, newBuffer, 0, buffer.length);
} else {
newBuffer = buffer.clone();
}
mAudioData.addLast(newBuffer);
// Update the display.
Canvas canvas = getHolder().lockCanvas();
if (canvas != null) {
drawWaveform(canvas);
getHolder().unlockCanvasAndPost(canvas);
}
}
/**
* Repaints the view's surface.
*
* #param canvas the {#link Canvas} object on which to draw.
*/
private void drawWaveform(Canvas canvas) {
// Clear the screen each time because SurfaceView won't do this for us.
canvas.drawColor(Color.BLACK);
float width = getWidth();
float height = getHeight();
float centerY = height / 2;
// We draw the history from oldest to newest so that the older audio
// data is further back and darker than the most recent data.
int colorDelta = 255 / (HISTORY_SIZE + 1);
int brightness = colorDelta;
for (short[] buffer : mAudioData) {
mPaint.setColor(Color.argb(brightness, 128, 255, 192));
float lastX = -1;
float lastY = -1;
// For efficiency, we don't draw all of the samples in the buffer,
// but only the ones that align with pixel boundaries.
for (int x = 0; x < width; x++) {
int index = (int) ((x / width) * buffer.length);
short sample = buffer[index];
float y = (sample / MAX_AMPLITUDE_TO_DRAW) * centerY + centerY;
if (lastX != -1) {
canvas.drawLine(lastX, lastY, x, y, mPaint);
}
lastX = x;
lastY = y;
}
brightness += colorDelta;
}
}
}

Android Donut Chart

I have created a donut chart, which is shown below:
MY resultant Donut chart should be in the following way:
My Question is, How can i achieve the lines with image (They are rounded off in second screen shot)
For reference, Here is the code which I have written:
public class PieChartView extends View {
private int[] values = {30, 60, 90, 100, 150};
private int c[] = {Color.MAGENTA,Color.BLUE,Color.RED,Color.CYAN,Color.YELLOW};
private int valuesLength = values.length;
private RectF rectF;
private Paint slicePaint, textPaint;
private Path path;
public PieChartView(Context context, AttributeSet attrs) {
super(context, attrs);
valuesLength = values.length;
slicePaint = new Paint();
slicePaint.setAntiAlias(true);
slicePaint.setDither(true);
slicePaint.setStyle(Paint.Style.FILL);
path = new Path();
}
#SuppressLint("DrawAllocation")
#Override
protected void onDraw(Canvas canvas) {
if(values != null) {
int startTop = 0;
int startLeft = 0;
int endBottom = getHeight();
int endRight = endBottom;// This makes an equal square.
rectF = new RectF(startLeft, startTop, endRight, endBottom);
float[] scaledValues = scale();
float sliceStartPoint = 0;
path.addCircle(rectF.centerX(), rectF.centerY(), 125, Direction.CW);
canvas.clipPath(path, Op.DIFFERENCE);
for(int i = 0; i < valuesLength; i++) {
slicePaint.setColor(c[i]);
path.reset();
path.addArc(rectF, sliceStartPoint, scaledValues[i]);
path.lineTo(rectF.centerX(), rectF.centerY());
canvas.drawPath(path, slicePaint);
sliceStartPoint += scaledValues[i];//This updates the starting point of next slice.
}
}
}
private float[] scale() {
float[] scaledValues = new float[this.values.length];
float total = getTotal(); //Total all values supplied to the chart
for (int i = 0; i < this.values.length; i++) {
scaledValues[i] = (this.values[i] / total) * 360; //Scale each value
}
return scaledValues;
}
private float getTotal() {
float total = 0;
for (float val : this.values)
total += val;
return total;
}
}
Also, How can I find out a co-ordinate from an angle(Start or sweep angle). If i want to draw a line from centre of a circle to the coordinate?

