WIP: MsgPack stubs, Level Filesystem Module

* Add some encoding/decoding functions for binary msgpack format for
  levels and doodads. Currently it writes msgpack files that can be
  decoded and printed by Python (mp2json.py) but it can't re-read from
  the binary format. For now, levels will continue to write in JSON
  format.
* Add filesystem abstraction functions to the balance/ package to search
  multiple paths to find Levels and Doodads, to make way for
  system-level doodads.

Building.md

@@ -4,6 +4,10 @@ Makefile commands for Linux:
 
 * `make setup`: install Go dependencies and set up the build environment
 * `make build`: build the Doodle and Doodad binaries to the `bin/` folder.
+* `make build-free`: build the shareware binaries to the `bin/` folder. See
+  Build Tags below.
+* `make build-debug`: build a debug binary (not release-mode) to the `bin/`
+  folder. See Build Tags below.
 * `make run`: run a local dev build of Doodle in debug mode
 * `make guitest`: run a local dev build in the GUITest scene
 * `make test`: run the test suite
@@ -17,6 +21,33 @@ Makefile commands for Linux:
   * `make docker.fedora`
 * `make clean`: clean all build artifacts
 
+## Build Tags
+
+### shareware
+
+> Files ending with `_free.go` are for the shareware release as opposed to
+> `_paid.go` for the full version.
+
+Builds the game in the free shareware release mode.
+
+Run `make build-free` to build the shareware binary.
+
+Shareware releases of the game have the following changes compared to the default
+(release) mode:
+
+* No access to the Doodad Editor scene in-game (soft toggle)
+
+### developer
+
+> Files ending with `_developer.go` are for the developer build as opposed to
+> `_release.go` for the public version.
+
+Developer builds support extra features over the standard release version:
+
+* Ability to write the JSON file format for Levels and Doodads.
+
+Run `make build-debug` to build a developer version of the program.
+
 ## Linux
 
 Dependencies are Go, SDL2 and SDL2_ttf:

Makefile

@@ -27,6 +27,13 @@ build-free:
 	go build $(LDFLAGS) -tags="shareware" -i -o bin/doodle cmd/doodle/main.go
 	go build $(LDFLAGS) -tags="shareware" -i -o bin/doodad cmd/doodad/main.go
 
+# `make build-debug` to build the binary in developer mode.
+.PHONY: build-debug
+build-debug:
+	gofmt -w .
+	go build $(LDFLAGS) -tags="developer" -i -o bin/doodle cmd/doodle/main.go
+	go build $(LDFLAGS) -tags="developer" -i -o bin/doodad cmd/doodad/main.go
+
 # `make doodads` to build the doodads from the dev-assets folder.
 .PHONY: doodads
 doodads:

dev-assets/doodads/azulian/azulian.js

@@ -1,4 +1,52 @@
 function main() {
 	log.Info("Azulian '%s' initialized!", Self.Doodad.Title);
-	Self.ShowLayer(2);
+
+	var playerSpeed = 12;
+	var gravity = 4;
+	var Vx = Vy = 0;
+
+	var animating = false;
+	var animStart = animEnd = 0;
+	var animFrame = animStart;
+
+	setInterval(function() {
+		if (animating) {
+			if (animFrame < animStart || animFrame > animEnd) {
+				animFrame = animStart;
+			}
+
+			animFrame++;
+			if (animFrame === animEnd) {
+				animFrame = animStart;
+			}
+			Self.ShowLayer(animFrame);
+		} else {
+			Self.ShowLayer(animStart);
+		}
+	}, 100);
+
+	Events.OnKeypress(function(ev) {
+		Vx = 0;
+		Vy = 0;
+
+		if (ev.Right.Now) {
+			animStart = 2;
+			animEnd = animStart+4;
+			animating = true;
+			Vx = playerSpeed;
+		} else if (ev.Left.Now) {
+			animStart = 6;
+			animEnd = animStart+4;
+			animating = true;
+			Vx = -playerSpeed;
+		} else {
+			animating = false;
+		}
+
+		if (!Self.Grounded()) {
+			Vy += gravity;
+		}
+
+		// Self.SetVelocity(Point(Vx, Vy));
+	})
 }

