1st Round of Doodad Sprites + Improve Doodad Tool

* Improve the `doodad convert` command to convert a series of input
  images into multiple Frames of a Doodad:
  `doodad convert frame1.png frame2.png frameN.png output.doodad`
* Add the initial round of dev-asset sprites for the default Doodads:
  * Button, Button-TypeB and Sticky Button
  * Red, Blue, Green and Yellow Locked Doors and Keys
  * Electric Door
  * Trapdoor Down
* Add dev-assets/palette.json that defines our default doodad color
  palette. Eventually the JSON will be used by the `doodad` tool to give
  the layers meaningful names.

cmd/doodad/commands/convert.go

@@ -35,11 +35,19 @@ func init() {
 				Usage: "chroma key color for transparency on input image files",
 				Value: "#ffffff",
 			},
+			cli.StringFlag{
+				Name:  "title, t",
+				Usage: "set the title of the level or doodad being created",
+			},
+			cli.StringFlag{
+				Name:  "palette, p",
+				Usage: "use a palette JSON to define color swatch properties",
+			},
 		},
 		Action: func(c *cli.Context) error {
-			if c.NArg() != 2 {
+			if c.NArg() < 2 {
 				return cli.NewExitError(
-					"Usage: doodad convert <input.png> <output.level>\n"+
+					"Usage: doodad convert <input.png...> <output.doodad>\n"+
 						"   Image file types: png, bmp\n"+
 						"   Drawing file types: level, doodad",
 					1,
@@ -57,15 +65,15 @@ func init() {
 
 			args := c.Args()
 			var (
-				inputFile  = args[0]
-				inputType  = strings.ToLower(filepath.Ext(inputFile))
-				outputFile = args[1]
+				inputFiles = args[:len(args)-1]
+				inputType  = strings.ToLower(filepath.Ext(inputFiles[0]))
+				outputFile = args[len(args)-1]
 				outputType = strings.ToLower(filepath.Ext(outputFile))
 			)
 
 			if inputType == extPNG || inputType == extBMP {
 				if outputType == extLevel || outputType == extDoodad {
-					if err := imageToDrawing(c, chroma, inputFile, outputFile); err != nil {
+					if err := imageToDrawing(c, chroma, inputFiles, outputFile); err != nil {
 						return cli.NewExitError(err.Error(), 1)
 					}
 					return nil
@@ -73,7 +81,7 @@ func init() {
 				return cli.NewExitError("Image inputs can only output to Doodle drawings", 1)
 			} else if inputType == extLevel || inputType == extDoodad {
 				if outputType == extPNG || outputType == extBMP {
-					if err := drawingToImage(c, chroma, inputFile, outputFile); err != nil {
+					if err := drawingToImage(c, chroma, inputFiles, outputFile); err != nil {
 						return cli.NewExitError(err.Error(), 1)
 					}
 					return nil
@@ -86,15 +94,22 @@ func init() {
 	}
 }
 
-func imageToDrawing(c *cli.Context, chroma render.Color, inputFile, outputFile string) error {
-	reader, err := os.Open(inputFile)
+func imageToDrawing(c *cli.Context, chroma render.Color, inputFiles []string, outputFile string) error {
+	// Read the source images. Ensure they all have the same boundaries.
+	var (
+		imageBounds image.Point
+		chunkSize   int // the square shape for the Doodad chunk size
+		images      []image.Image
+	)
+
+	for i, filename := range inputFiles {
+		reader, err := os.Open(filename)
 		if err != nil {
 			return cli.NewExitError(err.Error(), 1)
 		}
 
 		img, format, err := image.Decode(reader)
-	log.Info("format: %s", format)
-	_ = img
+		log.Info("Parsed image %d of %d. Format: %s", i+1, len(inputFiles), format)
 		if err != nil {
 			return cli.NewExitError(err.Error(), 1)
 		}
@@ -103,13 +118,22 @@ func imageToDrawing(c *cli.Context, chroma render.Color, inputFile, outputFile s
 		var (
 			bounds    = img.Bounds()
 			imageSize = bounds.Size()
-		chunkSize int // the square shape for Doodad chunk size
 		)
+
+		// Validate all images are the same size.
+		if i == 0 {
+			imageBounds = imageSize
 			if imageSize.X > imageSize.Y {
 				chunkSize = imageSize.X
 			} else {
 				chunkSize = imageSize.Y
 			}
+		} else if imageSize != imageBounds {
+			return cli.NewExitError("your source images are not all the same dimensions", 1)
+		}
+
+		images = append(images, img)
+	}
 
