Loading Screen

* pkg/loadscreen implements a global Loading Screen for loading heavy
  levels for playing or editing.
* All chunks in a level are pre-rendered to bitmap before gameplay
  begins, which reduces stutter as chunks were being lazily rendered on
  first appearance before.
* The loading screen can be played with in the developer console:
  $ loadscreen.Show()
  $ loadscreen.Hide()
  Along with ShowWithProgress(), SetProgress(float64) and IsActive()
* Chunker: separate the concerns between Bitmaps an (SDL2) Textures.
* Chunker.Prerender() converts a chunk to a bitmap (a Go image.Image)
  and caches it, only re-rendering if marked as dirty.
* Chunker.Texture() will use the pre-cached bitmap if available to
  immediately produce the SDL2 texture.

Other miscellaneous changes:

* Added to the Colored Pencil palette: Sandstone
* Added "perlin noise" brush pattern

Note: this commit introduces instability and crashes:

* New `asyncSetup()` functions run on a goroutine, but SDL2 texture
  calls must run on the main thread.
* Chunker avoids this by caching bitmaps, not textures.
* Wallpaper though is unstable, sometimes works, sometimes has graphical
  glitches, sometimes crashes the game.
* Wallpaper.Load() and the *Texture() functions are where it crashes.

pkg/balance/theme.go

@@ -29,6 +29,22 @@ var (
 		Shadow: render.Black,
 	}
 
+	// Loading Screen fonts.
+	LoadScreenFont = render.Text{
+		Size:   46,
+		Color:  render.Pink,
+		Stroke: render.SkyBlue,
+		Shadow: render.Black,
+	}
+	LoadScreenSecondaryFont = render.Text{
+		FontFilename: "DejaVuSans.ttf",
+		Size:         18,
+		Color:        render.SkyBlue,
+		Shadow:       render.SkyBlue.Darken(128),
+		// Color:        render.RGBA(255, 153, 0, 255),
+		// Shadow:       render.RGBA(200, 80, 0, 255),
+	}
+
 	// Window and panel styles.
 	TitleConfig = ui.Config{
 		Background:   render.MustHexColor("#FF9900"),

pkg/doodle.go

@@ -12,6 +12,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/keybind"
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/modal"
+	"git.kirsle.net/apps/doodle/pkg/modal/loadscreen"
 	"git.kirsle.net/apps/doodle/pkg/native"
 	"git.kirsle.net/apps/doodle/pkg/pattern"
 	"git.kirsle.net/apps/doodle/pkg/shmem"
@@ -160,8 +161,9 @@ func (d *Doodle) Run() error {
 				DebugCollision = !DebugCollision
 			}
 
-			// Is a UI modal active?
+			// Make sure no UI modals (alerts, confirms)
-			if modal.Handled(ev) == false {
+			// or loadscreen are currently visible.
+			if !modal.Handled(ev) {
 				// Run the scene's logic.
 				err = d.Scene.Loop(d, ev)
 				if err != nil {
@@ -174,6 +176,9 @@ func (d *Doodle) Run() error {
 		// Draw the scene.
 		d.Scene.Draw(d)
 
+		// Draw the loadscreen if it is active.
+		loadscreen.Loop(render.NewRect(d.width, d.height), d.Engine)
+
 		// Draw modals on top of the game UI.
 		modal.Draw()
 

pkg/editor_scene.go

@@ -15,6 +15,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/license"
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/modal"
+	"git.kirsle.net/apps/doodle/pkg/modal/loadscreen"
 	"git.kirsle.net/apps/doodle/pkg/usercfg"
 	"git.kirsle.net/apps/doodle/pkg/userdir"
 	"git.kirsle.net/go/render"
@@ -64,6 +65,21 @@ func (s *EditorScene) Setup(d *Doodle) error {
 		{"Swatch:", s.debSwatch},
 	}
 