lib/render/color.go

@@ -7,6 +7,8 @@ import (
 	"image/color"
 	"regexp"
 	"strconv"
+
+	"github.com/vmihailenco/msgpack"
 )
 
 var (
@@ -155,6 +157,52 @@ func (c *Color) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+func (c Color) EncodeMsgpack(enc *msgpack.Encoder) error {
+	return enc.EncodeString(fmt.Sprintf(
+		`"#%02x%02x%02x"`,
+		c.Red, c.Green, c.Blue,
+	))
+}
+
+func (c Color) DecodeMsgpack(dec *msgpack.Decoder) error {
+	hex, err := dec.DecodeString()
+	if err != nil {
+		return fmt.Errorf("Color.DecodeMsgpack: %s", err)
+	}
+
+	parsed, err := HexColor(hex)
+	if err != nil {
+		return fmt.Errorf("Color.DecodeMsgpack: HexColor: %s", err)
+	}
+
+	c.Red = parsed.Red
+	c.Blue = parsed.Blue
+	c.Green = parsed.Green
+	c.Alpha = parsed.Alpha
+	return nil
+}
+
+// // MarshalMsgpack serializes the Color for msgpack.
+// func (c Color) MarshalMsgpack() ([]byte, error) {
+// 	data := []uint8{
+// 		c.Red, c.Green, c.Blue, c.Alpha,
+// 	}
+// 	return msgpack.Marshal(data)
+// }
+//
+// // UnmarshalMsgpack decodes a Color from msgpack format.
+// func (c *Color) UnmarshalMsgpack(b []byte) error {
+// 	var data []uint8
+// 	if err := msgpack.Unmarshal(data, b); err != nil {
+// 		return err
+// 	}
+// 	c.Red = 255
+// 	c.Green = data[1]
+// 	c.Blue = data[2]
+// 	c.Alpha = data[3]
+// 	return nil
+// }
+
 // Add a relative color value to the color.
 func (c Color) Add(r, g, b, a int) Color {
 	var (

mp2json.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+"""mp2json: convert a msgpack binary file into JSON for debugging."""
+
+import msgpack
+import json
+import sys
+
+if len(sys.argv) < 2:
+    print("Usage: mp2json <filename.level>")
+
+with open(sys.argv[1], 'rb') as fh:
+    header = fh.read(8)
+    magic = header[:6].decode("utf-8")
+    if magic != "DOODLE":
+        print("input file doesn't appear to be a doodle drawing binary")
+        sys.exit(1)
+
+    reader = msgpack.Unpacker(fh, raw=False, max_buffer_size=10*1024*1024)
+    for o in reader:
+        print(o)
+        print(json.dumps(o, indent=2))

pkg/balance/debug.go

@@ -30,6 +30,9 @@ var (
 	// Put a border around all Canvas widgets.
 	DebugCanvasBorder = render.Invisible
 	DebugCanvasLabel  = false // Tag the canvas with a label.
+
+	// Pretty-print JSON files when writing.
+	JSONIndent = false
 )
 
