WIP Zoom Tool

* Added Feature Flag support, run doodle with --experimental to enable
  all flags. Eraser Tool is behind a feature flag now.
* + and - on the top row of keyboard keys will zoom the drawing in and
  out in Edit Mode. The wallpaper zooms nicely enough, but level
  chunkers need work.
* A View menu is added with Zoom in/out, reset zoom, and scroll to
  origin options. The whole menu is behind the Zoom feature flag.
* Update README with lots of details for fun debug mode options to play
  around with.

README.md

@@ -142,7 +142,9 @@ A brief introduction to the built-in doodads available so far:
 
 # Developer Console
 
-Press `Enter` at any time to open the developer console.
+Press `Enter` at any time to open the developer console. The console
+provides commands and advanced functionality, and is also where cheat
+codes can be entered.
 
 Commands supported:
 
@@ -154,8 +156,8 @@ new
   Show the "New Level" screen to start editing a new map.
 
 save [filename]
-  Save the current map in Edit Mode. The filename is required if the map has
+  Save the current map in Edit Mode. The filename is required
-  not been saved yet.
+  if the map has not been saved yet.
 
 edit [filename]
   Open a map or doodad in Edit Mode.
@@ -166,14 +168,39 @@ play [filename]
 echo <text>
   Flash a message to the console.
 
+alert <text>
+  Test an alert box modal with a custom message.
+
 clear
   Clear the console output history.
 
