From 6f5bd910c8ca06923d8f15cbae38beda0d9f6684 Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Sun, 12 Sep 2021 14:42:39 -0700
Subject: [PATCH] Zoom Progress: Actor/Link Tool Hitboxes

* When the Actor Tool or Link Tool is active, mouse-over hitboxes on the
  level's actors now works correctly while zoomed and scrolling in the
  level.
* Regression: Level chunks don't appear outside a certain range from
  origin while zoomed in.
* Regression: Actors don't draw their sprite while zoomed in, but do
  when zoomed out.
---
 pkg/uix/canvas_editable.go | 29 +++++++++++++++++++++++++----
 pkg/uix/canvas_present.go  | 13 ++++---------
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/pkg/uix/canvas_editable.go b/pkg/uix/canvas_editable.go
index 85dc527..edd20d9 100644
--- a/pkg/uix/canvas_editable.go
+++ b/pkg/uix/canvas_editable.go
@@ -304,9 +304,20 @@ func (w *Canvas) loopEditable(ev *event.State) error {
 
 		var deleteActors = []*level.Actor{}
 		for _, actor := range w.actors {
+
+			// Compute the bounding box on screen where this doodad
+			// visually appears.
+			var scrollBias = render.Point{
+				X: w.Scroll.X,
+				Y: w.Scroll.Y,
+			}
+			if w.Zoom != 0 {
+				scrollBias.X = w.ZoomDivide(scrollBias.X)
+				scrollBias.Y = w.ZoomDivide(scrollBias.Y)
+			}
 			box := render.Rect{
-				X: actor.Actor.Point.X - P.X - w.Scroll.X,
-				Y: actor.Actor.Point.Y - P.Y - w.Scroll.Y,
+				X: actor.Actor.Point.X - P.X - scrollBias.X,
+				Y: actor.Actor.Point.Y - P.Y - scrollBias.Y,
 				W: actor.Canvas.Size().W,
 				H: actor.Canvas.Size().H,
 			}
@@ -356,9 +367,19 @@ func (w *Canvas) loopEditable(ev *event.State) error {
 				continue
 			}
 
+			// Compute the bounding box on screen where this doodad
+			// visually appears.
+			var scrollBias = render.Point{
+				X: w.Scroll.X,
+				Y: w.Scroll.Y,
+			}
+			if w.Zoom != 0 {
+				scrollBias.X = w.ZoomDivide(scrollBias.X)
+				scrollBias.Y = w.ZoomDivide(scrollBias.Y)
+			}
 			box := render.Rect{
-				X: actor.Actor.Point.X - P.X - w.Scroll.X,
-				Y: actor.Actor.Point.Y - P.Y - w.Scroll.Y,
+				X: actor.Actor.Point.X - P.X - scrollBias.X,
+				Y: actor.Actor.Point.Y - P.Y - scrollBias.Y,
 				W: actor.Canvas.Size().W,
 				H: actor.Canvas.Size().H,
 			}
diff --git a/pkg/uix/canvas_present.go b/pkg/uix/canvas_present.go
index 82b1b99..9a801f9 100644
--- a/pkg/uix/canvas_present.go
+++ b/pkg/uix/canvas_present.go
@@ -69,15 +69,10 @@ func (w *Canvas) Present(e render.Engine, p render.Point) {
 	//   (0, 0) = (0,0, 127,127)      chunk A
 	//   (1, 0) = (128,128, 255,255)  chunk B
 	// At 2x zoom, Chunk A is still half on screen at -128 scroll
-	if w.Zoom > 0 {
-		// Since disappearing chunks happens on Zoom In the most?
-		// Grow the viewport's X and Y offsets back the other
-		// way, so chunks sliding off the screen don't unload early.
-		// This kinda thing makes no difference at all?
-		// var orig = Viewport
-		// Viewport.X = w.ZoomDivide(w.chunks.Size)
-		// Viewport.Y = w.ZoomDivide(w.chunks.Size)
-	}
+	// if w.Zoom > 0 {
+	// 	Viewport.X = w.ZoomDivide(w.chunks.Size)
+	// 	Viewport.Y = w.ZoomDivide(w.chunks.Size)
+	// }
 
 	// Get the chunks in the viewport and cache their textures.
 	for coord := range w.chunks.IterViewportChunks(Viewport) {