gim: make incoming edges separate along the drawn rectangle edge, instead of all overlapping onto the same point

gg/gg.go

@@ -437,6 +437,9 @@ func Equal(g1, g2 *Graph) bool {
 	return true
 }
 
+// TODO Walk, but by edge
+// TODO Walk, but without end. AKA FSM
+
 // Walk will traverse the Graph, calling the callback on every Vertex in the
 // Graph once. If startWith is non-nil then that Vertex will be the first one
 // passed to the callback and used as the starting point of the traversal. If

gim/geo/rect.go

@@ -11,11 +11,15 @@ type Rect struct {
 	Size    XY
 }
 
-// Edge returns the coordinate of the edge indicated by the given direction (Up,
-// Down, Left, or Right). The coordinate will be for the axis applicable to the
-// direction, so for Left/Right it will be the x coordinate and for Up/Down the
-// y.
-func (r Rect) Edge(dir XY) int {
+// Edge describes a straight edge starting at its first XY and ending at its
+// second
+type Edge [2]XY
+
+// EdgeCoord returns the coordinate of the edge indicated by the given direction
+// (Up, Down, Left, or Right). The coordinate will be for the axis applicable to
+// the direction, so for Left/Right it will be the x coordinate and for Up/Down
+// the y.
+func (r Rect) EdgeCoord(dir XY) int {
 	switch dir {
 	case Up:
 		return r.TopLeft[1]
@@ -49,25 +53,37 @@ func (r Rect) Corner(xDir, yDir XY) XY {
 	}
 }
 
-// EdgeMidpoint returns the point which is the midpoint of the edge dientified by the
-// direction (Up/Down/Left/Right)
-func (r Rect) EdgeMidpoint(dir XY, rounder Rounder) XY {
-	var a, b XY
+// Edge returns an Edge instance for the edge of the Rect indicated by the given
+// direction (Up, Down, Left, or Right). secDir indicates the direction the
+// returned Edge should be pointing (i.e. the order of its XY's) and must be
+// perpendicular to dir
+func (r Rect) Edge(dir, secDir XY) Edge {
+	var e Edge
 	switch dir {
 	case Up:
-		a, b = r.Corner(Left, Up), r.Corner(Right, Up)
+		e[0], e[1] = r.Corner(Left, Up), r.Corner(Right, Up)
 	case Down:
-		a, b = r.Corner(Left, Down), r.Corner(Right, Down)
+		e[0], e[1] = r.Corner(Left, Down), r.Corner(Right, Down)
 	case Left:
-		a, b = r.Corner(Left, Up), r.Corner(Left, Down)
+		e[0], e[1] = r.Corner(Left, Up), r.Corner(Left, Down)
 	case Right:
-		a, b = r.Corner(Right, Up), r.Corner(Right, Down)
+		e[0], e[1] = r.Corner(Right, Up), r.Corner(Right, Down)
 	default:
 		panic(fmt.Sprintf("unsupported direction: %#v", dir))
 	}
 
-	mid := a.Midpoint(b, rounder)
-	return mid
+	switch secDir {
+	case Left, Up:
+		e[0], e[1] = e[1], e[0]
+	default:
+		// do nothing
+	}
+	return e
+}
+
+// Midpoint returns the point which is the midpoint of the Edge
+func (e Edge) Midpoint(rounder Rounder) XY {
+	return e[0].Midpoint(e[1], rounder)
 }
 
 func (r Rect) halfSize(rounder Rounder) XY {

gim/geo/rect_test.go

@@ -12,15 +12,29 @@ func TestRect(t *T) {
 		Size:    XY{2, 2},
 	}
 
-	assert.Equal(t, 2, r.Edge(Up))
-	assert.Equal(t, 3, r.Edge(Down))
-	assert.Equal(t, 1, r.Edge(Left))
-	assert.Equal(t, 2, r.Edge(Right))
+	assert.Equal(t, 2, r.EdgeCoord(Up))
+	assert.Equal(t, 3, r.EdgeCoord(Down))
+	assert.Equal(t, 1, r.EdgeCoord(Left))
+	assert.Equal(t, 2, r.EdgeCoord(Right))
 
-	assert.Equal(t, XY{1, 2}, r.Corner(Left, Up))
-	assert.Equal(t, XY{1, 3}, r.Corner(Left, Down))
-	assert.Equal(t, XY{2, 2}, r.Corner(Right, Up))
-	assert.Equal(t, XY{2, 3}, r.Corner(Right, Down))
+	lu := XY{1, 2}
+	ld := XY{1, 3}
+	ru := XY{2, 2}
+	rd := XY{2, 3}
+
+	assert.Equal(t, lu, r.Corner(Left, Up))
+	assert.Equal(t, ld, r.Corner(Left, Down))
+	assert.Equal(t, ru, r.Corner(Right, Up))
+	assert.Equal(t, rd, r.Corner(Right, Down))
+
+	assert.Equal(t, Edge{lu, ld}, r.Edge(Left, Down))
+	assert.Equal(t, Edge{ru, rd}, r.Edge(Right, Down))
+	assert.Equal(t, Edge{lu, ru}, r.Edge(Up, Right))
+	assert.Equal(t, Edge{ld, rd}, r.Edge(Down, Right))
+	assert.Equal(t, Edge{ld, lu}, r.Edge(Left, Up))
+	assert.Equal(t, Edge{rd, ru}, r.Edge(Right, Up))
+	assert.Equal(t, Edge{ru, lu}, r.Edge(Up, Left))
+	assert.Equal(t, Edge{rd, ld}, r.Edge(Down, Left))
 }
 
