doodle/pkg/uix/canvas.go
Noah Petherbridge 215ed5c847 Stabilize Load Screen by Deferring SDL2 Calls
* The loading screen for Edit and Play modes is stable and the risk of
  game crash is removed. The root cause was the setupAsync() functions
  running on a background goroutine, and running SDL2 draw functions
  while NOT on the main thread, which causes problems.
* The fix is all SDL2 Texture draws become lazy loaded: when the main
  thread is presenting, any Wallpaper or ui.Image that has no texture
  yet gets one created at that time from the cached image.Image.
* All internal game logic then uses image.Image types, to cache bitmaps
  of Level Chunks, Wallpaper images, Sprite icons, etc. and the game is
  free to prepare these asynchronously; only the main thread ever
  Presents and the SDL2 textures initialize on first appearance.
* Several functions had arguments cleaned up: Canvas.LoadLevel() does
  not need the render.Engine as (e.g. wallpaper) textures don't render
  at that stage.
2021-07-19 17:14:00 -07:00

338 lines
9.9 KiB
Go

package uix
import (
"fmt"
"runtime"
"strings"
"git.kirsle.net/apps/doodle/pkg/balance"
"git.kirsle.net/apps/doodle/pkg/collision"
"git.kirsle.net/apps/doodle/pkg/doodads"
"git.kirsle.net/apps/doodle/pkg/drawtool"
"git.kirsle.net/apps/doodle/pkg/filesystem"
"git.kirsle.net/apps/doodle/pkg/level"
"git.kirsle.net/apps/doodle/pkg/log"
"git.kirsle.net/apps/doodle/pkg/scripting"
"git.kirsle.net/apps/doodle/pkg/wallpaper"
"git.kirsle.net/go/render"
"git.kirsle.net/go/render/event"
"git.kirsle.net/go/ui"
)
// Canvas is a custom ui.Widget that manages a single drawing.
type Canvas struct {
ui.Frame
Palette *level.Palette
// Editable and Scrollable go hand in hand and, if you initialize a
// 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.
// Custom label to place in the lower-right corner of the canvas.
// Used for e.g. the quantity badge on Inventory items.
CornerLabel string
// Selected draw tool/mode, default Pencil, for editable canvases.
Tool drawtool.Tool
BrushSize int // thickness of selected brush
// MaskColor will force every pixel to render as this color regardless of
// the palette index of that pixel. Otherwise pixels behave the same and
// the palette does work as normal. Set to render.Invisible (zero value)
// to remove the mask.
MaskColor render.Color
// Actor ID to follow the camera on automatically, i.e. the main player.
FollowActor string
// Debug tools
// NoLimitScroll suppresses the scroll limit for bounded levels.
NoLimitScroll bool
// Underlying chunk data for the drawing.
level *level.Level
chunks *level.Chunker
modified bool // set to True when the drawing has been modified, like in Editor Mode.
// Actors to superimpose on top of the drawing.
actor *Actor // if this canvas IS an actor
actors []*Actor // if this canvas CONTAINS actors (i.e., is a level)
// Collision memory for the actors.
collidingActors map[string]string // mapping their IDs to each other
// Doodad scripting engine supervisor.
// NOTE: initialized and managed by the play_scene.
scripting *scripting.Supervisor
// Wallpaper settings.
wallpaper *Wallpaper
// When the Canvas wants to delete Actors, but ultimately it is upstream
// that controls the actors. Upstream should delete them and then reinstall
// the actor list from scratch.
OnDeleteActors func([]*level.Actor)
OnDragStart func(*level.Actor)
// -- WHEN Canvas.Tool is "Link" --
// When the Canvas wants to link two actors together. Arguments are the IDs
// of the two actors.
OnLinkActors func(a, b *Actor)
linkFirst *Actor
// Collision handlers for level geometry.
OnLevelCollision func(*Actor, *collision.Collide)
/********
* Editable canvas private variables.
