Develop Reference

How to download an offline map for a particular country

I am developing an Android app. And I want a particular area map which I can add in my app and use it for offline navigation. How can it be possible?
I didn’t get a solution. I’m using the below link, but it doesn’t work.
I display a satellite map. I have put tiles files in the asset folder, but it does not work for me.
public class CustomMapTileProvider implements TileProvider {
private static final int TILE_WIDTH = 256;
private static final int TILE_HEIGHT = 256;
private static final int BUFFER_SIZE = 16 * 1024;
private AssetManager mAssets;
public CustomMapTileProvider(AssetManager assets) {
mAssets = assets;
}
private static final SparseArray<Rect> TILE_ZOOMS = new SparseArray<Rect>() {{
put(8, new Rect(135, 180, 135, 181 ));
put(9, new Rect(270, 361, 271, 363 ));
put(10, new Rect(541, 723, 543, 726 ));
put(11, new Rect(1082, 1447, 1086, 1452));
put(12, new Rect(2165, 2894, 2172, 2905));
put(13, new Rect(4330, 5789, 4345, 5810));
put(14, new Rect(8661, 11578, 8691, 11621));
}};
private boolean hasTile(int x, int y, int zoom) {
Rect b = TILE_ZOOMS.get(zoom);
return b == null ? false : (b.left <= x && x <= b.right && b.top <= y && y <= b.bottom);
}
#Override
public Tile getTile(int x, int y, int zoom) {
y = fixYCoordinate(y, zoom);
if (hasTile(x, y, zoom)) {
byte[] image = readTileImage(x, y, zoom);
return image == null ? null : new Tile(TILE_WIDTH, TILE_HEIGHT, image);
}
else {
return NO_TILE;
}
}
private int fixYCoordinate(int y, int zoom) {
int size = 1 << zoom; // size = 2^zoom
return size - 1 - y;
}
private byte[] readTileImage(int x, int y, int zoom) {
InputStream in = null;
ByteArrayOutputStream buffer = null;
try {
in = mAssets.open(getTileFilename(x, y, zoom));
//in = mAssets.open("world_countries.mbtiles");
buffer = new ByteArrayOutputStream();
int nRead;
byte[] data = new byte[BUFFER_SIZE];
while ((nRead = in.read(data, 0, BUFFER_SIZE)) != -1) {
buffer.write(data, 0, nRead);
}
buffer.flush();
return buffer.toByteArray();
}
catch (IOException e) {
e.printStackTrace();
return null;
}
catch (OutOfMemoryError e) {
e.printStackTrace();
return null;
}
finally {
if (in != null)
try {
in.close();
}
catch (Exception ignored) {
}
if (buffer != null)
try {
buffer.close();
}
catch (Exception ignored) {
}
}
}
private String getTileFilename(int x, int y, int zoom) {
return "map/" + zoom + '/' + x + '/' + y + ".png";
}
}

How to close a response body when Tile not exists?

I put tiles on top of the map. There are areas where there are no tiles and I get a leak W/OkHttpClient: A connection to http://*****.***/ was leaked. Did you forget to close a response body? . How to fix this error? I know about this solution, but I do not know the exact boundaries, so this method does not fit.
My code:
TileProvider tileProvider = new UrlTileProvider(256, 256) {
#Override
public URL getTileUrl(int x, int y, int zoom) {
String s = String.format("http://****.***/tiles/%d/%d/%d.png", zoom, x, y);
if (!checkTileExists(x, y, zoom)) {
return null;
}
try {
return new URL(s);
} catch (MalformedURLException e) {
throw new AssertionError(e);
}
}
private boolean checkTileExists(int x, int y, int zoom) {
int minZoom = 7;
int maxZoom = 17;
if ((zoom < minZoom || zoom > maxZoom)) {
return false;
}
return true;
}
};
tileOverlay = mMap.addTileOverlay(new TileOverlayOptions().tileProvider(tileProvider));

