makeImageData: svg elements missing on large diagrams

GoJS
1

Hello,

I have a large diagram where each node has an svg icon. Total diagram size is about 18000x10000.
When creating an png with makeImageData (max size is set to diagram size), a png with the correct dimensions is created, but the svg node icons east of ~16000 pixels are not printed. On the other hand, links are drawn correctly, even east of 16000px. If I move some icons from east to west of 16000px, they are displayed correctly in the png. I am using Electron.

In order to be able to set an appropriate maximum size for the image to be generated, I need to understand what is the cause for the missing icons.

As the png has been created correctly, it doesn’t seem to be a memory issue.
There is a limit to the canvas size, but the whole canvas is displayed, so this also seems to be unrelated.

Could you give me a hint what could be causes these missing icons?

2

Edit: Sorry, I didn’t read you correctly. We’ll investigate this.

3

Here is an example of what I mean:

Works in Firefox. However in Chrome the last few nodes do not display an icon.

Seems to be related to the numbers mentioned here, for Chrome this is mentioned:

Maximum height/width: 32,767 pixels
Maximum area: 268,435,456 pixels (e.g., 16,384 x 16,384)

However the dimension of the example is both within the maximum height/width and the area, so I don’t understand what’s happening.

4

This is probably a browser bug that we have no control over, however you could make multiple images of the diagram like we do in the printing intro page, and concat them yourself somehow.

5

Okay thanks. Checking the different browsers it seems okay to assume 16,384 as the maximum width/height for the image.

6

Do you also need to consider mobile devices, especially smartphones? That’s why the default maximum image size for Diagram.makeImageData is 2000x2000.

7

Are you referring to the 4,096 x 4,096 limit on Windows Phone 8 and Safari or to the memory demand for creating the image?
We need to consider mobile devices, mainly tablets. I will make sure to test this on all platforms we support and adjust the maximum if necessary. Thanks for pointing this out!

8

I was referring to the overall memory usage. JavaScript is bad enough by itself.