CODEWITHSUNDEEP
androidgraphics
hguser
hguser

Reputation: 36058

Line intersection rendering in Android

In my Android application I will retrieve data from a server where some coordinates will be returned back. Then I use these coordinates to create lines and draw them in the view.

I want a line rendered in different manners. For example: line rendering

enter image description here

The line at the top is the original line, and I want it rendered as the shapes at the below.

And there are some lines which intersect with each other. Then the intersection may be rendered as follows:

enter image description here

The manner of intersection rendering at the left is what I want.

So I wonder whether the Android graphics api supports these kinds of operations?

Upvotes: 4

Views: 691

Answers (1)

XGouchet
XGouchet

Reputation: 10203

If you're using the Android Canvas to do this drawing your path twice, with a different stroke size and color. Here's an example which creates a Bitmap with an image similar to what you want : 

    // Creates a 256*256 px bitmap
    Bitmap bitmap = Bitmap.createBitmap(256, 256, Config.ARGB_8888);

    // creates a Canvas which draws on the Bitmap
    Canvas c = new Canvas(bitmap);

    // Creates a path (draw an X)
    Path path = new Path();
    path.moveTo(64, 64);
    path.lineTo(192, 192);
    path.moveTo(64, 192);
    path.lineTo(192, 64);

    // the Paint to draw the path
    Paint paint = new Paint();
    paint.setStyle(Style.STROKE);

    // First pass : draws the "outer" border in red
    paint.setColor(Color.argb(255, 255, 0, 0));
    paint.setStrokeWidth(40);
    c.drawPath(path, paint);

    // Second pass : draws the inner border in pink
    paint.setColor(Color.argb(255, 255, 192, 192));
    paint.setStrokeWidth(30);
    c.drawPath(path, paint);

    // Use the bitmap in the layout
    ((ImageView) findViewById(R.id.image1)).setImageBitmap(bitmap);

Upvotes: 2

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