Take picture with drawable/paint on face using vision api

What I am trying?
I am trying to take picture with drawable/paint on face but, i am not able to get both on same picture.
What I have tried?
I have tried using CameraSource.takePicture but i am just getting face without any drawable/paint on it.
mCameraSource.takePicture(shutterCallback, new CameraSource.PictureCallback() {
#Override
public void onPictureTaken(byte[] bytes) {
try {
String mainpath = getExternalStorageDirectory() + separator + "TestXyz" + separator + "images" + separator;
File basePath = new File(mainpath);
if (!basePath.exists())
Log.d("CAPTURE_BASE_PATH", basePath.mkdirs() ? "Success": "Failed");
String path = mainpath + "photo_" + getPhotoTime() + ".jpg";
File captureFile = new File(path);
captureFile.createNewFile();
if (!captureFile.exists())
Log.d("CAPTURE_FILE_PATH", captureFile.createNewFile() ? "Success": "Failed");
FileOutputStream stream = new FileOutputStream(captureFile);
stream.write(bytes);
stream.flush();
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
I also tried using :
mPreview.setDrawingCacheEnabled(true);
Bitmap drawingCache = mPreview.getDrawingCache();
try {
String mainpath = getExternalStorageDirectory() + separator + "TestXyz" + separator + "images" + separator;
File basePath = new File(mainpath);
if (!basePath.exists())
Log.d("CAPTURE_BASE_PATH", basePath.mkdirs() ? "Success": "Failed");
String path = mainpath + "photo_" + getPhotoTime() + ".jpg";
File captureFile = new File(path);
captureFile.createNewFile();
if (!captureFile.exists())
Log.d("CAPTURE_FILE_PATH", captureFile.createNewFile() ? "Success": "Failed");
FileOutputStream stream = new FileOutputStream(captureFile);
drawingCache.compress(Bitmap.CompressFormat.PNG, 100, stream);
stream.flush();
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
in this case i am only getting what i draw on face. Here, mPreview is the CameraSourcePreview.
Just added capture button and added above code in this google example.

You are very close to achieve what you need :)
You have:
An image from the Camera of the face (First code snippet)
An image from the Canvas of the eyes overlay (Second code snippet)
What you need:
An image that has the face with the eyes overlay on top - A merged image.
How to merge?
To merge 2 images simply use a canvas, like so:
public Bitmap mergeBitmaps(Bitmap face, Bitmap overlay) {
// Create a new image with target size
int width = face.getWidth();
int height = face.getHeight();
Bitmap newBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Rect faceRect = new Rect(0,0,width,height);
Rect overlayRect = new Rect(0,0,overlay.getWidth(),overlay.getHeight());
// Draw face and then overlay (Make sure rects are as needed)
Canvas canvas = new Canvas(newBitmap);
canvas.drawBitmap(face, faceRect, faceRect, null);
canvas.drawBitmap(overlay, overlayRect, faceRect, null);
return newBitmap
}
Then you can save the new image, as you are doing now.
Full code would look like:
mCameraSource.takePicture(shutterCallback, new
CameraSource.PictureCallback() {
#Override
public void onPictureTaken(byte[] bytes) {
// Generate the Face Bitmap
BitmapFactory.Options options = new BitmapFactory.Options();
Bitmap face = BitmapFactory.decodeByteArray(bytes, 0, bytes.length, options);
// Generate the Eyes Overlay Bitmap
mPreview.setDrawingCacheEnabled(true);
Bitmap overlay = mPreview.getDrawingCache();
// Generate the final merged image
Bitmap result = mergeBitmaps(face, overlay);
// Save result image to file
try {
String mainpath = getExternalStorageDirectory() + separator + "TestXyz" + separator + "images" + separator;
File basePath = new File(mainpath);
if (!basePath.exists())
Log.d("CAPTURE_BASE_PATH", basePath.mkdirs() ? "Success": "Failed");
String path = mainpath + "photo_" + getPhotoTime() + ".jpg";
File captureFile = new File(path);
captureFile.createNewFile();
if (!captureFile.exists())
Log.d("CAPTURE_FILE_PATH", captureFile.createNewFile() ? "Success": "Failed");
FileOutputStream stream = new FileOutputStream(captureFile);
result.compress(Bitmap.CompressFormat.PNG, 100, stream);
stream.flush();
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
Note that the above is just an example code.
You should probably move the merging and saving to a file to a background thread.

