Develop Reference

Textures with programmable color in Rajawali

All works great for me with Rajawali in Android, except textures.
I would like to programmatically load a transparent image as a texture, with a chessboard pattern where each black square is in fact fully transparent while each white square is just white.
I would like to use this as a texture over an object, that otherwise has diffuse and specular color properties that can be changed programmatically. So if the user has inputted the color blue, I would like the object to show a blue-white pattern.
How can I do that?
The rajawali tutorials do not really help, since for textures rajawali changed a lot in the last update. Also the Rajawali examples app does not really help, as they all seem to deal with environment maps.
What I tried was e.g.:
protected void initScene() {
objParser = new LoaderOBJ(mContext.getResources(), mTextureManager, R.raw.stdblock_obj);
try{
Texture jetTexture = new Texture("jetTexture", R.drawable.chessboardtexture);
mTextureManager.getInstance().addTexture(jetTexture);
semiglossMaterial.addTexture(jetTexture);
semiglossMaterial.setColorInfluence(0);
}catch(TextureException e){
e.printStackTrace();
}
}
The object is rendered, but without any texture. The chessboard image does have a size power-of-2, and it is located in the right folder R.raw.stdblock_obj. It is a jpg image, but I also tried png which didn't work either.
I also tried a different approach:
semiglossMaterial.enableLighting(true);
semiglossMaterial.setDiffuseMethod(new DiffuseMethod.Lambert());
phongMethod.setShininess(iShininess); semiglossMaterial.addTexture(new Texture("jetTexture",R.drawable.chessboardtexture));
semiglossMaterial.addTexture(new AlphaMapTexture("alphaMapTex", R.drawable.simpletexture3));
semiglossMaterial.setColorInfluence(0);
but also this did not work.
Anyone an idea?

You have to add that texture as a child, a child of the .obj file, if you don´t know how many child have your .obj and the name of them, use:
"your3DobjectName".numChildren(),
then use a simple
for(int i = 0; i < "your3DobjectName".numChildren(); i++)
{
String name = "your3DobjectName".getChildAt(i).name();
Log.d("rajawali", "Name: "+name);
}
At this way you will know how many childs and the name of your childs declared at your obj

how to merge Images and impose on each other

Suppose I'm uploading two or more than two pics in some Framelayout. Hereby I'm uploading three pics with a same person in three different position in all those three pictures. Then what image processing libraries in Android or java or Native's are available to do something as shown in the pic.
I would like to impose multiple pictures on each other.
Something like these:-
One idea is to :
Do some layering in all those pictures and find mismatching areas in the pics and merge them.
How one can merge multiple picture with other? By checking the di-similarity and merge with each other?
Are there any Third party Api's or some Photoshop service which can help me in doing these kinda image processing?

In this case you are not just trying to combine the images. You really want to combine a scene containing the same object in different positions.
Therefore, it is not just a simple combination or an alpha compositve where the color of a given pixel in the output image is the sum of the value of this pixel in each image, divided by the number of images.
In this case, you might do:
Determine the scene background analysing the pixels that do not change considering multiple images.
Begin with the output image being just the background.
For each image, remove the background to get the desired object and combine it with the output image.
There is a Marvin plug-in to perform this task, called MergePhoto. The program below use that plug-in to combine a set of parkour photos.
import marvin.image.MarvinImage;
import marvin.io.MarvinImageIO;
import marvin.plugin.MarvinImagePlugin;
import marvin.util.MarvinPluginLoader;
public class MergePhotosApp {
public MergePhotosApp(){
// 1. load images 01.jpg, 02.jpg, ..., 05.jpg into a List
List<MarvinImage> images = new ArrayList<MarvinImage>();
for(int i=1; i<=5; i++){
images.add(MarvinImageIO.loadImage("./res/0"+i+".jpg"));
}
// 2. Load plug-in and process the image
MarvinImagePlugin merge = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.combine.mergePhotos");
merge.setAttribute("threshold", 38);
// 3. Process the image list and save the output
MarvinImage output = images.get(0).clone();
merge.process(images, output);
MarvinImageIO.saveImage(output, "./res/merge_output.jpg");
}
public static void main(String[] args) {
new MergePhotosApp();
}
}
The input images and the output image are shown below.