 func TestRectCenter(t *T) {

gim/line.go

@@ -39,16 +39,19 @@ var arrows = map[geo.XY]string{
 	geo.Right: ">",
 }
 
-type line [2]*box
+type line struct {
+	from, to *box
+	toI      int
+}
 
 // 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 (l line) secondaryDir(primary geo.XY) geo.XY {
-	fromRect, toRect := l[0].rect(), l[1].rect()
+	fromRect, toRect := l.from.rect(), l.to.rect()
 	rels := make([]int, len(geo.Units))
 	for i, dir := range geo.Units {
-		rels[i] = toRect.Edge(dir.Inv()) - fromRect.Edge(dir)
+		rels[i] = toRect.EdgeCoord(dir.Inv()) - fromRect.EdgeCoord(dir)
 		if dir == geo.Up || dir == geo.Left {
 			rels[i] *= -1
 		}
@@ -74,13 +77,22 @@ func (l line) secondaryDir(primary geo.XY) geo.XY {
 	return secondary
 }
 
-func (l line) draw(term *terminal.Terminal, dir geo.XY) {
-	from, to := *l[0], *l[1]
-	dirSec := l.secondaryDir(dir)
+//func (l line) startEnd(flowDir, secFlowDir geo.XY) (geo.XY, geo.XY) {
+//	from, to := *(l.from), *(l.to)
+//	start := from.rect().EdgeMidpoint(flowDir, rounder) // ezpz
+//}
+
+func (l line) draw(term *terminal.Terminal, flowDir, secFlowDir geo.XY) {
+	from, to := *(l.from), *(l.to)
+	dirSec := l.secondaryDir(flowDir)
+
+	flowDirInv := flowDir.Inv()
+	start := from.rect().Edge(flowDir, secFlowDir).Midpoint(rounder)
+
+	endSlot := l.toI*2 + 1
+	endSlotXY := geo.XY{endSlot, endSlot}
+	end := to.rect().Edge(flowDirInv, secFlowDir)[0].Add(secFlowDir.Mul(endSlotXY))
 
-	dirInv := dir.Inv()
-	start := from.rect().EdgeMidpoint(dir, rounder)
-	end := to.rect().EdgeMidpoint(dirInv, rounder)
 	mid := start.Midpoint(end, rounder)
 
 	along := func(xy, dir geo.XY) int {
@@ -91,26 +103,26 @@ func (l line) draw(term *terminal.Terminal, dir geo.XY) {
 	}
 
 	var pts []geo.XY
-	midPrim := along(mid, dir)
+	midPrim := along(mid, flowDir)
 	endSec := along(end, dirSec)
 	for curr := start; curr != end; {
 		pts = append(pts, curr)
-		if prim := along(curr, dir); prim == midPrim {
+		if prim := along(curr, flowDir); prim == midPrim {
 			if sec := along(curr, dirSec); sec != endSec {
 				curr = curr.Add(dirSec)
 				continue
 			}
 		}
-		curr = curr.Add(dir)
+		curr = curr.Add(flowDir)
 	}
 
 	for i, pt := range pts {
 		var str string
 		switch {
 		case i == 0:
-			str = edgeSegments[dir]
+			str = edgeSegments[flowDir]
 		case i == len(pts)-1:
-			str = arrows[dir]
+			str = arrows[flowDir]
 		default:
 			prev, next := pts[i-1], pts[i+1]
 			seg := [2]geo.XY{

gim/view.go

@@ -150,9 +150,9 @@ func (view *view) draw(term *terminal.Terminal) {
 	var lines []line
 	for _, b := range boxes {
 		v := boxesM[b]
-		for _, e := range v.In {
+		for i, e := range v.In {
 			bFrom := boxesMr[e.From]
-			lines = append(lines, line{bFrom, b})
+			lines = append(lines, line{from: bFrom, to: b, toI: i})
 		}
 	}
 
@@ -164,6 +164,6 @@ func (view *view) draw(term *terminal.Terminal) {
 		b.draw(term)
 	}
 	for _, line := range lines {
-		line.draw(term, view.primFlowDir)
+		line.draw(term, view.primFlowDir, view.secFlowDir)
 	}
 }