 exit
 quit
   Close the developer console.
+
+boolProp <property> <true/false>
+  Toggle certain boolean settings in the game. Most of these
+  are debugging related. `boolProp list` shows the available
+  props.
+
+eval <expression>
+$ <expression>
+  Execute a line of JavaScript code in the console. Several
+  of the game's core data types are available here; `d` is
+  the master game struct; d.Scene is the pointer to the
+  current scene. d.Scene.UI.Canvas may point to the level edit
+  canvas in Editor Mode. Object.keys() can enumerate public
+  functions and variables.
+
+repl
+  Enters an interactive JavaScript shell, where the console
+  stays open and pre-fills a $ prompt for subsequent commands.
 ```
 
+The JavaScript console is a feature for advanced users and was
+used while developing the game. Cool things you can do with it
+may be documented elsewhere.
+
 ## Cheat Codes
 
 The following cheats can be entered into the developer console.
@@ -205,6 +232,64 @@ Experimental:
     The player character must always remain on screen though so you can't
     scroll too far away.
 
+Unsupported shell commands (here be dragons):
+
+* `reload`: reloads the current 'scene' within the game engine, using the
+  existing scene's data. If playing a level this will start the level over.
+  If editing a level this will reload the editor, but your recent unsaved
+  changes _should_ be left intact.
+* `guitest`: loads the GUI Test scene within the game. This was where I
+  was testing UI widgets early on; not well maintained; the `close`
+  command can get you out of it.
+
+## Environment Variables
+
+To enable certain debug features or customize some aspects of the game,
+run it with environment variables like the following:
+
+```bash
+# Draw a semi-transparent yellow background over all level chunks
+$ DEBUG_CHUNK_COLOR=FFFF0066 ./doodle
+
+# Set a window size for the application
+# (equivalent to: doodle --window 1024x768)
+$ DOODLE_W=1024 DOODLE_H=768 ./doodle
+
+# Turn on lots of fun debug features.
+$ DEBUG_CANVAS_LABEL=1 DEBUG_CHUNK_COLOR=FFFF00AA \
+  DEBUG_CANVAS_BORDER=FF0 ./doodle
+```
+
+Supported variables include:
+
+* `DOODLE_W` and `DOODLE_H` set the width and height of the application
+  window. Equivalent to the `--window` command-line option.
+* `D_SCROLL_SPEED` (int): tune the canvas scrolling speed. Default might
+  be around 8 or so.
+* `D_DOODAD_SIZE` (int): default size for newly created doodads
+* `D_SHELL_BG` (color): set the background color of the developer console
+* `D_SHELL_FG` (color): text color for the developer console
+* `D_SHELL_PC` (color): color for the shell prompt text
+* `D_SHELL_LN` (int): set the number of lines of output history the
+  console will show. This dictates how 'tall' it rises from the bottom
+  of the screen. Large values will cover the entire screen with console
+  whenever the shell is open.
+* `D_SHELL_FS` (int): set the font size for the developer shell. Default
+  is about 16. This also affects the size of "flashed" text that appears
+  at the bottom of the screen.
+* `DEBUG_CHUNK_COLOR` (color): set a background color over each chunk
+  of drawing (level or doodad). A solid color will completely block out
+  the wallpaper; semitransparent is best.
+* `DEBUG_CANVAS_BORDER` (color): the game will draw an insert colored
+  border around every "Canvas" widget (drawing) on the screen. The level
+  itself is a Canvas and every individual Doodad or actor in the level is
+  its own Canvas.
+* `DEBUG_CANVAS_LABEL` (bool): draws a text label over every Canvas
+  widget on the screen, showing its name or Actor ID and some properties,
+  such as Level Position (LP) and World Position (WP) of actors within
+  a level. LP is their placement in the level file and WP is their
+  actual position now (in case it moves).