I don't know if this will qualify to be in your definition of "natives", but there is the following .NET library that could help: http://dynamicimage.apphb.com/
If the library itself can give you want you want, then depending on your architecture you could set up a small ASP.NET site to do the image manipulation on the server.

Check the accepted answer here.
In above link there is merging of two images which is done by openCV sdk.
If you dont want to use openCV and just want to try with your self then you will have to play little with framlayout and with three imageview. Give options to user to select specific part of the image to show for all three images. So the selected part will be shown of the selected image. on this way you will get the result like above what you have said.
Hope you got my point. If not then let me know.
Enjoy coding... :)

You can overlay the images using openCV you can check at OpenCV and here or here
// Read the main background image
cv::Mat image= cv::imread("Background.png");
// Read the mans character image to be placed
cv::Mat character= cv::imread("character.png");
// define where you want to place the image
cv::Mat newImage;
//The 10,10 are the initial coordinates in pixels
newImage= image(cv::Rect(10,10,character.cols,character.rows));
// add it to the background, The 1 is the aplha values
cv::addWeighted(newImage,1,character,1,0,newImage);
// show result
cv::namedWindow("with character");
cv::imshow("with character",image);
//Write Image
cv::imwrite("output.png", newImage);
or you can create it as a watermark effect
Or you can try it in java like merging two images
try using this class
public class MergeImages {
public static void main(String[] args) {
File inner = new File("Inner.png");
File outter = new File("Outter.png");
try {
BufferedImage biInner = ImageIO.read(inner);
BufferedImage biOutter = ImageIO.read(outter);
System.out.println(biInner);
System.out.println(biOutter);
Graphics2D g = biOutter.createGraphics();
g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.8f));
int x = (biOutter.getWidth() - biInner.getWidth()) / 2;
int y = (biOutter.getHeight() - biInner.getHeight()) / 2;
System.out.println(x + "x" + y);
g.drawImage(biInner, x, y, null);
g.dispose();
ImageIO.write(biOutter, "PNG", new File("Outter.png"));
} catch (Exception e) {
e.printStackTrace();
}
}
}

Android: bitmap size exceeds VM budget (frame by frame)

I get this error all the time. And as I can see, there are a lot of questions already on stackoverflow.com, but sadly, I don't find any answers which will suit me.
I have 60 PNG images (2,5MB all together) which I would like to put it in animation.
I tried with three different ways.
1
mAnimation = new AnimationDrawable();
mAnimation.addFrame((BitmapDrawable)getResources().getDrawable(R.drawable.yawning_00001), FPS_12);
...
mAnimation.addFrame((BitmapDrawable)getResources().getDrawable(R.drawable.yawning_00063), FPS_12);
mAnimation.start();
2
XML
<animation-list android:oneshot="true">
<item android:drawable="#drawable/yawning_00001" android:duration="83" />
...
<item android:drawable="#drawable/yawning_00063" android:duration="83" />
</animation-list>
Java
ImageView img = (ImageView)findViewById(R.id.animation);
img.setBackgroundResource(R.drawable.yawning);
AnimationDrawable frameAnimation = (AnimationDrawable) img.getBackground();
frameAnimation.start();
3
With class extending ImageView (I will just show important stuff here)
public void loadAnimation(String prefix, int nframes) {
mBitmapList.clear();
for (int x = 0; x < nframes; x++) {
String zeros = "000";
if (x < 10) {
zeros += "0";
}
String name = prefix + "_" + zeros + x;
Log.d(TAG, "loading animation frame: " + name);
int res_id = mContext.getResources().getIdentifier(name, "drawable", mContext.getPackageName());
d = (BitmapDrawable) mContext.getResources().getDrawable(res_id);
mBitmapList.add(d.getBitmap());
}
}
In all cases I get the same error... All some around after 15 picture loads.
E/AndroidRuntime(1591): java.lang.OutOfMemoryError: bitmap size exceeds VM budget
I am begging to wonder if this is frame animations are even possible in Android.
Does anybody maybe have a alternative to frame by frame animation? If yes, please link to any showcase.