 func init() {

pkg/balance/filesystem.go

@@ -0,0 +1,118 @@
+package balance
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"git.kirsle.net/apps/doodle/pkg/enum"
+	"git.kirsle.net/apps/doodle/pkg/userdir"
+)
+
+// Binary file format headers for Levels and Doodads.
+//
+// The header is 8 bytes long: "DOODLE" + file format version + file type number.
+const (
+	BinMagic            = "DOODLE"
+	BinVersion    uint8 = 1 // version of the file format we support
+	BinLevelType  uint8 = 1
+	BinDoodadType uint8 = 2
+)
+
+// MakeHeader creates the binary file header.
+func MakeHeader(filetype uint8) []byte {
+	header := make([]byte, len(BinMagic)+2)
+	for i := 0; i < len(BinMagic); i++ {
+		header[i] = BinMagic[i]
+	}
+
+	header[len(header)-2] = BinVersion
+	header[len(header)-1] = filetype
+
+	return header
+}
+
+// ReadHeader reads and verifies a header from a filehandle.
+func ReadHeader(filetype uint8, fh io.Reader) error {
+	header := make([]byte, len(BinMagic)+2)
+	_, err := fh.Read(header)
+	if err != nil {
+		return fmt.Errorf("ReadHeader: %s", err)
+	}
+
+	if string(header[:len(BinMagic)]) != BinMagic {
+		return errors.New("not a doodle drawing (no magic number in header)")
+	}
+
+	// Verify the file format version and type.
+	var (
+		fileVersion = header[len(header)-2]
+		fileType    = header[len(header)-1]
+	)
+
+	if fileVersion == 0 || fileVersion > BinVersion {
+		return errors.New("binary format was created using a newer version of the game")
+	} else if fileType != filetype {
+		return errors.New("drawing type is not the type we expected")
+	}
+
+	return nil
+}
+
+/*
+FindFile looks for a file (level or doodad) in a few places.
+
+The filename should already have a ".level" or ".doodad" file extension. If
+neither is given, the exact filename will be searched in all places.
+
+1. Check in the files built into the program binary.
+2. Check for system files in the binary's assets/ folder.
+3. Check the user folders.
+
+Returns the file path and an error if not found anywhere.
+*/
+func FindFile(filename string) (string, error) {
+	var filetype string
+
+	// Any hint on what type of file we're looking for?
+	if strings.HasSuffix(filename, enum.LevelExt) {
+		filetype = enum.LevelExt
+	} else if strings.HasSuffix(filename, enum.DoodadExt) {
+		filetype = enum.DoodadExt
+	}
+
+	// Search level directories.
+	if filetype == enum.LevelExt || filetype == "" {
+		// system levels
+		candidate := filepath.Join(".", "assets", "levels", filename)
+		if _, err := os.Stat(candidate); !os.IsNotExist(err) {
+			return candidate, nil
+		}
+
+		// user levels
+		candidate = userdir.LevelPath(filename)
+		if _, err := os.Stat(candidate); !os.IsNotExist(err) {
+			return candidate, nil
+		}
+	}
+
+	// Search doodad directories.
+	if filetype == enum.DoodadExt || filetype == "" {
+		// system doodads
+		candidate := filepath.Join(".", "assets", "doodads", filename)
+		if _, err := os.Stat(candidate); !os.IsNotExist(err) {
+			return candidate, nil
+		}
+
+		// user doodads
+		candidate = userdir.DoodadPath(filename)
+		if _, err := os.Stat(candidate); !os.IsNotExist(err) {
+			return candidate, nil
+		}
+	}
+
+	return "", errors.New("file not found")
+}

pkg/editor_scene.go

@@ -3,7 +3,6 @@ package doodle
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 
@@ -171,7 +170,7 @@ func (s *EditorScene) Draw(d *Doodle) error {
 func (s *EditorScene) LoadLevel(filename string) error {
 	s.filename = filename
 
-	level, err := level.LoadJSON(filename)
+	level, err := level.LoadFile(filename)
 	fmt.Printf("%+v\n", level)
 	if err != nil {
 		return fmt.Errorf("EditorScene.LoadLevel(%s): %s", filename, err)
@@ -213,20 +212,7 @@ func (s *EditorScene) SaveLevel(filename string) error {
 	m.Palette = s.UI.Canvas.Palette
 	m.Chunker = s.UI.Canvas.Chunker()
 
-	json, err := m.ToJSON()
-	if err != nil {
-		return fmt.Errorf("SaveLevel error: %s", err)
-	}
-
-	// Save it to their profile directory.
-	filename = userdir.LevelPath(filename)
-	log.Info("Write Level: %s", filename)
-	err = ioutil.WriteFile(filename, json, 0644)
-	if err != nil {
-		return fmt.Errorf("Create map file error: %s", err)
-	}
-
-	return nil
+	return m.WriteFile(filename)
 }
 
 // LoadDoodad loads a doodad from disk.

