Discover how frames are encoded, use that knowledge to (finally) get the viewport locked in

cmd/view-map/main.go

@@ -28,7 +28,7 @@ var (
 
 type env struct {
 	gameMap *maps.GameMap
-	set     sets.MapSet
+	set     *sets.MapSet
 }
 
 type runState struct {
@@ -159,8 +159,8 @@ func present(win *pixelgl.Window, state *runState) {
 
 	// Draw the boundary
 	rect := pixel.R(
-		float64(gameMap.MinWidth)-1, float64(gameMap.MinLength)-1,
-		float64(gameMap.MaxWidth)+1, float64(gameMap.MaxLength)+1,
+		float64(gameMap.MinWidth)-0.5, float64(gameMap.MinLength)-0.5,
+		float64(gameMap.MaxWidth)+0.5, float64(gameMap.MaxLength)+0.5,
 	)
 
 	imd.Color = pixel.RGB(255, 0, 0)
@@ -210,9 +210,10 @@ func makeColour(cell *maps.Cell, colIdx int) pixel.RGBA {
 		scale = mult(0.004)
 	case 14:
 		scale = mult(0.004)
+	case 15:
+		scale = mult(1.0)
 	default:
 		scale = mult(0.01) // close to maximum resolution, low-value fields will be lost
-
 	}
 
 	col := scale(float64(cell.At(colIdx)))
@@ -290,9 +291,9 @@ func runStep(win *pixelgl.Window, state *runState) *runState {
 		log.Printf("%#v -> %d,%d", vec, x, y)
 		cell := state.env.gameMap.Cells.At(x, y, state.zIdx)
 		log.Printf(
-			"x=%d y=%d z=%d Object0SurfaceArea=%d Object3CenterArea=%d (%s) SquadRelated=%d",
+			"x=%d y=%d z=%d SurfaceTile=%d (%s) SurfaceFrame=%d SquadRelated=%d",
 			x, y, state.zIdx,
-			cell.Object0SurfaceArea, cell.Object3CenterArea, state.env.set.Palette[int(cell.Object3CenterArea)],
+			cell.Surface.Index(), state.env.set.Palette[int(cell.Surface.Index())], cell.Surface.Frame(),
 			cell.SquadRelated,
 		)
 		log.Printf("CellIdx%d=%d. Full cell data: %#v", state.cellIdx, cell.At(state.cellIdx), cell)

doc/formats/maps.md

@@ -287,7 +287,7 @@ Skipping the header we know about, we have data like this:
 
 It would be very neat if the per-cell data started at 0x100 and took 16 bytes
 per coordinate, but to get objects in my map to line up properly with cells in
-WH40K_TD.exe, I've had to start parsing these rows at `0x0120` instead. Still
+WH40K_TD.exe, I've had to start parsing these rows at `0x0110` instead. Still
 tentative!
 
 Total number of possible coordinates is 100x130x7 = 91,000 = 1,456,000 bytes.
@@ -379,8 +379,8 @@ I've added a `view-map` command to explore the data graphically. Each of the 16
 bytes in a cell row must have a function; comparing a known map to how it looks
 in WH40K_TD.exe can help me to unravel that function.
 
-Here's a side-by-side comparison of Chapter3.MAP, investigating CellIndex=3 and
-Z index = 0
+Here's an (out-of-date) side-by-side comparison of Chapter3.MAP, investigating
+CellIndex=3 and Z index = 0.
 
 ![Map comparison](img/chapter_01_cell_index_3.png)
 
@@ -400,17 +400,15 @@ Investigation has so far suggested the following:
     *  0x40: Animated object
 * `Cell[2]` hasn't been seen with a value > 0 yet
 * `Cell[3]` Object 0 (Surface) Area (Sets/*.set lookup)
-* `Cell[4]` Unsure at present, but it varies between a narrow range of values.
-  I've seen 128 - 147. Broadly matches the terrain layout.
-* `Cell[5]` Object 1 (Left) Area (Sets/*.set lookup) **ASSUMED**.
-    * It's in the right place, and there seems to be correspondence, but not as
-      neatly as the other 3 columns. Often off-by-1
-* `Cell[6]` Wide range of values, 0 - 161 observed. Seems to have identity with
-   some blood splatters, etc
+* `Cell[4]` Object 0 (Surface) Sprite + ???
+    * Bottom bits encode the sprite (frame number in the .obj file)
+    * 0x80 is set too. A flag?
+* `Cell[5]` Object 1 (Left) Area (Sets/*.set lookup)
+* `Cell[6]` Object 1 (Surface) Sprite + ???
 * `Cell[7]` Object 2 (Right) Area (Sets/*.set lookup)
-* `Cell[8]` Wide range of values, 0 - 159 observed. 
+* `Cell[6]` Object 2 (Right) Sprite + ???
 * `Cell[9]` Object 3 (Center) Area (Sets/*.set lookup)
-* `Cell[10]` Varies from 0 - 248. Unclear what for, broadly follows terrain
+* `Cell[10]` Object 3 (Right) Sprite + ???
 * `Cell[11]` all 255?
 * `Cell[12]` all 0?
 * `Cell[13]` all 0?
@@ -435,10 +433,6 @@ So `CellIdx == 9` points to the center object's Area, looked up in the set file!
 