+
 # Author
 
 Copyright (C) 2020 Noah Petherbridge. All rights reserved.

cmd/doodle/main.go

@@ -77,6 +77,10 @@ func main() {
 			Name:  "guitest",
 			Usage: "enter the GUI Test scene on startup",
 		},
+		&cli.BoolFlag{
+			Name:  "experimental",
+			Usage: "enable experimental Feature Flags",
+		},
 	}
 
 	app.Action = func(c *cli.Context) error {
@@ -92,6 +96,11 @@ func main() {
 			}
 		}
 
+		// Enable feature flags?
+		if c.Bool("experimental") {
+			balance.FeaturesOn()
+		}
+
 		// SDL engine.
 		engine := sdl.New(
 			fmt.Sprintf("%s v%s", branding.AppName, branding.Version),

pkg/balance/feature_flags.go

@@ -0,0 +1,15 @@
+package balance
+
+// Feature Flags to turn on/off experimental content.
+var Feature = feature{
+	Zoom: false,
+}
+
+// FeaturesOn turns on all feature flags, from CLI --experimental option.
+func FeaturesOn() {
+	Feature.Zoom = true
+}
+
+type feature struct {
+	Zoom bool
+}

pkg/doodle.go

@@ -137,7 +137,11 @@ func (d *Doodle) Run() error {
 		} else {
 			// Global event handlers.
 			if keybind.Shutdown(ev) {
-				d.ConfirmExit()
+				if d.Debug { // fast exit in -debug mode.
+					d.running = false
+				} else {
+					d.ConfirmExit()
+				}
 				continue
 			}
 

pkg/editor_scene.go

@@ -202,6 +202,23 @@ func (s *EditorScene) Loop(d *Doodle, ev *event.State) error {
 		s.UI.Canvas.RedoStroke()
 	}
 
+	// Zoom in/out.
+	if balance.Feature.Zoom {
+		if keybind.ZoomIn(ev) {
+			d.Flash("Zoom in")
+			s.UI.Canvas.Zoom++
+		} else if keybind.ZoomOut(ev) {
+			d.Flash("Zoom out")
+			s.UI.Canvas.Zoom--
+		} else if keybind.ZoomReset(ev) {
+			d.Flash("Reset zoom")
+			s.UI.Canvas.Zoom = 0
+		} else if keybind.Origin(ev) {
+			d.Flash("Scrolled back to level origin (0,0)")
+			s.UI.Canvas.ScrollTo(render.Origin)
+		}
+	}
+
 	s.UI.Loop(ev)
 
 	// Switching to Play Mode?

pkg/editor_ui.go

@@ -547,26 +547,43 @@ func (u *EditorUI) SetupMenuBar(d *Doodle) *ui.MenuBar {
 	editMenu.AddItemAccel("Redo", "Ctrl-Y", func() {
 		u.Canvas.RedoStroke()
 	})
-	editMenu.AddSeparator()
-	editMenu.AddItem("Level options", func() {
-		log.Info("Opening the window")
-
-		// Open the New Level window in edit-settings mode.
-		u.levelSettingsWindow.Hide()
-		u.levelSettingsWindow = nil
-		u.SetupPopups(u.d)
-		u.levelSettingsWindow.Show()
-	})
 
 	////////
 	// Level menu
 	if u.Scene.DrawingType == enum.LevelDrawing {
 		levelMenu := menu.AddMenu("Level")
+		levelMenu.AddItem("Page settings", func() {
+			log.Info("Opening the window")
+
+			// Open the New Level window in edit-settings mode.
+			u.levelSettingsWindow.Hide()
+			u.levelSettingsWindow = nil
+			u.SetupPopups(u.d)
+			u.levelSettingsWindow.Show()
+		})
 		levelMenu.AddItemAccel("Playtest", "P", func() {
 			u.Scene.Playtest()
 		})
 	}
 
+	////////
+	// View menu
+	if balance.Feature.Zoom {
+		viewMenu := menu.AddMenu("View")
+		viewMenu.AddItemAccel("Zoom in", "+", func() {
+			u.Canvas.Zoom++
+		})
+		viewMenu.AddItemAccel("Zoom out", "-", func() {
+			u.Canvas.Zoom--
+		})
+		viewMenu.AddItemAccel("Reset zoom", "1", func() {
+			u.Canvas.Zoom = 0
+		})
+		viewMenu.AddItemAccel("Scroll drawing to origin", "0", func() {
+			u.Canvas.ScrollTo(render.Origin)
+		})
+	}
+
 	////////
 	// Tools menu
 	toolMenu := menu.AddMenu("Tools")

pkg/keybind/keybind.go

@@ -45,6 +45,26 @@ func Redo(ev *event.State) bool {
 	return ev.Ctrl && ev.KeyDown("y")
 }
 
+// ZoomIn (+)
+func ZoomIn(ev *event.State) bool {
+	return ev.KeyDown("=") || ev.KeyDown("+")
+}
+
+// ZoomOut (-)
+func ZoomOut(ev *event.State) bool {
+	return ev.KeyDown("-")
+}
+
+// ZoomReset (1)
+func ZoomReset(ev *event.State) bool {
+	return ev.KeyDown("1")
+}
+
+// Origin (0) -- scrolls the canvas back to 0,0 in Editor Mode.
+func Origin(ev *event.State) bool {
+	return ev.KeyDown("0")
+}
+
