diff --git a/buttonbar.go b/buttonbar.go
index f494d34..3c2d081 100644
--- a/buttonbar.go
+++ b/buttonbar.go
@@ -30,7 +30,7 @@ func (b *ButtonBar) Arrange(ctx *Context, bounds Rectangle) {
 		}
 		offset := bounds.X
 		for i := range b.Buttons {
-			b.Buttons[i].Arrange(ctx, RectSize(offset, bounds.Y, length, bounds.H))
+			b.Buttons[i].Arrange(ctx, Rect(offset, bounds.Y, length, bounds.H))
 			offset += length
 		}
 	default:
@@ -39,7 +39,7 @@ func (b *ButtonBar) Arrange(ctx *Context, bounds Rectangle) {
 		}
 		offset := bounds.Y
 		for i := range b.Buttons {
-			b.Buttons[i].Arrange(ctx, RectSize(bounds.X, offset, bounds.W, length))
+			b.Buttons[i].Arrange(ctx, Rect(bounds.X, offset, bounds.W, length))
 			offset += length
 		}
 	}
diff --git a/buyflowerbutton.go b/buyflowerbutton.go
index 7aecec2..dc5b905 100644
--- a/buyflowerbutton.go
+++ b/buyflowerbutton.go
@@ -88,7 +88,7 @@ func (b *BuyFlowerButton) Render(ctx *Context) {
 	iconTexture := b.activeTexture(ctx)
 
 	pos := Pt(b.Bounds.X, b.Bounds.Y)
-	iconTexture.CopyResize(ctx.Renderer, RectSize(pos.X, pos.Y-60, b.Bounds.W, 120))
+	iconTexture.CopyResize(ctx.Renderer, Rect(pos.X, pos.Y-60, b.Bounds.W, 120))
 	if (b.IsMouseOver && !b.IsDisabled) || b.IsActive {
 		SetDrawColor(ctx.Renderer, TransparentWhite)
 		ctx.Renderer.FillRect(b.Bounds.SDLPtr())
@@ -102,7 +102,7 @@ func (b *BuyFlowerButton) Render(ctx *Context) {
 		left := b.Bounds.W - 8 - b.hoverOffset
 		top := pos.Y + b.Bounds.H - 20
 		if left < 0 {
-			part := Rect(-left, 0, b.hoverTexture.Size().X, b.hoverTexture.Size().Y)
+			part := RectAbs(-left, 0, b.hoverTexture.Size().X, b.hoverTexture.Size().Y)
 			b.hoverTexture.CopyPart(ctx.Renderer, part, Pt(pos.X, top))
 		} else {
 			b.hoverTexture.Copy(ctx.Renderer, Pt(pos.X+left, top))
diff --git a/cmd/tins2020/tins2020.go b/cmd/tins2020/tins2020.go
index a989243..333b7d3 100644
--- a/cmd/tins2020/tins2020.go
+++ b/cmd/tins2020/tins2020.go
@@ -118,7 +118,7 @@ func run() error {
 	dialogs.ShowIntro(ctx)
 
 	w, h := window.GetSize()
-	app.Arrange(ctx, tins2020.Rect(0, 0, w, h))
+	app.Arrange(ctx, tins2020.RectAbs(0, 0, w, h))
 