Here's how i finally did it after two days of search with help of this library https://github.com/Ken-Yang/AndroidPieChart
And equations to center text done with help of my friends and alot of search
on MainActivity onCreate or oncreateView if you are using fragments:
PieChart pie = (PieChart) rootView.findViewById(R.id.pieChart);
ArrayList<Float> alPercentage = new ArrayList<Float>();
alPercentage.add(2.0f);
alPercentage.add(8.0f);
alPercentage.add(20.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.0f);
alPercentage.add(10.85f);
alPercentage.add(9.15f);
try {
// setting data
pie.setAdapter(alPercentage);
// setting a listener
pie.setOnSelectedListener(new OnSelectedLisenter() {
#Override
public void onSelected(int iSelectedIndex) {
Toast.makeText(getActivity(),
"Select index:" + iSelectedIndex,
Toast.LENGTH_SHORT).show();
}
});
} catch (Exception e) {
if (e.getMessage().equals(PieChart.ERROR_NOT_EQUAL_TO_100)) {
Log.e("kenyang", "percentage is not equal to 100");
}
}
public class PieChart extends View {
public interface OnSelectedLisenter {
public abstract void onSelected(int iSelectedIndex);
}
private OnSelectedLisenter onSelectedListener = null;
private static final String TAG = PieChart.class.getName();
public static final String ERROR_NOT_EQUAL_TO_100 = "NOT_EQUAL_TO_100";
private static final int DEGREE_360 = 360;
private static String[] PIE_COLORS = null;
private static int iColorListSize = 0;
ArrayList<Float> array;
private Paint paintPieFill;
private Paint paintPieBorder;
private Paint paintCenterCircle;
private ArrayList<Float> alPercentage = new ArrayList<Float>();
private int mCenterX = 320;
private int mCenterY = 320;
private int iDisplayWidth, iDisplayHeight;
private int iSelectedIndex = -1;
private int iCenterWidth = 0;
private int iShift = 0;
private int iMargin = 0; // margin to left and right, used for get Radius
private int iDataSize = 0;
private Canvas canvas1;
private RectF r = null;
private RectF centerCircle = null;
private float fDensity = 0.0f;
private float fStartAngle = 0.0f;
private float fEndAngle = 0.0f;
float fX;
float fY;
public PieChart(Context context, AttributeSet attrs) {
super(context, attrs);
PIE_COLORS = getResources().getStringArray(R.array.colors);
iColorListSize = PIE_COLORS.length;
array = new ArrayList<Float>();
fnGetDisplayMetrics(context);
iShift = (int) fnGetRealPxFromDp(30);
iMargin = (int) fnGetRealPxFromDp(40);
centerCircle = new RectF(200, 200, 440, 440);
// used for paint circle
paintPieFill = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieFill.setStyle(Paint.Style.FILL);
// used for paint centerCircle
paintCenterCircle = new Paint(Paint.ANTI_ALIAS_FLAG);
paintCenterCircle.setStyle(Paint.Style.FILL);
paintCenterCircle.setColor(Color.WHITE);
// used for paint border
paintPieBorder = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieBorder.setStyle(Paint.Style.STROKE);
paintPieBorder.setStrokeWidth(fnGetRealPxFromDp(3));
paintPieBorder.setColor(Color.WHITE);
Log.i(TAG, "PieChart init");
}
// set listener
public void setOnSelectedListener(OnSelectedLisenter listener) {
this.onSelectedListener = listener;
}
float temp = 0;
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Log.i(TAG, "onDraw");
float centerX = (r.left + r.right) / 2;
float centerY = (r.top + r.bottom) / 2;
float radius1 = (r.right - r.left) / 2;
radius1 *= 0.5;
float startX = mCenterX;
float startY = mCenterY;
float radius = mCenterX;
float medianAngle = 0;
Path path = new Path();
for (int i = 0; i < iDataSize; i++) {
// check whether the data size larger than color list size
if (i >= iColorListSize) {
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i
% iColorListSize]));
} else {
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i]));
}
fEndAngle = alPercentage.get(i);
// convert percentage to angle
fEndAngle = fEndAngle / 100 * DEGREE_360;
// if the part of pie was selected then change the coordinate
if (iSelectedIndex == i) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
float fAngle = fStartAngle + fEndAngle / 2;
double dxRadius = Math.toRadians((fAngle + DEGREE_360)
% DEGREE_360);
fY = (float) Math.sin(dxRadius);
fX = (float) Math.cos(dxRadius);
canvas.translate(fX * iShift, fY * iShift);
}
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieFill);
float angle = (float) ((fStartAngle + fEndAngle / 2) * Math.PI / 180);
float stopX = (float) (startX + (radius/2) * Math.cos(angle));
float stopY = (float) (startY + (radius/2) * Math.sin(angle));
// if the part of pie was selected then draw a border
if (iSelectedIndex == i) {
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieBorder);
canvas.drawLine(startX, startY, stopX, stopY, paintPieFill);
canvas.restore();
}
fStartAngle = fStartAngle + fEndAngle;
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// get screen size
iDisplayWidth = MeasureSpec.getSize(widthMeasureSpec);
iDisplayHeight = MeasureSpec.getSize(heightMeasureSpec);
if (iDisplayWidth > iDisplayHeight) {
iDisplayWidth = iDisplayHeight;
}
/*
* determine the rectangle size
*/
iCenterWidth = iDisplayWidth / 2;
int iR = iCenterWidth - iMargin;
if (r == null) {
r = new RectF(iCenterWidth - iR, // top
iCenterWidth - iR, // left
iCenterWidth + iR, // right
iCenterWidth + iR); // bottom
}
if (centerCircle == null) {
// centerCircle=new RectF(left, top, right, bottom);
}
setMeasuredDimension(iDisplayWidth, iDisplayWidth);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// get degree of the touch point
double dx = Math.atan2(event.getY() - iCenterWidth, event.getX()
- iCenterWidth);
float fDegree = (float) (dx / (2 * Math.PI) * DEGREE_360);
fDegree = (fDegree + DEGREE_360) % DEGREE_360;
// get the percent of the selected degree
float fSelectedPercent = fDegree * 100 / DEGREE_360;
// check which pie was selected
float fTotalPercent = 0;
for (int i = 0; i < iDataSize; i++) {
fTotalPercent += alPercentage.get(i);
if (fTotalPercent > fSelectedPercent) {
iSelectedIndex = i;
break;
}
}
if (onSelectedListener != null) {
onSelectedListener.onSelected(iSelectedIndex);
}
invalidate();
return super.onTouchEvent(event);
}
private void fnGetDisplayMetrics(Context cxt) {
final DisplayMetrics dm = cxt.getResources().getDisplayMetrics();
fDensity = dm.density;
}
private float fnGetRealPxFromDp(float fDp) {
return (fDensity != 1.0f) ? fDensity * fDp : fDp;
}
public void setAdapter(ArrayList<Float> alPercentage) throws Exception {
this.alPercentage = alPercentage;
iDataSize = alPercentage.size();
float fSum = 0;
for (int i = 0; i < iDataSize; i++) {
fSum += alPercentage.get(i);
}
if (fSum != 100) {
Log.e(TAG, ERROR_NOT_EQUAL_TO_100);
iDataSize = 0;
throw new Exception(ERROR_NOT_EQUAL_TO_100);
}
}
<com.example.piecharts.PieChart
android:id="#+id/pieChart"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</com.example.piecharts.PieChart>