 // GotoPlay (P) play tests the current level in the editor.
 func GotoPlay(ev *event.State) bool {
 	return ev.KeyDown("p")

pkg/uix/canvas.go

@@ -29,6 +29,7 @@ type Canvas struct {
 	// NewCanvas() with editable=true, they are both enabled.
 	Editable   bool // Clicking will edit pixels of this canvas.
 	Scrollable bool // Cursor keys will scroll the viewport of this canvas.
+	Zoom       int  // Zoom level on the canvas.
 
 	// Selected draw tool/mode, default Pencil, for editable canvases.
 	Tool      drawtool.Tool
@@ -289,10 +290,17 @@ func (w *Canvas) ViewportRelative() render.Rect {
 // the mouse cursor.
 func (w *Canvas) WorldIndexAt(screenPixel render.Point) render.Point {
 	var P = ui.AbsolutePosition(w)
-	return render.Point{
+	world := render.Point{
 		X: screenPixel.X - P.X - w.Scroll.X,
 		Y: screenPixel.Y - P.Y - w.Scroll.Y,
 	}
+
+	// Handle Zoomies
+	if w.Zoom != 0 {
+		world.X = w.ZoomMultiply(world.X)
+		world.Y = w.ZoomMultiply(world.Y)
+	}
+	return world
 }
 
 // Chunker returns the underlying Chunker object.

pkg/uix/canvas_editable.go

@@ -28,6 +28,10 @@ func (w *Canvas) commitStroke(tool drawtool.Tool, addHistory bool) {
 		return
 	}
 
+	// Zoom the stroke coordinates (this modifies the pointer)
+	zStroke := w.ZoomStroke(w.currentStroke)
+	_ = zStroke
+
 	// Mark the canvas as modified.
 	w.modified = true
 

pkg/uix/canvas_present.go

@@ -42,9 +42,16 @@ func (w *Canvas) Present(e render.Engine, p render.Point) {
 			} else {
 				tex = chunk.Texture(e)
 			}
+
+			// Zoom in the texture.
+			texSize := tex.Size()
+			if w.Zoom != 0 {
+				texSize.W = w.ZoomMultiply(texSize.W)
+				texSize.H = w.ZoomMultiply(texSize.H)
+			}
 			src := render.Rect{
-				W: tex.Size().W,
+				W: texSize.W,
-				H: tex.Size().H,
+				H: texSize.H,
 			}
 
 			// If the source bitmap is already bigger than the Canvas widget
@@ -69,6 +76,16 @@ func (w *Canvas) Present(e render.Engine, p render.Point) {
 				H: src.H,
 			}
 
+			// Zoom the destination rect.
+			if w.Zoom != 0 {
+				// dst.X += int(w.GetZoomMultiplier())
+				// dst.Y += int(w.GetZoomMultiplier())
+				// dst.X = w.ZoomMultiply(dst.X)
+				// dst.Y = w.ZoomMultiply(dst.Y)
+				// dst.W = w.ZoomMultiply(dst.W)
+				// dst.H = w.ZoomMultiply(dst.H)
+			}
+
 			// TODO: all this shit is in TrimBox(), make it DRY
 
 			// If the destination width will cause it to overflow the widget

pkg/uix/canvas_wallpaper.go

@@ -2,6 +2,7 @@ package uix
 
 import (
 	"git.kirsle.net/apps/doodle/pkg/level"
+	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/wallpaper"
 	"git.kirsle.net/go/render"
 )
@@ -70,45 +71,96 @@ func (w *Canvas) loopContainActorsInsideLevel(a *Actor) {
 }
 
 // PresentWallpaper draws the wallpaper.
+// Point p is the one given to Canvas.Present(), i.e., the position of the
+// top-left corner of the Canvas widget relative to the application window.
 func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 	var (
-		wp       = w.wallpaper
+		wp   = w.wallpaper
-		S        = w.Size()
+		S    = w.Size()
-		size     = wp.corner.Size()
+		size = wp.corner.Size()
+
+		// Get the relative viewport of world coordinates looked at by the canvas.
+		// The X,Y values are the negative Scroll value
+		// The W,H values are the Canvas size same as var S above.
 		Viewport = w.ViewportRelative()
-		origin   = render.Point{
+
-			X: p.X + w.Scroll.X + w.BoxThickness(1),
+		// origin and limit seem to be the boundaries of where on screen
-			Y: p.Y + w.Scroll.Y + w.BoxThickness(1),
+		// we are rendering inside.
-		}
+		origin = render.Point{
-		limit = render.Point{
+			X: p.X + w.Scroll.X, // + w.BoxThickness(1),
-			// NOTE: we add + the texture size so we would actually draw one
+			Y: p.Y + w.Scroll.Y, // + w.BoxThickness(1),
-			// full extra texture out-of-bounds for the repeating backgrounds.
