Trim map based on trailer data

internal/maps/maps.go

@@ -15,8 +15,8 @@ import (
 )
 
 var (
-	expectedMagic         = []byte("\x08\x00WHMAP\x00")
+	expectedMagic         = []byte("\x15\x00AMB_MAP\x00")
-	expectedSetNameOffset = uint32(0x34)
+	expectedSetNameOffset = uint32(0x10)
 	notImplemented        = fmt.Errorf("Not implemented")
 )
 
@@ -25,27 +25,17 @@ const (
 	MaxLength = 100 // Y coordinate
 	MaxWidth  = 130 // X coordinate
 
-	CellSize = 16 // seems to be
+	CellSize = 13 // seems to be
 
-	cellDataOffset = 0x110 // definitely
+	cellDataOffset = 0xc0
 	cellCount      = MaxHeight * MaxLength * MaxWidth
 )
 
 type Header struct {
-	IsCampaignMap uint32 // Tentatively: 0 = no, 1 = yes
+	Magic   [10]byte // "\x15\x00AMB_MAP\x00"
-	MinWidth      uint32
+	SetName [8]byte  // Links to a filename in `/Sets/*.set`
-	MinLength     uint32
-	MaxWidth      uint32
-	MaxLength     uint32
-	Unknown1      uint32
-	Unknown2      uint32
-	Unknown3      uint32
-	Unknown4      uint32
-	Magic         [8]byte // "\x08\x00WHMAP\x00"
-	Unknown5      uint32
-	Unknown6      uint32
-	SetName       [8]byte // Links to a filename in `/Sets/*.set`
 	// Need to investigate the rest of the header too
+	IsCampaignMap byte
 }
 
 type TrailerHeader struct {
@@ -82,18 +72,6 @@ type Thingy struct {}
 
 type Thingies []Thingy
 
-func (h Header) Width() int {
-	return int(h.MaxWidth - h.MinWidth)
-}
-
-func (h Header) Length() int {
-	return int(h.MaxLength - h.MinLength)
-}
-
-func (h Header) Height() int {
-	return MaxHeight
-}
-
 func (h Header) MapSetName() string {
 	idx := bytes.IndexByte(h.SetName[:], 0)
 	if idx < 0 {
@@ -114,7 +92,7 @@ type ObjRef struct {
 
 // The index into a set palette to retrieve the object
 func (o ObjRef) Index() int {
-	return int(o.AreaByte)
+	return int(o.AreaByte & 0x7f)
 }
 
 func (o ObjRef) Sprite() int {
@@ -125,12 +103,13 @@ func (o ObjRef) Sprite() int {
 // The top bit seems to say whether we should draw or not.
 func (o ObjRef) IsActive() bool {
 	return (o.SpriteAndFlagByte & 0x80) == 0x80
-}
+} // PARIS is 78 x 60 x 7
-
+//          4E   3C   7
+/*
 type Cell struct {
 	DoorAndCanisterRelated    byte
-	DoorLockAndReactorRelated byte
+//	DoorLockAndReactorRelated byte
-	Unknown2                  byte
+//	Unknown2                  byte
 	Surface                   ObjRef
 	Left                      ObjRef
 	Right                     ObjRef
@@ -139,43 +118,60 @@ type Cell struct {
 	Unknown12                 byte
 	Unknown13                 byte
 	Unknown14                 byte
-	SquadRelated              byte
+//	SquadRelated              byte
+}*/
+
+type Cell struct {
+	Unknown1 byte
+	Surface  ObjRef
+	Left     ObjRef
+	Right    ObjRef
+	Center   ObjRef
+	Unknown2 [4]byte
+
+	/*
+	   	DoorAndCanisterRelated    byte
+	   //	DoorLockAndReactorRelated byte
+	   //	Unknown2                  byte
+	   	Surface                   ObjRef
+	   	Left                      ObjRef
+	   	Right                     ObjRef
+	   	Center                    ObjRef
+	   	Unknown11                 byte
+	   	Unknown12                 byte
+	   	Unknown13                 byte
+	   	Unknown14                 byte
+	   	SquadRelated              byte*/
 }
 