Android OpenGL ES Issue only with a specific GPU without any Error in LogCat

I have accurately tested my app before release it, on Emulator set with different screen size (and with different Android SDK and CPU emulations), and many real devices. No problems, everything works fine. Now an user has reported a bug with his tablet.
I'm testing the app on tons of devices and the issue happens only if the devices use some kind of soc ARM with PowerVR SGX544 and Android 4.x.
The app doesn't use any texture, only GL11, GL10 and GLView to plot some graph, and runs smooth also on old cheap smartphones with at least Gingerbread... but with this Power VR the result of the plot is an unreadable and laggy graphic glitch
No error in the Eclipse logs,
No crash or code deprecation warning
Must I assume that the bug is in the GPU driver?
The code of the section with the bug (I cannot be more syntetic because I get no error)
public class My3dView extends GLView implements
Grapher,
TouchHandler.TouchHandlerInterface
{
private float lastTouchX, lastTouchY;
private TouchHandler touchHandler;
private float zoomLevel = 1, targetZoom, zoomStep = 0, currentZoom;
private FPS fps = new FPS();
private Graph3d graph;
public My3dView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public My3dView(Context context) {
super(context);
touchHandler = new TouchHandler(this);
init();
}
private void init() {
startLooping();
zoomController.setOnZoomListener(this);
Matrix.setIdentityM(matrix1, 0);
Matrix.rotateM(matrix1, 0, -75, 1, 0, 0);
}
public void onVisibilityChanged(boolean visible) {
}
#Override
protected void glDraw() {
if ((zoomStep < 0 && zoomLevel > targetZoom) ||
(zoomStep > 0 && zoomLevel < targetZoom)) {
zoomLevel += zoomStep;
} else if (zoomStep != 0) {
zoomStep = 0;
zoomLevel = targetZoom;
isDirty = true;
if (!shouldRotate()) {
stopLooping();
}
}
super.glDraw();
}
#Override
public void onDetachedFromWindow() {
zoomController.setVisible(false);
super.onDetachedFromWindow();
}
public void onTouchDown(float x, float y) {
zoomController.setVisible(true);
stopLooping();
lastTouchX = x;
lastTouchY = y;
}
public void onTouchMove(float x, float y) {
float deltaX = x - lastTouchX;
float deltaY = y - lastTouchY;
if (deltaX > 1 || deltaX < -1 || deltaY > 1 || deltaY < -1) {
setRotation(deltaX, deltaY);
glDraw();
lastTouchX = x;
lastTouchY = y;
}
}
public void onTouchUp(float x, float y) {
float vx = touchHandler.velocityTracker.getXVelocity();
float vy = touchHandler.velocityTracker.getYVelocity();
setRotation(vx/100, vy/100);
if (shouldRotate()) {
startLooping();
}
}
public void onTouchZoomDown(float x1, float y1, float x2, float y2) {
}
public void onTouchZoomMove(float x1, float y1, float x2, float y2) {
}
#Override
public boolean onTouchEvent(MotionEvent event) {
return touchHandler != null ? touchHandler.onTouchEvent(event) : super.onTouchEvent(event);
}
private float[] matrix1 = new float[16], matrix2 = new float[16], matrix3 = new float[16];
private float angleX, angleY;
private boolean isDirty;
private Function function;
private static final float DISTANCE = 15f;
void setRotation(float x, float y) {
angleX = x;
angleY = y;
}
boolean shouldRotate() {
final float limit = .5f;
return angleX < -limit || angleX > limit || angleY < -limit || angleY > limit;
}
public void setFunction(Function f) {
function = f;
zoomLevel = 1;
isDirty = true;
}
#Override
public void onSurfaceCreated(GL10 gl, int width, int height) {
gl.glDisable(GL10.GL_DITHER);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
gl.glClearColor(0, 0, 0, 1);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glDisable(GL10.GL_LIGHTING);
graph = new Graph3d((GL11) gl);
isDirty = true;
angleX = .5f;
angleY = 0;
gl.glViewport(0, 0, width, height);
initFrustum(gl, DISTANCE * zoomLevel);
currentZoom = zoomLevel;
}
#Override