-			// This is cuz for scrolling we offset the draw spot on a loop.
-			X: origin.X + S.W - w.BoxThickness(1) + size.W,
-			Y: origin.Y + S.H - w.BoxThickness(1) + size.H,
 		}
+		limit render.Point // TBD later
 	)
 
+	// Grow or shrink the render limit if we're zoomed.
+	if w.Zoom != 0 {
+		// I was surprised to discover that just zooming the texture
+		// quadrant size handled most of the problem! For reference, the
+		// Blueprint wallpaper has a size of 120x120 for the tiling pattern.
+		size.H = w.ZoomMultiply(size.H)
+		size.W = w.ZoomMultiply(size.W)
+	}
+
+	// SCRATCH
+	// at bootup, scroll position 0,0:
+	//		origin=44,20    p=44,20     p=relative to application window
+	// scroll right and down to -60,-60:
+	//		origin=-16,-40   p=44,20    and looks good in that direction
+	// scroll left and up to 60,60:
+	//		origin=104,80    p=44,20
+	//		becomes origin=44,20  p=44,20   d=-16,-40
+	// the latter case is handled below. walking thru:
+	//    if o(104) > p(44):
+	//        while o(104) > p(44):
+	//            o -= size(120) of texture block
+	//            o is now -16,-40
+	//        while o(-16) > p(44): it's not; break
+	//    dx = o(-16)
+	//    origin.X = p.X
+	//    (becomes origin=44,20  p=44,20  d=-16,-40)
+	//
+	// The visual bug is: if you scroll left or up on an Unbounded level from
+	// the origin (0, 0), the tiling of the wallpaper jumps to the right and
+	// down by an offset of 44x20 pixels.
+	//
+	// what is meant to happen:
+	// -
+
 	// For tiled textures, compute the offset amount. If we are scrolled away
 	// from the Origin (0,0) we find out by how far (subtract full tile sizes)
 	// and use the remainder as an offset for drawing the tiles.
+	// p      = position on screen of the Canvas widget
+	// origin = p.X + Scroll.X, p.Y + scroll.Y
+	// note: negative Scroll values means to the right and down
 	var dx, dy int
 	if origin.X > p.X {
-		for origin.X > p.X && origin.X > size.W {
+		// View is scrolled leftward (into negative world coordinates)
-			origin.X -= size.W
-		}
 		dx = origin.X
-		origin.X = p.X
+		for dx > p.X {
+			dx -= size.W
+		}
+		origin.X = 0 // note: origin 0,0 will be the corner of the app window
 	}
 	if origin.Y > p.Y {
-		for origin.Y > p.Y && origin.Y > size.H {
+		// View is scrolled upward (into negative world coordinates)
-			origin.Y -= size.H
-		}
 		dy = origin.Y
-		origin.Y = p.Y
+		for dy > p.Y {
+			dy -= size.H
+		}
+		origin.Y = 0
 	}
 
-	// And capping the scroll delta in the other direction.
+	limit = render.Point{
+		// NOTE: we add + the texture size so we would actually draw one
+		// full extra texture out-of-bounds for the repeating backgrounds.
+		// This is cuz for scrolling we offset the draw spot on a loop.
+		X: origin.X + S.W + size.W,
+		Y: origin.Y + S.H + size.H,
+	}
+
+	// And capping the scroll delta in the other direction. Always draw
+	// pixels until the Canvas size is covered.
 	if limit.X < S.W {
 		limit.X = S.W
 	}
@@ -117,10 +169,12 @@ func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 		limit.Y = S.H
 	}
 
+	// TODO: was still getting some slight flicker on the right and bottom
+	// when scrolling.. add a bit extra margin.
 	limit.X += size.W
 	limit.Y += size.H
 
-	// Tile the repeat texture.
+	// Tile the repeat texture. Start from 1 full wallpaper tile out of bounds
 	for x := origin.X - size.W; x < limit.X; x += size.W {
 		for y := origin.Y - size.H; y < limit.Y; y += size.H {
 			src := render.Rect{
@@ -134,8 +188,20 @@ func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 				H: src.H,
 			}
 
+			// Zoom the output texture.
+			if w.Zoom != 0 {
+				// dst.X = w.ZoomMultiply(dst.X - p.X)
+				// dst.Y = w.ZoomMultiply(dst.Y - p.Y)
+				// dst.W = w.ZoomMultiply(dst.W)
+				// dst.H = w.ZoomMultiply(dst.H)
+			}
+