You will need to recycle your images in some way because you won't have enough memory ever for 60 images.
You think your images are 2,5 meg all together but this the compressed png version of your files.
If you want to know how much memory you are using with your files when uncompressed in bitmap format in memory just do : width*height*number of images*bytes per pixel....Then you'll know why you crash :D
AnimationDrawable are not meant for that kind of heavy usage. You should start looking at SurfaceViews and then you'll be free to implement whatever memory management method you want to use to display your animation.
http://developer.android.com/reference/android/view/SurfaceView.html
Good luck.

Sometimes, The memory leak come from some where which isn't the line of code show in stack trace. I think you should read below article carefully then check your own code to omit some special issue, such as:
Do not keep long-lived references to a context-activity (a reference to an activity should have the same life cycle as the activity itself)
Try using the context-application instead of a context-activity
Avoid non-static inner classes in an activity if you don't control their life cycle, use a static inner class and make a weak reference to the activity inside. The solution to this issue is to use a static inner class with a WeakReference to the outer class, as done in ViewRoot and its W inner class for instance**
Article
EDIT:
You also should check these:
Call recycle() to remove unused bitmap
use sampleSize > 1 to reduce bitmap size.
Bitmap.createBitmap(width,
height, new BitmapFactory.Options().inSampleSize=4)

Spritesheet programmatically cutting: best practices

I have a big spritesheet (3808x1632) composed by 42 frames.
I would present an animation with these frames and I use a thread to load a bitmap array with all the frames, with a splash screen waiting for its end.
I'm not using a SurfaceView (and a draw function of a canvas), I just load frame by frame in an ImageView in my main layout.
My approach is similar to Loading a large number of images from a spritesheet
The completion actually takes almost 15 seconds, not acceptable.
I use this kind of function:
for (int i=0; i<TotalFramesTeapotBG; i++) {
xStartTeapotBG = (i % framesInRowsTeapotBG) * frameWidthTeapotBG;
yStartTeapotBG = (i / framesInRowsTeapotBG) * frameHeightTeapotBG;
mVectorTeapotBG.add(Bitmap.createBitmap(framesBitmapTeapotBG, xStartTeapotBG, yStartTeapotBG, frameWidthTeapotBG, frameHeightTeapotBG));
}
framesBitmapTeapotBG is the big spritesheet.
Looking more deeply, I've read in the logcat that the createBitmap function takes a lot of time, maybe because the spritesheet is too big.
I found somewhere that I could make a window on the big spritesheet, using the rect function and canvas, creating small bitmaps to be loaded in the array, but it was not really clear. I'm talking about that post: cut the portion of bitmap
My question is: how can I speed the spritesheet cut?
Edit:
I'm trying to use this approach but I cannot see the final animation:
for (int i=0; i<TotalFramesTeapotBG; i++) {
xStartTeapotBG = (i % framesInRowsTeapotBG) * frameWidthTeapotBG;
yStartTeapotBG = (i / framesInRowsTeapotBG) * frameHeightTeapotBG;
Bitmap bmFrame = Bitmap.createBitmap(frameWidthTeapotBG, frameHeightTeapotBG, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmFrame);
Rect src = new Rect(xStartTeapotBG, yStartTeapotBG, frameWidthTeapotBG, frameHeightTeapotBG);
Rect dst = new Rect(0, 0, frameWidthTeapotBG, frameHeightTeapotBG);
c.drawBitmap(framesBitmapTeapotBG, src, dst, null);
mVectorTeapotBG.add(bmFrame);
}
Probably, the Bitmap bmFrame is not correctly managed.

