all: use color.NRGBA in public API

color.RGBA has two problems with regards to using it.

First the color values need to be premultiplied, whereas most APIs
have non-premultiplied values. This is mainly to preserve color components
with low alpha values.

Second there are two ways to premultiply with sRGB. One is to premultiply
after sRGB conversion, the other is before. This makes using the API more
confusing.

Using color.NRGBA in sRGB makes it align with CSS.e

Signed-off-by: Egon Elbre <egonelbre@gmail.com>

app/headless/backend_test.go

@@ -19,15 +19,16 @@ import (
 
 var dumpImages = flag.Bool("saveimages", false, "save test images")
 
-var clearCol = color.RGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+var clearCol = color.NRGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+var clearColExpect = f32color.NRGBAToRGBA(clearCol)
 
 func TestFramebufferClear(t *testing.T) {
 	b := newBackend(t)
 	sz := image.Point{X: 800, Y: 600}
 	fbo := setupFBO(t, b, sz)
 	img := screenshot(t, fbo, sz)
-	if got := img.RGBAAt(0, 0); got != clearCol {
+	if got := img.RGBAAt(0, 0); got != clearColExpect {
-		t.Errorf("got color %v, expected %v", got, clearCol)
+		t.Errorf("got color %v, expected %v", got, clearColExpect)
 	}
 }
 
@@ -43,14 +44,14 @@ func TestSimpleShader(t *testing.T) {
 	b.BindProgram(p)
 	b.DrawArrays(backend.DrawModeTriangles, 0, 3)
 	img := screenshot(t, fbo, sz)
-	if got := img.RGBAAt(0, 0); got != clearCol {
+	if got := img.RGBAAt(0, 0); got != clearColExpect {
-		t.Errorf("got color %v, expected %v", got, clearCol)
+		t.Errorf("got color %v, expected %v", got, clearColExpect)
 	}
 	// Just off the center to catch inverted triangles.
 	cx, cy := 300, 400
 	shaderCol := f32color.RGBA{R: .25, G: .55, B: .75, A: 1.0}
-	if got, exp := img.RGBAAt(cx, cy), shaderCol.SRGB(); got != exp {
+	if got, exp := img.RGBAAt(cx, cy), shaderCol.SRGB(); got != f32color.NRGBAToRGBA(exp) {
-		t.Errorf("got color %v, expected %v", got, exp)
+		t.Errorf("got color %v, expected %v", got, f32color.NRGBAToRGBA(exp))
 	}
 }
 
@@ -90,13 +91,13 @@ func TestInputShader(t *testing.T) {
 	b.BindInputLayout(layout)
 	b.DrawArrays(backend.DrawModeTriangles, 0, 3)
 	img := screenshot(t, fbo, sz)
-	if got := img.RGBAAt(0, 0); got != clearCol {
+	if got := img.RGBAAt(0, 0); got != clearColExpect {
-		t.Errorf("got color %v, expected %v", got, clearCol)
+		t.Errorf("got color %v, expected %v", got, clearColExpect)
 	}
 	cx, cy := 300, 400
 	shaderCol := f32color.RGBA{R: .25, G: .55, B: .75, A: 1.0}
-	if got, exp := img.RGBAAt(cx, cy), shaderCol.SRGB(); got != exp {
+	if got, exp := img.RGBAAt(cx, cy), shaderCol.SRGB(); got != f32color.NRGBAToRGBA(exp) {
-		t.Errorf("got color %v, expected %v", got, exp)
+		t.Errorf("got color %v, expected %v", got, f32color.NRGBAToRGBA(exp))
 	}
 }
 
@@ -106,21 +107,21 @@ func TestFramebuffers(t *testing.T) {
 	fbo1 := newFBO(t, b, sz)
 	fbo2 := newFBO(t, b, sz)
 	var (
-		col1 = color.RGBA{R: 0xad, G: 0xbe, B: 0xef, A: 0xde}
+		col1 = color.NRGBA{R: 0xad, G: 0xbe, B: 0xef, A: 0xde}
-		col2 = color.RGBA{R: 0xfe, G: 0xba, B: 0xbe, A: 0xca}
+		col2 = color.NRGBA{R: 0xfe, G: 0xba, B: 0xbe, A: 0xca}
 	)
-	fcol1, fcol2 := f32color.RGBAFromSRGB(col1), f32color.RGBAFromSRGB(col2)
+	fcol1, fcol2 := f32color.LinearFromSRGB(col1), f32color.LinearFromSRGB(col2)
 	b.BindFramebuffer(fbo1)
 	b.Clear(fcol1.Float32())
 	b.BindFramebuffer(fbo2)
 	b.Clear(fcol2.Float32())
 	img := screenshot(t, fbo1, sz)
-	if got := img.RGBAAt(0, 0); got != col1 {
+	if got := img.RGBAAt(0, 0); got != f32color.NRGBAToRGBA(col1) {
-		t.Errorf("got color %v, expected %v", got, col1)
+		t.Errorf("got color %v, expected %v", got, f32color.NRGBAToRGBA(col1))
 	}
 	img = screenshot(t, fbo2, sz)
-	if got := img.RGBAAt(0, 0); got != col2 {
+	if got := img.RGBAAt(0, 0); got != f32color.NRGBAToRGBA(col2) {
-		t.Errorf("got color %v, expected %v", got, col2)
+		t.Errorf("got color %v, expected %v", got, f32color.NRGBAToRGBA(col2))
 	}
 }
 