 	for {
 		for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
@@ -133,7 +133,7 @@ func run() error {
 					ctx.Settings.Window.Location = tins2020.PtPtr(x, y)
 				case sdl.WINDOWEVENT_SIZE_CHANGED:
 					w, h := window.GetSize()
-					app.Arrange(ctx, tins2020.Rect(0, 0, w, h))
+					app.Arrange(ctx, tins2020.RectAbs(0, 0, w, h))
 					ctx.Settings.Window.Size = tins2020.PtPtr(w, h)
 				}
 			}
diff --git a/conversion_test.go b/conversion_test.go
new file mode 100644
index 0000000..a5cf9e1
--- /dev/null
+++ b/conversion_test.go
@@ -0,0 +1,42 @@
+package tins2020_test
+
+import (
+	"math/rand"
+	"testing"
+)
+
+type native struct{ a, b, c, d int }
+
+type similar struct{ a, b, c, d int }
+
+func (s similar) toNative() native { return native{s.a, s.b, s.c, s.d} }
+
+type wrapper struct{ native }
+
+func (w wrapper) toNative() native { return w.native }
+
+func nativeFunction(n native) int { return n.a + n.b + n.c + n.d }
+
+func BenchmarkNative(b *testing.B) {
+	var sum int
+	for i := 0; i < b.N; i++ {
+		n := native{rand.Int(), rand.Int(), rand.Int(), rand.Int()}
+		sum += nativeFunction(n)
+	}
+}
+
+func BenchmarkSimilar(b *testing.B) {
+	var sum int
+	for i := 0; i < b.N; i++ {
+		s := similar{rand.Int(), rand.Int(), rand.Int(), rand.Int()}
+		sum += nativeFunction(s.toNative())
+	}
+}
+
+func BenchmarkWrapper(b *testing.B) {
+	var sum int
+	for i := 0; i < b.N; i++ {
+		w := wrapper{native{rand.Int(), rand.Int(), rand.Int(), rand.Int()}}
+		sum += nativeFunction(w.toNative())
+	}
+}
diff --git a/gamecontrols.go b/gamecontrols.go
index 4294e0b..9d95285 100644
--- a/gamecontrols.go
+++ b/gamecontrols.go
@@ -77,10 +77,10 @@ func (c *GameControls) updateFlowerControls(ctx *Context) {
 
 func (c *GameControls) Arrange(ctx *Context, bounds Rectangle) {
 	c.Bounds = bounds
-	c.menu.Arrange(ctx, RectSize(bounds.X, bounds.Y, buttonBarWidth, bounds.H))
-	c.top.Arrange(ctx, Rect(bounds.X+bounds.W/2+8, bounds.Y, bounds.Right(), bounds.Y+64))
-	c.flowers.Arrange(ctx, RectSize(bounds.Right()-buttonBarWidth, bounds.Y, buttonBarWidth, bounds.H))
-	c.otherTools.Arrange(ctx, RectSize(bounds.Right()-buttonBarWidth, bounds.Bottom()-2*buttonBarWidth, buttonBarWidth, 2*buttonBarWidth))
+	c.menu.Arrange(ctx, Rect(bounds.X, bounds.Y, buttonBarWidth, bounds.H))
+	c.top.Arrange(ctx, RectAbs(bounds.X+bounds.W/2+8, bounds.Y, bounds.Right(), bounds.Y+64))
+	c.flowers.Arrange(ctx, Rect(bounds.Right()-buttonBarWidth, bounds.Y, buttonBarWidth, bounds.H))
+	c.otherTools.Arrange(ctx, Rect(bounds.Right()-buttonBarWidth, bounds.Bottom()-2*buttonBarWidth, buttonBarWidth, 2*buttonBarWidth))
 }
 
 func (c *GameControls) Init(ctx *Context) error {
@@ -185,7 +185,7 @@ func (c *GameControls) Handle(ctx *Context, event sdl.Event) bool {
 func (c *GameControls) Render(ctx *Context) {
 	topBar := MustHexColor("#0000007f")
 	SetDrawColor(ctx.Renderer, topBar)
-	ctx.Renderer.FillRect(Rect(c.menu.Bounds.Right(), 0, c.flowers.Bounds.X, 64).SDLPtr())
+	ctx.Renderer.FillRect(RectAbs(c.menu.Bounds.Right(), 0, c.flowers.Bounds.X, 64).SDLPtr())
 	ctx.Fonts.Font("balance").RenderCopyAlign(ctx.Renderer, FmtMoney(c.game.Balance), Pt(c.top.Bounds.X-8, 58), MustHexColor("#4AC69A"), TextAlignmentRight)
 
