package uix import ( "git.kirsle.net/apps/doodle/lib/render" "git.kirsle.net/apps/doodle/lib/ui" "git.kirsle.net/apps/doodle/pkg/balance" "git.kirsle.net/apps/doodle/pkg/drawtool" "git.kirsle.net/apps/doodle/pkg/level" "git.kirsle.net/apps/doodle/pkg/log" "git.kirsle.net/apps/doodle/pkg/shmem" ) // 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 { if w.level == nil { log.Error("Canvas.UndoStroke: no Level currently available to the canvas") return false } latest := w.level.UndoHistory.Latest() if latest != nil { for point := range latest.IterPoints() { w.chunks.Delete(point) } } return w.level.UndoHistory.Undo() } // RedoStroke rolls the level's UndoHistory forwards again and replays the // recently undone changes. func (w *Canvas) RedoStroke() bool { if w.level == nil { log.Error("Canvas.UndoStroke: no Level currently available to the canvas") return false } ok := w.level.UndoHistory.Redo() if !ok { return false } latest := w.level.UndoHistory.Latest() // We stored the ActiveSwatch on this stroke as we drew it. Recover it // and place the pixels back down. if swatch, ok := latest.ExtraData.(*level.Swatch); ok { for point := range latest.IterPoints() { w.chunks.Set(point, swatch) } return true } log.Error("Canvas.UndoStroke: undo was successful but no Swatch was stored on the Stroke.ExtraData!") 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) } } // 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() ) // 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) // Make it double thick. double := stroke.Copy() double.PointA = render.NewPoint(stroke.PointA.X, stroke.PointA.Y+1) double.PointB = render.NewPoint(stroke.PointB.X, stroke.PointB.Y+1) strokes = append(strokes, double) double = stroke.Copy() double.PointA = render.NewPoint(stroke.PointA.X+1, stroke.PointA.Y) double.PointB = render.NewPoint(stroke.PointB.X+1, stroke.PointB.Y) strokes = append(strokes, double) } } 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) // w.Point() // 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 { 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. for point := range stroke.IterPoints() { if !point.Inside(VP) { continue } 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, } if balance.DebugCanvasStrokeColor != render.Invisible { e.DrawPoint(balance.DebugCanvasStrokeColor, dest) } else { e.DrawPoint(stroke.Color, dest) } } } }