+	// Show the loading screen.
+	loadscreen.ShowWithProgress()
+	go func() {
+		if err := s.setupAsync(d); err != nil {
+			log.Error("EditorScene.setupAsync: %s", err)
+		}
+		loadscreen.Hide()
+	}()
+
+	return nil
+}
+
+// setupAsync initializes trhe editor scene in the background,
+// underneath a loading screen.
+func (s *EditorScene) setupAsync(d *Doodle) error {
 	// Initialize the user interface. It references the palette and such so it
 	// must be initialized after those things.
 	s.d = d
@@ -81,10 +97,17 @@ func (s *EditorScene) Setup(d *Doodle) error {
 	case enum.LevelDrawing:
 		if s.Level != nil {
 			log.Debug("EditorScene.Setup: received level from scene caller")
+			loadscreen.SetSubtitle(
+				"Opening: "+s.Level.Title,
+				"by "+s.Level.Author,
+			)
 			s.UI.Canvas.LoadLevel(d.Engine, s.Level)
 			s.UI.Canvas.InstallActors(s.Level.Actors)
 		} else if s.filename != "" && s.OpenFile {
 			log.Debug("EditorScene.Setup: Loading map from filename at %s", s.filename)
+			loadscreen.SetSubtitle(
+				"Opening: " + s.filename,
+			)
 			if err := s.LoadLevel(s.filename); err != nil {
 				d.Flash("LoadLevel error: %s", err)
 			} else {
@@ -113,6 +136,12 @@ func (s *EditorScene) Setup(d *Doodle) error {
 			s.UI.Canvas.ScrollTo(render.Origin)
 			s.UI.Canvas.Scrollable = true
 		}
+
+		// Update the loading screen with level info.
+		loadscreen.SetSubtitle(
+			"Opening: "+s.Level.Title,
+			"by "+s.Level.Author,
+		)
 	case enum.DoodadDrawing:
 		// Getting a doodad from file?
 		if s.filename != "" && s.OpenFile {
@@ -140,6 +169,12 @@ func (s *EditorScene) Setup(d *Doodle) error {
 			s.UI.Canvas.LoadDoodad(s.Doodad)
 		}
 
+		// Update the loading screen with level info.
+		loadscreen.SetSubtitle(
+			s.Doodad.Title,
+			"by "+s.Doodad.Author,
+		)
+
 		// TODO: move inside the UI. Just an approximate position for now.
 		s.UI.Canvas.Resize(render.NewRect(s.DoodadSize, s.DoodadSize))
 		s.UI.Canvas.ScrollTo(render.Origin)
@@ -147,10 +182,20 @@ func (s *EditorScene) Setup(d *Doodle) error {
 		s.UI.Workspace.Compute(d.Engine)
 	}
 
+	// Pre-cache all bitmap images from the level chunks.
+	// Note: we are not running on the main thread, so SDL2 Textures
+	// don't get created yet, but we do the full work of caching bitmap
+	// images which later get fed directly into SDL2 saving speed at
+	// runtime, + the bitmap generation is pretty wicked fast anyway.
+	loadscreen.PreloadAllChunkBitmaps(s.UI.Canvas.Chunker())
+
 	// Recompute the UI Palette window for the level's palette.
 	s.UI.FinishSetup(d)
 
-	d.Flash("Editor Mode. Press 'P' to play this map.")
+	d.Flash("Editor Mode.")
+	if s.DrawingType == enum.LevelDrawing {
+		d.Flash("Press 'P' to playtest this level.")
+	}
 
 	return nil
 }
@@ -180,6 +225,11 @@ func (s *EditorScene) ConfirmUnload(fn func()) {
 
 // Loop the editor scene.
 func (s *EditorScene) Loop(d *Doodle, ev *event.State) error {
+	// Skip if still loading.
+	if loadscreen.IsActive() {
+		return nil
+	}
+
 	// Update debug overlay values.
 	*s.debTool = s.UI.Canvas.Tool.String()
 	*s.debSwatch = "???"
@@ -253,7 +303,7 @@ func (s *EditorScene) Loop(d *Doodle, ev *event.State) error {
 	// s.UI.Loop(ev)
 
 	// Switching to Play Mode?
-	if keybind.GotoPlay(ev) {
+	if s.DrawingType == enum.LevelDrawing && keybind.GotoPlay(ev) {
 		s.Playtest()
 	} else if keybind.LineTool(ev) {
 		d.Flash("Line Tool selected.")
@@ -286,6 +336,11 @@ func (s *EditorScene) Loop(d *Doodle, ev *event.State) error {
 