 	c.Container.Render(ctx)
diff --git a/iconbutton.go b/iconbutton.go
index 6682ea3..162d906 100644
--- a/iconbutton.go
+++ b/iconbutton.go
@@ -72,7 +72,7 @@ func (b *IconButton) Render(ctx *Context) {
 		} else if b.IconHeight != 0 {
 			size = Pt(b.IconHeight*size.X/size.Y, b.IconHeight)
 		}
-		iconTexture.CopyResize(ctx.Renderer, RectSize(b.Bounds.X+(b.Bounds.W-size.X)/2, b.Bounds.Y+(b.Bounds.H-size.Y)/2, size.X, size.Y))
+		iconTexture.CopyResize(ctx.Renderer, Rect(b.Bounds.X+(b.Bounds.W-size.X)/2, b.Bounds.Y+(b.Bounds.H-size.Y)/2, size.X, size.Y))
 	} else {
 		iconTexture.CopyResize(ctx.Renderer, b.Bounds)
 	}
diff --git a/largedialog.go b/largedialog.go
index 4339405..e16c2c1 100644
--- a/largedialog.go
+++ b/largedialog.go
@@ -56,9 +56,9 @@ type LargeDialog struct {
 func (d *LargeDialog) Arrange(ctx *Context, bounds Rectangle) {
 	const titleHeight = 64
 	d.ControlBase.Arrange(ctx, bounds)
-	d.title.Arrange(ctx, RectSize(bounds.X, bounds.Y, bounds.W, titleHeight))
-	d.close.Arrange(ctx, RectSize(bounds.W-64, 0, 64, 64))
-	d.content.Arrange(ctx, RectSize(bounds.X+titleHeight, 96, bounds.W-2*titleHeight, bounds.H-titleHeight))
+	d.title.Arrange(ctx, Rect(bounds.X, bounds.Y, bounds.W, titleHeight))
+	d.close.Arrange(ctx, Rect(bounds.W-64, 0, 64, 64))
+	d.content.Arrange(ctx, Rect(bounds.X+titleHeight, 96, bounds.W-2*titleHeight, bounds.H-titleHeight))
 }
 
 func (d *LargeDialog) Init(ctx *Context) error {
diff --git a/projection.go b/projection.go
index de31e7b..f31b493 100644
--- a/projection.go
+++ b/projection.go
@@ -55,11 +55,11 @@ func (p *projection) screenToMapRel(x, y int32) PointF {
 }
 
 func (p *projection) screenToTileFitRect(pos Point) Rectangle {
-	return RectSize(pos.X-p.tileFitScreenSize.X, pos.Y-p.tileFitScreenSize.Y, 2*p.tileFitScreenSize.X, 2*p.tileFitScreenSize.Y)
+	return Rect(pos.X-p.tileFitScreenSize.X, pos.Y-p.tileFitScreenSize.Y, 2*p.tileFitScreenSize.X, 2*p.tileFitScreenSize.Y)
 }
 
 func (p *projection) screenToTileRect(pos Point) Rectangle {
-	return RectSize(pos.X-p.tileScreenOffset.X, pos.Y-p.tileScreenOffset.Y, p.tileScreenSize.X, p.tileScreenSize.Y)
+	return Rect(pos.X-p.tileScreenOffset.X, pos.Y-p.tileScreenOffset.Y, p.tileScreenSize.X, p.tileScreenSize.Y)
 }
 
 func (p *projection) update(renderer *sdl.Renderer) {
@@ -74,8 +74,8 @@ func (p *projection) update(renderer *sdl.Renderer) {
 		log.Fatal(err)
 	}
 	p.windowCenter = Pt(windowW/2, windowH/2)
-	p.windowInteractRect = Rect(buttonBarWidth, 64, windowW-buttonBarWidth, windowH)
-	p.windowVisibleRect = Rect(buttonBarWidth, 0, windowW-buttonBarWidth, windowH+p.tileScreenSize.Y) // Adding a tile height to the bottom for trees that stick out from the cells below.
+	p.windowInteractRect = RectAbs(buttonBarWidth, 64, windowW-buttonBarWidth, windowH)
+	p.windowVisibleRect = RectAbs(buttonBarWidth, 0, windowW-buttonBarWidth, windowH+p.tileScreenSize.Y) // Adding a tile height to the bottom for trees that stick out from the cells below.
 }
 
 func (p *projection) visibleTiles(action func(int32, int32, Point)) {
diff --git a/rect.go b/rect.go
index f345692..27bd0d4 100644
--- a/rect.go
+++ b/rect.go
@@ -6,7 +6,7 @@ type Rectangle struct {
 	sdl.Rect
 }
 