I am able to capture image with drawable/paint on it by below solution :
private void captureImage() {
mPreview.setDrawingCacheEnabled(true);
Bitmap drawingCache = mPreview.getDrawingCache();
mCameraSource.takePicture(shutterCallback, new CameraSource.PictureCallback() {
#Override
public void onPictureTaken(byte[] bytes) {
int orientation = Exif.getOrientation(bytes);
Bitmap temp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
Bitmap picture = rotateImage(temp,orientation);
Bitmap overlay = Bitmap.createBitmap(mGraphicOverlay.getWidth(),mGraphicOverlay.getHeight(),picture.getConfig());
Canvas canvas = new Canvas(overlay);
Matrix matrix = new Matrix();
matrix.setScale((float)overlay.getWidth()/(float)picture.getWidth(),(float)overlay.getHeight()/(float)picture.getHeight());
// mirror by inverting scale and translating
matrix.preScale(-1, 1);
matrix.postTranslate(canvas.getWidth(), 0);
Paint paint = new Paint();
canvas.drawBitmap(picture,matrix,paint);
canvas.drawBitmap(drawingCache,0,0,paint);
try {
String mainpath = getExternalStorageDirectory() + separator + "MaskIt" + separator + "images" + separator;
File basePath = new File(mainpath);
if (!basePath.exists())
Log.d("CAPTURE_BASE_PATH", basePath.mkdirs() ? "Success": "Failed");
String path = mainpath + "photo_" + getPhotoTime() + ".jpg";
File captureFile = new File(path);
captureFile.createNewFile();
if (!captureFile.exists())
Log.d("CAPTURE_FILE_PATH", captureFile.createNewFile() ? "Success": "Failed");
FileOutputStream stream = new FileOutputStream(captureFile);
overlay.compress(Bitmap.CompressFormat.PNG, 100, stream);
stream.flush();
stream.close();
picture.recycle();
drawingCache.recycle();
mPreview.setDrawingCacheEnabled(false);
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
Sometimes orientation issue also occurs on some devices. For that i used Exif class and rotateImage() function.
Exif Class (reference from here) :
public class Exif {
private static final String TAG = "CameraExif";
// Returns the degrees in clockwise. Values are 0, 90, 180, or 270.
public static int getOrientation(byte[] jpeg) {
if (jpeg == null) {
return 0;
}
int offset = 0;
int length = 0;
// ISO/IEC 10918-1:1993(E)
while (offset + 3 < jpeg.length && (jpeg[offset++] & 0xFF) == 0xFF) {
int marker = jpeg[offset] & 0xFF;
// Check if the marker is a padding.
if (marker == 0xFF) {
continue;
}
offset++;
// Check if the marker is SOI or TEM.
if (marker == 0xD8 || marker == 0x01) {
continue;
}
// Check if the marker is EOI or SOS.
if (marker == 0xD9 || marker == 0xDA) {
break;
}
// Get the length and check if it is reasonable.
length = pack(jpeg, offset, 2, false);
if (length < 2 || offset + length > jpeg.length) {
Log.e(TAG, "Invalid length");
return 0;
}
// Break if the marker is EXIF in APP1.
if (marker == 0xE1 && length >= 8 &&
pack(jpeg, offset + 2, 4, false) == 0x45786966 &&
pack(jpeg, offset + 6, 2, false) == 0) {
offset += 8;
length -= 8;
break;
}
// Skip other markers.
offset += length;
length = 0;
}
// JEITA CP-3451 Exif Version 2.2
if (length > 8) {
// Identify the byte order.
int tag = pack(jpeg, offset, 4, false);
if (tag != 0x49492A00 && tag != 0x4D4D002A) {
Log.e(TAG, "Invalid byte order");
return 0;
}
boolean littleEndian = (tag == 0x49492A00);
// Get the offset and check if it is reasonable.
int count = pack(jpeg, offset + 4, 4, littleEndian) + 2;
if (count < 10 || count > length) {
Log.e(TAG, "Invalid offset");
return 0;
}
offset += count;
length -= count;
// Get the count and go through all the elements.
count = pack(jpeg, offset - 2, 2, littleEndian);
while (count-- > 0 && length >= 12) {
// Get the tag and check if it is orientation.
tag = pack(jpeg, offset, 2, littleEndian);
if (tag == 0x0112) {
// We do not really care about type and count, do we?
int orientation = pack(jpeg, offset + 8, 2, littleEndian);
switch (orientation) {
case 1:
return 0;
case 3:
return 3;
case 6:
return 6;
case 8:
return 8;
}
Log.i(TAG, "Unsupported orientation");
return 0;
}
offset += 12;
length -= 12;
}
}
Log.i(TAG, "Orientation not found");
return 0;
}
private static int pack(byte[] bytes, int offset, int length,
boolean littleEndian) {
int step = 1;
if (littleEndian) {
offset += length - 1;
step = -1;
}
int value = 0;
while (length-- > 0) {
value = (value << 8) | (bytes[offset] & 0xFF);
offset += step;
}
return value;
}
}
rotateImage function :
private Bitmap rotateImage(Bitmap bm, int i) {
Matrix matrix = new Matrix();
switch (i) {
case ExifInterface.ORIENTATION_NORMAL:
return bm;
case ExifInterface.ORIENTATION_FLIP_HORIZONTAL:
matrix.setScale(-1, 1);
break;
case ExifInterface.ORIENTATION_ROTATE_180:
matrix.setRotate(180);
break;
case ExifInterface.ORIENTATION_FLIP_VERTICAL:
matrix.setRotate(180);
matrix.postScale(-1, 1);
break;
case ExifInterface.ORIENTATION_TRANSPOSE:
matrix.setRotate(90);
matrix.postScale(-1, 1);
break;
case ExifInterface.ORIENTATION_ROTATE_90:
matrix.setRotate(90);
break;
case ExifInterface.ORIENTATION_TRANSVERSE:
matrix.setRotate(-90);
matrix.postScale(-1, 1);
break;
case ExifInterface.ORIENTATION_ROTATE_270:
matrix.setRotate(-90);
break;
default:
return bm;
}
try {
Bitmap bmRotated = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
bm.recycle();
return bmRotated;
} catch (OutOfMemoryError e) {
e.printStackTrace();
return null;
}
}