@@ -129,7 +130,7 @@ func setupFBO(t *testing.T, b backend.Device, size image.Point) backend.Framebuf
 	b.BindFramebuffer(fbo)
 	// ClearColor accepts linear RGBA colors, while 8-bit colors
 	// are in the sRGB color space.
-	col := f32color.RGBAFromSRGB(clearCol)
+	col := f32color.LinearFromSRGB(clearCol)
 	b.Clear(col.Float32())
 	b.ClearDepth(0.0)
 	b.Viewport(0, 0, size.X, size.Y)

app/headless/headless_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"gioui.org/f32"
+	"gioui.org/internal/f32color"
 	"gioui.org/op"
 	"gioui.org/op/clip"
 	"gioui.org/op/paint"
@@ -18,7 +19,7 @@ func TestHeadless(t *testing.T) {
 	defer release()
 
 	sz := w.size
-	col := color.RGBA{A: 0xff, R: 0xca, G: 0xfe}
+	col := color.NRGBA{A: 0xff, R: 0xca, G: 0xfe}
 	var ops op.Ops
 	paint.ColorOp{Color: col}.Add(&ops)
 	// Paint only part of the screen to avoid the glClear optimization.
@@ -34,8 +35,8 @@ func TestHeadless(t *testing.T) {
 	if isz := img.Bounds().Size(); isz != sz {
 		t.Errorf("got %v screenshot, expected %v", isz, sz)
 	}
-	if got := img.RGBAAt(0, 0); got != col {
+	if got := img.RGBAAt(0, 0); got != f32color.NRGBAToRGBA(col) {
-		t.Errorf("got color %v, expected %v", got, col)
+		t.Errorf("got color %v, expected %v", got, f32color.NRGBAToRGBA(col))
 	}
 }
 
@@ -43,8 +44,8 @@ func TestClipping(t *testing.T) {
 	w, release := newTestWindow(t)
 	defer release()
 
-	col := color.RGBA{A: 0xff, R: 0xca, G: 0xfe}
+	col := color.NRGBA{A: 0xff, R: 0xca, G: 0xfe}
-	col2 := color.RGBA{A: 0xff, R: 0x00, G: 0xfe}
+	col2 := color.NRGBA{A: 0xff, R: 0x00, G: 0xfe}
 	var ops op.Ops
 	paint.ColorOp{Color: col}.Add(&ops)
 	clip.RRect{
@@ -77,10 +78,10 @@ func TestClipping(t *testing.T) {
 			t.Fatal(err)
 		}
 	}
-	bg := color.RGBA{A: 0xff, R: 0xff, G: 0xff, B: 0xff}
+	bg := color.NRGBA{A: 0xff, R: 0xff, G: 0xff, B: 0xff}
 	tests := []struct {
 		x, y  int
-		color color.RGBA
+		color color.NRGBA
 	}{
 		{120, 120, col},
 		{130, 130, col2},
@@ -88,8 +89,8 @@ func TestClipping(t *testing.T) {
 		{230, 230, bg},
 	}
 	for _, test := range tests {
-		if got := img.RGBAAt(test.x, test.y); got != test.color {
+		if got := img.RGBAAt(test.x, test.y); got != f32color.NRGBAToRGBA(test.color) {
-			t.Errorf("(%d,%d): got color %v, expected %v", test.x, test.y, got, test.color)
+			t.Errorf("(%d,%d): got color %v, expected %v", test.x, test.y, got, f32color.NRGBAToRGBA(test.color))
 		}
 	}
 }
@@ -99,9 +100,9 @@ func TestDepth(t *testing.T) {
 	defer release()
 	var ops op.Ops
 
-	blue := color.RGBA{B: 0xFF, A: 0xFF}
+	blue := color.NRGBA{B: 0xFF, A: 0xFF}
 	paint.FillShape(&ops, blue, clip.Rect(image.Rect(0, 0, 50, 100)).Op())
-	red := color.RGBA{R: 0xFF, A: 0xFF}
+	red := color.NRGBA{R: 0xFF, A: 0xFF}
 	paint.FillShape(&ops, red, clip.Rect(image.Rect(0, 0, 100, 50)).Op())
 	if err := w.Frame(&ops); err != nil {
 		t.Fatal(err)
@@ -118,15 +119,15 @@ func TestDepth(t *testing.T) {
 	}
 	tests := []struct {
 		x, y  int
-		color color.RGBA
+		color color.NRGBA
 	}{
 		{25, 25, red},
 		{75, 25, red},
 		{25, 75, blue},
 	}
 	for _, test := range tests {
-		if got := img.RGBAAt(test.x, test.y); got != test.color {
+		if got := img.RGBAAt(test.x, test.y); got != f32color.NRGBAToRGBA(test.color) {
-			t.Errorf("(%d,%d): got color %v, expected %v", test.x, test.y, got, test.color)
+			t.Errorf("(%d,%d): got color %v, expected %v", test.x, test.y, got, f32color.NRGBAToRGBA(test.color))
 		}
 	}
 }

gpu/gpu.go

@@ -78,13 +78,13 @@ type drawState struct {
 	// Current paint.ImageOp
 	image imageOpData
 	// Current paint.ColorOp, if any.
-	color color.RGBA
+	color color.NRGBA
 
 	// Current paint.LinearGradientOp.
 	stop1  f32.Point
 	stop2  f32.Point
-	color1 color.RGBA
+	color1 color.NRGBA
-	color2 color.RGBA
+	color2 color.NRGBA
 }
 
 type pathOp struct {
@@ -138,9 +138,9 @@ type imageOpData struct {
 
 type linearGradientOpData struct {
 	stop1  f32.Point
-	color1 color.RGBA
+	color1 color.NRGBA
 	stop2  f32.Point
-	color2 color.RGBA
+	color2 color.NRGBA
 }
 
 func (op *clipOp) decode(data []byte) {
@@ -183,11 +183,11 @@ func decodeImageOp(data []byte, refs []interface{}) imageOpData {
 	}
 }
 
