Switch from encoding/binary to struc

It's not perfect, but struc can deserialize the whole thing into one
struct while encoding/binary can't. It's nice to have that.

cmd/loader/main.go

@@ -139,16 +139,15 @@ func loadMapsFrom(mapsPath string) {
 	}
 
 	log.Printf("Maps in %s:", mapsPath)
-	for key, gameMap := range gameMaps {
+	for key, gm := range gameMaps {
-		rect := gameMap.Rect()
+		rect := gm.Rect()
-		hdr := gameMap.Header
 		fmt.Printf(
 			"    * `%s`: IsCampaignMap=%v W=%v:%v L=%v:%v SetName=%s\n",
 			key,
-			hdr.IsCampaignMap,
+			gm.IsCampaignMap,
 			rect.Min.X, rect.Max.X,
 			rect.Min.Y, rect.Max.Y,
-			string(hdr.SetName[:]),
+			string(gm.SetName),
 		)
 	}
 }

cmd/view-minimap/main.go

@@ -181,8 +181,8 @@ func (e *env) Draw(screen *ebiten.Image) error {
 
 	for y := int(rect.Min.Y); y < int(rect.Max.Y); y++ {
 		for x := int(rect.Min.X); x < int(rect.Max.X); x++ {
-			cell := gameMap.Cells.At(x, y, int(e.state.zIdx))
+			cell := gameMap.At(x, y, int(e.state.zIdx))
-			imd.Set(x, y, makeColour(&cell, e.state.cellIdx))
+			imd.Set(x, y, makeColour(cell, e.state.cellIdx))
 		}
 	}
 

go.mod

@@ -8,7 +8,9 @@ require (
 	github.com/hajimehoshi/ebiten v1.11.1
 	github.com/jfreymuth/oggvorbis v1.0.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/lunixbochs/struc v0.0.0-20200521075829-a4cb8d33dbbe
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/samuel/go-pcx v0.0.0-20180426214139-d9c017170db4
 	github.com/stretchr/testify v1.5.1
 	golang.org/x/exp v0.0.0-20200331195152-e8c3332aa8e5 // indirect
@@ -16,4 +18,5 @@ require (
 	golang.org/x/mobile v0.0.0-20200329125638-4c31acba0007 // indirect
 	golang.org/x/sys v0.0.0-20200413165638-669c56c373c4 // indirect
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
+	gopkg.in/restruct.v1 v1.0.0-20190323193435-3c2afb705f3c
 )

go.sum

@@ -40,9 +40,13 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/lunixbochs/struc v0.0.0-20200521075829-a4cb8d33dbbe h1:ewr1srjRCmcQogPQ/NCx6XCk6LGVmsVCc9Y3vvPZj+Y=
+github.com/lunixbochs/struc v0.0.0-20200521075829-a4cb8d33dbbe/go.mod h1:vy1vK6wD6j7xX6O6hXe621WabdtNkou2h7uRtTfRMyg=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4/go.mod h1:4OwLy04Bl9Ef3GJJCoec+30X3LQs/0/m4HFRt/2LUSA=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/samuel/go-pcx v0.0.0-20180426214139-d9c017170db4 h1:Y/KOCu+ZLB730PudefxfsKVjtI0m0RhvFk9a0l4O1+c=
@@ -107,5 +111,7 @@ gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogR
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/restruct.v1 v1.0.0-20190323193435-3c2afb705f3c h1:7j7Yy/3gedviEts3jKY0bEruQkTFKh+8pDmEFaM6UBc=
+gopkg.in/restruct.v1 v1.0.0-20190323193435-3c2afb705f3c/go.mod h1:WJaLhyHHEQFOgwIxu/SJxvUHJA18glYsMETBTMIySTY=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

internal/assetstore/map.go

@@ -74,8 +74,8 @@ func (m *Map) LoadSprites() error {
 }
 
 // FIXME: get rid of this
-func (m *Map) Cell(x, y, z int) maps.Cell {
+func (m *Map) Cell(x, y, z int) *maps.Cell {
-	return m.raw.Cells.At(x, y, z)
+	return m.raw.At(x, y, z)
 }
 
 // SpritesForCell returns the sprites needed to correctly render this cell.

