Method Draw

private/segdisp/sixteen/sixteen.go:380–440

Draw draws the current state of the segment display onto the canvas. The canvas must be at least MinCols x MinRows cells, or an error will be returned. Any options provided to draw overwrite the values provided to New.

(cvs *canvas.Canvas, opts ...Option)

// returned.
// Any options provided to draw overwrite the values provided to New.
func (d *Display) Draw(cvs *canvas.Canvas, opts ...Option) error {
	for _, o := range opts {
		o.set(d)
	}

	bc, bcAr, err := segdisp.ToBraille(cvs)
	if err != nil {
		return err
	}

	attr := NewAttributes(bcAr)
	var sOpts []segment.Option
	if len(d.cellOpts) > 0 {
		sOpts = append(sOpts, segment.CellOpts(d.cellOpts...))
	}
	for _, segArg := range []struct {
		s    Segment
		opts []segment.Option
	}{
		{A1, nil},
		{A2, nil},

		{F, nil},
		{J, []segment.Option{segment.SkipSlopesLTE(2)}},
		{B, []segment.Option{segment.ReverseSlopes()}},

		{G1, []segment.Option{segment.SkipSlopesLTE(2)}},
		{G2, []segment.Option{segment.SkipSlopesLTE(2)}},

		{E, nil},
		{M, []segment.Option{segment.SkipSlopesLTE(2)}},
		{C, []segment.Option{segment.ReverseSlopes()}},

		{D1, []segment.Option{segment.ReverseSlopes()}},
		{D2, []segment.Option{segment.ReverseSlopes()}},
	} {
		if !d.segments[segArg.s] {
			continue
		}
		sOpts := append(sOpts, segArg.opts...)
		ar := attr.hvSegArea(segArg.s)
		if err := segment.HV(bc, ar, hvSegType[segArg.s], sOpts...); err != nil {
			return fmt.Errorf("failed to draw segment %v, segment.HV => %v", segArg.s, err)
		}
	}

	var dsOpts []segment.DiagonalOption
	if len(d.cellOpts) > 0 {
		dsOpts = append(dsOpts, segment.DiagonalCellOpts(d.cellOpts...))
	}
	for _, seg := range []Segment{H, K, N, L} {
		if !d.segments[seg] {
			continue
		}
		ar := attr.diaSegArea(seg)
		if err := segment.Diagonal(bc, ar, attr.segSize, diaSegType[seg], dsOpts...); err != nil {
			return fmt.Errorf("failed to draw segment %v, segment.Diagonal => %v", seg, err)
		}