public void onDrawFrame(GL10 gl10) {
GL11 gl = (GL11) gl10;
if (currentZoom != zoomLevel) {
initFrustum(gl, DISTANCE * zoomLevel);
currentZoom = zoomLevel;
}
if (isDirty) {
graph.update(gl, function, zoomLevel);
isDirty = false;
}
gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0, 0, -DISTANCE*zoomLevel);
Matrix.setIdentityM(matrix2, 0);
float ax = Math.abs(angleX);
float ay = Math.abs(angleY);
if (ay * 3 < ax) {
Matrix.rotateM(matrix2, 0, angleX, 0, 1, 0);
} else if (ax * 3 < ay) {
Matrix.rotateM(matrix2, 0, angleY, 1, 0, 0);
} else {
if (ax > ay) {
Matrix.rotateM(matrix2, 0, angleX, 0, 1, 0);
Matrix.rotateM(matrix2, 0, angleY, 1, 0, 0);
} else {
Matrix.rotateM(matrix2, 0, angleY, 1, 0, 0);
Matrix.rotateM(matrix2, 0, angleX, 0, 1, 0);
}
}
Matrix.multiplyMM(matrix3, 0, matrix2, 0, matrix1, 0);
gl.glMultMatrixf(matrix3, 0);
System.arraycopy(matrix3, 0, matrix1, 0, 16);
graph.draw(gl);
}
private void initFrustum(GL10 gl, float distance) {
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
float near = distance * (1/3f);
float far = distance * 3f;
float dimen = near/5f;
float h = dimen * height / width;
gl.glFrustumf(-dimen, dimen, -h, h, near, far);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
}
}
The code where I setup FloatBuffers :
class Graph3d {
private final int N = 48;
private ShortBuffer verticeIdx;
private FloatBuffer vertexBuf;
private ByteBuffer colorBuf;
private int vertexVbo, colorVbo, vertexElementVbo;
private boolean useVBO;
private int nVertex;
Graph3d(GL11 gl) {
short[] b = new short[N*N];
int p = 0;
for (int i = 0; i < N; i++) {
short v = 0;
for (int j = 0; j < N; v += N+N, j+=2) {
b[p++] = (short)(v+i);
b[p++] = (short)(v+N+N-1-i);
}
v = (short) (N*(N-2));
i++;
for (int j = N-1; j >= 0; v -= N+N, j-=2) {
b[p++] = (short)(v+N+N-1-i);
b[p++] = (short)(v+i);
}
}
verticeIdx = buildBuffer(b);
String extensions = gl.glGetString(GL10.GL_EXTENSIONS);
useVBO = extensions.indexOf("vertex_buffer_object") != -1;
Calculator.log("VBOs support: " + useVBO + " version " + gl.glGetString(GL10.GL_VERSION));
if (useVBO) {
int[] out = new int[3];
gl.glGenBuffers(3, out, 0);
vertexVbo = out[0];
colorVbo = out[1];
vertexElementVbo = out[2];
}
}
private static FloatBuffer buildBuffer(float[] b) {
ByteBuffer bb = ByteBuffer.allocateDirect(b.length << 2);
bb.order(ByteOrder.nativeOrder());
FloatBuffer sb = bb.asFloatBuffer();
sb.put(b);
sb.position(0);
return sb;
}
private static ShortBuffer buildBuffer(short[] b) {
ByteBuffer bb = ByteBuffer.allocateDirect(b.length << 1);
bb.order(ByteOrder.nativeOrder());
ShortBuffer sb = bb.asShortBuffer();
sb.put(b);
sb.position(0);
return sb;
}
private static ByteBuffer buildBuffer(byte[] b) {
ByteBuffer bb = ByteBuffer.allocateDirect(b.length << 1);
bb.order(ByteOrder.nativeOrder());
bb.put(b);
bb.position(0);
return bb;
}
public void update(GL11 gl, Function f, float zoom) {
final int NTICK = Calculator.useHighQuality3d ? 5 : 0;
final float size = 4*zoom;
final float minX = -size, maxX = size, minY = -size, maxY = size;
Calculator.log("update VBOs " + vertexVbo + ' ' + colorVbo + ' ' + vertexElementVbo);
nVertex = N*N+6+8 + NTICK*6;
int nFloats = nVertex * 3;
float vertices[] = new float[nFloats];
byte colors[] = new byte[nVertex << 2];
if (f != null) {
Calculator.log("Graph3d update");
float sizeX = maxX - minX;
float sizeY = maxY - minY;
float stepX = sizeX / (N-1);
float stepY = sizeY / (N-1);
int pos = 0;
double sum = 0;
float y = minY;
float x = minX - stepX;
int nRealPoints = 0;
for (int i = 0; i < N; i++, y+=stepY) {
float xinc = (i & 1) == 0 ? stepX : -stepX;
x += xinc;
for (int j = 0; j < N; ++j, x+=xinc, pos+=3) {
float z = (float) f.eval(x, y);
vertices[pos] = x;
vertices[pos+1] = y;
vertices[pos+2] = z;
if (z == z) { // not NAN
sum += z * z;
++nRealPoints;
}
}
}
float maxAbs = (float) Math.sqrt(sum / nRealPoints);