-func decodeColorOp(data []byte) color.RGBA {
+func decodeColorOp(data []byte) color.NRGBA {
 	if opconst.OpType(data[0]) != opconst.TypeColor {
 		panic("invalid op")
 	}
-	return color.RGBA{
+	return color.NRGBA{
 		R: data[1],
 		G: data[2],
 		B: data[3],
@@ -209,13 +209,13 @@ func decodeLinearGradientOp(data []byte) linearGradientOpData {
 			X: math.Float32frombits(bo.Uint32(data[9:])),
 			Y: math.Float32frombits(bo.Uint32(data[13:])),
 		},
-		color1: color.RGBA{
+		color1: color.NRGBA{
 			R: data[17+0],
 			G: data[17+1],
 			B: data[17+2],
 			A: data[17+3],
 		},
-		color2: color.RGBA{
+		color2: color.NRGBA{
 			R: data[21+0],
 			G: data[21+1],
 			B: data[21+2],
@@ -749,7 +749,7 @@ func (d *drawOps) collect(cache *resourceCache, root *op.Ops, viewport image.Poi
 	state := drawState{
 		clip:  clip,
 		rect:  true,
-		color: color.RGBA{A: 0xff},
+		color: color.NRGBA{A: 0xff},
 	}
 	d.collectOps(&d.reader, state)
 }
@@ -930,13 +930,13 @@ func (d *drawState) materialFor(cache *resourceCache, rect f32.Rectangle, off f3
 	switch d.matType {
 	case materialColor:
 		m.material = materialColor
-		m.color = f32color.RGBAFromSRGB(d.color)
+		m.color = f32color.LinearFromSRGB(d.color)
 		m.opaque = m.color.A == 1.0
 	case materialLinearGradient:
 		m.material = materialLinearGradient
 
-		m.color1 = f32color.RGBAFromSRGB(d.color1)
+		m.color1 = f32color.LinearFromSRGB(d.color1)
-		m.color2 = f32color.RGBAFromSRGB(d.color2)
+		m.color2 = f32color.LinearFromSRGB(d.color2)
 		m.opaque = m.color1.A == 1.0 && m.color2.A == 1.0
 
 		m.uvTrans = trans.Mul(gradientSpaceTransform(clip, off, d.stop1, d.stop2))

internal/f32color/rgba.go

@@ -7,7 +7,7 @@ import (
 	"math"
 )
 
-// RGBA is a 32 bit floating point linear space color.
+// RGBA is a 32 bit floating point linear premultiplied color space.
 type RGBA struct {
 	R, G, B, A float32
 }
@@ -23,11 +23,14 @@ func (col RGBA) Float32() (r, g, b, a float32) {
 }
 
 // SRGBA converts from linear to sRGB color space.
-func (col RGBA) SRGB() color.RGBA {
+func (col RGBA) SRGB() color.NRGBA {
-	return color.RGBA{
+	if col.A == 0 {
-		R: uint8(linearTosRGB(col.R)*255 + .5),
+		return color.NRGBA{}
-		G: uint8(linearTosRGB(col.G)*255 + .5),
+	}
-		B: uint8(linearTosRGB(col.B)*255 + .5),
+	return color.NRGBA{
+		R: uint8(linearTosRGB(col.R/col.A)*255 + .5),
+		G: uint8(linearTosRGB(col.G/col.A)*255 + .5),
+		B: uint8(linearTosRGB(col.B/col.A)*255 + .5),
 		A: uint8(col.A*255 + .5),
 	}
 }
@@ -38,17 +41,50 @@ func (col RGBA) Opaque() RGBA {
 	return col
 }
 
-// RGBAFromSRGB converts from SRGBA to RGBA.
+// LinearFromSRGB converts from SRGBA to RGBA.
-func RGBAFromSRGB(col color.RGBA) RGBA {
+func LinearFromSRGB(col color.NRGBA) RGBA {
-	r, g, b, a := col.RGBA()
+	af := float32(col.A) / 0xFF
 	return RGBA{
-		R: sRGBToLinear(float32(r) / 0xffff),
+		R: sRGBToLinear(float32(col.R)/0xff) * af,
-		G: sRGBToLinear(float32(g) / 0xffff),
+		G: sRGBToLinear(float32(col.G)/0xff) * af,
-		B: sRGBToLinear(float32(b) / 0xffff),
+		B: sRGBToLinear(float32(col.B)/0xff) * af,
-		A: float32(a) / 0xFFFF,
+		A: af,
 	}
 }
 
+// NRGBAToRGBA converts from non-premultiplied sRGB color to premultiplied sRGB color.
+//
+// Each component in the result is `sRGBToLinear(c * alpha)`, where `c`
+// is the linear color.
+func NRGBAToRGBA(col color.NRGBA) color.RGBA {
+	if col.A == 0xFF {
+		return color.RGBA(col)
+	}
+	c := LinearFromSRGB(col)
+	return color.RGBA{
+		R: uint8(linearTosRGB(c.R)*255 + .5),
+		G: uint8(linearTosRGB(c.G)*255 + .5),
+		B: uint8(linearTosRGB(c.B)*255 + .5),
+		A: col.A,
+	}
+}
+
+// RGBAToNRGBA converts from premultiplied sRGB color to non-premultiplied sRGB color.
+func RGBAToNRGBA(col color.RGBA) color.NRGBA {
+	if col.A == 0xFF {
+		return color.NRGBA(col)
+	}
+
+	linear := RGBA{
+		R: sRGBToLinear(float32(col.R) / 0xff),
+		G: sRGBToLinear(float32(col.G) / 0xff),
+		B: sRGBToLinear(float32(col.B) / 0xff),
+		A: float32(col.A) / 0xff,
+	}
+
+	return linear.SRGB()
+}
+
 // linearTosRGB transforms color value from linear to sRGB.
 func linearTosRGB(c float32) float32 {
 	// Formula from EXT_sRGB.
@@ -74,14 +110,8 @@ func sRGBToLinear(c float32) float32 {
 	}
 }
 
