Unfilled ellipses are not the default and fill(transparent) doesn't work.

[derekmulcahy]

I was trying to draw an unfilled ellipse. This code draws an unfilled ellipse and not a black filled ellipse.

    ellipse(tft.width()/2, tft.height()/2, 40, 40)
                    .fill((color_t)TFT_BLACK)
                    .draw();

This code draws an ellipse filled with black.

    ellipse(tft.width()/2, tft.height()/2, 40, 40)
                    .fill(transparent)
                    .draw();

I think the issue is the use of _fill as both a boolean and a value. It looks like seeed_graphics_base.cpp:102 should be

if (_fill != transparent) {

and not

if (_fill) {

[derekmulcahy]

Fixed by PR #6

[derekmulcahy]

Fixed and tested!