convertTransform changes gradientTransform and breaks file

[JoKalliauer]

Input

SVG:

Output

SVG:

Differences

changes

• <radialGradient id="C" cx="0" cy="0" r="819.2" gradientTransform="matrix(.001 .001 -.002 .002 85.201 25.541)" xlink:href="#c"/> to <radialGradient id="C" cx="0" cy="0" r="819.2" gradientTransform="translate(85.201 25.541) scale(.001 .004)" xlink:href="#c"/>
• <radialGradient id="aa" cx="0" cy="0" r="819.2" gradientTransform="matrix(.001 .002 -.002 .001 29.401 9.9406)" xlink:href="#b"/> to <radialGradient id="aa" cx="0" cy="0" r="819.2" gradientTransform="rotate(60 3.808 27.497) scale(.002)" xlink:href="#b"/>

Copyright

source: https://commons.wikimedia.org/wiki/File:Hematopoiesis_(human)_diagram_en.svg

[JoKalliauer]

Because it is difficult to see the difference I make a minimal (not) working example

Input-SVG

Output-SVG

Input-Code

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" font-family="'Liberation Sans', Arial" viewBox="0 0 96 42">
  <radialGradient xlink:href="#a" id="d" cx="0" cy="0" r="819.2" gradientTransform="matrix(.001 .001 -.002 .002 85.201 25.541)"/>
  <radialGradient xlink:href="#b" id="e" cx="0" cy="0" r="819.2" gradientTransform="matrix(.004 .023 -.028 .005 23.901 19.641)"/>
  <radialGradient xlink:href="#c" id="f" cx="0" cy="0" r="819.2" gradientTransform="matrix(.001 .002 -.002 .001 29.401 9.9406)"/>
  <linearGradient id="b" gradientUnits="userSpaceOnUse">
    <stop offset=".9" stop-color="#d0c2dd"/>
    <stop offset="1" stop-color="#c2a0e4"/>
  </linearGradient>
  <linearGradient id="c" gradientUnits="userSpaceOnUse">
    <stop offset=".2" stop-color="#fefefe"/>
    <stop offset=".5" stop-color="#f0ebf4"/>
    <stop offset="1" stop-color="#d0c2dd" stop-opacity="0"/>
  </linearGradient>
  <linearGradient id="a" gradientUnits="userSpaceOnUse">
    <stop offset=".2" stop-color="#ddbbfd"/>
    <stop offset=".7" stop-color="#bd7bff"/>
    <stop offset="1" stop-color="#aa54ff" stop-opacity="0"/>
  </linearGradient>
  <path fill="#aa64ed" stroke="#9139e9" stroke-linecap="round" stroke-linejoin="round" stroke-width=".5" d="M75 22v1l-1-2h-1zm-2-1c-1-2-4-2-6-3-4 0-6 0-8 2-1 2-2 5 0 7 1 3 2 5 4 6 4 3 8 4 13 4s8 0 12-2 4-4 5-8a12 12 0 0 0-2-6l-3-6a14 14 0 0 0-10-6c-5-1-8 1-9 3-1 3 0 5 1 6l2 1 1 2z"/>
  <path fill="url(#d)" d="m86 24 1 1-1 2h-1c-1 1-1 0-2-1l1-1 1-1h1z"/>
  <path fill="url(#e)" d="M47 15a21 21 0 0 1-20 24 28 28 0 0 1-17-3 19 19 0 0 1-9-12c-2-5 0-10 4-15s9-7 16-8c6-2 12-1 17 2 5 2 8 7 9 12z"/>
  <path fill="url(#f)" d="M28 11V9l1-1c2 0 2 1 2 2v1h-3z"/>
</svg>

Output-Code

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" font-family="'Liberation Sans', Arial" viewBox="0 0 96 42">
  <radialGradient xlink:href="#a" id="d" cx="0" cy="0" r="819.2" gradientTransform="translate(85.201 25.541) scale(.001 .004)"/>
  <radialGradient xlink:href="#b" id="e" cx="0" cy="0" r="819.2" gradientTransform="matrix(.004 .023 -.028 .005 23.901 19.641)"/>
  <radialGradient xlink:href="#c" id="f" cx="0" cy="0" r="819.2" gradientTransform="rotate(60 3.808 27.497) scale(.002)"/>
  <linearGradient id="b" gradientUnits="userSpaceOnUse">
    <stop offset=".9" stop-color="#d0c2dd"/>
    <stop offset="1" stop-color="#c2a0e4"/>
  </linearGradient>
  <linearGradient id="c" gradientUnits="userSpaceOnUse">
    <stop offset=".2" stop-color="#fefefe"/>
    <stop offset=".5" stop-color="#f0ebf4"/>
    <stop offset="1" stop-color="#d0c2dd" stop-opacity="0"/>
  </linearGradient>
  <linearGradient id="a" gradientUnits="userSpaceOnUse">
    <stop offset=".2" stop-color="#ddbbfd"/>
    <stop offset=".7" stop-color="#bd7bff"/>
    <stop offset="1" stop-color="#aa54ff" stop-opacity="0"/>
  </linearGradient>
  <path fill="#aa64ed" stroke="#9139e9" stroke-linecap="round" stroke-linejoin="round" stroke-width=".5" d="M75 22v1l-1-2h-1zm-2-1c-1-2-4-2-6-3-4 0-6 0-8 2-1 2-2 5 0 7 1 3 2 5 4 6 4 3 8 4 13 4s8 0 12-2 4-4 5-8a12 12 0 0 0-2-6l-3-6a14 14 0 0 0-10-6c-5-1-8 1-9 3-1 3 0 5 1 6l2 1 1 2z"/>
  <path fill="url(#d)" d="m86 24 1 1-1 2h-1c-1 1-1 0-2-1l1-1 1-1h1z"/>
  <path fill="url(#e)" d="M47 15a21 21 0 0 1-20 24 28 28 0 0 1-17-3 19 19 0 0 1-9-12c-2-5 0-10 4-15s9-7 16-8c6-2 12-1 17 2 5 2 8 7 9 12z"/>
  <path fill="url(#f)" d="M28 11V9l1-1c2 0 2 1 2 2v1h-3z"/>
</svg>

[SethFalco]

I'm reopening this, as it does partially resolve the issue, but there are still some changes in the test file provided.

[johnkenny54]

It looks like the problem here is that there's code in convertTransform that limits the precision of the decomposition to no more than the maximum number of decimal digits in the matrix - in this case, the matrix entries are all 3 digits, so it is changing precision from 5 to 3. The comment in the code says "Calculating with larger precision doesn't add any value", but that's clearly not true in this case. If this code is removed, everything seems OK. I'll look in to what effect removing this limit has.

[SethFalco]

Ahh, so it's the same issue as this, then:

#1810 (comment)

[johnkenny54]

Partially. There are a number of issues with rounding. With the default config, what I see when I make this change is:

• convertTransform changes gradientTransform and breaks file #1268 is resolved
• the first file in Plugin 'convertTransform' corrupts image #1810 is resolved
• the second file in Plugin 'convertTransform' corrupts image #1810 is not changed

There are several other issues that are improved, but not fully resolved: #988, #1021, #1222

I'll check this against the full set of regression files, assuming nothing bad happens there I'll create a PR.