-func Rect(x1, y1, x2, y2 int32) Rectangle {
+func RectAbs(x1, y1, x2, y2 int32) Rectangle {
 	if x1 > x2 {
 		x1, x2 = x2, x1
 	}
@@ -16,7 +16,7 @@ func Rect(x1, y1, x2, y2 int32) Rectangle {
 	return Rectangle{sdl.Rect{X: x1, Y: y1, W: x2 - x1, H: y2 - y1}}
 }
 
-func RectSize(x, y, w, h int32) Rectangle { return Rectangle{sdl.Rect{X: x, Y: y, W: w, H: h}} }
+func Rect(x, y, w, h int32) Rectangle { return Rectangle{sdl.Rect{X: x, Y: y, W: w, H: h}} }
 
 func (r Rectangle) Bottom() int32 { return r.Y + r.H }
 
diff --git a/research.go b/research.go
index ed0fce2..a4d4312 100644
--- a/research.go
+++ b/research.go
@@ -92,8 +92,8 @@ func (r *Research) Init(ctx *Context) error {
 
 func (r *Research) Arrange(ctx *Context, bounds Rectangle) {
 	r.Container.Arrange(ctx, bounds)
-	r.specialists.Arrange(ctx, RectSize(r.Bounds.X, r.Bounds.Y+40, r.Bounds.W, r.Bounds.H-40))
-	r.input.Arrange(ctx, RectSize(r.Bounds.X, r.Bounds.X+r.Bounds.H-48, r.Bounds.W, 24))
+	r.specialists.Arrange(ctx, Rect(r.Bounds.X, r.Bounds.Y+40, r.Bounds.W, r.Bounds.H-40))
+	r.input.Arrange(ctx, Rect(r.Bounds.X, r.Bounds.X+r.Bounds.H-48, r.Bounds.W, 24))
 	r.input.Alignment = TextAlignmentCenter
 
 	center := Pt(r.Bounds.X+r.Bounds.W/2, r.Bounds.Y+r.Bounds.H/2)
@@ -103,7 +103,7 @@ func (r *Research) Arrange(ctx *Context, bounds Rectangle) {
 		angle := (float64((10-i)%10)*0.16 + .2) * math.Pi
 		pos := Pt(int32(distance*math.Cos(angle)), int32(.8*distance*math.Sin(angle)))
 		digitCenter := center.Add(pos)
-		r.digits[i].Arrange(ctx, RectSize(digitCenter.X-24, digitCenter.Y-24, 48, 48))
+		r.digits[i].Arrange(ctx, Rect(digitCenter.X-24, digitCenter.Y-24, 48, 48))
 	}
 }
 
diff --git a/textures.go b/textures.go
index 4d0eb7b..83bf6f9 100644
--- a/textures.go
+++ b/textures.go
@@ -29,11 +29,11 @@ func (t *Texture) Size() Point { return t.size }
 // func (t *Texture) SDLRectPtr() *sdl.Rect { return t.rect.SDLPtr() }
 
 func (t *Texture) Copy(renderer *sdl.Renderer, dst Point) {
-	t.CopyResize(renderer, RectSize(dst.X, dst.Y, t.size.X, t.size.Y))
+	t.CopyResize(renderer, Rect(dst.X, dst.Y, t.size.X, t.size.Y))
 }
 
 func (t *Texture) CopyPart(renderer *sdl.Renderer, src Rectangle, dst Point) {
-	t.CopyPartResize(renderer, src, RectSize(dst.X, dst.Y, src.W, src.H))
+	t.CopyPartResize(renderer, src, Rect(dst.X, dst.Y, src.W, src.H))
 }
 
 func (t *Texture) CopyPartResize(renderer *sdl.Renderer, src Rectangle, dst Rectangle) {
@@ -41,7 +41,7 @@ func (t *Texture) CopyPartResize(renderer *sdl.Renderer, src Rectangle, dst Rect
 }
 
 func (t *Texture) CopyResize(renderer *sdl.Renderer, dst Rectangle) {
-	t.CopyPartResize(renderer, Rect(0, 0, t.size.X, t.size.Y), dst)
+	t.CopyPartResize(renderer, RectAbs(0, 0, t.size.X, t.size.Y), dst)
 }
 
 func (t *Texture) SetColor(color sdl.Color) {