gofpdf_precision.go

func testRender() {

	pdf := gofpdf.New("P", "mm", "A3", "")
	pdf.AddPage()

	const x = 200.0
	const y = 200.0
	const gapAngle = 40.00
	const segmAngle = 16.00
	const lineWidthOuterRing = 0.20
	const lineWidthInnerRing = 0.25

	drawArcs := func(val int, rx, ry float64) {

		for i := 0; i <= 19; i++ {
			drawSegm := (val & (0x01 << uint(i))) != 0
			if drawSegm {
				rotAngle := 90.0 - (gapAngle / 2.0)
				rotAngle -= segmAngle
				rotAngle -= segmAngle * float64(i)
				pdf.Arc(x, y, rx, ry, rotAngle, 0.0, segmAngle, "D")
			}
		}
	}

	pdf.SetFillColor(0, 0, 0)

	pdf.SetLineWidth(lineWidthOuterRing)
	drawArcs(0xFFAAAAB, 1.0, 1.0)

	pdf.SetLineWidth(lineWidthInnerRing)
	drawArcs(0xFFAAAAB, 0.775, 0.775)

	pdf.OutputFileAndClose("arcs.pdf")
}