pkg/level/chunk.go

@@ -12,6 +12,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/userdir"
 	"github.com/satori/go.uuid"
+	"github.com/vmihailenco/msgpack"
 	"golang.org/x/image/bmp"
 )
 
@@ -41,8 +42,9 @@ type Chunk struct {
 // JSONChunk holds a lightweight (interface-free) copy of the Chunk for
 // unmarshalling JSON files from disk.
 type JSONChunk struct {
-	Type int             `json:"type"`
-	Data json.RawMessage `json:"data"`
+	Type    int             `json:"type" msgpack:"0"`
+	Data    json.RawMessage `json:"data" msgpack:"-"`
+	BinData interface{}     `json:"-" msgpack:"1"`
 }
 
 // Accessor provides a high-level API to interact with absolute pixel coordinates
@@ -57,6 +59,9 @@ type Accessor interface {
 	Len() int
 	MarshalJSON() ([]byte, error)
 	UnmarshalJSON([]byte) error
+	// MarshalMsgpack() ([]byte, error)
+	// UnmarshalMsgpack([]byte) error
+	// Serialize() interface{}
 }
 
 // NewChunk creates a new chunk.
@@ -277,3 +282,66 @@ func (c *Chunk) UnmarshalJSON(b []byte) error {
 		return fmt.Errorf("Chunk.UnmarshalJSON: unsupported chunk type '%d'", c.Type)
 	}
 }
+
+func (c *Chunk) EncodeMsgpack(enc *msgpack.Encoder) error {
+	data := c.Accessor
+
+	generic := &JSONChunk{
+		Type:    c.Type,
+		BinData: data,
+	}
+
+	return enc.Encode(generic)
+}
+
+func (c *Chunk) DecodeMsgpack(dec *msgpack.Decoder) error {
+	generic := &JSONChunk{}
+	err := dec.Decode(generic)
+	if err != nil {
+		return fmt.Errorf("Chunk.DecodeMsgpack: %s", err)
+	}
+
+	switch c.Type {
+	case MapType:
+		c.Accessor = generic.BinData.(MapAccessor)
+	default:
+		return fmt.Errorf("Chunk.DecodeMsgpack: unsupported chunk type '%d'", c.Type)
+	}
+
+	return nil
+}
+
+// // MarshalMsgpack writes the chunk to msgpack format.
+// func (c *Chunk) MarshalMsgpack() ([]byte, error) {
+// 	// data, err := c.Accessor.MarshalMsgpack()
+// 	// if err != nil {
+// 	// 	return []byte{}, err
+// 	// }
+// 	data := c.Accessor
+//
+// 	generic := &JSONChunk{
+// 		Type:    c.Type,
+// 		BinData: data,
+// 	}
+// 	b, err := msgpack.Marshal(generic)
+// 	return b, err
+// }
+//
+// // UnmarshalMsgpack loads the chunk from msgpack format.
+// func (c *Chunk) UnmarshalMsgpack(b []byte) error {
+// 	// Parse it generically so we can hand off the inner "data" object to the
+// 	// right accessor for unmarshalling.
+// 	generic := &JSONChunk{}
+// 	err := msgpack.Unmarshal(b, generic)
+// 	if err != nil {
+// 		return fmt.Errorf("Chunk.UnmarshalMsgpack: failed to unmarshal into generic JSONChunk type: %s", err)
+// 	}
+//
+// 	switch c.Type {
+// 	case MapType:
+// 		c.Accessor = NewMapAccessor()
+// 		return c.Accessor.UnmarshalMsgpack(generic.Data)
+// 	default:
+// 		return fmt.Errorf("Chunk.UnmarshalMsgpack: unsupported chunk type '%d'", c.Type)
+// 	}
+// }

pkg/level/chunk_map.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	"git.kirsle.net/apps/doodle/lib/render"
+	"github.com/vmihailenco/msgpack"
 )
 
