doodle/pkg/uix/canvas_strokes.go

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package uix
import (
2022-09-24 22:17:25 +00:00
"git.kirsle.net/SketchyMaze/doodle/pkg/balance"
"git.kirsle.net/SketchyMaze/doodle/pkg/drawtool"
"git.kirsle.net/SketchyMaze/doodle/pkg/level"
"git.kirsle.net/SketchyMaze/doodle/pkg/log"
"git.kirsle.net/SketchyMaze/doodle/pkg/pattern"
"git.kirsle.net/SketchyMaze/doodle/pkg/shmem"
"git.kirsle.net/go/render"
"git.kirsle.net/go/ui"
)
// canvas_strokes.go: functions related to drawtool.Stroke and the Canvas.
// AddStroke installs a new Stroke to be superimposed over drawing data
// in the canvas.
//
// The stroke is added to the canvas's map by its ID so it can be removed later.
// The stroke must have a non-zero ID value set or this function will panic.
// drawtool.NewStroke() creates an initialized Stroke object to use here.
func (w *Canvas) AddStroke(stroke *drawtool.Stroke) {
if stroke.ID == 0 {
panic("Canvas.AddStroke: the Stroke is missing an ID; was it initialized properly?")
}
w.strokes[stroke.ID] = stroke
}
// RemoveStroke uninstalls a Stroke from the canvas using its ID.
//
// Returns true if the stroke existed to begin with, false if not.
func (w *Canvas) RemoveStroke(stroke *drawtool.Stroke) bool {
if _, ok := w.strokes[stroke.ID]; ok {
delete(w.strokes, stroke.ID)
return true
}
return false
}
// UndoStroke rolls back the level's UndoHistory and deletes the pixels last
// added to the level. Returns false and emits a warning to the log if the
// canvas has no level loaded properly.
func (w *Canvas) UndoStroke() bool {
var undoer *drawtool.History
if w.level != nil {
undoer = w.level.UndoHistory
} else if w.doodad != nil {
if w.doodad.UndoHistory == nil {
// HACK: if UndoHistory was not initialized properly.
w.doodad.UndoHistory = drawtool.NewHistory(balance.UndoHistory)
}
undoer = w.doodad.UndoHistory
} else {
log.Error("Canvas.UndoStroke: no Level or Doodad currently available to the canvas")
return false
}
latest := undoer.Latest()
if latest != nil {
// TODO: only single-thickness lines will restore the original color;
// thick lines just delete their pixels from the world due to performance.
// But the Eraser Tool is always thick, which always should restore its
// pixels. Can't do anything about that, so the inefficient thick rect
// restore is used only for Eraser at least.
if latest.Thickness > 0 {
if latest.Shape == drawtool.Eraser {
for rect := range latest.IterThickPoints() {
var (
xMin = rect.X
xMax = rect.X + rect.W
yMin = rect.Y
yMax = rect.Y + rect.H
)
for x := xMin; x < xMax; x++ {
for y := yMin; y < yMax; y++ {
if v, ok := latest.OriginalPoints[render.NewPoint(x, y)]; ok {
if swatch, ok := v.(*level.Swatch); ok {
w.chunks.Set(render.NewPoint(x, y), swatch)
}
}
}
}
}
} else {
for rect := range latest.IterThickPoints() {
w.chunks.DeleteRect(rect)
}
}
} else {
for point := range latest.IterPoints() {
// Was there a previous swatch at this point to restore?
if v, ok := latest.OriginalPoints[point]; ok {
if swatch, ok := v.(*level.Swatch); ok {
w.chunks.Set(point, swatch)
continue
}
}
w.chunks.Delete(point)
}
}
}
return undoer.Undo()
}
// RedoStroke rolls the level's UndoHistory forwards again and replays the
// recently undone changes.
func (w *Canvas) RedoStroke() bool {
var undoer *drawtool.History
if w.level != nil {
undoer = w.level.UndoHistory
} else if w.doodad != nil {
undoer = w.doodad.UndoHistory
} else {
log.Error("Canvas.UndoStroke: no Level or Doodad currently available to the canvas")
return false
}
ok := undoer.Redo()
if !ok {
return false
}
latest := undoer.Latest()
// We stored the ActiveSwatch on this stroke as we drew it. Recover it
// and place the pixels back down.
w.currentStroke = latest
w.commitStroke(w.Tool, false)
return ok
}
// presentStrokes is called as part of Present() and draws the strokes whose
// pixels are currently visible within the viewport.
func (w *Canvas) presentStrokes(e render.Engine) {
// Turn stroke map into a list.
var strokes []*drawtool.Stroke
for _, stroke := range w.strokes {
strokes = append(strokes, stroke)
}
w.DrawStrokes(e, strokes)
// Dynamic actor links visible in the ActorTool and LinkTool.
if w.Tool == drawtool.ActorTool || w.Tool == drawtool.LinkTool {
w.presentActorLinks(e)
}
// Text Tool preview.
if w.Tool == drawtool.TextTool && drawtool.TT.Label != nil {
drawtool.TT.Label.Present(e, shmem.Cursor)
}
}
// presentActorLinks draws strokes connecting actors together by their links.