-// MulAlpha scales all color components by alpha/255.
+// MulAlpha applies the alpha to the color.
-func MulAlpha(c color.RGBA, alpha uint8) color.RGBA {
+func MulAlpha(c color.NRGBA, alpha uint8) color.NRGBA {
-	// TODO: Optimize. This is pretty slow.
+	c.A = uint8(uint32(c.A) * uint32(alpha) / 0xFF)
-	a := float32(alpha) / 255.
+	return c
-	rgba := RGBAFromSRGB(c)
-	rgba.A *= a
-	rgba.R *= a
-	rgba.G *= a
-	rgba.B *= a
-	return rgba.SRGB()
 }

internal/rendertest/bench_test.go

@@ -157,7 +157,7 @@ func draw1000Circles(gtx layout.Context) {
 		op.Offset(f32.Pt(float32(x*10), 0)).Add(ops)
 		for y := 0; y < 10; y++ {
 			paint.FillShape(ops,
-				color.RGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
+				color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 				clip.RRect{Rect: f32.Rect(0, 0, 10, 10), NE: 5, SE: 5, SW: 5, NW: 5}.Op(ops),
 			)
 			op.Offset(f32.Pt(0, float32(100))).Add(ops)
@@ -179,7 +179,7 @@ func draw1000CirclesInstanced(gtx layout.Context) {
 		op.Offset(f32.Pt(float32(x*10), 0)).Add(ops)
 		for y := 0; y < 10; y++ {
 			pi := op.Push(ops)
-			paint.ColorOp{Color: color.RGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120}}.Add(ops)
+			paint.ColorOp{Color: color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120}}.Add(ops)
 			c.Add(ops)
 			pi.Pop()
 			op.Offset(f32.Pt(0, float32(100))).Add(ops)
@@ -208,7 +208,7 @@ func drawIndividualShapes(gtx layout.Context, th *material.Theme) chan op.CallOp
 			op.Offset(f32.Pt(float32(x*50), 0)).Add(ops)
 			for y := 0; y < 9; y++ {
 				paint.FillShape(ops,
-					color.RGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
+					color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 					clip.RRect{Rect: f32.Rect(0, 0, 25, 25), NE: 10, SE: 10, SW: 10, NW: 10}.Op(ops),
 				)
 				op.Offset(f32.Pt(0, float32(50))).Add(ops)

internal/rendertest/clip_test.go

@@ -14,7 +14,7 @@ import (
 
 func TestPaintRect(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.Red)
 		r.expect(49, 0, colornames.Red)
@@ -26,7 +26,7 @@ func TestPaintRect(t *testing.T) {
 func TestPaintClippedRect(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		clip.RRect{Rect: f32.Rect(25, 25, 60, 60)}.Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(24, 35, colornames.White)
@@ -41,7 +41,7 @@ func TestPaintClippedCirle(t *testing.T) {
 		r := float32(10)
 		clip.RRect{Rect: f32.Rect(20, 20, 40, 40), SE: r, SW: r, NW: r, NE: r}.Add(o)
 		clip.Rect(image.Rect(0, 0, 30, 50)).Add(o)
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(21, 21, colornames.White)
 		r.expect(25, 30, colornames.Red)
@@ -70,7 +70,7 @@ func TestPaintArc(t *testing.T) {
 		p.Line(f32.Pt(-50, 0))
 		p.Outline().Add(o)
 
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 128, 128)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 128, 128)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(0, 25, colornames.Red)
@@ -123,7 +123,7 @@ func TestStrokedPathBevelFlat(t *testing.T) {
 		p.Quad(f32.Pt(-10, -10), f32.Pt(-30, 30))
 		p.Stroke(width, sty).Add(o)
 
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(10, 50, colornames.Red)
@@ -150,7 +150,7 @@ func TestStrokedPathBevelRound(t *testing.T) {
 		p.Quad(f32.Pt(-10, -10), f32.Pt(-30, 30))
 		p.Stroke(width, sty).Add(o)
 
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(10, 50, colornames.Red)
@@ -177,7 +177,7 @@ func TestStrokedPathBevelSquare(t *testing.T) {
 		p.Quad(f32.Pt(-10, -10), f32.Pt(-30, 30))
 		p.Stroke(width, sty).Add(o)
 
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(10, 50, colornames.Red)
@@ -204,7 +204,7 @@ func TestStrokedPathRoundRound(t *testing.T) {
 		p.Quad(f32.Pt(-10, -10), f32.Pt(-30, 30))
 		p.Stroke(width, sty).Add(o)
 
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(10, 50, colornames.Red)
@@ -232,7 +232,7 @@ func TestStrokedPathFlatMiter(t *testing.T) {
 			p.Line(f32.Pt(50, 0))
 
 			p.Stroke(width, sty).Add(o)
-			paint.Fill(o, colornames.Red)
+			paint.Fill(o, red)
 		}
 
 		{
@@ -246,7 +246,7 @@ func TestStrokedPathFlatMiter(t *testing.T) {
 			p.Line(f32.Pt(50, 0))
 
 			p.Stroke(2, clip.StrokeStyle{}).Add(o)
-			paint.Fill(o, colornames.Black)
+			paint.Fill(o, black)
 		}
 
 	}, func(r result) {
@@ -277,7 +277,7 @@ func TestStrokedPathFlatMiterInf(t *testing.T) {
 			p.Line(f32.Pt(50, 0))
 
 			p.Stroke(width, sty).Add(o)
-			paint.Fill(o, colornames.Red)
+			paint.Fill(o, red)
 		}
 