 // MapAccessor implements a chunk accessor by using a map of points to their
@@ -127,3 +128,65 @@ func (a MapAccessor) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+// // MarshalMsgpack serializes for msgpack.
+// func (a MapAccessor) MarshalMsgpack() ([]byte, error) {
+// 	dict := map[string]int{}
+// 	for point, sw := range a {
+// 		dict[point.String()] = sw.Index()
+// 	}
+// 	return msgpack.Marshal(dict)
+// }
+//
+// // Serialize converts the chunk accessor to a map for serialization.
+// func (a MapAccessor) Serialize() interface{} {
+// 	dict := map[string]int{}
+// 	for point, sw := range a {
+// 		dict[point.String()] = sw.Index()
+// 	}
+// 	return dict
+// }
+//
+// // UnmarshalMsgpack decodes from msgpack format.
+// func (a MapAccessor) UnmarshalMsgpack(b []byte) error {
+// 	var dict map[string]int
+// 	err := msgpack.Unmarshal(b, &dict)
+// 	if err != nil {
+// 		return err
+// 	}
+//
+// 	for coord, index := range dict {
+// 		point, err := render.ParsePoint(coord)
+// 		if err != nil {
+// 			return fmt.Errorf("MapAccessor.UnmarshalJSON: %s", err)
+// 		}
+// 		a[point] = NewSparseSwatch(index)
+// 	}
+//
+// 	return nil
+// }
+
+func (a MapAccessor) EncodeMsgpack(enc *msgpack.Encoder) error {
+	dict := map[string]int{}
+	for point, sw := range a {
+		dict[point.String()] = sw.Index()
+	}
+	return enc.Encode(dict)
+}
+
+func (a MapAccessor) DecodeMsgpack(dec *msgpack.Decoder) error {
+	v, err := dec.DecodeMap()
+	if err != nil {
+		return fmt.Errorf("MapAccessor.DecodeMsgpack: %s", err)
+	}
+	dict := v.(map[string]int)
+
+	for coord, index := range dict {
+		point, err := render.ParsePoint(coord)
+		if err != nil {
+			return fmt.Errorf("MapAccessor.UnmarshalJSON: %s", err)
+		}
+		a[point] = NewSparseSwatch(index)
+	}
+	return nil
+}

pkg/level/chunker.go

@@ -6,6 +6,7 @@ import (
 	"math"
 
 	"git.kirsle.net/apps/doodle/lib/render"
+	"github.com/vmihailenco/msgpack"
 )
 
 // Chunker is the data structure that manages the chunks of a level, and
@@ -240,3 +241,14 @@ func (c ChunkMap) MarshalJSON() ([]byte, error) {
 	out, err := json.Marshal(dict)
 	return out, err
 }
+
+// MarshalMsgpack to convert the chunk map to binary.
+func (c ChunkMap) MarshalMsgpack() ([]byte, error) {
+	dict := map[string]*Chunk{}
+	for point, chunk := range c {
+		dict[point.String()] = chunk
+	}
+
+	out, err := msgpack.Marshal(dict)
+	return out, err
+}

pkg/level/fmt_binary.go

@@ -0,0 +1,71 @@
+package level
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"git.kirsle.net/apps/doodle/pkg/balance"
+	"github.com/vmihailenco/msgpack"
+)
+
+// ToBinary serializes the level to binary format.
+func (m *Level) ToBinary() ([]byte, error) {
+	header := balance.MakeHeader(balance.BinLevelType)
+	out := bytes.NewBuffer(header)
+	encoder := msgpack.NewEncoder(out)
+	err := encoder.Encode(m)
+	return out.Bytes(), err
+}
+
+// WriteBinary writes a level to binary format on disk.
+func (m *Level) WriteBinary(filename string) error {
+	bin, err := m.ToBinary()
+	if err != nil {
+		return fmt.Errorf("Level.WriteBinary: encode error: %s", err)
+	}
+
+	err = ioutil.WriteFile(filename, bin, 0755)
+	if err != nil {
+		return fmt.Errorf("Level.WriteBinary: WriteFile error: %s", err)
+	}
+
+	return nil
+}
+
+// LoadBinary loads a map from binary file on disk.
+func LoadBinary(filename string) (*Level, error) {
+	fh, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer fh.Close()
+
+	// Read and verify the file header from the binary format.
+	err = balance.ReadHeader(balance.BinLevelType, fh)
+	if err != nil {
+		return nil, err
+	}
+
+	// Decode the file from disk.
+	m := New()
+	decoder := msgpack.NewDecoder(fh)
+	err = decoder.Decode(&m)
+	if err != nil {
+		return m, fmt.Errorf("level.LoadBinary: decode error: %s", err)
+	}
+
+	// Fill in defaults.
+	if m.Wallpaper == "" {
+		m.Wallpaper = DefaultWallpaper
+	}
+
+	// Inflate the chunk metadata to map the pixels to their palette indexes.
+	m.Chunker.Inflate(m.Palette)
+	m.Actors.Inflate()
+
+	// Inflate the private instance values.
+	m.Palette.Inflate()
+	return m, err
+}

