diff --git a/app/headless/headless.go b/app/headless/headless.go
index 10755226..8ad772dd 100644
--- a/app/headless/headless.go
+++ b/app/headless/headless.go
@@ -9,6 +9,8 @@ import (
 	"image"
 	"runtime"
 
+	"gioui.org/app/internal/glimpl"
+	"gioui.org/app/internal/srgb"
 	"gioui.org/gpu"
 	"gioui.org/gpu/gl"
 	"gioui.org/op"
@@ -18,12 +20,12 @@ import (
 type Window struct {
 	size image.Point
 	ctx  context
-	fbo  *gl.SRGBFBO
+	fbo  *srgb.SRGBFBO
 	gpu  *gpu.GPU
 }
 
 type context interface {
-	Functions() gl.Functions
+	Functions() *glimpl.Functions
 	MakeCurrent() error
 	ReleaseCurrent()
 	Release()
@@ -41,7 +43,7 @@ func NewWindow(width, height int) (*Window, error) {
 	}
 	err = contextDo(ctx, func() error {
 		f := ctx.Functions()
-		fbo, err := gl.NewSRGBFBO(f)
+		fbo, err := srgb.NewSRGBFBO(f)
 		if err != nil {
 			ctx.Release()
 			return err
diff --git a/app/headless/headless_darwin.go b/app/headless/headless_darwin.go
index 26d442ea..998173ac 100644
--- a/app/headless/headless_darwin.go
+++ b/app/headless/headless_darwin.go
@@ -4,7 +4,6 @@ package headless
 
 import (
 	"gioui.org/app/internal/glimpl"
-	"gioui.org/gpu/gl"
 )
 
 /*
@@ -16,7 +15,7 @@ import (
 import "C"
 
 type nsContext struct {
-	c        gl.Functions
+	c        *glimpl.Functions
 	ctx      C.CFTypeRef
 	prepared bool
 }
@@ -39,7 +38,7 @@ func (c *nsContext) ReleaseCurrent() {
 	C.gio_headless_clearCurrentContext(c.ctx)
 }
 
-func (c *nsContext) Functions() gl.Functions {
+func (c *nsContext) Functions() *glimpl.Functions {
 	return c.c
 }
 
diff --git a/app/headless/headless_js.go b/app/headless/headless_js.go
index f2e53bc3..90ca85eb 100644
--- a/app/headless/headless_js.go
+++ b/app/headless/headless_js.go
@@ -7,12 +7,11 @@ import (
 	"syscall/js"
 
 	"gioui.org/app/internal/glimpl"
-	"gioui.org/gpu/gl"
 )
 
 type jsContext struct {
 	ctx js.Value
-	f   gl.Functions
+	f   *glimpl.Functions
 }
 
 func newContext() (*jsContext, error) {
@@ -38,7 +37,7 @@ func newContext() (*jsContext, error) {
 	return c, nil
 }
 
-func (c *jsContext) Functions() gl.Functions {
+func (c *jsContext) Functions() *glimpl.Functions {
 	return c.f
 }
 
diff --git a/app/internal/egl/egl.go b/app/internal/egl/egl.go
index 98593470..c6b6a628 100644
--- a/app/internal/egl/egl.go
+++ b/app/internal/egl/egl.go
@@ -11,18 +11,18 @@ import (
 	"strings"
 
 	"gioui.org/app/internal/glimpl"
-	"gioui.org/gpu/gl"
+	"gioui.org/app/internal/srgb"
 )
 
 type Context struct {
-	c             gl.Functions
+	c             *glimpl.Functions
 	disp          _EGLDisplay
 	eglCtx        *eglContext
 	eglSurf       _EGLSurface
 	width, height int
 	refreshFBO    bool
 	// For sRGB emulation.
-	srgbFBO *gl.SRGBFBO
+	srgbFBO *srgb.SRGBFBO
 }
 
 type eglContext struct {
@@ -115,7 +115,7 @@ func NewContext(disp NativeDisplayType) (*Context, error) {
 	return c, nil
 }
 
-func (c *Context) Functions() gl.Functions {
+func (c *Context) Functions() *glimpl.Functions {
 	return c.c
 }
 