maxAbs *= .9f;
maxAbs = Math.min(maxAbs, 15);
maxAbs = Math.max(maxAbs, .001f);
final int limitColor = N*N*4;
for (int i = 0, j = 2; i < limitColor; i+=4, j+=3) {
float z = vertices[j];
if (z == z) {
final float a = z / maxAbs;
final float abs = a < 0 ? -a : a;
colors[i] = floatToByte(a);
colors[i+1] = floatToByte(1-abs*.3f);
colors[i+2] = floatToByte(-a);
colors[i+3] = (byte) 255;
} else {
vertices[j] = 0;
z = 0;
colors[i] = 0;
colors[i+1] = 0;
colors[i+2] = 0;
colors[i+3] = 0;
}
}
}
int base = N*N*3;
int colorBase = N*N*4;
int p = base;
final int baseSize = 2;
for (int i = -baseSize; i <= baseSize; i+=2*baseSize) {
vertices[p] = i; vertices[p+1] = -baseSize; vertices[p+2] = 0;
p += 3;
vertices[p] = i; vertices[p+1] = baseSize; vertices[p+2] = 0;
p += 3;
vertices[p] = -baseSize; vertices[p+1] = i; vertices[p+2] = 0;
p += 3;
vertices[p] = baseSize; vertices[p+1] = i; vertices[p+2] = 0;
p += 3;
}
for (int i = colorBase; i < colorBase+8*4; i += 4) {
colors[i] = 0;
colors[i+1] = 0;
colors[i+2] = (byte) 255;
colors[i+3] = (byte) 255;
}
base += 8*3;
colorBase += 8*4;
final float unit = 2;
final float axis[] = {
0, 0, 0,
unit, 0, 0,
0, 0, 0,
0, unit, 0,
0, 0, 0,
0, 0, unit,
};
System.arraycopy(axis, 0, vertices, base, 6*3);
for (int i = colorBase; i < colorBase+6*4; i+=4) {
colors[i] = (byte) 255;
colors[i+1] = (byte) 255;
colors[i+2] = (byte) 255;
colors[i+3] = (byte) 255;
}
base += 6*3;
colorBase += 6*4;
p = base;
final float tick = .03f;
final float offset = .01f;
for (int i = 1; i <= NTICK; ++i) {
vertices[p] = i-tick;
vertices[p+1] = -offset;
vertices[p+2] = -offset;
vertices[p+3] = i+tick;
vertices[p+4] = offset;
vertices[p+5] = offset;
p += 6;
vertices[p] = -offset;
vertices[p+1] = i-tick;
vertices[p+2] = -offset;
vertices[p+3] = offset;
vertices[p+4] = i+tick;
vertices[p+5] = offset;
p += 6;
vertices[p] = -offset;
vertices[p+1] = -offset;
vertices[p+2] = i-tick;
vertices[p+3] = offset;
vertices[p+4] = offset;
vertices[p+5] = i+tick;
p += 6;
}
for (int i = colorBase+NTICK*6*4-1; i >= colorBase; --i) {
colors[i] = (byte) 255;
}
vertexBuf = buildBuffer(vertices);
colorBuf = buildBuffer(colors);
if (useVBO) {
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, vertexVbo);
gl.glBufferData(GL11.GL_ARRAY_BUFFER, vertexBuf.capacity()*4, vertexBuf, GL11.GL_STATIC_DRAW);
vertexBuf = null;
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, colorVbo);
gl.glBufferData(GL11.GL_ARRAY_BUFFER, colorBuf.capacity(), colorBuf, GL11.GL_STATIC_DRAW);
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
colorBuf = null;
gl.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, vertexElementVbo);
gl.glBufferData(GL11.GL_ELEMENT_ARRAY_BUFFER, verticeIdx.capacity()*2, verticeIdx, GL11.GL_STATIC_DRAW);
gl.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, 0);
}
}
private byte floatToByte(float v) {
return (byte) (v <= 0 ? 0 : v >= 1 ? 255 : (int)(v*255));
}
public void draw(GL11 gl) {
if (useVBO) {
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, vertexVbo);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, 0);
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, colorVbo);
gl.glColorPointer(4, GL10.GL_UNSIGNED_BYTE, 0, 0);
gl.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
// gl.glDrawArrays(GL10.GL_LINE_STRIP, 0, N*N);
gl.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, vertexElementVbo);
gl.glDrawElements(GL10.GL_LINE_STRIP, N*N, GL10.GL_UNSIGNED_SHORT, 0);
gl.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, 0);
} else {
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuf);
gl.glColorPointer(4, GL10.GL_UNSIGNED_BYTE, 0, colorBuf);
gl.glDrawElements(GL10.GL_LINE_STRIP, N*N, GL10.GL_UNSIGNED_SHORT, verticeIdx);
}
final int N2 = N*N;
gl.glDrawArrays(GL10.GL_LINE_STRIP, 0, N2);
gl.glDrawArrays(GL10.GL_LINES, N2, nVertex - N2);
}
}