 		{
@@ -291,7 +291,7 @@ func TestStrokedPathFlatMiterInf(t *testing.T) {
 			p.Line(f32.Pt(50, 0))
 
 			p.Stroke(2, clip.StrokeStyle{}).Add(o)
-			paint.Fill(o, colornames.Black)
+			paint.Fill(o, black)
 		}
 
 	}, func(r result) {
@@ -312,7 +312,7 @@ func TestStrokedPathZeroWidth(t *testing.T) {
 			p.Line(f32.Pt(50, 0))
 			p.Stroke(width, sty).Add(o)
 
-			paint.Fill(o, colornames.Black)
+			paint.Fill(o, black)
 		}
 
 		{
@@ -322,7 +322,7 @@ func TestStrokedPathZeroWidth(t *testing.T) {
 			p.Line(f32.Pt(30, 0))
 			p.Stroke(0, sty).Add(o) // width=0, disable stroke
 
-			paint.Fill(o, colornames.Red)
+			paint.Fill(o, red)
 		}
 
 	}, func(r result) {

internal/rendertest/render_test.go

@@ -25,12 +25,12 @@ func TestTransformMacro(t *testing.T) {
 		// render the first Stacked item
 		m1 := op.Record(o)
 		dr := image.Rect(0, 0, 128, 50)
-		paint.FillShape(o, colornames.Black, clip.Rect(dr).Op())
+		paint.FillShape(o, black, clip.Rect(dr).Op())
 		c1 := m1.Stop()
 
 		// Render the second stacked item
 		m2 := op.Record(o)
-		paint.ColorOp{Color: colornames.Red}.Add(o)
+		paint.ColorOp{Color: red}.Add(o)
 		// Simulate a draw text call
 		stack := op.Push(o)
 		op.Offset(f32.Pt(0, 10)).Add(o)
@@ -62,7 +62,7 @@ func TestTransformMacro(t *testing.T) {
 func TestRepeatedPaintsZ(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		// Draw a rectangle
-		paint.FillShape(o, colornames.Black, clip.Rect(image.Rect(0, 0, 128, 50)).Op())
+		paint.FillShape(o, black, clip.Rect(image.Rect(0, 0, 128, 50)).Op())
 
 		builder := clip.Path{}
 		builder.Begin(o)
@@ -72,7 +72,7 @@ func TestRepeatedPaintsZ(t *testing.T) {
 		builder.Line(f32.Pt(-10, 0))
 		builder.Line(f32.Pt(0, -10))
 		builder.Outline().Add(o)
-		paint.Fill(o, colornames.Red)
+		paint.Fill(o, red)
 	}, func(r result) {
 		r.expect(5, 5, colornames.Red)
 		r.expect(11, 15, colornames.Black)
@@ -86,11 +86,11 @@ func TestNoClipFromPaint(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		a := f32.Affine2D{}.Rotate(f32.Pt(20, 20), math.Pi/4)
 		op.Affine(a).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(10, 10, 30, 30)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(10, 10, 30, 30)).Op())
 		a = f32.Affine2D{}.Rotate(f32.Pt(20, 20), -math.Pi/4)
 		op.Affine(a).Add(o)
 
-		paint.FillShape(o, colornames.Black, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+		paint.FillShape(o, black, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
 	}, func(r result) {
 		r.expect(1, 1, colornames.Black)
 		r.expect(20, 20, colornames.Black)
@@ -195,16 +195,16 @@ func TestNegativeOverlaps(t *testing.T) {
 }
 
 type Gradient struct {
-	From, To color.RGBA
+	From, To color.NRGBA
 }
 
 var gradients = []Gradient{
-	{From: color.RGBA{R: 0x00, G: 0x00, B: 0x00, A: 0xFF}, To: color.RGBA{R: 0xFF, G: 0xFF, B: 0xFF, A: 0xFF}},
+	{From: color.NRGBA{R: 0x00, G: 0x00, B: 0x00, A: 0xFF}, To: color.NRGBA{R: 0xFF, G: 0xFF, B: 0xFF, A: 0xFF}},
-	{From: color.RGBA{R: 0x19, G: 0xFF, B: 0x19, A: 0xFF}, To: color.RGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}},
+	{From: color.NRGBA{R: 0x19, G: 0xFF, B: 0x19, A: 0xFF}, To: color.NRGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}},
-	{From: color.RGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}, To: color.RGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}},
+	{From: color.NRGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}, To: color.NRGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}},
-	{From: color.RGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}, To: color.RGBA{R: 0x19, G: 0xFF, B: 0x19, A: 0xFF}},
+	{From: color.NRGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}, To: color.NRGBA{R: 0x19, G: 0xFF, B: 0x19, A: 0xFF}},
-	{From: color.RGBA{R: 0x19, G: 0xFF, B: 0xFF, A: 0xFF}, To: color.RGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}},
+	{From: color.NRGBA{R: 0x19, G: 0xFF, B: 0xFF, A: 0xFF}, To: color.NRGBA{R: 0xFF, G: 0x19, B: 0x19, A: 0xFF}},
-	{From: color.RGBA{R: 0xFF, G: 0xFF, B: 0x19, A: 0xFF}, To: color.RGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}},
+	{From: color.NRGBA{R: 0xFF, G: 0xFF, B: 0x19, A: 0xFF}, To: color.NRGBA{R: 0x19, G: 0x19, B: 0xFF, A: 0xFF}},
 }
 