 // Draw the current frame.
 func (s *EditorScene) Draw(d *Doodle) error {
+	// Skip if still loading.
+	if loadscreen.IsActive() {
+		return nil
+	}
+
 	// Clear the canvas and fill it with magenta so it's clear if any spots are missed.
 	d.Engine.Clear(render.RGBA(160, 120, 160, 255))
 

pkg/editor_ui.go

@@ -107,6 +107,8 @@ func NewEditorUI(d *Doodle, s *EditorScene) *EditorUI {
 		FillX: true,
 	})
 
+	// Play Button, for levels only.
+	if s.DrawingType == enum.LevelDrawing {
 		u.PlayButton = ui.NewButton("Play", ui.NewLabel(ui.Label{
 			Text: "Play (P)",
 			Font: balance.PlayButtonFont,
@@ -116,6 +118,7 @@ func NewEditorUI(d *Doodle, s *EditorScene) *EditorUI {
 			return nil
 		})
 		u.Supervisor.Add(u.PlayButton)
+	}
 
 	// Position the Canvas inside the frame.
 	u.Workspace.Pack(u.Canvas, ui.Pack{
@@ -234,7 +237,7 @@ func (u *EditorUI) Resized(d *Doodle) {
 	}
 
 	// Position the Play button over the workspace.
-	{
+	if u.PlayButton != nil {
 		btn := u.PlayButton
 		btn.Compute(d.Engine)
 
@@ -330,7 +333,9 @@ func (u *EditorUI) Present(e render.Engine) {
 	u.MenuBar.Present(e, u.MenuBar.Point())
 	u.StatusBar.Present(e, u.StatusBar.Point())
 	u.ToolBar.Present(e, u.ToolBar.Point())
+	if u.PlayButton != nil {
 		u.PlayButton.Present(e, u.PlayButton.Point())
+	}
 
 	u.screen.Present(e, render.Origin)
 

pkg/level/chunk.go

@@ -32,6 +32,7 @@ type Chunk struct {
 
 	// Texture cache properties so we don't redraw pixel-by-pixel every frame.
 	uuid               uuid.UUID
+	bitmap             image.Image
 	texture            render.Texturer
 	textureMasked      render.Texturer
 	textureMaskedColor render.Color
@@ -78,7 +79,7 @@ func NewChunk() *Chunk {
 func (c *Chunk) Texture(e render.Engine) render.Texturer {
 	if c.texture == nil || c.dirty {
 		// Generate the normal bitmap and one with a color mask if applicable.
-		tex, err := c.toBitmap(render.Invisible)
+		tex, err := c.generateTexture(render.Invisible)
 		if err != nil {
 			log.Error("Texture: %s", err)
 		}
@@ -93,8 +94,9 @@ func (c *Chunk) Texture(e render.Engine) render.Texturer {
 // TextureMasked returns a cached texture with the ColorMask applied.
 func (c *Chunk) TextureMasked(e render.Engine, mask render.Color) render.Texturer {
 	if c.textureMasked == nil || c.textureMaskedColor != mask {
-		// Generate the normal bitmap and one with a color mask if applicable.
+		// Force regenerate with the new mask color.
-		tex, err := c.toBitmap(mask)
+		c.dirty = true
+		tex, err := c.generateTexture(mask)
 		if err != nil {
 			log.Error("Texture: %s", err)
 		}
@@ -111,8 +113,24 @@ func (c *Chunk) SetDirty() {
 	c.dirty = true
 }
 
-// toBitmap puts the texture in a well named bitmap path in the cache folder.
+// CachedBitmap returns a cached render of the chunk as a bitmap image.
-func (c *Chunk) toBitmap(mask render.Color) (render.Texturer, error) {
+//
+// This is like Texture() but skips the step of actually producing an
+// (SDL2) texture. The benefit of this is that you can call it from
+// your non-main threads and offload the bitmap work into background
+// tasks, then when SDL2 needs the Texture, the cached bitmap is
+// immediately there saving time on the main thread.
+func (c *Chunk) CachedBitmap(mask render.Color) image.Image {
+	if c.bitmap == nil || c.dirty {
+		c.bitmap = c.ToBitmap(mask)
+	}
+	return c.bitmap
+}
+
+// generateTexture takes the chunk's Bitmap, turns it into an (SDL2)
+// texture, and caches the texture in memory until the chunk is marked
+// as dirty.
+func (c *Chunk) generateTexture(mask render.Color) (render.Texturer, error) {
 	// Generate a unique name for this chunk cache.
 	var name string
 	if c.uuid == uuid.Nil {
@@ -126,12 +144,21 @@ func (c *Chunk) toBitmap(mask render.Color) (render.Texturer, error) {
 		)
 	}
 
