setDrawColor sets incorrect color with CMYK input

[SmythConor]

When using setDrawColor with CMYK input, the color gets set incorrectly.
Reproduced on the live demo using the following code:

var doc = new jsPDF();

doc.setDrawColor(0.0, 0.0, 0.0, 1.0); // Should set draw color to black
doc.rect(20, 20, 10, 10);

The resulting output on the PDF displays a square with white borders.

The issue revolves around the encodeColorString function. When the "assume CMYK" branch is reached, the color values passed in are divided by 255 so they're being treated like RGB values. The documentation specifies that if using CMYK, the values passed in should be between 0.0 (0%) to 1.0 (100%) so there is no need to divide the parameters by anything to get the correct CMYK output.

Exact code snippet:

// assume CMYK
if (typeof ch1 === 'string') {
	color = [ch1, ch2, ch3, ch4, letterArray[2]].join(" ");
} else {
	switch (options.precision) {
		case 2:
                        // ** These should not be divided by 255 **
			color = [f2(ch1 / 255), f2(ch2 / 255), f2(ch3 / 255), f2(ch4 / 255), letterArray[2]].join(" ");
			break;

		case 3:
		default:
                        // ** These should not be divided by 255 **
			color = [f3(ch1 / 255), f3(ch2 / 255), f3(ch3 / 255), f3(ch4 / 255), letterArray[2]].join(" ");
	}
}

[Uzlopak]

What did you expect as a result?

[SmythConor]

I expect to see a black square.

[Uzlopak]

did you use setFillColor for the filling?

[SmythConor]

No, I used setDrawColor for the borders. I'm not calling rect with the fill styling so it should just draw the borders!

[Uzlopak]

Oh and The Last value gets 1/255 resulting in a wrong color?

[SmythConor]

Yes, but all the values gets divided by 255 resulting in the wrong color.

So from what I can tell, when the encodeColorString function assumes it's CMYK input, it should be handled like so:

// assume CMYK
if (typeof ch1 === 'string') {
	color = [ch1, ch2, ch3, ch4, letterArray[2]].join(" ");
} else {
	switch (options.precision) {
		case 2:
			color = [f2(ch1), f2(ch2), f2(ch3), f2(ch4), letterArray[2]].join(" ");
			break;
		case 3:
		default:
			color = [f3(ch1), f3(ch2), f3(ch3), f3(ch4), letterArray[2]].join(" ");
	}
}

This was the behaviour in 1.4.1.

[Uzlopak]

OK, I confirm this as a bug.

[SmythConor]

@arasabbasi just wondering if you could take a look at the pull request, maybe let me know why the build fails if the tests look like they're all green. Thanks!