internal/maps/maps.go

@@ -6,12 +6,12 @@ import (
 	"encoding/binary"
 	"fmt"
 	"image"
-	"io"
 	"io/ioutil"
-	"log"
 	"os"
 	"path/filepath"
 	"strings"
+
+	"github.com/lunixbochs/struc"
 )
 
 var (
@@ -31,93 +31,105 @@ const (
 	cellCount      = MaxHeight * MaxLength * MaxWidth
 )
 
-type Header struct {
+type GameMap struct {
-	IsCampaignMap uint32 // Tentatively: 0 = no, 1 = yes
+	// Main Header
-	MinWidth      uint32
+	IsCampaignMap bool   `struc:"uint32"` // Tentatively: 0 = no, 1 = yes
-	MinLength     uint32
+	MinWidth      int    `struc:"uint32"`
-	MaxWidth      uint32
+	MinLength     int    `struc:"uint32"`
-	MaxLength     uint32
+	MaxWidth      int    `struc:"uint32"`
-	Unknown1      uint32
+	MaxLength     int    `struc:"uint32"`
-	Unknown2      uint32
+	Unknown1      int    `struc:"uint32"`
-	Unknown3      uint32
+	Unknown2      int    `struc:"uint32"`
-	Unknown4      uint32
+	Unknown3      int    `struc:"uint32"`
-	Magic         [8]byte // "\x08\x00WHMAP\x00"
+	Unknown4      int    `struc:"uint32"`
-	Unknown5      uint32
+	Magic         []byte `struc:"[8]byte"` // "\x08\x00WHMAP\x00"
-	Unknown6      uint32
+	Unknown5      int    `struc:"uint32"`
-	SetName       [8]byte // Links to a filename in `/Sets/*.set`
+	Unknown6      int    `struc:"uint32"`
-	// Need to investigate the rest of the header too
+	SetName       string `struc:"[8]byte"` // Links to a filename in `/Sets/*.set`
+	Padding       []byte `struc:"[212]byte"`
+
+	// Per-cell data
+	NumCells int    `struc:"skip"` // FIXME: We can't use []Cell below without this field
+	Cells    []Cell `struc:"[]Cell,sizefrom=NumCells"`
+
+	// Trailer header
+	Discard1 [3]byte `struc:"[3]byte"` // First byte is size of trailer header?
+
+	TrailerMaxWidth  int `struc:"uint32"`
+	TrailerMaxLength int `struc:"uint32"`
+	TrailerMinWidth  int `struc:"uint32"`
+	TrailerMinLength int `struc:"uint32"`
+
+	NumCharacters int `struc:"uint32"`
+
+	TrailerUnknown1 int `struc:"uint32"`
+	TrailerUnknown2 int `struc:"uint16"`
+	TrailerUnknown3 int `struc:"uint16"`
+	TrailerUnknown4 int `struc:"uint32"`
+
+	NumThingies int    `struc:"uint32"`
+	Padding1    []byte `struc:"[20]byte"`
+
+	// FIXME: The rest is trash until Character & Thingy are worked out
+
+	Characters []Character `struc:"[]Character,sizefrom=NumCharacters"`
+	Thingies   []Thingy    `struc:"[]Thingy,sizefrom=NumThingies"`
+
+	Title    string `struc:"[255]byte"`
+	Briefing string `struc:"[2048]byte"`
+
+	// Maybe? each contains either 0 or 1? Hard to say
+	TrailerUnknown5 []byte `struc:"[85]byte"`
 }
 
-type TrailerHeader struct {
+type Cell struct {
-	Discard1 [3]byte // No idea what this lot is
+	DoorAndCanisterRelated    byte `struc:"byte"`
-	MaxWidth  uint32
+	DoorLockAndReactorRelated byte `struc:"byte"`
-	MaxLength uint32
+	Unknown2                  byte `struc:"byte"`
-	MinWidth  uint32
+	Surface                   ObjRef
-	MinLength uint32
+	Left                      ObjRef
-
+	Right                     ObjRef
-	NumCharacters uint32
+	Center                    ObjRef
-
+	Unknown11                 byte `struc:"byte"`
-	Unknown1 uint32
+	Unknown12                 byte `struc:"byte"`
-	Unknown2 uint16
+	Unknown13                 byte `struc:"byte"`
-	Unknown3 uint16
+	Unknown14                 byte `struc:"byte"`
-	Unknown4 uint32
+	SquadRelated              byte `struc:"byte"`
-	NumThingies uint32
-	Padding1 [20]byte
-}
-
-type TrailerTrailer struct {
-	Title    [255]byte
-	Briefing [2048]byte
-	Unknown1 [85]uint8 // Maybe? each contains either 0 or 1? Hard to say
 }
 