pkg/level/fmt_json.go

@@ -6,32 +6,21 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+
+	"git.kirsle.net/apps/doodle/pkg/balance"
 )
 
 // ToJSON serializes the level as JSON.
 func (m *Level) ToJSON() ([]byte, error) {
 	out := bytes.NewBuffer([]byte{})
 	encoder := json.NewEncoder(out)
-	encoder.SetIndent("", "\t")
+	if balance.JSONIndent {
+		encoder.SetIndent("", "\t")
+	}
 	err := encoder.Encode(m)
 	return out.Bytes(), err
 }
 
-// WriteJSON writes a level to JSON on disk.
-func (m *Level) WriteJSON(filename string) error {
-	json, err := m.ToJSON()
-	if err != nil {
-		return fmt.Errorf("Level.WriteJSON: JSON encode error: %s", err)
-	}
-
-	err = ioutil.WriteFile(filename, json, 0755)
-	if err != nil {
-		return fmt.Errorf("Level.WriteJSON: WriteFile error: %s", err)
-	}
-
-	return nil
-}
-
 // LoadJSON loads a map from JSON file.
 func LoadJSON(filename string) (*Level, error) {
 	fh, err := os.Open(filename)
@@ -61,3 +50,18 @@ func LoadJSON(filename string) (*Level, error) {
 	m.Palette.Inflate()
 	return m, err
 }
+
+// WriteJSON writes a level to JSON on disk.
+func (m *Level) WriteJSON(filename string) error {
+	json, err := m.ToJSON()
+	if err != nil {
+		return fmt.Errorf("Level.WriteJSON: JSON encode error: %s", err)
+	}
+
+	err = ioutil.WriteFile(filename, json, 0755)
+	if err != nil {
+		return fmt.Errorf("Level.WriteJSON: WriteFile error: %s", err)
+	}
+
+	return nil
+}

pkg/level/fmt_readwrite.go

@@ -0,0 +1,65 @@
+package level
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"strings"
+
+	"git.kirsle.net/apps/doodle/pkg/balance"
+	"git.kirsle.net/apps/doodle/pkg/enum"
+	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/apps/doodle/pkg/userdir"
+)
+
+// LoadFile reads a level file from disk, checking a few locations.
+func LoadFile(filename string) (*Level, error) {
+	if !strings.HasSuffix(filename, enum.LevelExt) {
+		filename += enum.LevelExt
+	}
+
+	// Search the system and user paths for this level.
+	filename, err := balance.FindFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	// Try the binary format.
+	if level, err := LoadBinary(filename); err == nil {
+		return level, nil
+	} else {
+		log.Warn(err.Error())
+	}
+
+	// Then the JSON format.
+	if level, err := LoadJSON(filename); err == nil {
+		return level, nil
+	} else {
+		log.Warn(err.Error())
+	}
+
+	return nil, errors.New("invalid file type")
+}
+
+// WriteFile saves a level to disk in the user's config directory.
+func (m *Level) WriteFile(filename string) error {
+	if !strings.HasSuffix(filename, enum.LevelExt) {
+		filename += enum.LevelExt
+	}
+
+	// bin, err := m.ToBinary()
+	bin, err := m.ToJSON()
+	if err != nil {
+		return err
+	}
+
+	// Save it to their profile directory.
+	filename = userdir.LevelPath(filename)
+	log.Info("Write Level: %s", filename)
+	err = ioutil.WriteFile(filename, bin, 0644)
+	if err != nil {
+		return fmt.Errorf("level.WriteFile: %s", err)
+	}
+
+	return nil
+}

