Logical operation over layered DrawablePaths?


#1

Hi,

Because my english is poor and a image is sometimes better than words. This is 2 pictures to explain my problem.

void fillBackground (Graphics& g, 
					 bool isMouseOverButton, 
					 bool isButtonDown)
{
	const int width = getWidth();
	const int height = getHeight();

	const int hh = (height-2) / 2;

	Colour color11 = buttonColor.brighter	(0.40f); 
	Colour color12 = buttonColor.brighter	(0.05f);
	Colour color21 = buttonColor.darker		(0.05f);
	Colour color22 = buttonColor.darker		(0.40f);

	// Generate color scenario
	if (!isEnabled())
	{
		color11 = color11.darker (0.6f);
		color12 = color12.darker (0.6f);
		color21 = color21.darker (0.6f);
		color22 = color22.darker (0.6f);
	}
	else
	{
		if (isMouseOverButton)
		{
			color11 = color11.brighter (0.4f);
			color12 = color12.brighter (0.4f);
			color21 = color21.brighter (0.4f);
			color22 = color22.brighter (0.4f);
		}
		// cumuled
		if (isButtonDown)
		{
			color11 = color11.brighter (0.2f);
			color12 = color12.brighter (0.2f);
			color21 = color21.brighter (0.2f);
			color22 = color22.brighter (0.2f);
		}
	}

	FillType brush1 (ColourGradient (color11, 0, 2,		color12, 0, hh,			false));
	FillType brush2 (ColourGradient (color21, 0, 2+hh,	color22, 0, 2+hh+hh,	false));

	g.setFillType (brush1);
	g.fillRect (1, 1, width-2, hh);

	g.setFillType (brush2);
	g.fillRect (1, 1+hh, width-2, hh);

	if (isEnabled())
	{
		// Bump Approximation (light/shadow)

		// White (light from top left)
		g.setColour (Colours::white.withAlpha (0.25f));
		g.drawHorizontalLine (1, 1, width-3);
		g.drawVerticalLine (1, 1, height-3);

		// Black (shadow on bottom right)
		g.setColour (Colours::black.withAlpha (0.25f));
		g.drawHorizontalLine (height-1, 1, width);
		g.drawVerticalLine (width-1, 2, height-1);
	}

	// Main black border
	g.setColour (Colours::black);
	g.drawRect (0, 0, width-1, height-1, 1);
}

Maybe the solution is simple. I really hope and just want to keep the idea simple and clean, so just providing shapes like :


	Path item;

	if (name == "add") // cross shape
	{
		item.startNewSubPath	(0.00f, 0.30f);
		item.lineTo				(0.00f, 0.70f);
		item.lineTo				(0.30f, 0.70f);
		item.lineTo				(0.30f, 1.00f);
		item.lineTo				(0.70f, 1.00f);
		item.lineTo				(0.70f, 0.70f);
		item.lineTo				(1.00f, 0.70f);
		item.lineTo				(1.00f, 0.30f);
		item.lineTo				(0.70f, 0.30f);
		item.lineTo				(0.70f, 0.00f);
		item.lineTo				(0.30f, 0.00f);
		item.lineTo				(0.30f, 0.30f);
		item.closeSubPath		();
	}
	else
	if (name == "remove") // minus
	{
		item.startNewSubPath	(0.00f, 0.30f);
		item.lineTo				(0.00f, 0.70f);
		item.lineTo				(1.00f, 0.70f);
		item.lineTo				(1.00f, 0.30f);
		item.closeSubPath		();
	}

	return item;

Or maybe by a external xml description.

All ideas are welcome.

Thks.
Max


#2

Question so stupid? Maybe did I misunderstood something with paths?


#3

Sorry, I’m struggling to understand exactly what you’re asking…

The Path class doesn’t currently have any operations that will perform intersections - that’s quite a tricky algorithm and I never had chance to implement it.


#4

No worries, it was not a request for implementation, but just know if I missed something in the documentation. So it confirms that I need a little algorithm to mix two paths together. Thank you for your answer Jules.