Android draw bitmap on top of pie chart

Hi I'm trying to draw a pie chart and center a bitmap in each pie slice but I just can't figure the math out. Below is my code which most I found from a tutorial but the stuff in the onDraw method under the TODO is what I'm trying to add so I can draw my icon over the pie slice. Any help as to why it's not working would be greatly appreciated
public class PieChart extends View {
public interface OnSelectedLisenter{
public abstract void onSelected(int iSelectedIndex);
}
private static String[] PIE_COLORS = null;
private static int iColorListSize = 0;
private OnSelectedLisenter onSelectedListener = null;
private static final String TAG = PieChart.class.getName();
public static final String ERROR_NOT_EQUAL_TO_100 = "NOT_EQUAL_TO_100";
private static final int DEGREE_360 = 360;
private Paint paintPieFill;
private Paint paintPieBorder;
private ArrayList<Float> alPercentage = new ArrayList<Float>();
private int iDisplayWidth, iDisplayHeight;
private int iSelectedIndex = -1;
private int iCenterWidth = 0;
private int iMargin = 0;
private int iDataSize = 0;
private RectF r = null;
private float fDensity = 0.0f;
private float fStartAngle = 0.0f;
private float fEndAngle = 0.0f;
public PieChart(Context context, AttributeSet attrs) {
super(context, attrs);
fnGetDisplayMetrics(context);
PIE_COLORS = getResources().getStringArray(R.array.colors);
iColorListSize = PIE_COLORS.length;
iMargin = (int) fnGetRealPxFromDp(5);
// used for paint circle
paintPieFill = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieFill.setStyle(Paint.Style.FILL);
// used for paint border
paintPieBorder = new Paint(Paint.ANTI_ALIAS_FLAG);
paintPieBorder.setStyle(Paint.Style.STROKE);
paintPieBorder.setStrokeWidth(fnGetRealPxFromDp(3));
paintPieBorder.setColor(Color.WHITE);
}
// set listener
public void setOnSelectedListener(OnSelectedLisenter listener){
this.onSelectedListener = listener;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int i = 0; i < iDataSize; i++) {
if (i>=iColorListSize){
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i%iColorListSize]));
}else{
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i]));
}
fEndAngle = alPercentage.get(i);
fEndAngle = fEndAngle / 100 * DEGREE_360;
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieFill);
//TODO add icon to center of pie slice
float x = (float) ((r.right /4)*Math.cos(Math.toRadians(fStartAngle)));
float y = (float) ((r.right /4)*Math.sin(Math.toRadians(fStartAngle)));
x += getWidth()/2;
y += getHeight()/2;
canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher), x, y, paintPieFill);
fStartAngle = fStartAngle + fEndAngle;
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
iDisplayWidth = MeasureSpec.getSize(widthMeasureSpec);
iDisplayHeight = MeasureSpec.getSize(heightMeasureSpec);
if (iDisplayWidth>iDisplayHeight){
iDisplayWidth = iDisplayHeight;
}
iCenterWidth = iDisplayWidth / 2;
int iR = iCenterWidth-iMargin;
if (r == null) {
r = new RectF(iCenterWidth-iR, // top
iCenterWidth-iR, // left
iCenterWidth+iR, // rights
iCenterWidth+iR); // bottom
}
setMeasuredDimension(iDisplayWidth, iDisplayWidth);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
// get degree of the touch point
double dx = Math.atan2(event.getY() - iCenterWidth, event.getX() - iCenterWidth);
float fDegree = (float) (dx / (2 * Math.PI) * DEGREE_360);
fDegree = (fDegree + DEGREE_360) % DEGREE_360;
// get the percent of the selected degree
float fSelectedPercent = fDegree * 100 / DEGREE_360;
// check which pie was selected
float fTotalPercent = 0;
for (int i = 0; i < iDataSize; i++) {
fTotalPercent += alPercentage.get(i);
if (fTotalPercent > fSelectedPercent) {
iSelectedIndex = i;
break;
}
}
if (onSelectedListener != null){
onSelectedListener.onSelected(iSelectedIndex);
}
invalidate();
return super.onTouchEvent(event);
}
private void fnGetDisplayMetrics(Context cxt){
final DisplayMetrics dm = cxt.getResources().getDisplayMetrics();
fDensity = dm.density;
}
private float fnGetRealPxFromDp(float fDp){
return (fDensity!=1.0f) ? fDensity*fDp : fDp;
}
public void setAdapter(ArrayList<Float> alPercentage) throws Exception {
this.alPercentage = alPercentage;
iDataSize = alPercentage.size();
float fSum = 0;
for (int i = 0; i < iDataSize; i++) {
fSum+=alPercentage.get(i);
}
if (fSum!=100){
Log.e(TAG,ERROR_NOT_EQUAL_TO_100);
iDataSize = 0;
throw new Exception(ERROR_NOT_EQUAL_TO_100);
}
}
}