 func TestLinearGradient(t *testing.T) {
@@ -236,11 +236,11 @@ func TestLinearGradient(t *testing.T) {
 	}, func(r result) {
 		gr := pixelAligned
 		for _, g := range gradients {
-			from := f32color.RGBAFromSRGB(g.From)
+			from := f32color.LinearFromSRGB(g.From)
-			to := f32color.RGBAFromSRGB(g.To)
+			to := f32color.LinearFromSRGB(g.To)
 			for _, p := range samples {
 				exp := lerp(from, to, float32(p)/float32(r.img.Bounds().Dx()-1))
-				r.expect(p, int(gr.Min.Y+gradienth/2), exp.SRGB())
+				r.expect(p, int(gr.Min.Y+gradienth/2), f32color.NRGBAToRGBA(exp.SRGB()))
 			}
 			gr = gr.Add(f32.Pt(0, gradienth))
 		}
@@ -251,9 +251,9 @@ func TestLinearGradientAngled(t *testing.T) {
 	run(t, func(ops *op.Ops) {
 		paint.LinearGradientOp{
 			Stop1:  f32.Pt(64, 64),
-			Color1: colornames.Black,
+			Color1: black,
 			Stop2:  f32.Pt(0, 0),
-			Color2: colornames.Red,
+			Color2: red,
 		}.Add(ops)
 		st := op.Push(ops)
 		clip.Rect(image.Rect(0, 0, 64, 64)).Add(ops)
@@ -262,9 +262,9 @@ func TestLinearGradientAngled(t *testing.T) {
 
 		paint.LinearGradientOp{
 			Stop1:  f32.Pt(64, 64),
-			Color1: colornames.White,
+			Color1: white,
 			Stop2:  f32.Pt(128, 0),
-			Color2: colornames.Green,
+			Color2: green,
 		}.Add(ops)
 		st = op.Push(ops)
 		clip.Rect(image.Rect(64, 0, 128, 64)).Add(ops)
@@ -273,9 +273,9 @@ func TestLinearGradientAngled(t *testing.T) {
 
 		paint.LinearGradientOp{
 			Stop1:  f32.Pt(64, 64),
-			Color1: colornames.Black,
+			Color1: black,
 			Stop2:  f32.Pt(128, 128),
-			Color2: colornames.Blue,
+			Color2: blue,
 		}.Add(ops)
 		st = op.Push(ops)
 		clip.Rect(image.Rect(64, 64, 128, 128)).Add(ops)
@@ -284,9 +284,9 @@ func TestLinearGradientAngled(t *testing.T) {
 
 		paint.LinearGradientOp{
 			Stop1:  f32.Pt(64, 64),
-			Color1: colornames.White,
+			Color1: white,
 			Stop2:  f32.Pt(0, 128),
-			Color2: colornames.Magenta,
+			Color2: magenta,
 		}.Add(ops)
 		st = op.Push(ops)
 		clip.Rect(image.Rect(0, 64, 64, 128)).Add(ops)

internal/rendertest/transform_test.go

@@ -15,7 +15,7 @@ import (
 func TestPaintOffset(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		op.Offset(f32.Pt(10, 20)).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(59, 30, colornames.Red)
@@ -28,7 +28,7 @@ func TestPaintRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		a := f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/8)
 		op.Affine(a).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(20, 20, 60, 60)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(20, 20, 60, 60)).Op())
 	}, func(r result) {
 		r.expect(40, 40, colornames.Red)
 		r.expect(50, 19, colornames.Red)
@@ -41,7 +41,7 @@ func TestPaintShear(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		a := f32.Affine2D{}.Shear(f32.Point{}, math.Pi/4, 0)
 		op.Affine(a).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 40, 40)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 40, 40)).Op())
 	}, func(r result) {
 		r.expect(10, 30, colornames.White)
 	})
@@ -51,7 +51,7 @@ func TestClipPaintOffset(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		clip.RRect{Rect: f32.Rect(10, 10, 30, 30)}.Add(o)
 		op.Offset(f32.Pt(20, 20)).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 100, 100)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 100, 100)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(19, 19, colornames.White)
@@ -64,7 +64,7 @@ func TestClipOffset(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		op.Offset(f32.Pt(20, 20)).Add(o)
 		clip.RRect{Rect: f32.Rect(10, 10, 30, 30)}.Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 100, 100)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 100, 100)).Op())
 	}, func(r result) {
 		r.expect(0, 0, colornames.White)
 		r.expect(29, 29, colornames.White)
@@ -79,7 +79,7 @@ func TestClipScale(t *testing.T) {
 		a := f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(2, 2)).Offset(f32.Pt(10, 10))
 		op.Affine(a).Add(o)
 		clip.RRect{Rect: f32.Rect(10, 10, 20, 20)}.Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 1000, 1000)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 1000, 1000)).Op())
 	}, func(r result) {
 		r.expect(19+10, 19+10, colornames.White)
 		r.expect(20+10, 20+10, colornames.Red)
@@ -92,7 +92,7 @@ func TestClipRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		op.Affine(f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/4)).Add(o)
 		clip.RRect{Rect: f32.Rect(30, 30, 50, 50)}.Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 40, 100, 100)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 40, 100, 100)).Op())
 	}, func(r result) {
 		r.expect(39, 39, colornames.White)
 		r.expect(41, 41, colornames.Red)
@@ -188,7 +188,7 @@ func TestTransformOrder(t *testing.T) {
 
 		c := f32.Affine2D{}.Offset(f32.Pt(-10, -10)).Scale(f32.Point{}, f32.Pt(0.5, 0.5))
 		op.Affine(c).Add(o)
-		paint.FillShape(o, colornames.Red, clip.Rect(image.Rect(0, 0, 20, 20)).Op())
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 20, 20)).Op())
 	}, func(r result) {
 		// centered and with radius 40
 		r.expect(64-41, 64, colornames.White)

internal/rendertest/util_test.go

@@ -15,6 +15,7 @@ import (
 
 	"gioui.org/app/headless"
 	"gioui.org/f32"
+	"gioui.org/internal/f32color"
 	"gioui.org/op"
 	"gioui.org/op/paint"
 	"golang.org/x/image/colornames"
@@ -25,6 +26,15 @@ var (
 	squares    paint.ImageOp
 )
 
+var (
+	red     = f32color.RGBAToNRGBA(colornames.Red)
+	green   = f32color.RGBAToNRGBA(colornames.Green)
+	blue    = f32color.RGBAToNRGBA(colornames.Blue)
+	magenta = f32color.RGBAToNRGBA(colornames.Magenta)
+	black   = f32color.RGBAToNRGBA(colornames.Black)
+	white   = f32color.RGBAToNRGBA(colornames.White)
+)
+
 func init() {
 	// build the texture we use for testing
 	size := 512

op/paint/doc.go

@@ -9,6 +9,6 @@ taking the current transformation into account.
 The current brush is set by either a ColorOp for a constant color, or
 ImageOp for an image, or LinearGradientOp for gradients.
 
