Question

I’ve used the following code to make 3 points, draw them to a bitmap, then draw the bitmap to the main form, however it seems to always draw point 3 before point 2, because the Y co-ordinate is lower then point 2’s. Is there a way to get over this, as I need a curve that curves up and down, rather than just up

            Bitmap bit = new Bitmap(490, 490);
            Graphics g = Graphics.FromImage(bit);
            Graphics form = this.CreateGraphics();
            pntPoints[0] = this.pictureBox1.Location;

            pntPoints[1] = new Point(100,300);
            pntPoints[2] = new Point(200, 150);
            g.DrawCurve(p, pntPoints);


            form.DrawImage(bit, 0, 5);

            bit.Dispose();
            g.Dispose();

Answer 1

Y-coordinate for point 3 is not lower, it’s actually higher. The (0;0) point of Graphics is in the left top corner, and the Y value increases from the top down rather than from the bottom up. So a point (0;100) will be higher than (0;200) on the result image.

If you want a curve that goes up then down, you should place your first point in (0; 489), your second point in (100, 190) and your third point in (200, 340).