 ![Pinning down cell index 9](img/chapter01_cell_index_9.png
 
-I still see weird artifacts on middle Z-layers making me think I'm off the
-stride or perhaps there's a data block partway through or something. Or maybe
-the data's just born that way.
-
 ## Trailer
 
 Assuming the theory above is correct, we have trailer data starting at

internal/maps/maps.go

@@ -26,7 +26,7 @@ const (
 
 	CellSize = 16 // seems to be
 
-	cellDataOffset = 0x120 // tentatively
+	cellDataOffset = 0x110 // tentatively
 	cellCount      = MaxHeight * MaxLength * MaxWidth
 )
 
@@ -68,18 +68,28 @@ func (h Header) MapSetFilename() string {
 	return string(h.SetName[0:idx:idx]) + ".set"
 }
 
+type ObjRef struct {
+	AreaByte            byte
+	FrameAndUnknownByte byte
+}
+
+// The index into a set palette to retrieve the object
+func (o ObjRef) Index() int {
+	return int(o.AreaByte)
+}
+
+func (o ObjRef) Frame() int {
+	return int(o.FrameAndUnknownByte - 0x80)
+}
+
 type Cell struct {
 	DoorAndCanisterRelated    byte
 	DoorLockAndReactorRelated byte
 	Unknown2                  byte
-	Object0SurfaceArea        byte
-	Unknown4                  byte
-	Object1LeftArea           byte
-	Unknown6                  byte
-	Object2RightArea          byte
-	Unknown8                  byte
-	Object3CenterArea         byte
-	Unknown10                 byte
+	Surface                   ObjRef
+	Left                      ObjRef
+	Right                     ObjRef
+	Center                    ObjRef
 	Unknown11                 byte
 	Unknown12                 byte
 	Unknown13                 byte
@@ -96,21 +106,21 @@ func (c *Cell) At(n int) byte {
 	case 2:
 		return c.Unknown2
 	case 3:
-		return c.Object0SurfaceArea
+		return c.Surface.AreaByte
 	case 4:
-		return c.Unknown4
+		return c.Surface.FrameAndUnknownByte
 	case 5:
-		return c.Object1LeftArea
+		return c.Left.AreaByte
 	case 6:
-		return c.Unknown6
+		return c.Left.FrameAndUnknownByte
 	case 7:
-		return c.Object2RightArea
+		return c.Right.AreaByte
 	case 8:
-		return c.Unknown8
+		return c.Right.FrameAndUnknownByte
 	case 9:
-		return c.Object3CenterArea
+		return c.Center.AreaByte
 	case 10:
-		return c.Unknown10
+		return c.Center.FrameAndUnknownByte
 	case 11:
 		return c.Unknown11
 	case 12:

internal/sets/sets.go

@@ -19,13 +19,13 @@ type MapSet struct {
 	Palette []string
 }
 
-func LoadSets(dir string) (map[string]MapSet, error) {
+func LoadSets(dir string) (map[string]*MapSet, error) {
 	fis, err := ioutil.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}
 
-	out := make(map[string]MapSet, len(fis))
+	out := make(map[string]*MapSet, len(fis))
 
 	for _, fi := range fis {
 		filename := filepath.Join(dir, fi.Name())
@@ -48,35 +48,34 @@ func LoadSets(dir string) (map[string]MapSet, error) {
 	return out, nil
 }
 
-func LoadSet(filename string) (MapSet, error) {
-	var out MapSet
-	var err error
+func LoadSet(filename string) (*MapSet, error) {
+	out := &MapSet{}
 
 	s, err := asciiscan.New(filename)
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	defer s.Close()
 
 	out.Description, err = s.ConsumeString()
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	out.Defs, err = consumeDefs(s)
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	for {
 		str, err := s.ConsumeString()
 		if err != nil {
 			if err == io.EOF {
-				err = nil
+				return out, nil
 			}
 
-			return out, err
+			return nil, err
 		}
 
 		out.Palette = append(out.Palette, str)