How do you fill a shape of canvas (on touch**)?

MIT App Inventor Help
1

I am making an app in which there will be many circles which will be unfilled, i have to fill a circle with color when user touches it,
i have read this topic : Fill any shape with a color? but not found helpful for me
Kindly help and share any solution.

2

The code is like this, now i want, when user touches, targeting that circle and filling it.

3

what about this thead:
Flood Fill Extension. Fill area of an image with a color - Extensions - MIT App Inventor Community

and this one:
[FREE] Extended Canvas Flood Fill Extension - Extensions - MIT App Inventor Community

1 Like
4

@Kevinkun how to use this

5

Code : https://snipboard.io/Pygmsi.jpg
results : https://snipboard.io/isH7C6.jpg
all screen filled, if player clicked out of circle, i dont want this functionality, can u help

6

how this circle come? are they regular circle? you draw it by using 'DrawCircle' block? are these circles overlap ?

7

@Kevinkun see code, check the for loop, they came from draw circle(unfill) block

8

You did not answer my questions. do you have only one circle on the canvas?

9

No, multiple, they are generated through loops in X and Y axis

10

you need to find out which circle center is the most closest to the point of your touch.then redraw this circle with fill=true.
No need that 2 extensions I mentioned.

11

How do i find that? any approximation formula or way?

12

When a new circle is created in your loop, save the circle centre coordinates to a list.

13

But what need to store the coordinates are:
20, 20 201, 20 202, 20.......
like this, all this are multiples of 20 @TIMAI2

14

center.x = mod (touch.x-10, 20) +10
center.y = mod (touch.y-10, 20) +10

not tested myself

15

Not working
code : https://snipboard.io/649loD.jpg
image : https://snipboard.io/UvfQlp.jpg
See the top left of screen, all circles are going there

16

image
image1097×291 40.8 KB

1 Like
17

The term for this is
Snap To Grid.

You can't do this without one or more of the math blocks that cut off fractional parts of a number, like
mod
floor
ceil
quotient (thanks @Kevinkun )

1 Like
18

@ABG ohh okk , actually i'm new in mit inventor, i was using thunkable from past 4-5 years but shifted to mit because of its features
@Kevinkun thnkss :smile: its working now

19

@Kevinkun one more thing, can u pls explain the formula, i dont want to exact copy paste, i want to learn from my mistakes

20

Set the radius to 10 then run the code, that will help to understand.