Incomplete Pattern Fill in high resolution PNG export

[Sandy Scott]

When exporting a file to PNG, the pattern does not fill the whole shape.

The hatching at the left of the attached image is correct, but should also appear along the top edge - the path is an inverted & flipped "L-shape".

Bug #1437726 appears related, but covers PDF export, not PNG.

Inkscape 0.92.3 (2405546, 2018-03-11) for Windows, 64 Bit MSI installer

EDIT: After investigation, the issue appears when the output resolution is higher than 288 DPI (for this specific file). Bug title updated.

[Sandy Scott (iainascott)]

Original SVG file

[Alvin Penner (apenner)]

- reproduced when I use the tab called "Page" as the export area
- not reproduced when I use the tab called "Drawing" as the export area. attached is the result in this case. The Drawing tab modifies the border position x0, y0 to solve the problem. (Don't know what controls x0, y0.)

It looks as if this drawing has been at some point converted from a 72 dpi drawing to a 96 dpi drawing, according to the matrix transform on the group called Walls, perhaps the borders got redefined at that point.

[Sandy Scott (iainascott)]

I made a simplified version of this file, then uploaded the wrong one. Attached, with updated output files. I've stripped out all other objects and layers, and any XML nodes that didn't appear to affect the drawing on the screen.

I'm not seeing a major differences between page & drawing export - both are missing the same section of pattern, though there a few extranneous points of the pattern are appearing on the inside edge of the path, I think the difference between the two is the sub-pixel positioning of the edge when anti-aliased in the raster output.

[Sandy Scott (iainascott)]

Output from pattern error v4 when using "Page" selection

[Sandy Scott (iainascott)]

Output from pattern error v4 when using "Drawing" selection

[Alvin Penner (apenner)]

well, that is strange, here is the output I get when I export the file "pattern_v4" using "Drawing". The output looks correct, as far as I can tell.

[Alvin Penner (apenner)]

here are the settings I used

[Sandy Scott (iainascott)]

My renders were are 300 dpi, so this seems to be related to the DPI of the output. I did a series of tests to find out where the cut-off point is, and 289 dpi is where the problems start for me, and the problems get worse as the DPI increases.

The attached image shows a few different DPI settings (scaled, so the attached image isn't massive).

[Sandy Scott (iainascott)]

Multi DPI comparison

[Alvin Penner (apenner)]

confirmed on Windows 10, Inkscape 0.92.3 (2405546, 2018-03-11) at 300 dpi.

[Jonathan Hofinger (jhofinger)]

Hi, this has been reported to Gitlab (https://gitlab.com/inkscape/inkscape/issues/927), so closing here.

Closed by https://gitlab.com/jhofinger