-	// Get the temp bitmap image.
+	// Get (and/or cache) the chunk to a bitmap image.
-	return c.ToBitmap(name, mask)
+	// Note: the 1st call to Bitmap or after SetDirty will
+	// generate the image and store it cached.
+	bitmap := c.CachedBitmap(mask)
+
+	// Cache the texture data with the current renderer.
+	tex, err := shmem.CurrentRenderEngine.StoreTexture(name, bitmap)
+	return tex, err
 }
 
 // ToBitmap exports the chunk's pixels as a bitmap image.
-func (c *Chunk) ToBitmap(filename string, mask render.Color) (render.Texturer, error) {
+// NOT CACHED! This will always run the logic. Use Bitmap() if you
+// want a cached bitmap image that only generates itself once, and
+// again when marked dirty.
+func (c *Chunk) ToBitmap(mask render.Color) image.Image {
 	canvas := c.SizePositive()
 	imgSize := image.Rectangle{
 		Min: image.Point{},
@@ -189,9 +216,7 @@ func (c *Chunk) ToBitmap(filename string, mask render.Color) (render.Texturer, e
 		)
 	}
 
-	// Cache the texture data with the current renderer.
+	return img
-	tex, err := shmem.CurrentRenderEngine.StoreTexture(filename, img)
-	return tex, err
 }
 
 // Set proxies to the accessor and flags the texture as dirty.

pkg/level/chunker.go

@@ -188,6 +188,43 @@ func (c *Chunker) Redraw() {
 	}
 }
 
+// Prerender visits every chunk and fetches its texture, in order to pre-load
+// the whole drawing for smooth gameplay rather than chunks lazy rendering as
+// they enter the screen.
+func (c *Chunker) Prerender() {
+	for _, chunk := range c.Chunks {
+		_ = chunk.CachedBitmap(render.Invisible)
+	}
+}
+
+// PrerenderN will pre-render the texture for N number of chunks and then
+// yield back to the caller. Returns the number of chunks that still need
+// textures rendered; zero when the last chunk has been prerendered.
+func (c *Chunker) PrerenderN(n int) (remaining int) {
+	var (
+		total         int // total no. of chunks available
+		totalRendered int // no. of chunks with textures
+		modified      int // number modified this call
+	)
+
+	for _, chunk := range c.Chunks {
+		total++
+		if chunk.bitmap != nil {
+			totalRendered++
+			continue
+		}
+
+		if modified < n {
+			_ = chunk.CachedBitmap(render.Invisible)
+			totalRendered++
+			modified++
+		}
+	}
+
+	remaining = total - totalRendered
+	return
+}
+
 // Get a pixel at the given coordinate. Returns the Palette entry for that
 // pixel or else returns an error if not found.
 func (c *Chunker) Get(p render.Point) (*Swatch, error) {

pkg/level/palette_defaults.go

@@ -61,6 +61,12 @@ var (
 					Solid:   true,
 					Pattern: "noise.png",
 				},
+				{
+					Name:    "sandstone",
+					Color:   render.RGBA(215, 114, 44, 255),
+					Solid:   true,
+					Pattern: "perlin-noise.png",
+				},
 				{
 					Name:    "fire",
 					Color:   render.Red,

