Sometimes can't fill rectangle

[vrmvgf]

I draw and fill two rectangles, but the one drawn with variables can't be filled. Is there something wrong?

    public void button1_Click(object sender, EventArgs e)
    {
        var g = new SixLabors.ImageSharp.Image<Rgba32>(100,100);
        g.Mutate(x => x.Fill(Color.White));
        int IH2 = 50; int IB=60; int IH1 =30;
        float SCALE = 1.0F; 
        float HS = SCALE * IH2; float B1S = SCALE * IB; float H1S = SCALE * IH1;
        float YSHFT = 50.0F + HS / 2; float XSHFT = 50.0F - B1S / 2;
        IBrush bru1 = Brushes.Percent20(Color.Blue);

        g.Mutate(x => x.Draw(Color.Blue, 2, RectangleF.FromLTRB(XSHFT, YSHFT, XSHFT + B1S, YSHFT - H1S))
        .Fill(bru1, RectangleF.FromLTRB(XSHFT, YSHFT, XSHFT + B1S, YSHFT - H1S)));
        //Can't fill

        g.Mutate(x => x.Draw(Color.Blue, 2, RectangleF.FromLTRB(10, 10, 70, 30))
        .Fill(bru1, RectangleF.FromLTRB(10, 10, 70, 30)));
        //Can fill

        g.Save("bar1.jpg");
        pictureBox1.Image = System.Drawing.Image.FromFile("bar1.jpg");
    }

[JimBobSquarePants]

Your rectangle has a negative height.

[vrmvgf]

Thank you!

[tocsoft]

I would say this is probably still a bug despite it being a negative height. if we can outline it then we should be able to fill it.... deciding on the exact behaviour now would be the question.

Basically should we ignore the fact the hight was negative normalise the region and fill as though it was well formed and positive in the first place, or should the negative texture/brush be applied in some reversed direction (mostly important for image brushes but would probably also effect gradient brushes too.)

[JimBobSquarePants]

How were we able to outline it as a rectangle with negative height? Surely that is the bug?

[antonfirsov]

Shouldn't FromLTRB throw when Width or Height is negative?

[JimBobSquarePants]

That screenshot is actually System.Drawing RectangleF. I copied their implementation.