debugui: bug fix: pointingDelta should return (0, 0) for a new touch

hajimehoshi · hajimehoshi · commit 25cf29bb3f97 · 2025-09-23T17:48:11.000+09:00
Closes #45
diff --git a/widget.go b/widget.go
@@ -44,6 +44,10 @@ func (c *Context) pointingOver(bounds image.Rectangle) bool {
 }
 
 func (c *Context) pointingDelta() image.Point {
+	// The delta is always (0, 0) when a touch just started.
+	if c.pointing.isTouchActive() && c.pointing.justPressed() {
+		return image.Point{}
+	}
 	return c.pointingPosition().Sub(c.lastPointingPos)
 }
 

Original file line number	Diff line number	Diff line change
`@@ -44,6 +44,10 @@ func (c *Context) pointingOver(bounds image.Rectangle) bool {`
`44`	`44`	`}`
`45`	`45`
`46`	`46`	`func (c *Context) pointingDelta() image.Point {`
	`47`	`+ // The delta is always (0, 0) when a touch just started.`
	`48`	`+ if c.pointing.isTouchActive() && c.pointing.justPressed() {`
	`49`	`+ return image.Point{}`
	`50`	`+ }`
`47`	`51`	`return c.pointingPosition().Sub(c.lastPointingPos)`
`48`	`52`	`}`
`49`	`53`