Label: underline/strikthrough is not correct clipped on 'Clamp Content Test'

[aismann]

Works not if wrap is off:

wrap enabled works:

Also the last char is not correct clipped sometimes:

[aismann]

Works correct here (test issue with 56/57 ?) :

[rh101]

For tests 56/57, clamping the line works by not adding the character to the draw list, as you can see in Label::updateQuads(). The issue is that the line length is still the full length without clamping, so when the underline or strikethrough are being drawn, they don't factor in the clamp cut-off. That's always been the case, all the way back to Cocos2d-x.

For test 61, it works correctly because the label dimensions are being updated, so the line lengths match the actual displayed string length. It's a completely different operation than clamping, so can't be compared with tests 56/57.

[rh101]

A quick fix would be to change this:

if (_strikethroughEnabled)
{
    auto y = nextY - lineHeight / 2;
    _lineDrawNode->drawLine(Vec2(_linesOffsetX[i], y), Vec2(_linesWidth[i] + _linesOffsetX[i], y),
                            Color4F(lineColor), thickness);
}

if (_underlineEnabled)
{
    auto y = nextY - lineHeight;
    _lineDrawNode->drawLine(Vec2(_linesOffsetX[i], y), Vec2(_linesWidth[i] + _linesOffsetX[i], y),
                            Color4F(lineColor), thickness);
}

to this:

float startOffset = 0;
float endOffset  = 0;

if (_overflow == Overflow::CLAMP)
{
    startOffset = std::max(0.f, _linesOffsetX[i]);
    if (_hAlignment == TextHAlignment::LEFT || _hAlignment == TextHAlignment::CENTER)
    {
        endOffset = std::min(_linesWidth[i] + startOffset, _labelDimensions.width - startOffset);
    }
    else // _hAlignment == TextHAlignment::RIGHT
    {
        endOffset = std::min(_linesWidth[i] + startOffset, _labelDimensions.width);
    }
}
else
{
    startOffset = _linesOffsetX[i];
    endOffset  = _linesWidth[i] + _linesOffsetX[i];
}

if (_strikethroughEnabled)
{
    auto y = nextY - lineHeight / 2;
    _lineDrawNode->drawLine(Vec2(startOffset, y), Vec2(endOffset, y), Color4F(lineColor), thickness);
}

if (_underlineEnabled)
{
    auto y = nextY - lineHeight;
    _lineDrawNode->drawLine(Vec2(startOffset, y), Vec2(endOffset, y), Color4F(lineColor), thickness);
}

That forces the cut-off so it never goes past the boundary of the label. That fixes the issue:

If you want to create a PR with that fix, then go for it. If not, let me know and I'll make one.

[aismann]

@rh101
Its your pr.
Thanks.

[rh101]

PR #2515 should fix the underline and strike-through.

For the incorrect character clipping, that is a separate issue, and has to do with calls to isHorizontalClamped. That should be handled in separate PR. Actually, never mind, I'll put this fix in the same PR.

[aismann]

An own issue is better

[aismann]

Works and closed.