@@ -161,7 +161,7 @@ func (c *Context) MakeCurrent() error {
 	}
 	if c.srgbFBO == nil {
 		var err error
-		c.srgbFBO, err = gl.NewSRGBFBO(c.c)
+		c.srgbFBO, err = srgb.NewSRGBFBO(c.c)
 		if err != nil {
 			return err
 		}
diff --git a/gpu/gl/srgb.go b/app/internal/srgb/srgb.go
similarity index 52%
rename from gpu/gl/srgb.go
rename to app/internal/srgb/srgb.go
index 253fa157..9071beef 100644
--- a/gpu/gl/srgb.go
+++ b/app/internal/srgb/srgb.go
@@ -1,12 +1,14 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package gl
+package srgb
 
 import (
 	"fmt"
 	"runtime"
 	"strings"
 
+	"gioui.org/app/internal/glimpl"
+	"gioui.org/gpu/gl"
 	"gioui.org/internal/unsafe"
 )
 
@@ -14,28 +16,28 @@ import (
 // for gamma-correct rendering on platforms without
 // sRGB enabled native framebuffers.
 type SRGBFBO struct {
-	c             Functions
+	c             *glimpl.Functions
 	width, height int
-	frameBuffer   Framebuffer
-	depthBuffer   Renderbuffer
-	colorTex      Texture
+	frameBuffer   gl.Framebuffer
+	depthBuffer   gl.Renderbuffer
+	colorTex      gl.Texture
 	blitted       bool
-	quad          Buffer
-	prog          Program
+	quad          gl.Buffer
+	prog          gl.Program
 	es3           bool
 }
 
-func NewSRGBFBO(f Functions) (*SRGBFBO, error) {
+func NewSRGBFBO(f *glimpl.Functions) (*SRGBFBO, error) {
 	var es3 bool
-	glVer := f.GetString(VERSION)
-	ver, err := parseGLVersion(glVer)
+	glVer := f.GetString(gl.VERSION)
+	ver, err := gl.ParseGLVersion(glVer)
 	if err != nil {
 		return nil, err
 	}
 	if ver[0] >= 3 {
 		es3 = true
 	} else {
-		exts := f.GetString(EXTENSIONS)
+		exts := f.GetString(gl.EXTENSIONS)
 		if !strings.Contains(exts, "EXT_sRGB") {
 			return nil, fmt.Errorf("no support for OpenGL ES 3 nor EXT_sRGB")
 		}
@@ -47,57 +49,57 @@ func NewSRGBFBO(f Functions) (*SRGBFBO, error) {
 		colorTex:    f.CreateTexture(),
 		depthBuffer: f.CreateRenderbuffer(),
 	}
-	f.BindTexture(TEXTURE_2D, s.colorTex)
-	f.TexParameteri(TEXTURE_2D, TEXTURE_WRAP_S, CLAMP_TO_EDGE)
-	f.TexParameteri(TEXTURE_2D, TEXTURE_WRAP_T, CLAMP_TO_EDGE)
-	f.TexParameteri(TEXTURE_2D, TEXTURE_MAG_FILTER, NEAREST)
-	f.TexParameteri(TEXTURE_2D, TEXTURE_MIN_FILTER, NEAREST)
+	f.BindTexture(gl.TEXTURE_2D, s.colorTex)
+	f.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+	f.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+	f.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
+	f.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
 	return s, nil
 }
 
