From 91209fd5406d1135b5b5ea64db787a5db6c25dd2 Mon Sep 17 00:00:00 2001
From: gravestench <dknuth0101@gmail.com>
Date: Tue, 30 Mar 2021 11:04:25 -0700
Subject: [PATCH] add more ds1version methods

---
 d2common/d2fileformats/d2ds1/ds1.go         |  8 ++++----
 d2common/d2fileformats/d2ds1/ds1_version.go | 13 +++++++++++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/d2common/d2fileformats/d2ds1/ds1.go b/d2common/d2fileformats/d2ds1/ds1.go
index 8635c416..d78d553d 100644
--- a/d2common/d2fileformats/d2ds1/ds1.go
+++ b/d2common/d2fileformats/d2ds1/ds1.go
@@ -340,7 +340,7 @@ func (ds1 *DS1) loadSubstitutions(br *d2datautils.StreamReader) error {
 func (ds1 *DS1) getLayerSchema() []layerStreamType {
 	var layerStream []layerStreamType
 
-	if ds1.version < v4 {
+	if ds1.version.hasStandardLayers() {
 		layerStream = []layerStreamType{
 			layerStreamWall1,
 			layerStreamFloor1,
@@ -391,7 +391,7 @@ func (ds1 *DS1) getLayerSchema() []layerStreamType {
 func (ds1 *DS1) loadNPCs(br *d2datautils.StreamReader) error {
 	var err error
 
-	if ds1.version < v14 {
+	if !ds1.version.specifiesNPCs() {
 		return nil
 	}
 
@@ -432,7 +432,7 @@ func (ds1 *DS1) loadNPCs(br *d2datautils.StreamReader) error {
 				return fmt.Errorf("loading paths for NPC %d: %v", npcIdx, err)
 			}
 		} else {
-			if ds1.version >= v15 {
+			if ds1.version.specifiesNPCActions() {
 				br.SkipBytes(int(numPaths) * 3) //nolint:gomnd // Unknown data
 			} else {
 				br.SkipBytes(int(numPaths) * 2) //nolint:gomnd // Unknown data
@@ -463,7 +463,7 @@ func (ds1 *DS1) loadNpcPaths(br *d2datautils.StreamReader, objIdx, numPaths int)
 
 		newPath.Position = d2vector.NewPosition(float64(px), float64(py))
 
-		if ds1.version >= v15 {
+		if ds1.version.specifiesNPCActions() {
 			action, err := br.ReadInt32()
 			if err != nil {
 				return fmt.Errorf("reading action for path %d: %v", pathIdx, err)
diff --git a/d2common/d2fileformats/d2ds1/ds1_version.go b/d2common/d2fileformats/d2ds1/ds1_version.go
index b424c28d..94d9afa4 100644
--- a/d2common/d2fileformats/d2ds1/ds1_version.go
+++ b/d2common/d2fileformats/d2ds1/ds1_version.go
@@ -36,6 +36,11 @@ func (v ds1version) specifiesSubstitutionType() bool {
 	return v >= v10
 }
 
+func (v ds1version) hasStandardLayers() bool {
+	// 1 of each layer, very simple ds1
+	return v < v4
+}
+
 func (v ds1version) specifiesWalls() bool {
 	// just after header, specifies number of Walls
 	return v >= v4
@@ -57,3 +62,11 @@ func (v ds1version) hasObjects() bool {
 func (v ds1version) hasSubstitutions() bool {
 	return v >= v12
 }
+
+func (v ds1version) specifiesNPCs() bool {
+	return v > v14
+}
+
+func (v ds1version) specifiesNPCActions() bool {
+	return v > v15
+}