-All color.RGBA values are in the sRGB color space.
+All color.NRGBA values are in the sRGB color space.
 */
 package paint

op/paint/paint.go

@@ -21,7 +21,7 @@ import (
 // See NewImageOp for details.
 type ImageOp struct {
 	uniform bool
-	color   color.RGBA
+	color   color.NRGBA
 	src     *image.RGBA
 
 	// handle is a key to uniquely identify this ImageOp
@@ -31,16 +31,16 @@ type ImageOp struct {
 
 // ColorOp sets the brush to a constant color.
 type ColorOp struct {
-	Color color.RGBA
+	Color color.NRGBA
 }
 
 // LinearGradientOp sets the brush to a gradient starting at stop1 with color1 and
 // ending at stop2 with color2.
 type LinearGradientOp struct {
 	Stop1  f32.Point
-	Color1 color.RGBA
+	Color1 color.NRGBA
 	Stop2  f32.Point
-	Color2 color.RGBA
+	Color2 color.NRGBA
 }
 
 // PaintOp fills fills the current clip area with the current brush.
@@ -58,7 +58,7 @@ type PaintOp struct {
 func NewImageOp(src image.Image) ImageOp {
 	switch src := src.(type) {
 	case *image.Uniform:
-		col := color.RGBAModel.Convert(src.C).(color.RGBA)
+		col := color.NRGBAModel.Convert(src.C).(color.NRGBA)
 		return ImageOp{
 			uniform: true,
 			color:   col,
@@ -138,7 +138,7 @@ func (d PaintOp) Add(o *op.Ops) {
 }
 
 // FillShape fills the clip shape with a color.
-func FillShape(ops *op.Ops, c color.RGBA, shape clip.Op) {
+func FillShape(ops *op.Ops, c color.NRGBA, shape clip.Op) {
 	defer op.Push(ops).Pop()
 	shape.Add(ops)
 	Fill(ops, c)
@@ -148,7 +148,7 @@ func FillShape(ops *op.Ops, c color.RGBA, shape clip.Op) {
 // is intended to be used with a clip.Op already in place to limit
 // the painted area. Use FillShape unless you need to paint several
 // times within the same clip.Op.
-func Fill(ops *op.Ops, c color.RGBA) {
+func Fill(ops *op.Ops, c color.NRGBA) {
 	defer op.Push(ops).Pop()
 	ColorOp{Color: c}.Add(ops)
 	PaintOp{}.Add(ops)

widget/border.go

@@ -15,7 +15,7 @@ import (
 
 // Border lays out a widget and draws a border inside it.
 type Border struct {
-	Color        color.RGBA
+	Color        color.NRGBA
 	CornerRadius unit.Value
 	Width        unit.Value
 }

widget/icon.go

@@ -7,6 +7,7 @@ import (
 	"image/color"
 	"image/draw"
 
+	"gioui.org/internal/f32color"
 	"gioui.org/layout"
 	"gioui.org/op/paint"
 	"gioui.org/unit"
@@ -14,12 +15,12 @@ import (
 )
 
 type Icon struct {
-	Color color.RGBA
+	Color color.NRGBA
 	src   []byte
 	// Cached values.
 	op       paint.ImageOp
 	imgSize  int
-	imgColor color.RGBA
+	imgColor color.NRGBA
 }
 
 // NewIcon returns a new Icon from IconVG data.
@@ -28,7 +29,7 @@ func NewIcon(data []byte) (*Icon, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &Icon{src: data, Color: color.RGBA{A: 0xff}}, nil
+	return &Icon{src: data, Color: color.NRGBA{A: 0xff}}, nil
 }
 
 func (ic *Icon) Layout(gtx layout.Context, sz unit.Value) layout.Dimensions {
@@ -49,7 +50,7 @@ func (ic *Icon) image(sz int) paint.ImageOp {
 	img := image.NewRGBA(image.Rectangle{Max: image.Point{X: sz, Y: int(float32(sz) * dy / dx)}})
 	var ico iconvg.Rasterizer
 	ico.SetDstImage(img, img.Bounds(), draw.Src)
-	m.Palette[0] = ic.Color
+	m.Palette[0] = f32color.NRGBAToRGBA(ic.Color)
 	iconvg.Decode(&ico, ic.src, &iconvg.DecodeOptions{
 		Palette: &m.Palette,
 	})

widget/material/button.go

@@ -22,10 +22,10 @@ import (
 type ButtonStyle struct {
 	Text string
 	// Color is the text color.
-	Color        color.RGBA
+	Color        color.NRGBA
 	Font         text.Font
 	TextSize     unit.Value
-	Background   color.RGBA
+	Background   color.NRGBA
 	CornerRadius unit.Value
 	Inset        layout.Inset
 	Button       *widget.Clickable
@@ -33,15 +33,15 @@ type ButtonStyle struct {
 }
 
 type ButtonLayoutStyle struct {
-	Background   color.RGBA
+	Background   color.NRGBA
 	CornerRadius unit.Value
 	Button       *widget.Clickable
 }
 