 func (s *SRGBFBO) Blit() {
 	if !s.blitted {
-		prog, err := createProgram(s.c, blitVSrc, blitFSrc, []string{"pos", "uv"})
+		prog, err := gl.CreateProgram(s.c, blitVSrc, blitFSrc, []string{"pos", "uv"})
 		if err != nil {
 			panic(err)
 		}
 		s.prog = prog
 		s.c.UseProgram(prog)
-		s.c.Uniform1i(getUniformLocation(s.c, prog, "tex"), 0)
+		s.c.Uniform1i(gl.GetUniformLocation(s.c, prog, "tex"), 0)
 		s.quad = s.c.CreateBuffer()
-		s.c.BindBuffer(ARRAY_BUFFER, s.quad)
-		s.c.BufferData(ARRAY_BUFFER,
+		s.c.BindBuffer(gl.ARRAY_BUFFER, s.quad)
+		s.c.BufferData(gl.ARRAY_BUFFER,
 			unsafe.BytesView([]float32{
 				-1, +1, 0, 1,
 				+1, +1, 1, 1,
 				-1, -1, 0, 0,
 				+1, -1, 1, 0,
 			}),
-			STATIC_DRAW)
+			gl.STATIC_DRAW)
 		s.blitted = true
 	}
-	s.c.BindFramebuffer(FRAMEBUFFER, Framebuffer{})
+	s.c.BindFramebuffer(gl.FRAMEBUFFER, gl.Framebuffer{})
 	s.c.UseProgram(s.prog)
-	s.c.BindTexture(TEXTURE_2D, s.colorTex)
-	s.c.BindBuffer(ARRAY_BUFFER, s.quad)
-	s.c.VertexAttribPointer(0 /* pos */, 2, FLOAT, false, 4*4, 0)
-	s.c.VertexAttribPointer(1 /* uv */, 2, FLOAT, false, 4*4, 4*2)
+	s.c.BindTexture(gl.TEXTURE_2D, s.colorTex)
+	s.c.BindBuffer(gl.ARRAY_BUFFER, s.quad)
+	s.c.VertexAttribPointer(0 /* pos */, 2, gl.FLOAT, false, 4*4, 0)
+	s.c.VertexAttribPointer(1 /* uv */, 2, gl.FLOAT, false, 4*4, 4*2)
 	s.c.EnableVertexAttribArray(0)
 	s.c.EnableVertexAttribArray(1)
-	s.c.DrawArrays(TRIANGLE_STRIP, 0, 4)
-	s.c.BindTexture(TEXTURE_2D, Texture{})
+	s.c.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
+	s.c.BindTexture(gl.TEXTURE_2D, gl.Texture{})
 	s.c.DisableVertexAttribArray(0)
 	s.c.DisableVertexAttribArray(1)
-	s.c.BindFramebuffer(FRAMEBUFFER, s.frameBuffer)
-	s.c.InvalidateFramebuffer(FRAMEBUFFER, COLOR_ATTACHMENT0)
-	s.c.InvalidateFramebuffer(FRAMEBUFFER, DEPTH_ATTACHMENT)
+	s.c.BindFramebuffer(gl.FRAMEBUFFER, s.frameBuffer)
+	s.c.InvalidateFramebuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0)
+	s.c.InvalidateFramebuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT)
 	// The Android emulator requires framebuffer 0 bound at eglSwapBuffer time.
 	// Bind the sRGB framebuffer again in afterPresent.
-	s.c.BindFramebuffer(FRAMEBUFFER, Framebuffer{})
+	s.c.BindFramebuffer(gl.FRAMEBUFFER, gl.Framebuffer{})
 }
 
 func (s *SRGBFBO) AfterPresent() {
-	s.c.BindFramebuffer(FRAMEBUFFER, s.frameBuffer)
+	s.c.BindFramebuffer(gl.FRAMEBUFFER, s.frameBuffer)
 }
 
 func (s *SRGBFBO) Refresh(w, h int) error {
@@ -105,20 +107,20 @@ func (s *SRGBFBO) Refresh(w, h int) error {
 	if w == 0 || h == 0 {
 		return nil
 	}
-	s.c.BindTexture(TEXTURE_2D, s.colorTex)
+	s.c.BindTexture(gl.TEXTURE_2D, s.colorTex)
 	if s.es3 {
-		s.c.TexImage2D(TEXTURE_2D, 0, SRGB8_ALPHA8, w, h, RGBA, UNSIGNED_BYTE, nil)
+		s.c.TexImage2D(gl.TEXTURE_2D, 0, gl.SRGB8_ALPHA8, w, h, gl.RGBA, gl.UNSIGNED_BYTE, nil)
 	} else /* EXT_sRGB */ {
-		s.c.TexImage2D(TEXTURE_2D, 0, SRGB_ALPHA_EXT, w, h, SRGB_ALPHA_EXT, UNSIGNED_BYTE, nil)
+		s.c.TexImage2D(gl.TEXTURE_2D, 0, gl.SRGB_ALPHA_EXT, w, h, gl.SRGB_ALPHA_EXT, gl.UNSIGNED_BYTE, nil)
 	}
-	currentRB := Renderbuffer(s.c.GetBinding(RENDERBUFFER_BINDING))
-	s.c.BindRenderbuffer(RENDERBUFFER, s.depthBuffer)
-	s.c.RenderbufferStorage(RENDERBUFFER, DEPTH_COMPONENT16, w, h)
-	s.c.BindRenderbuffer(RENDERBUFFER, currentRB)
-	s.c.BindFramebuffer(FRAMEBUFFER, s.frameBuffer)
-	s.c.FramebufferTexture2D(FRAMEBUFFER, COLOR_ATTACHMENT0, TEXTURE_2D, s.colorTex, 0)
-	s.c.FramebufferRenderbuffer(FRAMEBUFFER, DEPTH_ATTACHMENT, RENDERBUFFER, s.depthBuffer)
-	if st := s.c.CheckFramebufferStatus(FRAMEBUFFER); st != FRAMEBUFFER_COMPLETE {
+	currentRB := gl.Renderbuffer(s.c.GetBinding(gl.RENDERBUFFER_BINDING))
+	s.c.BindRenderbuffer(gl.RENDERBUFFER, s.depthBuffer)
+	s.c.RenderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, w, h)
+	s.c.BindRenderbuffer(gl.RENDERBUFFER, currentRB)
+	s.c.BindFramebuffer(gl.FRAMEBUFFER, s.frameBuffer)
+	s.c.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, s.colorTex, 0)
+	s.c.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, s.depthBuffer)
+	if st := s.c.CheckFramebufferStatus(gl.FRAMEBUFFER); st != gl.FRAMEBUFFER_COMPLETE {
 		return fmt.Errorf("sRGB framebuffer incomplete (%dx%d), status: %#x error: %x", s.width, s.height, st, s.c.GetError())
 	}
 