 type Character struct {
-	Unknown1 uint32
+	Unknown1 int `struc:"uint32"`
+	// TODO: each character may have a fixed number of subrecords for inventory
 }
 
 type Characters []Character
 
 // TODO. These are triggers/reactors/etc.
-type Thingy struct {}
+type Thingy struct {
+	Unknown1 int `struc:"uint32"`
+}
 
 type Thingies []Thingy
 
-func (h Header) Width() int {
+func (g *GameMap) MapSetName() string {
-	return int(h.MaxWidth - h.MinWidth)
+	return g.SetName
 }
 
-func (h Header) Length() int {
+func (g *GameMap) MapSetFilename() string {
-	return int(h.MaxLength - h.MinLength)
+	return g.MapSetName() + ".set"
-}
-
-func (h Header) Height() int {
-	return MaxHeight
-}
-
-func (h Header) MapSetName() string {
-	idx := bytes.IndexByte(h.SetName[:], 0)
-	if idx < 0 {
-		idx = 8 // all 8 bytes are used
-	}
-
-	return string(h.SetName[0:idx:idx])
-}
-
-func (h Header) MapSetFilename() string {
-	return h.MapSetName() + ".set"
 }
 
 type ObjRef struct {
-	AreaByte          byte
+	AreaByte          byte `struc:"byte"`
-	SpriteAndFlagByte byte
+	SpriteAndFlagByte byte `struc:"byte"`
 }
 
 // The index into a set palette to retrieve the object
-func (o ObjRef) Index() int {
+func (o *ObjRef) Index() int {
 	return int(o.AreaByte)
 }
 
-func (o ObjRef) Sprite() int {
+func (o *ObjRef) Sprite() int {
 	// The top bit seems to be a flag of some kind
 	return int(o.SpriteAndFlagByte & 0x7f)
 }
@@ -127,21 +139,6 @@ func (o ObjRef) IsActive() bool {
 	return (o.SpriteAndFlagByte & 0x80) == 0x80
 }
 
-type Cell struct {
-	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:
@@ -181,46 +178,26 @@ func (c *Cell) At(n int) byte {
 	return 0
 }
 
-// Cells is always a fixed size; use At to get a cell according to x,y,z
+func (g *GameMap) At(x, y, z int) *Cell {
-type Cells []Cell
+	return &g.Cells[(z*MaxLength*MaxWidth)+(y*MaxWidth)+x]
-
-func (c Cells) At(x, y, z int) Cell {
-	return c[(z*MaxLength*MaxWidth)+(y*MaxWidth)+x]
 }
 
-func (h Header) Check() []error {
+func (g *GameMap) Check() error {
-	var out []error
+	if bytes.Compare(expectedMagic, g.Magic) != 0 {
-	if h.IsCampaignMap > 1 {
+		return fmt.Errorf("Unexpected magic value: %v", g.Magic)
-		out = append(out, fmt.Errorf("Expected 0 or 1 for IsCampaignMap, got %v", h.IsCampaignMap))
 	}
 
-	if bytes.Compare(expectedMagic, h.Magic[:]) != 0 {
+	// TODO: other consistency checks
-		out = append(out, fmt.Errorf("Unexpected magic value: %v", h.Magic))
-	}
 
-	return out
+	return nil
-}
-
-type GameMap struct {
-	Header
-	Cells
-	TrailerHeader
-	Characters
-	Thingies
-	TrailerTrailer
-
-	// TODO: parse this into sections. This is the text that comes from the
-	// .TXT file. Maybe we don't need it at all since it should be duplicated in
-	// the trailer.
-	Text string
 }
 
 func (m *GameMap) Rect() image.Rectangle {
 	return image.Rect(
-		int(m.Header.MinWidth),
+		int(m.MinWidth),
-		int(m.Header.MinLength),
+		int(m.MinLength),
-		int(m.Header.MaxWidth),
+		int(m.MaxWidth),
-		int(m.Header.MaxLength),
+		int(m.MaxLength),
 	)
 }
 
@@ -243,23 +220,17 @@ func LoadGameMap(prefix string) (*GameMap, error) {
 	return nil, fmt.Errorf("Couldn't find %s.{map,txt}, even ignoring case", prefix)
 }
 
