CGContextAddLineToPoint no current point.

[yuravake]

When drawing LineChart i have a lot of warnings in console "CGContextAddLineToPoint: no current point." and "CGContextClosePath: no current point."

So i think, that LineChartRenderer missing CGPathMoveToPoint line at 234 or so, but can't figure out how to make it work... %)

[liuxuan30]

can we reproduce it with ChartsDemo? I don't see it in my project.
Also, what line chart type you are using, cubic or linear, and have you enabled dataSet.isDrawFilledEnabled

[yuravake]

i managed to get same error in ChartsDemo when i changed LineChartDataSet in LineChart1ViewController to follows :
[set1 setColor:[UIColor blackColor]];
set1.lineWidth = 3.0;
set1.fillAlpha = 1;
set1.fillColor = [UIColor blackColor];
set1.drawCubicEnabled = YES;
set1.drawFilledEnabled = YES;
set1.drawCirclesEnabled = NO;
set1.drawValuesEnabled = NO;

[liuxuan30]

I see it with:

    set1.drawCubicEnabled = YES;
    set1.drawFilledEnabled = YES;

function: internal func drawCubicFill

234        CGContextAddLineToPoint(context, pt1.x, pt1.y)
235        CGContextAddLineToPoint(context, pt2.x, pt2.y)

I see size - minx >= 2 is false, so the path is not fully initialized yet. Pending fix. You can use drawLinear right now

[yuravake]

so, the graph actually draws correctly...its just console messages...

[liuxuan30]

Find out more:
It's related with the animation:
phaseX is 0 at first if you turned on animate X, so it calculates the size to be 0:
let size = Int(ceil(CGFloat(maxx - minx) * phaseX + CGFloat(minx))), if you turn off animate X, drawCubic is also fine.
Though it won't crash nor incorerct rendering, still needs attension to fix.

[yuravake]

Yes, without X animation all good, thanks.

[danielgindi]

@liuxuan30 thanks for narrowing the case :-)

[liuxuan30]

@danielgindi I would help to fix, but drawLinear and drawCubic is a little complicated to find out the proper solution :( still learning when having some chances