@@ -127,12 +129,12 @@ func (s *SRGBFBO) Refresh(w, h int) error {
 		// texture result in twice gamma corrected colors. Using a plain RGBA
 		// texture seems to work.
 		s.c.ClearColor(.5, .5, .5, 1.0)
-		s.c.Clear(COLOR_BUFFER_BIT)
+		s.c.Clear(gl.COLOR_BUFFER_BIT)
 		var pixel [4]byte
-		s.c.ReadPixels(0, 0, 1, 1, RGBA, UNSIGNED_BYTE, pixel[:])
+		s.c.ReadPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixel[:])
 		if pixel[0] == 128 { // Correct sRGB color value is ~188
-			s.c.TexImage2D(TEXTURE_2D, 0, RGBA, w, h, RGBA, UNSIGNED_BYTE, nil)
-			if st := s.c.CheckFramebufferStatus(FRAMEBUFFER); st != FRAMEBUFFER_COMPLETE {
+			s.c.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, gl.RGBA, gl.UNSIGNED_BYTE, nil)
+			if st := s.c.CheckFramebufferStatus(gl.FRAMEBUFFER); st != gl.FRAMEBUFFER_COMPLETE {
 				return fmt.Errorf("fallback RGBA framebuffer incomplete (%dx%d), status: %#x error: %x", s.width, s.height, st, s.c.GetError())
 			}
 		}
diff --git a/app/internal/window/gl_ios.go b/app/internal/window/gl_ios.go
index 8528bfbe..5e340c2f 100644
--- a/app/internal/window/gl_ios.go
+++ b/app/internal/window/gl_ios.go
@@ -22,7 +22,7 @@ import (
 
 type context struct {
 	owner                    *window
-	c                        gl.Functions
+	c                        *glimpl.Functions
 	ctx                      C.CFTypeRef
 	layer                    C.CFTypeRef
 	init                     bool
@@ -50,7 +50,7 @@ func newContext(w *window) (*context, error) {
 	return c, nil
 }
 
-func (c *context) Functions() gl.Functions {
+func (c *context) Functions() *glimpl.Functions {
 	return c.c
 }
 
diff --git a/app/internal/window/gl_js.go b/app/internal/window/gl_js.go
index 90661403..60f07e49 100644
--- a/app/internal/window/gl_js.go
+++ b/app/internal/window/gl_js.go
@@ -7,14 +7,14 @@ import (
 	"syscall/js"
 
 	"gioui.org/app/internal/glimpl"
-	"gioui.org/gpu/gl"
+	"gioui.org/app/internal/srgb"
 )
 
 type context struct {
 	ctx     js.Value
 	cnv     js.Value
-	f       gl.Functions
-	srgbFBO *gl.SRGBFBO
+	f       *glimpl.Functions
+	srgbFBO *srgb.SRGBFBO
 }
 
 func newContext(w *window) (*context, error) {
@@ -45,7 +45,7 @@ func newContext(w *window) (*context, error) {
 	return c, nil
 }
 
-func (c *context) Functions() gl.Functions {
+func (c *context) Functions() *glimpl.Functions {
 	return c.f
 }
 