 	// Generate the output drawing file.
 	switch strings.ToLower(filepath.Ext(outputFile)) {
@@ -117,9 +141,27 @@ func imageToDrawing(c *cli.Context, chroma render.Color, inputFile, outputFile s
 		log.Info("Output is a Doodad file (chunk size %d): %s", chunkSize, outputFile)
 		doodad := doodads.New(chunkSize)
 		doodad.GameVersion = doodle.Version
+		doodad.Title = c.String("title")
+		if doodad.Title == "" {
 			doodad.Title = "Converted Doodad"
+		}
 		doodad.Author = os.Getenv("USER")
-		doodad.Palette = imageToChunker(img, chroma, doodad.Layers[0].Chunker)
+
+		// Write the first layer and gather its palette.
+		palette, layer0 := imageToChunker(images[0], chroma, chunkSize)
+		doodad.Palette = palette
+		doodad.Layers[0].Chunker = layer0
+
+		// Write any additional layers.
+		if len(images) > 1 {
+			for i, img := range images[1:] {
+				_, chunker := imageToChunker(img, chroma, chunkSize)
+				doodad.Layers = append(doodad.Layers, doodads.Layer{
+					Name:    fmt.Sprintf("layer-%d", i+1),
+					Chunker: chunker,
+				})
+			}
+		}
 
 		err := doodad.WriteJSON(outputFile)
 		if err != nil {
@@ -127,12 +169,20 @@ func imageToDrawing(c *cli.Context, chroma render.Color, inputFile, outputFile s
 		}
 	case extLevel:
 		log.Info("Output is a Level file: %s", outputFile)
+		if len(images) > 1 {
+			log.Warn("Notice: levels only support one layer so only your first image will be used")
+		}
 
 		lvl := level.New()
 		lvl.GameVersion = doodle.Version
+		lvl.Title = c.String("title")
+		if lvl.Title == "" {
 			lvl.Title = "Converted Level"
+		}
 		lvl.Author = os.Getenv("USER")
-		lvl.Palette = imageToChunker(img, chroma, lvl.Chunker)
+		palette, chunker := imageToChunker(images[0], chroma, lvl.Chunker.Size)
+		lvl.Palette = palette
+		lvl.Chunker = chunker
 
 		err := lvl.WriteJSON(outputFile)
 		if err != nil {
@@ -145,9 +195,10 @@ func imageToDrawing(c *cli.Context, chroma render.Color, inputFile, outputFile s
 	return nil
 }
 
-func drawingToImage(c *cli.Context, chroma render.Color, inputFile, outputFile string) error {
+func drawingToImage(c *cli.Context, chroma render.Color, inputFiles []string, outputFile string) error {
 	var palette *level.Palette
 	var chunker *level.Chunker
+	inputFile := inputFiles[0]
 
 	switch strings.ToLower(filepath.Ext(inputFile)) {
 	case extLevel:
@@ -224,9 +275,10 @@ func drawingToImage(c *cli.Context, chroma render.Color, inputFile, outputFile s
 //
 // img: input image like a PNG
 // chroma: transparent color
-func imageToChunker(img image.Image, chroma render.Color, chunker *level.Chunker) *level.Palette {
+func imageToChunker(img image.Image, chroma render.Color, chunkSize int) (*level.Palette, *level.Chunker) {
 	var (
 		palette = level.NewPalette()
+		chunker = level.NewChunker(chunkSize)
 		bounds  = img.Bounds()
 	)
 