pkg/modal/loadscreen/loadscreen.go

@@ -0,0 +1,231 @@
+// Package loadscreen implements a modal "Loading" screen for the game, which
+// can be shown or hidden by gameplay scenes as needed.
+package loadscreen
+
+import (
+	"strings"
+
+	"git.kirsle.net/apps/doodle/pkg/balance"
+	"git.kirsle.net/apps/doodle/pkg/level"
+	"git.kirsle.net/apps/doodle/pkg/shmem"
+	"git.kirsle.net/apps/doodle/pkg/uix"
+	"git.kirsle.net/go/render"
+	"git.kirsle.net/go/ui"
+)
+
+// Configuration values.
+const (
+	ProgressWidth  = 300
+	ProgressHeight = 34
+)
+
+// State variables for the loading screen.
+var (
+	visible      bool
+	withProgress bool
+	subtitle     string // custom subtitle text, SetSubtitle().
+
+	// Animated title bar
+	titleBase = "Loading"
+	animState = 0
+	animation = []string{
+		".  ",
+		".. ",
+		"...",
+		" ..",
+		"  .",
+		"   ",
+	}
+	animSpeed uint64 = 32
+	titleVar  string
+
+	// UI widgets.
+	window         *ui.Frame
+	canvas         *uix.Canvas
+	secondary      *ui.Label // subtitle text
+	progressTrough *ui.Frame
+	progressBar    *ui.Frame
+	progressText   *ui.Label
+)
+
+// Show the basic loading screen without a progress bar.
+func Show() {
+	setup()
+	visible = true
+	withProgress = false
+	subtitle = ""
+}
+
+// ShowWithProgress initializes the loading screen with a progress bar starting at zero.
+func ShowWithProgress() {
+	setup()
+	visible = true
+	withProgress = true
+	subtitle = ""
+	SetProgress(0)
+}
+
+// SetSubtitle specifies secondary text beneath the Loading banner.
+// The subtitle is blanked on Show() and ShowWithProgress() and must
+// be specified by the caller if desired. Pass multiple values for
+// multiple lines of text.
+func SetSubtitle(value ...string) {
+	subtitle = strings.Join(value, "\n")
+}
+
+// IsActive returns whether the loading screen is currently visible.
+func IsActive() bool {
+	return visible
+}
+
+// Hide the loading screen.
+func Hide() {
+	visible = false
+}
+
+// SetProgress sets the current progress value for loading screens having a progress bar.
+func SetProgress(v float64) {
+	// Resize the progress bar in the trough.
+	if progressTrough != nil {
+		var (
+			troughSize = progressTrough.Size()
+			height     = progressBar.Size().H
+		)
+		progressBar.Resize(render.Rect{
+			W: int(float64(troughSize.W-4) * v),
+			H: height,
+		})
+	}
+}
+
+// Common function to initialize the loading screen.
+func setup() {
+	if window != nil {
+		return
+	}
+
+	titleVar = titleBase + animation[animState]
+
+	// Create the parent container that will stretch full screen.
+	window = ui.NewFrame("Loadscreen Window")
+	window.SetBackground(render.RGBA(0, 0, 1, 40))
+
+	// "Loading" text.
+	label := ui.NewLabel(ui.Label{
+		TextVariable: &titleVar,
+		Font:         balance.LoadScreenFont,
+	})
+	label.Compute(shmem.CurrentRenderEngine)
+	window.Place(label, ui.Place{
+		Top:    128,
+		Center: true,
+	})
+
+	// Subtitle text.
+	secondary = ui.NewLabel(ui.Label{
+		TextVariable: &subtitle,
+		Font:         balance.LoadScreenSecondaryFont,
+	})
+	window.Place(secondary, ui.Place{
+		Top:    128 + label.Size().H + 64,
+		Center: true,
+	})
+
+	// Progress bar.
+	progressTrough = ui.NewFrame("Progress Trough")
+	progressTrough.Configure(ui.Config{
+		Width:       ProgressWidth,
+		Height:      ProgressHeight,
+		BorderSize:  2,
+		BorderStyle: ui.BorderSunken,
+		Background:  render.DarkGrey,
+	})
+	window.Place(progressTrough, ui.Place{
+		Center: true,
+		Middle: true,
+	})
+
+	progressBar = ui.NewFrame("Progress Bar")
+	progressBar.Configure(ui.Config{
+		Width:      0,
+		Height:     ProgressHeight - 4,
+		Background: render.Green,
+	})
+	progressTrough.Pack(progressBar, ui.Pack{
+		Side: ui.W,
+	})
+}
+
+// Loop is called on every game loop. If the loadscreen is not active, nothing happens.
+// Otherwise the loading screen UI is drawn to screen.
+func Loop(windowSize render.Rect, e render.Engine) {
+	if !visible {
+		return
+	}
+
+	if window != nil {
+		// Initialize the wallpaper canvas?
+		if canvas == nil {
+			canvas = uix.NewCanvas(128, false)
+			canvas.LoadLevel(e, &level.Level{
+				Chunker:   level.NewChunker(100),
+				Palette:   level.NewPalette(),
+				PageType:  level.Bounded,
+				Wallpaper: "blueprint.png",
+			})
+		}
+		canvas.Resize(windowSize)
+		canvas.Compute(e)
+		canvas.Present(e, render.Origin)
+
+		window.Resize(windowSize)
+		window.Compute(e)
+		window.Present(e, render.Origin)
+
+		// Show/hide the progress bar.
+		progressTrough.Compute(e)
+		if withProgress && progressTrough.Hidden() {
+			progressTrough.Show()
+		} else if !withProgress && !progressTrough.Hidden() {
+			progressTrough.Hide()
+		}
+
+		// Show/hide the subtitle text.
+		if len(subtitle) > 0 && secondary.Hidden() {
+			secondary.Show()
+		} else if subtitle == "" && !secondary.Hidden() {
+			secondary.Hide()
+		}
+
+		// Animate the ellipses.
+		if shmem.Tick%animSpeed == 0 {
+			titleVar = titleBase + animation[animState]
+			animState++
+			if animState >= len(animation) {
+				animState = 0
+			}
+		}
+
+	}
+}
+
+// PreloadAllChunkBitmaps is a helper function to eager cache all bitmap
+// images of the chunks in a level drawing. It is designed to work with the
+// loading screen and will set the Progress percent based on the total number
+// of chunks vs. chunks remaining to pre-cache bitmaps from.
+func PreloadAllChunkBitmaps(chunker *level.Chunker) {
+	loadChunksTarget := len(chunker.Chunks)
+	for {
+		remaining := chunker.PrerenderN(10)
+
+		// Set the load screen progress % based on number of chunks to render.
+		if loadChunksTarget > 0 {
+			percent := float64(loadChunksTarget-remaining) / float64(loadChunksTarget)
+			SetProgress(percent)
+		}
+
+		if remaining == 0 {
+			break
+		}
+	}
+}

