all: [API] change op.Offset to take integer coordinates

op.Offset is a convenience function most often used by layouts. Layouts
usually operate in integer coordinates, and the float32 version of op.Offset
needlessly force conversions from int to float32. This change makes op.Offset
take integer coordinates, to better match its intended use.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

widget/dnd.go

@@ -64,7 +64,7 @@ func (d *Draggable) Layout(gtx layout.Context, w, drag layout.Widget) layout.Dim
 
 	if drag != nil && d.drag.Pressed() {
 		rec := op.Record(gtx.Ops)
-		op.Offset(pos).Add(gtx.Ops)
+		op.Offset(pos.Round()).Add(gtx.Ops)
 		drag(gtx)
 		op.Defer(gtx.Ops, rec.Stop())
 	}

widget/editor.go

@@ -724,7 +724,7 @@ func (e *Editor) PaintSelection(gtx layout.Context) {
 
 		dotStart := image.Pt(leftmost.x.Round(), leftmost.y)
 		dotEnd := image.Pt(rightmost.x.Round(), rightmost.y)
-		t := op.Offset(layout.FPt(scroll.Mul(-1))).Push(gtx.Ops)
+		t := op.Offset(scroll.Mul(-1)).Push(gtx.Ops)
 		size := image.Rectangle{
 			Min: dotStart.Sub(image.Point{Y: line.Ascent.Ceil()}),
 			Max: dotEnd.Add(image.Point{Y: line.Descent.Ceil()}),
@@ -760,7 +760,7 @@ func (e *Editor) PaintText(gtx layout.Context) {
 		}
 		l := subLayout(line, start, end)
 
-		t := op.Offset(layout.FPt(off)).Push(gtx.Ops)
+		t := op.Offset(off).Push(gtx.Ops)
 		op := clip.Outline{Path: e.shaper.Shape(e.font, e.textSize, l)}.Op().Push(gtx.Ops)
 		paint.PaintOp{}.Add(gtx.Ops)
 		op.Pop()

widget/enum.go

@@ -3,8 +3,6 @@
 package widget
 
 import (
-	"image"
-
 	"gioui.org/gesture"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
@@ -65,7 +63,7 @@ func (e *Enum) Layout(gtx layout.Context, k string, content layout.Widget) layou
 	m := op.Record(gtx.Ops)
 	dims := content(gtx)
 	c := m.Stop()
-	defer clip.Rect(image.Rectangle{Max: dims.Size}).Push(gtx.Ops).Pop()
+	defer clip.Rect{Max: dims.Size}.Push(gtx.Ops).Pop()
 
 	state := e.index(k)
 	if state == nil {

widget/label.go

@@ -119,7 +119,7 @@ func (l Label) Layout(gtx layout.Context, s text.Shaper, font text.Font, size un
 		lt := subLayout(line, start, end)
 
 		off := image.Point{X: start.x.Floor(), Y: start.y}
-		t := op.Offset(layout.FPt(off)).Push(gtx.Ops)
+		t := op.Offset(off).Push(gtx.Ops)
 		op := clip.Outline{Path: s.Shape(font, textSize, lt)}.Op().Push(gtx.Ops)
 		paint.PaintOp{}.Add(gtx.Ops)
 		op.Pop()

widget/material/button.go

@@ -297,9 +297,9 @@ func drawInk(gtx layout.Context, c widget.Press) {
 	ink := paint.ColorOp{Color: rgba}
 	ink.Add(gtx.Ops)
 	rr := size * .5
-	defer op.Offset(layout.FPt(c.Position).Add(f32.Point{
-		X: -rr,
-		Y: -rr,
+	defer op.Offset(c.Position.Add(image.Point{
+		X: -int(rr),
+		Y: -int(rr),
 	})).Push(gtx.Ops).Pop()
 	defer clip.UniformRRect(f32.Rectangle{Max: f32.Pt(size, size)}, rr).Push(gtx.Ops).Pop()
 	paint.PaintOp{}.Add(gtx.Ops)

widget/material/decorations.go

@@ -109,7 +109,7 @@ func (d *DecorationsStyle) layoutDecorations(gtx layout.Context) layout.Dimensio
 				if size.Y < dims.Size.Y {
 					size.Y = dims.Size.Y
 				}
-				op.Offset(f32.Point{X: float32(dims.Size.X)}).Add(gtx.Ops)
+				op.Offset(image.Pt(dims.Size.X, 0)).Add(gtx.Ops)
 			}
 			return layout.Dimensions{Size: size}
 		}),

widget/material/list.go

@@ -193,7 +193,7 @@ func (s ScrollbarStyle) layout(gtx layout.Context, axis layout.Axis, viewportSta
 
 				// Lay out the indicator.
 				offset := axis.Convert(image.Pt(viewStart, 0))
-				defer op.Offset(layout.FPt(offset)).Push(gtx.Ops).Pop()
+				defer op.Offset(offset).Push(gtx.Ops).Pop()
 				paint.FillShape(gtx.Ops, s.Indicator.Color, clip.RRect{
 					Rect: f32.Rectangle{
 						Max: indicatorDimsF,

widget/material/loader.go

@@ -35,18 +35,18 @@ func (l LoaderStyle) Layout(gtx layout.Context) layout.Dimensions {
 		diam = gtx.Px(unit.Dp(24))
 	}
 	sz := gtx.Constraints.Constrain(image.Pt(diam, diam))
-	radius := float32(sz.X) * .5
-	defer op.Offset(f32.Pt(radius, radius)).Push(gtx.Ops).Pop()
+	radius := sz.X / 2
+	defer op.Offset(image.Pt(radius, radius)).Push(gtx.Ops).Pop()
 
 	dt := float32((time.Duration(gtx.Now.UnixNano()) % (time.Second)).Seconds())
 	startAngle := dt * math.Pi * 2
 	endAngle := startAngle + math.Pi*1.5
 