Well I figured it out here is my final onDraw method hopefully this helps someone else
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int i = 0; i < iDataSize; i++) {
if (i>=iColorListSize){
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i%iColorListSize]));
}else{
paintPieFill.setColor(Color.parseColor(PIE_COLORS[i]));
}
fEndAngle = alPercentage.get(i);
fEndAngle = fEndAngle / 100 * DEGREE_360;
canvas.drawArc(r, fStartAngle, fEndAngle, true, paintPieFill);
float angle = (fStartAngle + (fStartAngle+fEndAngle))/2;
float x = (float) ((r.right /4)*Math.cos(Math.toRadians(angle)));
float y = (float) ((r.right /4)*Math.sin(Math.toRadians(angle)));
x += r.right/2;
y += r.right/2;
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
x -= bmp.getWidth()/2;
y -= bmp.getHeight()/2;
canvas.drawBitmap(bmp, x, y, paintPieFill);
fStartAngle = fStartAngle + fEndAngle;
}
}

pixelate image in code

I've searched for how to pixelate an image in android via code, the results are varied.
I've found libraries and tutorials on how to apply other effects found here: http://xjaphx.wordpress.com/learning/tutorials/
Can someone clear things up for me, what is the simplest way of pixelating an image on the fly in android
Also it would be handy if it was a function that I could how many rounds or how much I wanted the image pixelating.
Thank in advance.

The simplest way to pixelate the image would be to scale image down using "nearest neighbour" algorithm, and then scale up, using the same algorithm.
Filtering over the image trying to find an average takes much more time, but does not actually give any improvements in result quality, after all you do intentionally want your image distorted.

I have done this before in vb.net and its easily made into a function whose parameter can control how pixelated you want it.
The basic idea is to scan the image in section of blocks of X width and y height. for each block you find the average RGB value and set all those pixels to that color. the smaller the block size the less pixelated.
int avR,avB,avG; // store average of rgb
int pixel;
Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y++ pixelationamount) {
avR = 0; avG = 0; avB =0;
for(int xx =x; xx <pixelationAmount;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <pixelationAmount;yy++){ // this is scanning the colors
pixel = src.getPixel(x, y);
avR += (int) (color.red(pixel);
avG+= (int) (color.green(pixel);
avB += (int) (color.blue(pixel);
}
}
avrR/= pixelationAmount^2; //divide all by the amount of samples taken to get an average
avrG/= pixelationAmount^2;
avrB/= pixelationAmount^2;
for(int xx =x; xx <pixelationAmount;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <pixelationAmount;yy++){ // this is going back over the block
bmOut.setPixel(xx, yy, Color.argb(255, avR, avG,avB)); //sets the block to the average color
}
}
}
}
sorry about the bad formatting (wrote it in notepad quickly) but thought it might give you a framework to make your own pixelate function

This is corrected of above algorithm that works:
Bitmap bmOut = Bitmap.createBitmap(OriginalBitmap.getWidth(),OriginalBitmap.getHeight(),OriginalBitmap.getConfig());
int pixelationAmount = 50; //you can change it!!
int width = OriginalBitmap.getWidth();
int height = OriginalBitmap.getHeight();
int avR,avB,avG; // store average of rgb
int pixel;
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y+= pixelationAmount) {
avR = 0; avG = 0; avB =0;
int bx = x + pixelationAmount;
int by = y + pixelationAmount;
if(by >= height) by = height;
if(bx >= width)bx = width;
for(int xx =x; xx < bx;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy < by;yy++){ // this is scanning the colors
pixel = OriginalBitmap.getPixel(xx, yy);
avR += (int) (Color.red(pixel));
avG+= (int) (Color.green(pixel));
avB += (int) (Color.blue(pixel));
}
}
avR/= pixelationAmount^2; //divide all by the amount of samples taken to get an average
avG/= pixelationAmount^2;
avB/= pixelationAmount^2;
for(int xx =x; xx < bx;xx++)// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
for(int yy= y; yy <by;yy++){ // this is going back over the block
bmOut.setPixel(xx, yy, Color.argb(255, avR, avG,avB)); //sets the block to the average color
}
}
}
iv.setImageBitmap(bmOut);
anyway it was not what i was looking for