pkg/modal/modal.go

@@ -4,6 +4,7 @@ package modal
 import (
 	"git.kirsle.net/apps/doodle/pkg/balance"
 	"git.kirsle.net/apps/doodle/pkg/keybind"
+	"git.kirsle.net/apps/doodle/pkg/modal/loadscreen"
 	"git.kirsle.net/go/render"
 	"git.kirsle.net/go/render/event"
 	"git.kirsle.net/go/ui"
@@ -44,7 +45,16 @@ func Reset() {
 
 // Handled runs the modal manager's logic. Returns true if a modal
 // is presently active, to signal to Doodle not to run game logic.
+//
+// This function also returns true if the pkg/modal/loadscreen is
+// currently active.
 func Handled(ev *event.State) bool {
+	// The loadscreen counts as a modal for this purpose.
+	if loadscreen.IsActive() {
+		return true
+	}
+
+	// Check if we have a modal currently active.
 	if !ready || current == nil {
 		return false
 	}

pkg/pattern/pattern.go

@@ -37,7 +37,11 @@ var Builtins = []Pattern{
 		Filename: "ink.png",
 	},
 	{
-		Name:     "Dashed Lines",
+		Name:     "Perlin Noise",
+		Filename: "perlin-noise.png",
+	},
+	{
+		Name:     "Bubbles",
 		Filename: "circles.png",
 	},
 	{

pkg/play_scene.go

@@ -9,6 +9,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/keybind"
 	"git.kirsle.net/apps/doodle/pkg/level"
 	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/apps/doodle/pkg/modal/loadscreen"
 	"git.kirsle.net/apps/doodle/pkg/physics"
 	"git.kirsle.net/apps/doodle/pkg/scripting"
 	"git.kirsle.net/apps/doodle/pkg/uix"
@@ -75,6 +76,23 @@ func (s *PlayScene) Setup(d *Doodle) error {
 	s.scripting = scripting.NewSupervisor()
 	s.supervisor = ui.NewSupervisor()
 