@@ -265,6 +317,7 @@ func imageToChunker(img image.Image, chroma render.Color, chunker *level.Chunker
 	for _, hex := range sortedColors {
 		palette.Swatches = append(palette.Swatches, uniqueColor[hex])
 	}
+	palette.Inflate()
 
-	return palette
+	return palette, chunker
 }

dev-assets/doodads/buttons/README.md

@@ -0,0 +1,12 @@
+# Button Doodads
+
+```bash
+doodad convert -t "Sticky Button" sticky1.png sticky2.png sticky-button.doodad
+doodad install-script sticky.js sticky-button.doodad
+
+doodad convert -t "Button" button1.png button2.png button.doodad
+doodad install-script button.js button.doodad
+
+doodad convert -t "Button Type B" typeB1.png typeB2.png button-typeB.doodad
+doodad install-script button.js button-typeB.doodad
+```

dev-assets/doodads/buttons/button.js

@@ -0,0 +1,8 @@
+function main() {
+	console.log("Sticky Button initialized!");
+
+	Events.OnCollide( function() {
+		console.log("Touched!");
+		Self.Canvas.SetBackground(RGBA(255, 153, 0, 153))
+	})
+}

dev-assets/doodads/buttons/sticky.js

@@ -0,0 +1,8 @@
+function main() {
+	console.log("Sticky Button initialized!");
+
+	Events.OnCollide( function() {
+		console.log("Touched!");
+		Self.Canvas.SetBackground(RGBA(255, 153, 0, 153))
+	})
+}

dev-assets/doodads/doors/README.md

@@ -0,0 +1,15 @@
+# Button Doodads
+
+```bash
+doodad convert -t "Red Door" red1.png red2.png red-door.doodad
+doodad convert -t "Blue Door" blue1.png blue2.png blue-door.doodad
+doodad convert -t "Green Door" green1.png green2.png green-door.doodad
+doodad convert -t "Yellow Door" yellow1.png yellow2.png yellow-door.doodad
+
+doodad convert -t "Red Key" red-key.png red-key.doodad
+doodad convert -t "Blue Key" blue-key.png blue-key.doodad
+doodad convert -t "Green Key" green-key.png green-key.doodad
+doodad convert -t "Yellow Key" yellow-key.png yellow-key.doodad
+
+doodad convert -t "Electric Door" electric{1,2,3,4}.png electric-door.doodad
+```

dev-assets/doodads/palette.json

@@ -0,0 +1,35 @@
+{
+	"#000000": {
+		"name": "black"
+	},
+	"#666666": {
+		"name": "dark-grey"
+	},
+	"#999999": {
+		"name": "grey"
+	},
+	"#CCCCCC": {
+		"name": "light-grey"
+	},
+	"#FF0000": {
+		"name": "red"
+	},
+	"#0099FF": {
+		"name": "light-blue"
+	},
+	"#0000FF": {
+		"name": "blue"
+	},
+	"#009900": {
+		"name": "green"
+	},
+	"#999900": {
+		"name": "gold"
+	},
+	"#4D391B": {
+		"name": "brown"
+	},
+	"#8B652C": {
+		"name": "light-brown"
+	}
+}

dev-assets/doodads/trapdoors/README.md

@@ -0,0 +1,5 @@
+# Button Doodads
+
+```bash
+doodad convert -t "Trapdoor Down" down{1,2,3}.png trapdoor-down.doodad
+```

pkg/level/chunk_map.go

@@ -22,7 +22,7 @@ func (a MapAccessor) Inflate(pal *Palette) error {
 	for point, swatch := range a {
 		if swatch.IsSparse() {
 			// Replace this with the correct swatch from the palette.
-			if len(pal.Swatches) < swatch.paletteIndex {
+			if swatch.paletteIndex >= len(pal.Swatches) {
 				return fmt.Errorf("MapAccessor.Inflate: swatch for point %s has paletteIndex %d but palette has only %d colors",
 					point,
 					swatch.paletteIndex,