I have change previous algorithm completely and it really done something like mosaic filter!
the idea is to replace each block pixels with its below block pixels
use this function simply:
public void filter(){
Bitmap bmOut = Bitmap.createBitmap(OriginalBitmap.getWidth(),OriginalBitmap.getHeight(),OriginalBitmap.getConfig());
int pixelationAmount = 10;
Bitmap a = Bitmap.createBitmap(pixelationAmount,pixelationAmount,OriginalBitmap.getConfig());
Bitmap b = Bitmap.createBitmap(pixelationAmount,pixelationAmount,OriginalBitmap.getConfig());
int width = OriginalBitmap.getWidth();
int height = OriginalBitmap.getHeight();
int pixel;
int counter = 1;
int px = 0;int py = 0;int pbx=0;int pby=0;
for(int x = 0; x < width; x+= pixelationAmount) { // do the whole image
for(int y = 0; y < height; y+= pixelationAmount) {
int bx = x + pixelationAmount;
int by = y + pixelationAmount;
if(by >= height) by = height;
if(bx >= width)bx = width;
int xxx = -1;
int yyy = -1;
for(int xx =x; xx < bx;xx++){// YOU WILL WANT TO PUYT SOME OUT OF BOUNDS CHECKING HERE
xxx++;
yyy = -1;
for(int yy= y; yy < by;yy++){ // this is scanning the colors
yyy++;
pixel = OriginalBitmap.getPixel(xx, yy);
if(counter == 1)
{
a.setPixel(xxx, yyy, pixel);
px = x;//previous x
py = y;//previous y
pbx = bx;
pby = by;
}
else
b.setPixel(xxx, yyy, pixel);
}
}
counter++;
if(counter == 3)
{
int xxxx = -1;
int yyyy = -1;
for(int xx =x; xx < bx;xx++)
{
xxxx++;
yyyy = -1;
for(int yy= y; yy <by;yy++){
yyyy++;
bmOut.setPixel(xx, yy, b.getPixel(xxxx, yyyy));
}
}
for(int xx =px; xx < pbx;xx++)
{
for(int yy= py; yy <pby;yy++){
bmOut.setPixel(xx, yy, a.getPixel(xxxx, yyyy)); //sets the block to the average color
}
}
counter = 1;
}
}
}
image_view.setImageBitmap(bmOut);
}

This is the code I used:
ImageFilter is the parent class:
public abstract class ImageFilter {
protected int [] pixels;
protected int width;
protected int height;
public ImageFilter (int [] _pixels, int _width,int _height){
setPixels(_pixels,_width,_height);
}
public void setPixels(int [] _pixels, int _width,int _height){
pixels = _pixels;
width = _width;
height = _height;
}
/**
* a weighted Euclidean distance in RGB space
* #param c1
* #param c2
* #return
*/
public double colorDistance(int c1, int c2)
{
int red1 = Color.red(c1);
int red2 = Color.red(c2);
int rmean = (red1 + red2) >> 1;
int r = red1 - red2;
int g = Color.green(c1) - Color.green(c2);
int b = Color.blue(c1) - Color.blue(c2);
return Math.sqrt((((512+rmean)*r*r)>>8) + 4*g*g + (((767-rmean)*b*b)>>8));
}
public abstract int[] procImage();
}
public class PixelateFilter extends ImageFilter {
int pixelSize;
int[] colors;
/**
* #param _pixels
* #param _width
* #param _height
*/
public PixelateFilter(int[] _pixels, int _width, int _height) {
this(_pixels, _width, _height, 10);
}
public PixelateFilter(int[] _pixels, int _width, int _height, int _pixelSize) {
this(_pixels, _width, _height, _pixelSize, null);
}
public PixelateFilter(int[] _pixels, int _width, int _height, int _pixelSize, int[] _colors) {
super(_pixels, _width, _height);
pixelSize = _pixelSize;
colors = _colors;
}
/* (non-Javadoc)
* #see imageProcessing.ImageFilter#procImage()
*/
#Override
public int[] procImage() {
for (int i = 0; i < width; i += pixelSize) {
for (int j = 0; j < height; j += pixelSize) {
int rectColor = getRectColor(i, j);
fillRectColor(rectColor, i, j);
}
}
return pixels;
}
private int getRectColor(int col, int row) {
int r = 0, g = 0, b = 0;
int sum = 0;
for (int x = col; x < col + pixelSize; x++) {
for (int y = row; y < row + pixelSize; y++) {
int index = x + y * width;
if (index < width * height) {
int color = pixels[x + y * width];
r += Color.red(color);
g += Color.green(color);
b += Color.blue(color);
}
}
}
sum = pixelSize * pixelSize;
int newColor = Color.rgb(r / sum, g / sum, b / sum);
if (colors != null)
newColor = getBestMatch(newColor);
return newColor;
}
private int getBestMatch(int color) {
double diff = Double.MAX_VALUE;
int res = color;
for (int c : colors) {
double currDiff = colorDistance(color, c);
if (currDiff < diff) {
diff = currDiff;
res = c;
}
}
return res;
}
private void fillRectColor(int color, int col, int row) {
for (int x = col; x < col + pixelSize; x++) {
for (int y = row; y < row + pixelSize; y++) {
int index = x + y * width;
if (x < width && y < height && index < width * height) {
pixels[x + y * width] = color;
}
}
}
}
public static final Bitmap changeToPixelate(Bitmap bitmap, int pixelSize, int [] colors) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int[] pixels = new int[width * height];
bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
PixelateFilter pixelateFilter = new PixelateFilter(pixels, width, height, pixelSize, colors);
int[] returnPixels = pixelateFilter.procImage();
Bitmap returnBitmap = Bitmap.createBitmap(returnPixels, width, height, Bitmap.Config.ARGB_8888);
return returnBitmap;
}
}
Here is how you use it:
int [] colors = new int [] { Color.BLACK,Color.WHITE,Color.BLUE,Color.CYAN,Color.RED};
final Bitmap bmOut = PixelateFilter.changeToPixelate(OriginalBitmap, pixelSize,colors);

Develop Reference

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pixelate image in code

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