+	// Show the loading screen.
+	loadscreen.ShowWithProgress()
+	go func() {
+		if err := s.setupAsync(d); err != nil {
+			log.Error("PlayScene.setupAsync: %s", err)
+			return
+		}
+
+		loadscreen.Hide()
+	}()
+
+	return nil
+}
+
+// setupAsync initializes the play screen in the background, underneath
+// a Loading screen.
+func (s *PlayScene) setupAsync(d *Doodle) error {
 	// Create an invisible 'screen' frame for UI elements to use for positioning.
 	s.screen = ui.NewFrame("Screen")
 	s.screen.Resize(render.NewRect(d.width, d.height))
@@ -156,6 +174,7 @@ func (s *PlayScene) Setup(d *Doodle) error {
 		s.drawing.LoadLevel(d.Engine, s.Level)
 		s.drawing.InstallActors(s.Level.Actors)
 	} else if s.Filename != "" {
+		loadscreen.SetSubtitle("Opening: " + s.Filename)
 		log.Debug("PlayScene.Setup: loading map from file %s", s.Filename)
 		// NOTE: s.LoadLevel also calls s.drawing.InstallActors
 		s.LoadLevel(s.Filename)
@@ -168,6 +187,12 @@ func (s *PlayScene) Setup(d *Doodle) error {
 		s.drawing.InstallActors(s.Level.Actors)
 	}
 
+	// Set the loading screen text with the level metadata.
+	loadscreen.SetSubtitle(
+		s.Level.Title,
+		"by "+s.Level.Author,
+	)
+
 	// Load all actor scripts.
 	s.drawing.SetScriptSupervisor(s.scripting)
 	if err := s.scripting.InstallScripts(s.Level); err != nil {
@@ -188,6 +213,13 @@ func (s *PlayScene) Setup(d *Doodle) error {
 		d.Flash("%s", s.Level.Title)
 	}
 
+	// Pre-cache all bitmap images from the level chunks.
+	// Note: we are not running on the main thread, so SDL2 Textures
+	// don't get created yet, but we do the full work of caching bitmap
+	// images which later get fed directly into SDL2 saving speed at
+	// runtime, + the bitmap generation is pretty wicked fast anyway.
+	loadscreen.PreloadAllChunkBitmaps(s.Level.Chunker)
+
 	s.running = true
 
 	return nil
@@ -374,6 +406,11 @@ func (s *PlayScene) DieByFire(name string) {
 
 // Loop the editor scene.
 func (s *PlayScene) Loop(d *Doodle, ev *event.State) error {
+	// Skip if still loading.
+	if loadscreen.IsActive() {
+		return nil
+	}
+
 	// Update debug overlay values.
 	*s.debWorldIndex = s.drawing.WorldIndexAt(render.NewPoint(ev.CursorX, ev.CursorY)).String()
 	*s.debPosition = s.Player.Position().String() + " vel " + s.Player.Velocity().String()
@@ -420,6 +457,11 @@ func (s *PlayScene) Loop(d *Doodle, ev *event.State) error {
 
 // Draw the pixels on this frame.
 func (s *PlayScene) Draw(d *Doodle) error {
+	// Skip if still loading.
+	if loadscreen.IsActive() {
+		return nil
+	}
+
 	// Clear the canvas and fill it with white.
 	d.Engine.Clear(render.White)
 

pkg/shell.go

@@ -8,6 +8,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/balance"
 	"git.kirsle.net/apps/doodle/pkg/keybind"
 	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/apps/doodle/pkg/modal/loadscreen"
 	"git.kirsle.net/apps/doodle/pkg/shmem"
 	"git.kirsle.net/go/render"
 	"git.kirsle.net/go/render/event"
@@ -85,6 +86,13 @@ func NewShell(d *Doodle) Shell {
 			}
 			return ""
 		},
+		"loadscreen": map[string]interface{}{
+			"Show":             loadscreen.Show,
+			"ShowWithProgress": loadscreen.ShowWithProgress,
+			"Hide":             loadscreen.Hide,
+			"IsActive":         loadscreen.IsActive,
+			"SetProgress":      loadscreen.SetProgress,
+		},
 	}
 	for name, v := range bindings {
 		err := s.js.Set(name, v)