The short answer is better memory management.
The sprite sheet you're loading is huge, and then you're making a copy of it into a bunch of little bitmaps. Supposing the sprite sheet can't be any smaller, I'd suggest taking one of two approaches:
Use individual bitmaps. This will reduce the memory copies as well as the number of times Dalvik will have to grow the heap. However, these benefits may be limited by the need to load many images off the filesystem instead of just one. This would be the case in a normal computer, but Android systems may get different results since they're run off flash memory.
Blit directly from your sprite sheet. When drawing, just draw straight from sprite sheet using something like Canvas.drawBitmap(Bitmap bitmap, Rect src, Rect dst, Paint paint). This will reduce your file loads to one large allocation that probably only needs to happen once in the lifetime of your activity.
I think the second option is probably the better of the two since it will be easier on the memory system and be less work for the GC.

Thanks to stevehb for the suggestion, I finally got it:
for (int i = 0; i < TotalFramesTeapotBG; i++) {
xStartTeapotBG = (i % framesInRowsTeapotBG) * frameWidthTeapotBG;
yStartTeapotBG = (i / framesInRowsTeapotBG) * frameHeightTeapotBG;
Bitmap bmFrame = Bitmap.createBitmap(frameWidthTeapotBG, frameHeightTeapotBG, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmFrame);
Rect src = new Rect(xStartTeapotBG, yStartTeapotBG, xStartTeapotBG+frameWidthTeapotBG, yStartTeapotBG+frameHeightTeapotBG);
Rect dst = new Rect(0, 0, frameWidthTeapotBG, frameHeightTeapotBG);
c.drawBitmap(framesBitmapTeapotBG, src, dst, null);
mVectorTeapotBG.add(bmFrame);
}
The computation time falls incredibly! :)

Use a LevelListDrawable. Cut the sprites into individual frames and drop them in your drawable resource directory. Either programmatically or through an xml based level-list drawable create your drawable. Then use ImageView.setImageLevel() to pick your frame.

I use a method of slicing based on rows and columns. However your sprite sheet is rather huge. You have to think you are putting that whole sheet into memory. 3808x1632x4 is the size of the image in memory.
Anyway, what I do is I take an image (lets say a 128x128) and then tell it there are 4 columns and 2 rows in the Sprite(bitmap, 4, 2) constructor. Then you can slice and dice based on that. bitmap.getWidth() / 4 etc... pretty simple stuff. However if you want to do some real stuff use OpenGL and use textures.
Oh I also forgot to mention there are some onDraw stuff that needs to happen. Basically you keep an index counter and slice a rectangle from the bitmap and draw that from a source rectangle to a destination rectangle on the canvas.

Android: Canvas made out of multiple images won't save

Right my title isn't the best in the world. I've got a big code that's supposed to make on big bitmap out of multiple bitmaps. I've isolated the problem to this part of the code
bity = Bitmap.createBitmap(specialWidth,specialHeight,Bitmap.Config.ALPHA_8);
Canvas canvas = new Canvas(bity);
float left=0.0f;
for (int i = 0; i < imagesArrayz.length; i++){
float top=0.0f;
canvas.drawBitmap(imagesArrayz[i], left, top, null);
left+=imagesArrayz[i].getWidth();
}
To explain: "bity" is a globally defined Bitmap object and it's unassigned untill this point; imagesArrayz is an array of 5 Bitmaps that has already ben assigned and has ben assigned correctly (i tested it to see if each image is in the array)
After this i just have a function that saves the global variable bity to a file. THE PROBLEM is that instaid of saving my nicely drawn canvas it saves an empty jpg file of 0kb. Please help!

I answered my own question... Replace ALPHA_8 with ARGB_8888 and it all magically works.
Someone shoot me please...