How to implement the dashed skew line

How-to
1

Hi Gabor,
I want to implement the dashed line in line_draw_skew() function, but I have no idea.Can you give me some advices?

2

Hi,

Unfortunately, it’s not supported now. I suggest using an image in “Alpha 2 bit” format. Could it work for you?

PS: It’s a community forum and you can ask from the whole community not only from me. So please say “Hi”, instead of “Hi Gabor”. :slight_smile:

3

Alternatively there are two other ways you could do it:

  • If you can afford the memory, create many individual line objects and put them inside a parent object. Then you can move the parent object and the dashed lines will go with it.
  • Use the lv_canvas object and draw dashed lines on it. Con: no antialiasing IIRC.
4

lv_canvas_draw_line uses the “core” line draw algorithm in v6.0 so it’s anti-aliased and has perpendicular endings.

5

Good to know! Thanks!

6

Thanks for your answer, I have a try to implement dashed lines based on canvas. It just jumps dashed part of line, only display the point line,but it does not look very well.

7

Can you show the code (and/or a screenshot)?

8

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新建位图图像 (2).jpg1325×682 22.5 KB

9

It seems the issue is in your algorithm. Let’s start with a more simple example. Just draw one skew dashed line. How does it look like, and how do you draw it?

10

Hello, have you implemented this feature? I would like to consult with you