Store undo history as serialized patches

command.go

@@ -583,7 +583,9 @@ func (c *commandContext) AddSurface(resolution float32) bool {
 			it.Incr()
 		}
 	}
-	c.editor.merge(pcNew)
+	if err := c.editor.merge(pcNew); err != nil {
+		return false
+	}
 	c.setPointCloudUpdated()
 	return true
 }
@@ -631,8 +633,10 @@ func (c *commandContext) VoxelFilter(resolution float32) error {
 
 	if selected {
 		c.editor.passThrough(c.baseFilter(false))
-		c.editor.pop()
-		c.editor.merge(pcFiltered)
+		if err := c.editor.merge(pcFiltered); err != nil {
+			return err
+		}
+		c.editor.squashLatest()
 	} else {
 		if err := c.editor.SetPointCloud(pcFiltered, cloudMain); err != nil {
 			return err
@@ -731,7 +735,9 @@ func (c *commandContext) FinalizeCurrentMode() error {
 		for ; it.IsValid(); it.Incr() {
 			it.SetVec3(trans.Transform(it.Vec3()))
 		}
-		c.editor.merge(c.editor.ppSub)
+		if err := c.editor.merge(c.editor.ppSub); err != nil {
+			return err
+		}
 		c.setPointCloudUpdated()
 		c.UnsetCursors()
 	}

editor.go

@@ -12,7 +12,7 @@ const (
 )
 
 type editor struct {
-	history
+	*history
 	pp        *pc.PointCloud
 	ppSub     *pc.PointCloud
 	ppSubRect rect
@@ -33,17 +33,8 @@ func newEditor() *editor {
 	}
 }
 
-type history interface {
-	MaxHistory() int
-	SetMaxHistory(m int)
-	push(pp *pc.PointCloud) *pc.PointCloud
-	pop() *pc.PointCloud
-	undo() (*pc.PointCloud, bool)
-	clear()
-}
-
 func (e *editor) Undo() bool {
-	pp, ok := e.history.undo()
+	pp, ok := e.history.undo(e.pp)
 	if ok {
 		e.pp = pp
 	}
@@ -114,7 +105,12 @@ func (e *editor) SetPointCloud(pp *pc.PointCloud, id cloudID) error {
 	}
 	switch id {
 	case cloudMain:
-		e.pp = e.push(pcNew)
+		if e.pp != nil {
+			if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+				return err
+			}
+		}
+		e.pp = pcNew
 	case cloudSub:
 		e.ppSub = pcNew
 		it, err := pcNew.Vec3Iterator()
@@ -161,7 +157,10 @@ func (e *editor) label(fn func(int, mat.Vec3) (uint32, bool)) error {
 		itL.Incr()
 		i++
 	}
-	e.pp = e.push(pcNew)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pcNew
 	runtime.GC()
 	return nil
 }
@@ -171,7 +170,10 @@ func (e *editor) passThrough(fn func(int, mat.Vec3) bool) error {
 	if err != nil {
 		return err
 	}
-	e.pp = e.push(pp)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pp
 	runtime.GC()
 	return nil
 }
@@ -181,7 +183,10 @@ func (e *editor) passThroughByMask(sel []uint32, mask, val uint32) error {
 	if err != nil {
 		return err
 	}
-	e.pp = e.push(pp)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pp
 	runtime.GC()
 	return nil
 }
@@ -214,7 +219,10 @@ func (e *editor) relabelPointsInLabelRange(minLabel, maxLabel, newLabel uint32)
 		lt.SetUint32(newLabel)
 	}
 
-	e.pp = e.push(pcNew)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pcNew
 	runtime.GC()
 	return nil
 }
@@ -255,7 +263,10 @@ func (e *editor) unlabelPoints(labelsToKeep []uint32) error {
 		lt.SetUint32(0)
 	}
 
-	e.pp = e.push(pcNew)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pcNew
 	runtime.GC()
 	return nil
 }
@@ -347,7 +358,7 @@ func passThroughImpl(pp *pc.PointCloud, core func(_, _ *pc.PointCloud) int) (*pc
 	return pcNew, nil
 }
 
-func (e *editor) merge(pp *pc.PointCloud) {
+func (e *editor) merge(pp *pc.PointCloud) error {
 	pcNew := &pc.PointCloud{
 		PointCloudHeader: e.pp.PointCloudHeader.Clone(),
 		Points:           e.pp.Points + pp.Points,
@@ -356,6 +367,10 @@ func (e *editor) merge(pp *pc.PointCloud) {
 	pcNew.Width = pcNew.Points
 	pcNew.Height = 1
 
-	e.pp = e.push(pcNew)
+	if err := e.push(newUndoDataEntireCloud(e.pp)); err != nil {
+		return err
+	}
+	e.pp = pcNew
 	runtime.GC()
+	return nil
 }

history.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"bytes"
+
+	"github.com/seqsense/pcgol/pc"
+)
+
+type recordStore interface {
+	store(parts ...[]byte) record
+}
+
+type record interface {
+	load() []byte
+}
+
+type undoStep []record
+
+type history struct {
+	store      recordStore
+	steps      []undoStep
+	maxHistory int
+}
+
+func (h *history) MaxHistory() int {
+	return h.maxHistory
+}
+
+func (h *history) SetMaxHistory(m int) {
+	if m < 0 {
+		m = 0
+	}
+	h.maxHistory = m
+}
+
+func (h *history) push(d undoData) error {
+	var head bytes.Buffer
+	if err := encodeUndoData(&head, d); err != nil {
+		return err
+	}
+	h.steps = append(h.steps, undoStep{h.store.store(head.Bytes(), d.payload())})
+	for len(h.steps) > h.maxHistory {
+		h.steps[0] = nil
+		h.steps = h.steps[1:]
+	}
+	return nil
+}
+
+func (h *history) squashLatest() {
+	if n := len(h.steps); n >= 2 {
+		h.steps[n-2] = append(h.steps[n-2], h.steps[n-1]...)
+		h.steps[n-1] = nil
+		h.steps = h.steps[:n-1]
+	}
+}
+
+func (h *history) undo(pp *pc.PointCloud) (*pc.PointCloud, bool) {
+	n := len(h.steps)
+	if n == 0 {
+		return nil, false
+	}
+	step := h.steps[n-1]
+	for i := len(step) - 1; i >= 0; i-- {
+		d, err := decodeRecord(step[i].load())
+		if err != nil {
+			return nil, false
+		}
+		if pp, err = d.restore(pp); err != nil {
+			return nil, false
+		}
+	}
+	h.steps[n-1] = nil
+	h.steps = h.steps[:n-1]
+	return pp, true
+}
+
+func (h *history) clear() {
+	h.steps = nil
+}