Direct2d vertex shaded triangle / rectangle equivalent of GDI+ graphicspath

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C++

GDI+

graphics

Direct2D

So I've been working on an unmanaged C++ 2D MFC system in Visual Studio 2013 using GDI+ (Document View architecture). I need simple shapes shaded from each vertex of the shape - either a triangle with a color in each corner, blending those colors to the interior, or a rectangle doing the same.

In GDI plus, this is quite straightforward:

using namespace Gdiplus;
void DrawGradientTriangle( Graphics &rGraphics )
{
	Gdiplus::GraphicsPath gpath;
	gpath.AddLine( 100, 400, 200, 400 );
	gpath.AddLine( 200, 400, 150, 300 );
	gpath.CloseFigure();

	int nColorCount = 3;
	Color agdiClr[] =
	{
		Color::Red,
		Color::Green,
		Color::Blue
	};

	PathGradientBrush gbrush( &gpath );
	gbrush.SetSurroundColors( agdiClr, &nColorCount );
	gbrush.SetCenterColor( Color::White );
	rGraphics.FillPath( &gbrush, &gpath );
}

However, I have enough of these shapes that hardware acceleration would be appreciated, so I would like to move to D2D. Windows7 is the target and my understanding is that hardware acceleration is not necessarily provided with GDI+ in more recent OS's.

Is there any equivalent to this in Direct2D? I have been able to get most aspects of the system working well in D2D, but have not found any convenient way to mimic the above behavior. I know it can be done in Direct3D, but the infrastructure to get that going in an mfc program is a bit odious, and I'm not excited about going in that direction.

Any direction would be greatly appreciated.

What I have tried:

I have looked at more current options within D2D, especially drawing a gradient mesh (see https://github.com/Microsoft/Windows-universal-samples/blob/master/Samples/D2DGradientMesh/README.md) but these features appear to be only supported in Windows10 or later.