gim: move line drawing code into terminal. drawing the line body is kind of busted, but whatever

gim/line.go

@@ -8,68 +8,26 @@ import (
 type line struct {
 	from, to   *box
 	fromI, toI int
-	body       string
-}
-
-// given the "primary" direction the line should be headed, picks a possible
-// secondary one which may be used to detour along the path in order to reach
-// the destination (in the case that the two boxes are diagonal from each other)
-func secondaryDir(flowDir, start, end geo.XY) geo.XY {
-	var perpDir geo.XY
-	perpDir[0], perpDir[1] = flowDir[1], flowDir[0]
-	return end.Sub(start).Mul(perpDir.Abs()).Unit()
+	bodyBuf    *terminal.Buffer
 }
 
 func (l line) draw(buf *terminal.Buffer, flowDir, secFlowDir geo.XY) {
 	from, to := *(l.from), *(l.to)
-
 	start := from.rect().Edge(flowDir, secFlowDir)[0].Add(secFlowDir.Scale(l.fromI*2 + 1))
-	end := to.rect().Edge(flowDir.Inv(), secFlowDir)[0].Add(secFlowDir.Scale(l.toI*2 + 1))
-	dirSec := secondaryDir(flowDir, start, end)
-	mid := start.Midpoint(end, rounder)
-
-	along := func(xy, dir geo.XY) int {
-		if dir[0] != 0 {
-			return xy[0]
-		}
-		return xy[1]
-	}
-
-	// collect the points along the line into an array
-	var pts []geo.XY
-	midPrim := along(mid, flowDir)
-	endSec := along(end, dirSec)
-	for curr := start; curr != end; {
-		pts = append(pts, curr)
-		if prim := along(curr, flowDir); prim == midPrim {
-			if sec := along(curr, dirSec); sec != endSec {
-				curr = curr.Add(dirSec)
-				continue
-			}
-		}
-		curr = curr.Add(flowDir)
-	}
+	end := to.rect().Edge(flowDir.Inv(), secFlowDir)[0]
+	end = end.Add(flowDir.Inv())
+	end = end.Add(secFlowDir.Scale(l.toI*2 + 1))
 
-	// draw each point
-	for i, pt := range pts {
-		var r rune
-		switch {
-		case i == 0:
-			r = terminal.SingleLine.Perpendicular(flowDir)
-		case i == len(pts)-1:
-			r = terminal.SingleLine.Arrow(flowDir)
-		default:
-			prev, next := pts[i-1], pts[i+1]
-			r = terminal.SingleLine.Segment(prev.Sub(pt), next.Sub(pt))
-		}
-		buf.SetPos(pt)
-		buf.WriteRune(r)
-	}
+	buf.SetPos(start)
+	buf.WriteRune(terminal.SingleLine.Perpendicular(flowDir))
+	buf.DrawLine(start.Add(flowDir), end.Add(flowDir.Inv()), flowDir, terminal.SingleLine)
+	buf.SetPos(end)
+	buf.WriteRune(terminal.SingleLine.Arrow(flowDir))
 
 	// draw the body
-	if l.body != "" {
-		bodyPos := mid.Add(geo.Left.Scale(len(l.body) / 2))
-		buf.SetPos(bodyPos)
-		buf.WriteString(l.body)
+	if l.bodyBuf != nil {
+		mid := start.Midpoint(end, rounder)
+		bodyBufRect := geo.Rect{Size: l.bodyBuf.Size()}
+		buf.DrawBuffer(bodyBufRect.Centered(mid, rounder).TopLeft, l.bodyBuf)
 	}
 }

gim/terminal/shape.go

@@ -133,3 +133,60 @@ func (b *Buffer) DrawRect(r geo.Rect, ls LineStyle) {
 	b.WriteString(horiz)
 	b.WriteRune(ls.BottomRight)
 }
+
+// DrawLine draws a line from the start point to the ending one, primarily
+// moving in the given direction, using the given LineStyle to do so.
+func (b *Buffer) DrawLine(start, end, dir geo.XY, ls LineStyle) {
+	// given the "primary" direction the line should be headed, pick a possible
+	// secondary one which may be used to detour along the path in order to
+	// reach the destination (in the case that the two boxes are diagonal from
+	// each other)
+	var perpDir geo.XY
+	perpDir[0], perpDir[1] = dir[1], dir[0]
+	dirSec := end.Sub(start).Mul(perpDir.Abs()).Unit()
+
+	// TODO gross that this doesn't have some way of discovering the rounder.
+	// Maybe rounder should just be a global? ugh...
+	mid := start.Midpoint(end, geo.Round)
+
+	along := func(xy, dir geo.XY) int {
+		if dir[0] != 0 {
+			return xy[0]
+		}
+		return xy[1]
+	}
+
+	// collect the points along the line into an array
+	var pts []geo.XY
+	var curr geo.XY
+	midPrim := along(mid, dir)
+	endSec := along(end, dirSec)
+	for curr = start; curr != end; {
+		pts = append(pts, curr)
+		if prim := along(curr, dir); prim == midPrim {
+			if sec := along(curr, dirSec); sec != endSec {
+				curr = curr.Add(dirSec)
+				continue
+			}
+		}
+		curr = curr.Add(dir)
+	}
+	pts = append(pts, curr) // appending end
+
+	// draw each point
+	for i, pt := range pts {
+		var prev, next geo.XY
+		switch {
+		case i == 0:
+			prev = pt.Add(dir.Inv())
+			next = pts[i+1]
+		case i == len(pts)-1:
+			prev = pts[i-1]
+			next = pt.Add(dir)
+		default:
+			prev, next = pts[i-1], pts[i+1]
+		}
+		b.SetPos(pt)
+		b.WriteRune(ls.Segment(prev.Sub(pt), next.Sub(pt)))
+	}
+}

gim/view.go

@@ -163,12 +163,14 @@ func (view *view) draw(buf *terminal.Buffer) {
 		for i, e := range v.In {
 			bFrom := boxesMr[e.From]
 			fromI := findFromI(e.From, e)
+			buf := terminal.NewBuffer()
+			buf.WriteString(e.Value.V.(string))
 			lines = append(lines, line{
-				from:  bFrom,
-				fromI: fromI,
-				to:    b,
-				toI:   i,
-				body:  e.Value.V.(string),
+				from:    bFrom,
+				fromI:   fromI,
+				to:      b,
+				toI:     i,
+				bodyBuf: buf,
 			})
 		}
 	}