********/
// The current stroke actively being drawn by the user, during a
// mousedown-and-dragging event.
currentStroke *drawtool.Stroke
strokes map[int]*drawtool.Stroke // active stroke mapped by ID
lastPixel *level.Pixel
// We inherit the ui.Widget which manages the width and height.
Scroll render.Point // Scroll offset for which parts of canvas are visible.
}
// NewCanvas initializes a Canvas widget.
//
// If editable is true, Scrollable is also set to true, which means the arrow
// keys will scroll the canvas viewport which is desirable in Edit Mode.
func NewCanvas(size int, editable bool) *Canvas {
w := &Canvas{
Editable: editable,
Scrollable: editable,
Palette: level.NewPalette(),
BrushSize: 1,
chunks: level.NewChunker(size),
actors: make([]*Actor, 0),
wallpaper: &Wallpaper{},
strokes: map[int]*drawtool.Stroke{},
}
w.setup()
w.IDFunc(func() string {
var attrs []string
if w.Editable {
attrs = append(attrs, "editable")
} else {
attrs = append(attrs, "read-only")
}
if w.Scrollable {
attrs = append(attrs, "scrollable")
}
return fmt.Sprintf("Canvas<%d; %s>", size, strings.Join(attrs, "; "))
})
return w
}
// Load initializes the Canvas using an existing Palette and Grid.
func (w *Canvas) Load(p *level.Palette, g *level.Chunker) {
w.Palette = p
w.chunks = g
w.modified = false
if len(w.Palette.Swatches) > 0 {
w.SetSwatch(w.Palette.Swatches[0])
}
}
// LoadLevel initializes a Canvas from a Level object.
func (w *Canvas) LoadLevel(level *level.Level) {
w.level = level
w.Load(level.Palette, level.Chunker)
// TODO: wallpaper paths
filename := balance.EmbeddedWallpaperBasePath + level.Wallpaper
if runtime.GOOS != "js" {
// Check if the wallpaper wasn't found. Check bindata and file system.
if _, err := filesystem.FindFileEmbedded(filename, level); err != nil {
log.Error("LoadLevel: wallpaper %s did not appear to exist, default to notebook.png", filename)
filename = balance.EmbeddedWallpaperBasePath + "notebook.png"
}
}
wp, err := wallpaper.FromFile(filename, level)
if err != nil {
log.Error("wallpaper FromFile(%s): %s", filename, err)
}
w.wallpaper.maxWidth = level.MaxWidth
w.wallpaper.maxHeight = level.MaxHeight
err = w.wallpaper.Load(level.PageType, wp)
if err != nil {
log.Error("wallpaper Load: %s", err)
}
}
// LoadDoodad initializes a Canvas from a Doodad object.
func (w *Canvas) LoadDoodad(d *doodads.Doodad) {
// TODO more safe
w.Load(d.Palette, d.Layers[0].Chunker)
}
// LoadDoodadToLayer initializes a Canvas from a Doodad object and picks
// a layer to load.
func (w *Canvas) LoadDoodadToLayer(d *doodads.Doodad, index int) {
if index < 0 || index > len(d.Layers) {
log.Error("LoadDoodadToLayer: index %d out of range", index)
return
}
w.Load(d.Palette, d.Layers[index].Chunker)
}
// SetSwatch changes the currently selected swatch for editing.
func (w *Canvas) SetSwatch(s *level.Swatch) {
w.Palette.ActiveSwatch = s
}
// setup common configs between both initializers of the canvas.
func (w *Canvas) setup() {
// XXX: Debug code.
if balance.DebugCanvasBorder != render.Invisible {
w.Configure(ui.Config{
BorderColor: balance.DebugCanvasBorder,
BorderSize: 2,
BorderStyle: ui.BorderSolid,
})
}
}
// Loop is called on the scene's event loop to handle mouse interaction with
// the canvas, i.e. to edit it.
func (w *Canvas) Loop(ev *event.State) error {
// Process the arrow keys scrolling the level in Edit Mode.