 func (c *Cell) At(n int) byte {
 	switch n {
 	case 0:
-		return c.DoorAndCanisterRelated
+		return c.Unknown1
 	case 1:
-		return c.DoorLockAndReactorRelated
-	case 2:
-		return c.Unknown2
-	case 3:
 		return c.Surface.AreaByte
-	case 4:
+	case 2:
 		return c.Surface.SpriteAndFlagByte
-	case 5:
+	case 3:
 		return c.Left.AreaByte
-	case 6:
+	case 4:
 		return c.Left.SpriteAndFlagByte
-	case 7:
+	case 5:
 		return c.Right.AreaByte
-	case 8:
+	case 6:
 		return c.Right.SpriteAndFlagByte
-	case 9:
+	case 7:
 		return c.Center.AreaByte
-	case 10:
+	case 8:
 		return c.Center.SpriteAndFlagByte
+	case 9:
+		return c.Unknown2[0]
+	case 10:
+		return c.Unknown2[1]
 	case 11:
-		return c.Unknown11
+		return c.Unknown2[2]
 	case 12:
-		return c.Unknown12
+		return c.Unknown2[3]
-	case 13:
-		return c.Unknown13
-	case 14:
-		return c.Unknown14
-	case 15:
-		return c.SquadRelated
 	}
 
 	return 0
@@ -184,15 +180,23 @@ func (c *Cell) At(n int) byte {
 // Cells is always a fixed size; use At to get a cell according to x,y,z
 type Cells []Cell
 
+// 6 Possibilities for being laid out in memory. Most likely:
+// XXYYZZ
+// OR
+// XYZXYZ
+
 func (c Cells) At(x, y, z int) Cell {
-	return c[(z*MaxLength*MaxWidth)+(y*MaxWidth)+x]
+	//	log.Printf("At (%v,%v,%v)=%v", x, y, z, x*y*z)
+	return c[(z*MaxLength*MaxWidth)+
+		(y*MaxWidth)+
+		x]
 }
 
 func (h Header) Check() []error {
 	var out []error
-	if h.IsCampaignMap > 1 {
+	//	if h.IsCampaignMap > 1 {
-		out = append(out, fmt.Errorf("Expected 0 or 1 for IsCampaignMap, got %v", h.IsCampaignMap))
+	//		out = append(out, fmt.Errorf("Expected 0 or 1 for IsCampaignMap, got %v", h.IsCampaignMap))
-	}
+	//	}
 
 	if bytes.Compare(expectedMagic, h.Magic[:]) != 0 {
 		out = append(out, fmt.Errorf("Unexpected magic value: %v", h.Magic))
@@ -217,10 +221,10 @@ type GameMap struct {
 
 func (m *GameMap) Rect() image.Rectangle {
 	return image.Rect(
-		int(m.Header.MinWidth),
+		int(m.TrailerHeader.MinWidth),
-		int(m.Header.MinLength),
+		int(m.TrailerHeader.MinLength),
-		int(m.Header.MaxWidth),
+		int(m.TrailerHeader.MaxWidth-1),
-		int(m.Header.MaxLength),
+		int(m.TrailerHeader.MaxLength-1),
 	)
 }
 
@@ -327,6 +331,11 @@ func loadMapFile(filename string) (*GameMap, error) {
 		return nil, fmt.Errorf("Error parsing cells for %s: %v", filename, err)
 	}
 
+	// no gzip.SeekReader, so discard unread trailer bytes for now
+	if _, err := io.CopyN(ioutil.Discard, zr, int64(3320-2)); err != nil { // observed
+		return nil, err
+	}
+
 	if err := binary.Read(zr, binary.LittleEndian, &out.TrailerHeader); err != nil {
 		return nil, fmt.Errorf("Error parsing trailer header for %s: %v", filename, err)
 	}