gim: make outgoing edges also be split along the rectangle

gim/geo/geo.go

@@ -41,6 +41,24 @@ func abs(i int) int {
 	return i
 }
 
+// Abs returns the XY with all fields made positive, if they weren't already
+func (xy XY) Abs() XY {
+	return XY{abs(xy[0]), abs(xy[1])}
+}
+
+// Unit returns the XY with each field divided by its absolute value (i.e.
+// scaled down to 1 or -1). Fields which are 0 are left alone
+func (xy XY) Unit() XY {
+	for i := range xy {
+		if xy[i] > 0 {
+			xy[i] = 1
+		} else if xy[i] < 0 {
+			xy[i] = -1
+		}
+	}
+	return xy
+}
+
 // Len returns the length (aka magnitude) of the XY as a vector, using the
 // Rounder to round to an int
 func (xy XY) Len(r Rounder) int {

gim/line.go

@@ -41,58 +41,24 @@ var arrows = map[geo.XY]string{
 
 type line struct {
 	from, to   *box
-	toI      int
+	fromI, 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.from.rect(), l.to.rect()
-	rels := make([]int, len(geo.Units))
-	for i, dir := range geo.Units {
-		rels[i] = toRect.EdgeCoord(dir.Inv()) - fromRect.EdgeCoord(dir)
-		if dir == geo.Up || dir == geo.Left {
-			rels[i] *= -1
+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()
 }
-	}
-
-	var secondary geo.XY
-	var secondaryMax int
-	var secondarySet bool
-	for i, rel := range rels {
-		if geo.Units[i] == primary {
-			continue
-		} else if geo.Units[i][0] == 0 && primary[0] == 0 {
-			continue
-		} else if geo.Units[i][1] == 0 && primary[1] == 0 {
-			continue
-		} else if !secondarySet || rel > secondaryMax {
-			secondary = geo.Units[i]
-			secondaryMax = rel
-			secondarySet = true
-		}
-	}
-
-	return secondary
-}
-
-//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))
 
+	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 {

gim/main.go

@@ -17,7 +17,7 @@ import (
 // - Absolute positioning of some/all vertices
 
 // TODO
-// - assign edges to "slots" on boxes
+// - in current example, order of edges leaving "a" is fucked
 // - edge values
 // - be able to draw circular graphs
 // - audit all steps, make sure everything is deterministic
@@ -76,8 +76,8 @@ func mkGraph() (*gg.Graph, gg.Value) {
 func main() {
 	rand.Seed(time.Now().UnixNano())
 	term := terminal.New()
-	term.Reset()
-	term.HideCursor()
+	//term.Reset()
+	//term.HideCursor()
 
 	g, start := mkGraph()
 	v := view{
@@ -88,9 +88,10 @@ func main() {
 		center:      geo.Zero.Midpoint(term.WindowSize(), rounder),
 	}
 
-	for range time.Tick(frameperiod) {
+	//for range time.Tick(frameperiod) {
 	term.Reset()
 	v.draw(term)
 	term.Flush()
-	}
+	//}
+	time.Sleep(1 * time.Hour)
 }

gim/view.go

@@ -146,13 +146,29 @@ func (view *view) draw(term *terminal.Terminal) {
 		primPos += maxPrim + primPadding
 	}
 
+	// returns the index of this edge in from's Out
+	// TODO this might not be deterministic? Out is never ordered technically
+	findFromI := func(from *gg.Vertex, e gg.Edge) int {
+		for i, fe := range from.Out {
+			if fe == e {
+				return i
+			}
+		}
+		panic("edge not found in from.Out")
+	}
+
 	// create lines
 	var lines []line
 	for _, b := range boxes {
 		v := boxesM[b]
 		for i, e := range v.In {
 			bFrom := boxesMr[e.From]
-			lines = append(lines, line{from: bFrom, to: b, toI: i})
+			lines = append(lines, line{
+				from:  bFrom,
+				fromI: findFromI(e.From, e),
+				to:    b,
+				toI:   i,
+			})
 		}
 	}