// canvas_scrolling.go
w.loopEditorScroll(ev)
if err := w.loopFollowActor(ev); err != nil {
log.Error("Follow actor: %s", err) // not fatal but nice to know
}
_ = w.loopConstrainScroll()
// Current time of this loop so we can advance animations.
// now := time.Now()
// Remove any actors that were destroyed the previous tick.
var newActors []*Actor
for _, a := range w.actors {
if a.flagDestroy {
continue
}
newActors = append(newActors, a)
}
if len(newActors) < len(w.actors) {
w.actors = newActors
}
// Check collisions between actors.
if w.scripting != nil {
if err := w.loopActorCollision(); err != nil {
log.Error("loopActorCollision: %s", err)
}
}
// If the canvas is editable, only care if it's over our space.
if w.Editable {
cursor := render.NewPoint(ev.CursorX, ev.CursorY)
if cursor.Inside(ui.AbsoluteRect(w)) {
return w.loopEditable(ev)
}
}
return nil
}
// Viewport returns a rect containing the viewable drawing coordinates in this
// canvas. The X,Y values are the scroll offset (top left) and the W,H values
// are the scroll offset plus the width/height of the Canvas widget.
//
// The Viewport rect are the Absolute World Coordinates of the drawing that are
// visible inside the Canvas. The X,Y is the top left World Coordinate and the
// W,H are the bottom right World Coordinate, making this rect an absolute
// slice of the world. For a normal rect with a relative width and height,
// use ViewportRelative().
//
// The rect X,Y are the negative Scroll Value.
// The rect W,H are the Canvas widget size minus the Scroll Value.
func (w *Canvas) Viewport() render.Rect {
var S = w.Size()
return render.Rect{
X: -w.Scroll.X,
Y: -w.Scroll.Y,
W: S.W - w.Scroll.X,
H: S.H - w.Scroll.Y,
}
}
// ViewportRelative returns a relative viewport where the Width and Height
// values are zero-relative: so you can use it with point.Inside(viewport)
// to see if a World Index point should be visible on screen.
//
// The rect X,Y are the negative Scroll Value
// The rect W,H are the Canvas widget size.
func (w *Canvas) ViewportRelative() render.Rect {
var S = w.Size()
return render.Rect{
X: -w.Scroll.X,
Y: -w.Scroll.Y,
W: S.W,
H: S.H,
}
}
// WorldIndexAt returns the World Index that corresponds to a Screen Pixel
// on the screen. If the screen pixel is the mouse coordinate (relative to
// the application window) this will return the World Index of the pixel below
// the mouse cursor.
func (w *Canvas) WorldIndexAt(screenPixel render.Point) render.Point {
var P = ui.AbsolutePosition(w)
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 {
// Zoom Out - logic is 100% correct, do not touch.
// ZoomDivide's logic at time of writing is to:
// return int(float64(v) * divider)
// Where divider is a map of w.Zoom to:
// -2=4 -1=2 0=1 1=0.5 2=0.25 3=0.125
// The -2 and -1 do the right things (zoom out), zoom
// in was jank. NOW FIXED with the following maps:
// -2=4 -1=2 0=1 1=0.675 2=0.5 3=0.404
// Values for zoom levels 1 and 3 are jank but works?
world.X = w.ZoomDivide(world.X)
world.Y = w.ZoomDivide(world.Y)
}
return world
}
// Chunker returns the underlying Chunker object.
func (w *Canvas) Chunker() *level.Chunker {
return w.chunks
}
// ScrollTo sets the viewport scroll position.
func (w *Canvas) ScrollTo(to render.Point) {
w.Scroll.X = to.X
w.Scroll.Y = to.Y
}
// ScrollBy adjusts the viewport scroll position.
func (w *Canvas) ScrollBy(by render.Point) {
w.Scroll.Add(by)
}
// Compute the canvas.
func (w *Canvas) Compute(e render.Engine) {
}