-// A game map is composed of two files: .map and .txt
+// A game map is composed of two files: .map and .txt. We ignore the text file,
+// since the content is replicated in the map file.
 func LoadGameMapByFiles(mapFile, txtFile string) (*GameMap, error) {
 	out, err := loadMapFile(mapFile)
 	if err != nil {
 		return nil, err
 	}
 
-	// TODO: load text and parse into sections
+	if err := out.Check(); err != nil {
-	txt, err := ioutil.ReadFile(txtFile)
-	if err != nil {
 		return nil, err
 	}
-	out.Text = string(txt)
-
-	for _, err := range out.Check() {
-		log.Printf("%s: %v", mapFile, err)
-	}
 
 	return out, nil
 }
@@ -297,6 +268,7 @@ func LoadGameMaps(dir string) (map[string]*GameMap, error) {
 
 func loadMapFile(filename string) (*GameMap, error) {
 	var out GameMap
+	out.NumCells = cellCount
 
 	mf, err := os.Open(filename)
 	if err != nil {
@@ -312,52 +284,18 @@ func loadMapFile(filename string) (*GameMap, error) {
 
 	defer zr.Close()
 
-	if err := binary.Read(zr, binary.LittleEndian, &out.Header); err != nil {
+	if err := struc.UnpackWithOrder(zr, &out, binary.LittleEndian); err != nil {
-		return nil, fmt.Errorf("Error parsing %s: %v", filename, err)
-	}
-
-	// no gzip.SeekReader, so discard unread header bytes for now
-	discardSize := int64(cellDataOffset - binary.Size(&out.Header))
-	if _, err := io.CopyN(ioutil.Discard, zr, discardSize); err != nil {
 		return nil, err
 	}
 
-	out.Cells = make(Cells, cellCount)
+	// Trim any trailing nulls off of the strings
-	if err := binary.Read(zr, binary.LittleEndian, &out.Cells); err != nil {
+	trimRight(&out.SetName)
-		return nil, fmt.Errorf("Error parsing cells for %s: %v", filename, err)
+	trimRight(&out.Title)
-	}
+	trimRight(&out.Briefing)
 
-	if err := binary.Read(zr, binary.LittleEndian, &out.TrailerHeader); err != nil {
-		return nil, fmt.Errorf("Error parsing trailer header for %s: %v", filename, err)
-	}
-
-	log.Printf("Trailer Header: %#+v", out.TrailerHeader)
-	/*
-	// TODO: until we know how large each character record should be, we can't read this lot
-
-	out.Characters = make(Characters, int(out.TrailerHeader.NumCharacters))
-	if err := binary.Read(zr, binary.LittleEndian, &out.Characters); err != nil {
-		return nil, fmt.Errorf("Error parsing characters for %s: %v", filename, err)
-	}
-
-	out.Thingies = make(Thingies, int(out.TrailerHeader.NumThingies))
-	if err := binary.Read(zr, binary.LittleEndian, &out.Thingies); err != nil {
-		return nil, fmt.Errorf("Error parsing thingies for %s: %v", filename, err)
-	}
-
-	if err := binary.Read(zr, binary.LittleEndian, &out.TrailerTrailer); err != nil {
-		return nil, fmt.Errorf("Error parsing trailer trailer for %s: %v", filename, err)
-	}
-	log.Printf("Trailer Trailer: %s", out.TrailerTrailer.String())
-*/
 	return &out, nil
 }
 
-func (t *TrailerTrailer) String() string {
+func trimRight(s *string) {
-	return fmt.Sprintf(
+	*s = strings.TrimRight(*s, "\x00")
-		"title=%q briefing=%q rest=%#+v",
-		strings.TrimRight(string(t.Title[:]), "\x00"),
-		strings.TrimRight(string(t.Briefing[:]), "\x00"),
-		t.Unknown1,
-	)
 }

internal/scenario/manage.go

@@ -9,7 +9,7 @@ type CellPoint struct {
 	Z int
 }
 
-func (s *Scenario) CellAtCursor() (maps.Cell, CellPoint) {
+func (s *Scenario) CellAtCursor() (*maps.Cell, CellPoint) {
 	cell := s.area.Cell(int(s.selectedCell.X), int(s.selectedCell.Y), 0)
 	return cell, CellPoint{IsoPt: s.selectedCell, Z: 0}
 }