How can I save the image on a canvas to bitmap?
There are several related posts, but I didn't find the one works for me. To make it clear, here is my problem
What's on my canvas:
An bitmap image which was drawn to the canvas using canvas.drawBitmap(oldBitmap, x, y, null);
Some paths drawn overlay to this image on the same canvas using canvas.drawPath.
Both the image and the paths are draw on a customized SurfaceView. And both they are draw to the canvas in the onDraw function. Or more specific, the implementation is in the following link:
Android: custom draw on an given image (with SurfaceView)
Now I need to save the image on canvas (the oldBitmap and paths I drew) to a newBitmap. Could someone tell me how to do that?
Related
I need to save a number of formatted circles to a Bitmap whenever a button is pushed, and then draw those circles to the canvas. I was looking around, but had a great deal of trouble finding resources on how to save a shape I had created that was not an already created resource file. Any advice on how to go about this would be appreciated.
Say you are in your custom view, but it should work also with a OnTouchListener in any view.
Create a mutable bitmap with Bitmap.createBitmap() with the same width and height of your view
use your logic for getting information of the circles, for example you can use onTouchEvent() to get the coordinates of you finger(s)
with this information you can use Bitmap.setPixel() to save it to the bitmap
optional, onDraw() you can draw your bitmap with Canvas.drawBitmap()
In case you need to draw shapes to the bitmap you can create a new Canvas(bitmap) and draw on this canvas: the pixels will be set on the bitmap.
My program is a simple flood-fill game application for android, namely, the user can paint and draw something on the canvas. Now I want to provide a sharing option to the users. I guess that I must begin with copying the canvas to a bitmap object. I could not find a satisfactory answer because it is generally suggested "to create a new canvas, then..." but I got a canvas like that,
Canvas canvas = holder.lockCanvas();
then I use it. So, how can I copy my current canvas to a bitmap object?
Thanks
As suggested Maulik.J, I looked at converting a canvas into bitmap image in android again.
I could not understand from a bit close expression of this link. But, then I saw below text taken from http://developer.android.com/guide/topics/graphics/2d-graphics.html#draw-with-canvas . So, I solved this problem with the help of Maulik.J and the following text:
The Bitmap is always required for a Canvas. You can set up a new Canvas like this:
Bitmap b = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
Now your Canvas will draw onto the defined Bitmap. After drawing upon it with the Canvas, you can then carry your Bitmap to another Canvas with one of the Canvas.drawBitmap(Bitmap,...) methods. It's recommended that you ultimately draw your final graphics through a Canvas offered to you by View.onDraw() or SurfaceHolder.lockCanvas()
I created a second Canvas object having a bitmap which has same dimensions with my real canvas, I drew all my illustrations on this second temporary canvas. Then, I drew its bitmap on my real canvas.
Thanks.
It seems to be a very trivial thing, but I am not able to find a sample code for it.
I am trying to do a very simple thing. On a canvas I plan to draw a round rect and save that in a drawable which I can then set as a background of a button.
Now I am looking for 2 things, how to draw and create a round rect so that the transparency effect can be created (like in a png drawable)
Second how to save the canvas to an image.
Please help
Please try to use this code.
Bitmap bitmap=BitmapFactory.decodeResource(getResources(),R.color.transparant);
canvas.drawBitmap(bitmap, matrix, paint);
I'm using a SurfaceView and canvas. Over time The canvas draws the same bitmap image but at different position. So every time the position of the bitmap moves, any drawings on the bitmap has to be be moved as well. So is there a way to just have the drawings on the bitmap image stay so that when the image moves(when canvas redraws the bitmap at a different location on screen), any drawings on the image moves with it as well?
You can setup a Bitmap to be the backing buffer for your canvas so that drawing to the canvas is, effective, drawing to that Bitmap. This way you can keep it around and do whatever you want with it.
Is there a way to do it? I d like to save the canvas screen as a Bitmap object, and then draw it again, to the screen.
You can construct a Canvas passing in a Bitmap onto which the canvas will draw. See http://developer.android.com/reference/android/graphics/Canvas.html#Canvas(android.graphics.Bitmap)
You need to construct a Bitmap appropriately sized to the view into which you want to draw.
Just guessing here, but if you are doing this because you want to draw off screen then draw the bitmap on all at once you might also look at SurfaceHolder/SurfaceView.