sub-rect-trimmed-bounds.yaml

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# The sub-rect fraction is measured against the stretch size, not the primitive

# rect. Gecko trims the rect of a repeating background to the fill area while

# leaving its origin on the first tile, so the rect can be much narrower than

# one repetition and dividing by it reads the fraction at the wrong scale.

# One repetition here is 3600 and the rect is 400, so the rect reads the

# fraction 9x too large. The visible part is 360..400 of the repetition, i.e.

# texels 2..3 of the 20x20 sheet, which is grey. Measured against the rect it

# saturates to texels 18..20 -- the sheet's blue border -- painting the whole

# visible area one flat wrong colour. That is how bug 2069245 appeared as a

# black square over the content, and it is the same defect as bug 2068996.

root:

  items:

    - image: checkerboard(2, 1, 1, 16, 16)

      bounds: 0 0 400 400

      stretch-size: 3600 3600

      clip-rect: [360, 360, 40, 40]