-	defer clipLoader(gtx.Ops, startAngle, endAngle, radius).Push(gtx.Ops).Pop()
+	defer clipLoader(gtx.Ops, startAngle, endAngle, float32(radius)).Push(gtx.Ops).Pop()
 	paint.ColorOp{
 		Color: l.Color,
 	}.Add(gtx.Ops)
-	defer op.Offset(f32.Pt(-radius, -radius)).Push(gtx.Ops).Pop()
+	defer op.Offset(image.Pt(-radius, -radius)).Push(gtx.Ops).Pop()
 	paint.PaintOp{}.Add(gtx.Ops)
 	op.InvalidateOp{}.Add(gtx.Ops)
 	return layout.Dimensions{

widget/material/progresscircle.go

@@ -7,7 +7,6 @@ import (
 	"image/color"
 	"math"
 
-	"gioui.org/f32"
 	"gioui.org/layout"
 	"gioui.org/op"
 	"gioui.org/op/paint"
@@ -35,10 +34,10 @@ func (p ProgressCircleStyle) Layout(gtx layout.Context) layout.Dimensions {
 		diam = gtx.Px(unit.Dp(24))
 	}
 	sz := gtx.Constraints.Constrain(image.Pt(diam, diam))
-	radius := float32(sz.X) * .5
-	defer op.Offset(f32.Pt(radius, radius)).Push(gtx.Ops).Pop()
+	radius := sz.X / 2
+	defer op.Offset(image.Pt(radius, radius)).Push(gtx.Ops).Pop()
 
-	defer clipLoader(gtx.Ops, -math.Pi/2, -math.Pi/2+math.Pi*2*p.Progress, radius).Push(gtx.Ops).Pop()
+	defer clipLoader(gtx.Ops, -math.Pi/2, -math.Pi/2+math.Pi*2*p.Progress, float32(radius)).Push(gtx.Ops).Pop()
 	paint.ColorOp{
 		Color: p.Color,
 	}.Add(gtx.Ops)

widget/material/slider.go

@@ -50,7 +50,7 @@ func (s SliderStyle) Layout(gtx layout.Context) layout.Dimensions {
 	size := axis.Convert(image.Pt(sizeMain, sizeCross))
 
 	o := axis.Convert(image.Pt(thumbRadius, 0))
-	trans := op.Offset(layout.FPt(o)).Push(gtx.Ops)
+	trans := op.Offset(o).Push(gtx.Ops)
 	gtx.Constraints.Min = axis.Convert(image.Pt(sizeMain-2*thumbRadius, sizeCross))
 	s.Float.Layout(gtx, thumbRadius, s.Min, s.Max)
 	gtx.Constraints.Min = gtx.Constraints.Min.Add(axis.Convert(image.Pt(0, sizeCross)))

widget/material/switch.go

@@ -44,7 +44,7 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 	trackWidth := gtx.Px(unit.Dp(36))
 	trackHeight := gtx.Px(unit.Dp(16))
 	thumbSize := gtx.Px(unit.Dp(20))
-	trackOff := float32(thumbSize-trackHeight) * .5
+	trackOff := (thumbSize - trackHeight) / 2
 
 	// Draw track.
 	trackCorner := float32(trackHeight) / 2
@@ -60,7 +60,7 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 		col = f32color.Disabled(col)
 	}
 	trackColor := s.Color.Track
-	t := op.Offset(f32.Point{Y: trackOff}).Push(gtx.Ops)
+	t := op.Offset(image.Point{Y: trackOff}).Push(gtx.Ops)
 	cl := clip.UniformRRect(trackRect, trackCorner).Push(gtx.Ops)
 	paint.ColorOp{Color: trackColor}.Add(gtx.Ops)
 	paint.PaintOp{}.Add(gtx.Ops)
@@ -70,9 +70,9 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 	// Draw thumb ink.
 	inkSize := gtx.Px(unit.Dp(44))
 	rr := float32(inkSize) * .5
-	inkOff := f32.Point{
-		X: float32(trackWidth)*.5 - rr,
-		Y: -rr + float32(trackHeight)*.5 + trackOff,
+	inkOff := image.Point{
+		X: trackWidth/2 - int(rr),
+		Y: -int(rr) + trackHeight/2 + trackOff,
 	}
 	t = op.Offset(inkOff).Push(gtx.Ops)
 	gtx.Constraints.Min = image.Pt(inkSize, inkSize)
@@ -85,8 +85,8 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 
 	// Compute thumb offset.
 	if s.Switch.Value {
-		xoff := float32(trackWidth - thumbSize)
-		defer op.Offset(f32.Point{X: xoff}).Push(gtx.Ops).Pop()
+		xoff := trackWidth - thumbSize
+		defer op.Offset(image.Point{X: xoff}).Push(gtx.Ops).Pop()
 	}
 
 	thumbRadius := float32(thumbSize) / 2
@@ -115,9 +115,9 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 
 	// Set up click area.
 	clickSize := gtx.Px(unit.Dp(40))
-	clickOff := f32.Point{
-		X: thumbRadius - float32(clickSize)*.5,
-		Y: (float32(trackHeight)-float32(clickSize))*.5 + trackOff,
+	clickOff := image.Point{
+		X: (thumbSize - clickSize) / 2,
+		Y: (trackHeight-clickSize)/2 + trackOff,
 	}
 	defer op.Offset(clickOff).Push(gtx.Ops).Pop()
 	sz := image.Pt(clickSize, clickSize)