 type IconButtonStyle struct {
-	Background color.RGBA
+	Background color.NRGBA
 	// Color is the icon color.
-	Color color.RGBA
+	Color color.NRGBA
 	Icon  *widget.Icon
 	// Size is the icon size.
 	Size   unit.Value
@@ -272,7 +272,7 @@ func drawInk(gtx layout.Context, c widget.Press) {
 	const col = 0.8
 	ba, bc := byte(alpha*0xff), byte(col*0xff)
 	defer op.Push(gtx.Ops).Pop()
-	rgba := f32color.MulAlpha(color.RGBA{A: 0xff, R: bc, G: bc, B: bc}, ba)
+	rgba := f32color.MulAlpha(color.NRGBA{A: 0xff, R: bc, G: bc, B: bc}, ba)
 	ink := paint.ColorOp{Color: rgba}
 	ink.Add(gtx.Ops)
 	rr := size * .5

widget/material/checkable.go

@@ -17,10 +17,10 @@ import (
 
 type checkable struct {
 	Label              string
-	Color              color.RGBA
+	Color              color.NRGBA
 	Font               text.Font
 	TextSize           unit.Value
-	IconColor          color.RGBA
+	IconColor          color.NRGBA
 	Size               unit.Value
 	shaper             text.Shaper
 	checkedStateIcon   *widget.Icon

widget/material/doc.go

@@ -36,7 +36,7 @@
 // Theme-global parameters: For changing the look of all widgets drawn with a
 // particular theme, adjust the `Theme` fields:
 //
-//     theme.Color.Primary = color.RGBA{...}
+//     theme.Color.Primary = color.NRGBA{...}
 //
 // Widget-local parameters: For changing the look of a particular widget,
 // adjust the widget specific theme object:

widget/material/editor.go

@@ -18,11 +18,11 @@ type EditorStyle struct {
 	Font     text.Font
 	TextSize unit.Value
 	// Color is the text color.
-	Color color.RGBA
+	Color color.NRGBA
 	// Hint contains the text displayed when the editor is empty.
 	Hint string
 	// HintColor is the color of hint text.
-	HintColor color.RGBA
+	HintColor color.NRGBA
 	Editor    *widget.Editor
 
 	shaper text.Shaper

widget/material/label.go

@@ -16,7 +16,7 @@ type LabelStyle struct {
 	// Face defines the text style.
 	Font text.Font
 	// Color is the text color.
-	Color color.RGBA
+	Color color.NRGBA
 	// Alignment specify the text alignment.
 	Alignment text.Alignment
 	// MaxLines limits the number of lines. Zero means no limit.

widget/material/loader.go

@@ -17,7 +17,7 @@ import (
 )
 
 type LoaderStyle struct {
-	Color color.RGBA
+	Color color.NRGBA
 }
 
 func Loader(th *Theme) LoaderStyle {

widget/material/progressbar.go

@@ -15,7 +15,7 @@ import (
 )
 
 type ProgressBarStyle struct {
-	Color    color.RGBA
+	Color    color.NRGBA
 	Progress int
 }
 
@@ -27,7 +27,7 @@ func ProgressBar(th *Theme, progress int) ProgressBarStyle {
 }
 
 func (p ProgressBarStyle) Layout(gtx layout.Context) layout.Dimensions {
-	shader := func(width float32, color color.RGBA) layout.Dimensions {
+	shader := func(width float32, color color.NRGBA) layout.Dimensions {
 		maxHeight := unit.Dp(4)
 		rr := float32(gtx.Px(unit.Dp(2)))
 

widget/material/slider.go

@@ -28,7 +28,7 @@ func Slider(th *Theme, float *widget.Float, min, max float32) SliderStyle {
 
 type SliderStyle struct {
 	Min, Max float32
-	Color    color.RGBA
+	Color    color.NRGBA
 	Float    *widget.Float
 }
 

widget/material/switch.go

@@ -19,8 +19,8 @@ import (
 
 type SwitchStyle struct {
 	Color struct {
-		Enabled  color.RGBA
+		Enabled  color.NRGBA
-		Disabled color.RGBA
+		Disabled color.NRGBA
 	}
 	Switch *widget.Bool
 }
@@ -124,7 +124,7 @@ func (s SwitchStyle) Layout(gtx layout.Context) layout.Dimensions {
 	return layout.Dimensions{Size: dims}
 }
 
-func drawDisc(ops *op.Ops, sz float32, col color.RGBA) {
+func drawDisc(ops *op.Ops, sz float32, col color.NRGBA) {
 	defer op.Push(ops).Pop()
 	rr := sz / 2
 	r := f32.Rectangle{Max: f32.Point{X: sz, Y: sz}}

widget/material/theme.go

@@ -14,10 +14,10 @@ import (
 type Theme struct {
 	Shaper text.Shaper
 	Color  struct {
-		Primary color.RGBA
+		Primary color.NRGBA
-		Text    color.RGBA
+		Text    color.NRGBA
-		Hint    color.RGBA
+		Hint    color.NRGBA
-		InvText color.RGBA
+		InvText color.NRGBA
 	}
 	TextSize unit.Value
 	Icon     struct {
@@ -53,10 +53,10 @@ func mustIcon(ic *widget.Icon, err error) *widget.Icon {
 	return ic
 }
 
-func rgb(c uint32) color.RGBA {
+func rgb(c uint32) color.NRGBA {
 	return argb(0xff000000 | c)
 }
 
-func argb(c uint32) color.RGBA {
+func argb(c uint32) color.NRGBA {
-	return color.RGBA{A: uint8(c >> 24), R: uint8(c >> 16), G: uint8(c >> 8), B: uint8(c)}
+	return color.NRGBA{A: uint8(c >> 24), R: uint8(c >> 16), G: uint8(c >> 8), B: uint8(c)}
 }