// TODO: the strokes are computed dynamically every tick in here, might be a
// way to better optimize later.
func (w *Canvas) presentActorLinks(e render.Engine) {
var (
strokes = []*drawtool.Stroke{}
actorMap = map[string]*Actor{}
)
// Loop over actors and collect linked ones into the map.
for _, actor := range w.actors {
if len(actor.Actor.Links) > 0 {
actorMap[actor.ID()] = actor
}
}
// If no links, stop.
if len(actorMap) == 0 {
return
}
// The glow colored line. Huge hacky block of code but makes for some
// basic visualization for now.
var color = balance.LinkLineColor
var lightenStep = float64(balance.LinkLighten) / 16
var step = shmem.Tick % balance.LinkAnimSpeed
if step < 32 {
for i := uint64(0); i < step; i++ {
color = color.Lighten(int(lightenStep))
}
if step > 16 {
for i := uint64(0); i < step-16; i++ {
color = color.Darken(int(lightenStep))
}
}
}
// Loop over the linked actors and draw stroke lines.
for _, actor := range actorMap {
for _, linkID := range actor.Actor.Links {
if _, ok := actorMap[linkID]; !ok {
continue
}
var (
aP = actor.Position()
aS = actor.Size()
bP = actorMap[linkID].Position()
bS = actorMap[linkID].Size()
)
// Adapt actor positions per the zoom level.
aP.X = w.ZoomMultiply(aP.X)
aP.Y = w.ZoomMultiply(aP.Y)
bP.X = w.ZoomMultiply(bP.X)
bP.Y = w.ZoomMultiply(bP.Y)
// Draw a line connecting the centers of each actor together.
stroke := drawtool.NewStroke(drawtool.Line, color)
stroke.PointA = render.Point{
X: aP.X + (aS.W / 2),
Y: aP.Y + (aS.H / 2),
}
stroke.PointB = render.Point{
X: bP.X + (bS.W / 2),
Y: bP.Y + (bS.H / 2),
}
strokes = append(strokes, stroke)
}
}
w.DrawStrokes(e, strokes)
}
// DrawStrokes is the common base function behind presentStrokes and
// presentActorLinks to actually draw the lines to the canvas.
func (w *Canvas) DrawStrokes(e render.Engine, strokes []*drawtool.Stroke) {
var (
P = ui.AbsolutePosition(w) // Canvas point in UI
VP = w.ViewportRelative() // Canvas scroll viewport
)
for _, stroke := range strokes {
// If none of this stroke is in our viewport, don't waste time
// looping through it.
if stroke.Shape == drawtool.Freehand || stroke.Shape == drawtool.Eraser {
if len(stroke.Points) >= 2 {
if !stroke.Points[0].Inside(VP) && !stroke.Points[len(stroke.Points)-1].Inside(VP) {
continue
}
}
} else {
// TODO: a very long line that starts and ends outside the viewport
// but passes thru it would disappear when both ends are out of
// view.
if !stroke.PointA.Inside(VP) && !stroke.PointB.Inside(VP) {
continue
}
}
// Iter the points and draw what's visible.
if stroke.Thickness > 0 {
for rect := range stroke.IterThickPoints() {
if !rect.Intersects(VP) {
continue
}
// Does the swatch have a pattern to sample?
color := stroke.Color
if stroke.Pattern != "" {
color = pattern.SampleColor(stroke.Pattern, color, rect.Point())
}
// Destination rectangle to draw to screen, taking into account
// the position of the Canvas itself.
dest := render.Rect{
X: rect.X + P.X + w.Scroll.X + w.BoxThickness(1),
Y: rect.Y + P.Y + w.Scroll.Y + w.BoxThickness(1),
W: rect.W,
H: rect.H,
}
// Cap the render square so it doesn't leave the Canvas and
// overlap other UI elements!
if dest.X < P.X {
// Left edge. TODO: right edge
delta := P.X - dest.X
dest.X = P.X
dest.W -= delta
}
if dest.Y < P.Y {
// Top edge. TODO: bottom edge
delta := P.Y - dest.Y
dest.Y = P.Y
dest.H -= delta
}
if balance.DebugCanvasStrokeColor != render.Invisible {
e.DrawBox(balance.DebugCanvasStrokeColor, dest)
} else {
e.DrawBox(color, dest)
}
}
} else {
var color = stroke.Color
if balance.DebugCanvasStrokeColor != render.Invisible {
color = balance.DebugCanvasStrokeColor
}
// TODO: iterating all the points is very costly!
// Strokes don't properly render your Pattern anyway (glitchy mess),
// so let them just be simple DrawLine etc. calls.
// This optimization specifically speeds up the Actor Link Lines.
if stroke.Shape == drawtool.Line {
var (
pointA = render.Point{
X: P.X + w.Scroll.X + w.BoxThickness(1) + stroke.PointA.X,
Y: P.Y + w.Scroll.Y + w.BoxThickness(1) + stroke.PointA.Y,
}
pointB = render.Point{
X: P.X + w.Scroll.X + w.BoxThickness(1) + stroke.PointB.X,
Y: P.Y + w.Scroll.Y + w.BoxThickness(1) + stroke.PointB.Y,
}
)
e.DrawLine(color, pointA, pointB)
continue
}
for point := range stroke.IterPoints() {
if !point.Inside(VP) {
continue
}
// Does the swatch have a pattern to sample?
if stroke.Pattern != "" {
color = pattern.SampleColor(stroke.Pattern, color, point)
}
dest := render.Point{
X: P.X + w.Scroll.X + w.BoxThickness(1) + point.X,
Y: P.Y + w.Scroll.Y + w.BoxThickness(1) + point.Y,
}
e.DrawPoint(color, dest)
}
}
}
}