You can achieve the effect that you want by breaking it into smaller steps.
Take the picture
Send the bitmap to Google Mobile Vision to detect the "landmarks" in the face and the probability that each eye is open
Paint the appropriate "eyes" onto your image
When using Google Mobile Vision's FaceDetector, you'll get back a SparseArray of Face objects (which may contain more than one face, or which may be empty). So you'll need to handle these cases. But you can loop through the SparseArray and find the Face object that you want to play with.
static Bitmap processFaces(Context context, Bitmap picture) {
// Create a "face detector" object, using the builder pattern
FaceDetector detector = new FaceDetector.Builder(context)
.setTrackingEnabled(false) // disable tracking to improve performance
.setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
.build();
// create a "Frame" object, again using a builder pattern (and passing in our picture)
Frame frame = new Frame.Builder().setBitmap(picture).build(); // build frame
// get a sparse array of face objects
SparseArray<Face> faces = detector.detect(frame); // detect the faces
// This example just deals with a single face for the sake of simplicity,
// but you can change this to deal with multiple faces.
if (faces.size() != 1) return picture;
// make a mutable copy of the background image that we can modify
Bitmap bmOverlay = Bitmap.createBitmap(picture.getWidth(), picture.getHeight(), picture.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(picture, 0, 0, null);
// get the Face object that we want to manipulate, and process it
Face face = faces.valueAt(0);
processFace(face, canvas);
detector.release();
return bmOverlay;
}
Once you've got a Face object, you can find the features that interest you like this
private static void processFace(Face face, Canvas canvas) {
// The Face object can tell you the probability that each eye is open.
// I'm comparing this probability to an arbitrary threshold of 0.6 here,
// but you can vary it between 0 and 1 as you please.
boolean leftEyeClosed = face.getIsLeftEyeOpenProbability() < .6;
boolean rightEyeClosed = face.getIsRightEyeOpenProbability() < .6;
// Loop through the face's "landmarks" (eyes, nose, etc) to find the eyes.
// landmark.getPosition() gives you the (x,y) coordinates of each feature.
for (Landmark landmark : face.getLandmarks()) {
if (landmark.getType() == Landmark.LEFT_EYE)
overlayEyeBitmap(canvas, leftEyeClosed, landmark.getPosition().x, landmark.getPosition().y);
if (landmark.getType() == Landmark.RIGHT_EYE)
overlayEyeBitmap(canvas, rightEyeClosed, landmark.getPosition().x, landmark.getPosition().y);
}
}
Then you can add your paint!
private static void overlayEyeBitmap(Canvas canvas, boolean eyeClosed, float cx, float cy) {
float radius = 40;
// draw the eye's background circle with appropriate color
Paint paintFill = new Paint();
paintFill.setStyle(Paint.Style.FILL);
if (eyeClosed)
paintFill.setColor(Color.YELLOW);
else
paintFill.setColor(Color.WHITE);
canvas.drawCircle(cx, cy, radius, paintFill);
// draw a black border around the eye
Paint paintStroke = new Paint();
paintStroke.setColor(Color.BLACK);
paintStroke.setStyle(Paint.Style.STROKE);
paintStroke.setStrokeWidth(5);
canvas.drawCircle(cx, cy, radius, paintStroke);
if (eyeClosed)
// draw horizontal line across closed eye
canvas.drawLine(cx - radius, cy, cx + radius, cy, paintStroke);
else {
// draw big off-center pupil on open eye
paintFill.setColor(Color.BLACK);
float cxPupil = cx - 10;
float cyPupil = cy + 10;
canvas.drawCircle(cxPupil, cyPupil, 25, paintFill);
}
}
In the snippet above, I just hardcoded the eye radii, to show proof of concept. You'll probably want to do some more flexible scaling, using some percentage of face.getWidth() to determine the appropriate values. But here's what this image processing can do:
Some more details about the Mobile Vision API are here, and Udacity's current Advanced Android course has a nice walkthrough of this stuff (taking a picture, sending it to Mobile Vision, and adding a bitmap onto it). The course is free, or you can just look at what they did on Github.