pkg/level/types.go

@@ -16,36 +16,36 @@ var (
 // Base provides the common struct keys that are shared between Levels and
 // Doodads.
 type Base struct {
-	Version     int    `json:"version"`     // File format version spec.
-	GameVersion string `json:"gameVersion"` // Game version that created the level.
-	Title       string `json:"title"`
-	Author      string `json:"author"`
+	Version     int    `json:"version" msgpack:"0"`     // File format version spec.
+	GameVersion string `json:"gameVersion" msgpack:"1"` // Game version that created the level.
+	Title       string `json:"title" msgpack:"2"`
+	Author      string `json:"author" msgpack:"3"`
 
 	// Every drawing type is able to embed other files inside of itself.
-	Files FileSystem `json:"files"`
+	Files FileSystem `json:"files" msgpack:"4"`
 }
 
 // Level is the container format for Doodle map drawings.
 type Level struct {
 	Base
-	Password string `json:"passwd"`
-	Locked   bool   `json:"locked"`
+	Password string `json:"passwd" msgpack:"10"`
+	Locked   bool   `json:"locked" msgpack:"11"`
 
 	// Chunked pixel data.
-	Chunker *Chunker `json:"chunks"`
+	Chunker *Chunker `json:"chunks" msgpack:"12"`
 
 	// The Palette holds the unique "colors" used in this map file, and their
 	// properties (solid, fire, slippery, etc.)
-	Palette *Palette `json:"palette"`
+	Palette *Palette `json:"palette" msgpack:"13"`
 
 	// Page boundaries and wallpaper settings.
-	PageType  PageType `json:"pageType"`
-	MaxWidth  int64    `json:"boundedWidth"` // only if bounded or bordered
-	MaxHeight int64    `json:"boundedHeight"`
-	Wallpaper string   `json:"wallpaper"`
+	PageType  PageType `json:"pageType" msgpack:"14"`
+	MaxWidth  int64    `json:"boundedWidth" msgpack:"15"` // only if bounded or bordered
+	MaxHeight int64    `json:"boundedHeight" msgpack:"16"`
+	Wallpaper string   `json:"wallpaper" msgpack:"17"`
 
 	// Actors keep a list of the doodad instances in this map.
-	Actors ActorMap `json:"actors"`
+	Actors ActorMap `json:"actors" msgpack:"18"`
 }
 
 // New creates a blank level object with all its members initialized.

pkg/play_scene.go

@@ -198,6 +198,11 @@ func (s *PlayScene) movePlayer(ev *events.State) {
 	}
 
 	s.Player.SetVelocity(velocity)
+
+	// TODO: invoke the player OnKeypress for animation testing
+	// if velocity != render.Origin {
+	s.scripting.To(s.Player.ID()).Events.RunKeypress(ev)
+	// }
 }
 
 // Drawing returns the private world drawing, for debugging with the console.

pkg/scripting/events.go

@@ -1,6 +1,7 @@
 package scripting
 
 import (
+	"git.kirsle.net/apps/doodle/lib/events"
 	"github.com/robertkrimen/otto"
 )
 
@@ -36,6 +37,16 @@ func (e *Events) RunCollide() error {
 	return e.run(CollideEvent)
 }
 
+// OnKeypress fires when another actor collides with yours.
+func (e *Events) OnKeypress(call otto.FunctionCall) otto.Value {
+	return e.register(KeypressEvent, call.Argument(0))
+}
+
+// RunKeypress invokes the OnCollide handler function.
+func (e *Events) RunKeypress(ev *events.State) error {
+	return e.run(KeypressEvent, ev)
+}
+
 // register a named event.
 func (e *Events) register(name string, callback otto.Value) otto.Value {
 	if !callback.IsFunction() {