 			// Trim the edges of the destination box, like in canvas.go#Present
+			odst := dst
 			render.TrimBox(&src, &dst, p, S, w.BoxThickness(1))
+			if dst.W == 0 {
+				log.Error("TrimBoxed! %s => %s", odst, dst)
+			}
 
 			e.Copy(wp.repeat, src, dst)
 		}
@@ -154,6 +220,15 @@ func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 				W: src.W,
 				H: src.H,
 			}
+
+			// Zoom the output texture.
+			if w.Zoom != 0 {
+				// dst.X = w.ZoomMultiply(dst.X - origin.X)
+				// dst.Y = w.ZoomMultiply(dst.Y - origin.Y)
+				// dst.W = w.ZoomMultiply(dst.W)
+				// dst.H = w.ZoomMultiply(dst.H)
+			}
+
 			render.TrimBox(&src, &dst, p, S, w.BoxThickness(1))
 			e.Copy(wp.left, src, dst)
 		}
@@ -170,6 +245,15 @@ func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 				W: src.W,
 				H: src.H,
 			}
+
+			// Zoom the output texture.
+			if w.Zoom != 0 {
+				// dst.X = w.ZoomMultiply(dst.X - origin.X)
+				// dst.Y = w.ZoomMultiply(dst.Y - origin.Y)
+				// dst.W = w.ZoomMultiply(dst.W)
+				// dst.H = w.ZoomMultiply(dst.H)
+			}
+
 			render.TrimBox(&src, &dst, p, S, w.BoxThickness(1))
 			e.Copy(wp.top, src, dst)
 		}
@@ -186,6 +270,15 @@ func (w *Canvas) PresentWallpaper(e render.Engine, p render.Point) error {
 				W: src.W,
 				H: src.H,
 			}
+
+			// Zoom the output texture.
+			if w.Zoom != 0 {
+				// dst.X = w.ZoomMultiply(dst.X - origin.X)
+				// dst.Y = w.ZoomMultiply(dst.Y - origin.Y)
+				// dst.W = w.ZoomMultiply(dst.W)
+				// dst.H = w.ZoomMultiply(dst.H)
+			}
+
 			render.TrimBox(&src, &dst, p, S, w.BoxThickness(1))
 			e.Copy(wp.corner, src, dst)
 		}

pkg/uix/canvas_zoom.go

@@ -0,0 +1,97 @@
+package uix
+
+import (
+	"git.kirsle.net/apps/doodle/pkg/drawtool"
+	"git.kirsle.net/go/render"
+)
+
+// Functions related to the Zoom Tool to magnify the size of the canvas.
+
+/*
+GetZoomMultiplier parses the .Zoom integer and returns a multiplier.
+
+Examples:
+
+	Zoom = 0: neutral (100% scale, 1x)
+	Zoom = 1: 2x zoom
+	Zoom = 2: 4x zoom
+	Zoom = 3: 8x zoom
+	Zoom = -1: 0.5x zoom
+	Zoom = -2: 0.25x zoom
+*/
+func (w *Canvas) GetZoomMultiplier() float64 {
+	// Get and bounds cap the zoom setting.
+	if w.Zoom < -2 {
+		w.Zoom = -2
+	} else if w.Zoom > 3 {
+		w.Zoom = 3
+	}
+
+	// Return the multipliers.
+	switch w.Zoom {
+	case -2:
+		return 0.25
+	case -1:
+		return 0.5
+	case 0:
+		return 1
+	case 1:
+		return 1.5
+	case 2:
+		return 2
+	case 3:
+		return 2.5
+	default:
+		return 1
+	}
+}
+
+/*
+ZoomMultiply multiplies a width or height value by the Zoom Multiplier and
+returns the modified integer.
+
+Usage is like:
+
+	// when building a render.Rect destination box.
+	dest.W *= ZoomMultiply(dest.W)
+	dest.H *= ZoomMultiply(dest.H)
+*/
+func (w *Canvas) ZoomMultiply(value int) int {
+	return int(float64(value) * w.GetZoomMultiplier())
+}
+
+/*
+ZoomStroke adjusts a drawn stroke on the canvas to account for the zoom level.
+
+Returns a copy Stroke value without changing the original.
+*/
+func (w *Canvas) ZoomStroke(stroke *drawtool.Stroke) drawtool.Stroke {
+	copy := drawtool.Stroke{
+		ID:             stroke.ID,
+		Shape:          stroke.Shape,
+		Color:          stroke.Color,
+		Thickness:      stroke.Thickness,
+		ExtraData:      stroke.ExtraData,
+		PointA:         stroke.PointA,
+		PointB:         stroke.PointB,
+		Points:         stroke.Points,
+		OriginalPoints: stroke.OriginalPoints,
+	}
+	return copy
+
+	// Multiply all coordinates in this stroke, which should be World
+	// Coordinates in the level data, by the zoom multiplier.
+	adjust := func(p render.Point) render.Point {
+		p.X = w.ZoomMultiply(p.X)
+		p.Y = w.ZoomMultiply(p.Y)
+		return p
+	}
+
+	copy.PointA = adjust(copy.PointA)
+	copy.PointB = adjust(copy.PointB)
+	for i := range copy.Points {
+		copy.Points[i] = adjust(copy.Points[i])
+	}
+
+	return copy
+}