Blurred custom tiles on Android Maps V2

I want to show a CustomOverlay on a Google Maps V2. The loading of the tiles works as expected, the only thing is, that the shown tiles are not appearing to be sharp at all, kind of blurry. Google did not get me to an usable answer.
I took the approach of adding classical 256px x 256px tiles for the TileProvider. I managed to get a tile source where the images were #2x (retina), which made the whole visual experience much sharper, but I would rather not use this source, as the data transfer rate is four times higher, hence not usable on mobile devices and slow internet speeds.
I included two different examples (screenshots) of the rendered map, both with the same configuration (OSM - 256x256 tiles) and with the provided TileProviderOsm. One is on a Galaxy Nexus and the other on a Nexus 5 phone. Both do not look like they were rendered correctly.
Any idea what I could do to prevent the blurriness or increase the sharpness?
My TileProvider looks like following:
public class TileProviderOsm extends UrlTileProvider {
private static final String MAP_URL = "http://tile.openstreetmap.org/%d/%d/%d.png";
private static int TILE_WIDTH = 256;
private static int TILE_HEIGHT = 256;
public static int MIN_ZOOM = 7;
public static int MAX_ZOOM = 15;
public TileProviderOsm() {
super(TILE_WIDTH, TILE_HEIGHT);
}
#Override
public synchronized URL getTileUrl(int x, int y, int zoom) {
String s = String.format(Locale.US, MAP_URL, zoom, x, y);
URL url = null;
try {
url = new URL(s);
} catch (MalformedURLException e) {
e.printStackTrace();
}
return url;
}
}
Here's how I add the overlay to the map:
map.addTileOverlay(new TileOverlayOptions().tileProvider(new TileProviderOsm()));
Here are some examples of the rendered Google Map:

I am solving this issue by drawing four tiles into one tile.
I wrote this TileProvider which is using another tile provider to create higher resolution tiles.
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import com.google.android.gms.maps.model.Tile;
import com.google.android.gms.maps.model.TileProvider;
import java.io.ByteArrayOutputStream;
public class CanvasTileProvider implements TileProvider {
static final int TILE_SIZE = 512;
private TileProvider mTileProvider;
public CanvasTileProvider(TileProvider tileProvider) {
mTileProvider = tileProvider;
}
#Override
public Tile getTile(int x, int y, int zoom) {
byte[] data;
Bitmap image = getNewBitmap();
Canvas canvas = new Canvas(image);
boolean isOk = onDraw(canvas, zoom, x, y);
data = bitmapToByteArray(image);
image.recycle();
if (isOk) {
Tile tile = new Tile(TILE_SIZE, TILE_SIZE, data);
return tile;
} else {
return mTileProvider.getTile(x, y, zoom);
}
}
Paint paint = new Paint();
private boolean onDraw(Canvas canvas, int zoom, int x, int y) {
x = x * 2;
y = y * 2;
Tile leftTop = mTileProvider.getTile(x, y, zoom + 1);
Tile leftBottom = mTileProvider.getTile(x, y + 1, zoom + 1);
Tile rightTop = mTileProvider.getTile(x + 1, y, zoom + 1);
Tile rightBottom = mTileProvider.getTile(x + 1, y + 1, zoom + 1);
if (leftTop == NO_TILE && leftBottom == NO_TILE && rightTop == NO_TILE && rightBottom == NO_TILE) {
return false;
}
Bitmap bitmap;
if (leftTop != NO_TILE) {
bitmap = BitmapFactory.decodeByteArray(leftTop.data, 0, leftTop.data.length);
canvas.drawBitmap(bitmap, 0, 0, paint);
bitmap.recycle();
}
if (leftBottom != NO_TILE) {
bitmap = BitmapFactory.decodeByteArray(leftBottom.data, 0, leftBottom.data.length);
canvas.drawBitmap(bitmap, 0, 256, paint);
bitmap.recycle();
}
if (rightTop != NO_TILE) {
bitmap = BitmapFactory.decodeByteArray(rightTop.data, 0, rightTop.data.length);
canvas.drawBitmap(bitmap, 256, 0, paint);
bitmap.recycle();
}
if (rightBottom != NO_TILE) {
bitmap = BitmapFactory.decodeByteArray(rightBottom.data, 0, rightBottom.data.length);
canvas.drawBitmap(bitmap, 256, 256, paint);
bitmap.recycle();
}
return true;
}
private Bitmap getNewBitmap() {
Bitmap image = Bitmap.createBitmap(TILE_SIZE, TILE_SIZE,
Bitmap.Config.ARGB_8888);
image.eraseColor(Color.TRANSPARENT);
return image;
}
private static byte[] bitmapToByteArray(Bitmap bm) {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, bos);
byte[] data = bos.toByteArray();
try {
bos.close();
} catch (Exception e) {
e.printStackTrace();
}
return data;
}
}

It's a problem with the zoom level and scaling of the map tiles. This seems to be a problem with the Maps API V2 for Android. The behavior is supposedly intended as stated here: gmaps-api-issues #4840
I solved it by requesting larger tiles from the WMS - just replace 256x256 with 512x512.

Efficiently load 5 larger than fullscreen Bitmaps into my Android Live Wallpaper and scroll them parralax

So I'm new to Java and this kind of coding.
I'm trying to make a Parrallax scrolling Live Wallpaper. But I'm having memory issues.
Well I have made it, and it works on on the phone I have. But I think the way i have done it is not very efficient at all. Because when I try it on other phones it doesn't work. It breaks at my Out Of Memory catcher. I added another layer and now it does the same thing on my phone too. So I am able to debug it. Basically I guess I'm using up-to or over 16 meg of memory.
If someone could take a look at my code and help me load in the bitmaps more efficiently that would be greatly appreciated.
Here is how I'm currently doing it:
static class Layer {
public Bitmap bitmap;
private float scale = 1.0f;
private Matrix matrix = new Matrix();
public Layer(Bitmap b) {
this.bitmap = b;
}
public void setScale(float factor) {
scale = factor;
}
public Matrix getMatrix(float x, float y) {
if (scale == 1) {
matrix.reset();
} else {
matrix.setScale(scale, scale);
}
matrix.postTranslate(x, y);
return matrix;
}
}
public static List<Integer> findLayers(Integer path) {
List<Integer> files = new ArrayList<Integer>();
files.add(R.drawable.planet_layer4);
files.add(R.drawable.planet_layer3);
files.add(R.drawable.planet_layer2);
files.add(R.drawable.planet_layer1);
files.add(R.drawable.planet_layer0);
return files;
}
private void loadLayers() {
try {
clearLayers();
for (Integer file: layerFiles) {
addLayer(file);
}
recalibrateLayers();
} catch (IOException e) {
layers.clear();
Toast.makeText(LiveWallpaper.this, "There was a problem loading the wallpaper. Please contact the developer.", Toast.LENGTH_LONG).show();
} catch (OutOfMemoryError oom) {
layers.clear();
Toast.makeText(LiveWallpaper.this, "Whoops, we ran out of memory trying to load the images. ", Toast.LENGTH_LONG).show();
}
}
private void addLayer(int name) throws IOException {
Bitmap layer = BitmapFactory.decodeResource(getResources(), name);
if (layer == null) {
throw new IOException("BitmapFactory couldn't decode asset " + name);
}
synchronized(layers) {
layers.add(new Layer(layer));
}
}
private void clearLayers() {
synchronized(layers) {
layers.clear();
}
}
private void recalibrateLayers() {
for (Layer layer : layers) {
final int bitmapHeight = layer.bitmap.getHeight();
layer.setScale((float)mHeight / (float)bitmapHeight);
}
}
#Override
public void onDestroy() {
super.onDestroy();
mHandler.removeCallbacks(mDrawParallax);
}
#Override
public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
super.onSurfaceChanged(holder, format, width, height);
mHeight = height;
recalibrateLayers();
drawBackgrounds();
}
And here is where I draw them.
/*
* Draw one frame of the animation. This method gets called repeatedly
* by posting a delayed Runnable. You can do any drawing you want in
* here.
*/
void drawBackgrounds() {
final SurfaceHolder holder = getSurfaceHolder();
final Rect frame = holder.getSurfaceFrame();
mFrame = frame;
Canvas c = null;
try {
c = holder.lockCanvas();
if (c != null) {
// draw something
drawParallax(c);
}
} finally {
if (c != null) holder.unlockCanvasAndPost(c);
}
}
void drawParallax(Canvas c) {
int frameWidth = mFrame.width();
for (int i=layers.size()-1; i>=0; i--) {
Layer layer = layers.get(i);
Bitmap bitmap = layer.bitmap;
float bitmapWidth = bitmap.getWidth() * layer.scale;
float max = frameWidth - bitmapWidth;
float offset = mOffset * max;
final Matrix m = layer.getMatrix(offset, 0);
c.drawBitmap(bitmap, m, null);
}
}