@@ -76,7 +76,7 @@ func (c *context) Unlock() {}
 func (c *context) MakeCurrent() error {
 	if c.srgbFBO == nil {
 		var err error
-		c.srgbFBO, err = gl.NewSRGBFBO(c.f)
+		c.srgbFBO, err = srgb.NewSRGBFBO(c.f)
 		if err != nil {
 			c.Release()
 			c.srgbFBO = nil
diff --git a/app/internal/window/gl_macos.go b/app/internal/window/gl_macos.go
index ffd9a58d..5c1f34d1 100644
--- a/app/internal/window/gl_macos.go
+++ b/app/internal/window/gl_macos.go
@@ -6,7 +6,6 @@ package window
 
 import (
 	"gioui.org/app/internal/glimpl"
-	"gioui.org/gpu/gl"
 )
 
 /*
@@ -19,7 +18,7 @@ import (
 import "C"
 
 type context struct {
-	c    gl.Functions
+	c    *glimpl.Functions
 	ctx  C.CFTypeRef
 	view C.CFTypeRef
 }
@@ -41,7 +40,7 @@ func newContext(w *window) (*context, error) {
 	return c, nil
 }
 
-func (c *context) Functions() gl.Functions {
+func (c *context) Functions() *glimpl.Functions {
 	return c.c
 }
 
diff --git a/app/internal/window/window.go b/app/internal/window/window.go
index 23d8501e..10083d8d 100644
--- a/app/internal/window/window.go
+++ b/app/internal/window/window.go
@@ -9,7 +9,7 @@ import (
 	"math"
 	"time"
 
-	"gioui.org/gpu/gl"
+	"gioui.org/app/internal/glimpl"
 	"gioui.org/io/event"
 	"gioui.org/io/system"
 	"gioui.org/unit"
@@ -32,7 +32,7 @@ type Callbacks interface {
 }
 
 type Context interface {
-	Functions() gl.Functions
+	Functions() *glimpl.Functions
 	Present() error
 	MakeCurrent() error
 	Release()
diff --git a/gpu/gl/backend.go b/gpu/gl/backend.go
index 394210c3..c0fcb6f2 100644
--- a/gpu/gl/backend.go
+++ b/gpu/gl/backend.go
@@ -74,7 +74,7 @@ type textureTriple struct {
 func NewBackend(f Functions) (*Backend, error) {
 	exts := strings.Split(f.GetString(EXTENSIONS), " ")
 	glVer := f.GetString(VERSION)
-	ver, err := parseGLVersion(glVer)
+	ver, err := ParseGLVersion(glVer)
 	if err != nil {
 		return nil, err
 	}
@@ -282,7 +282,7 @@ func (b *Backend) DepthFunc(f gpu.DepthFunc) {
 }
 
 func (b *Backend) NewProgram(vssrc, fssrc string, attr []string) (gpu.Program, error) {
-	p, err := createProgram(b.funcs, vssrc, fssrc, attr)
+	p, err := CreateProgram(b.funcs, vssrc, fssrc, attr)
 	if err != nil {
 		return nil, err
 	}
@@ -316,7 +316,7 @@ func (p *gpuProgram) Bind() {
 
 func (p *gpuProgram) UniformFor(uniform string) gpu.Uniform {
 	f := p.backend.funcs
-	return getUniformLocation(f, p.obj, uniform)
+	return GetUniformLocation(f, p.obj, uniform)
 }
 
 func (b *Backend) SetupVertexArray(slot int, size int, dataType gpu.DataType, stride, offset int) {
diff --git a/gpu/gl/util.go b/gpu/gl/util.go
index f1c26acf..17e95980 100644
--- a/gpu/gl/util.go
+++ b/gpu/gl/util.go
@@ -8,7 +8,7 @@ import (
 	"strings"
 )
 
-func createProgram(ctx Functions, vsSrc, fsSrc string, attribs []string) (Program, error) {
+func CreateProgram(ctx Functions, vsSrc, fsSrc string, attribs []string) (Program, error) {
 	vs, err := createShader(ctx, VERTEX_SHADER, vsSrc)
 	if err != nil {
 		return Program{}, err
@@ -37,7 +37,7 @@ func createProgram(ctx Functions, vsSrc, fsSrc string, attribs []string) (Progra
 	return prog, nil
 }
 
-func getUniformLocation(ctx Functions, prog Program, name string) Uniform {
+func GetUniformLocation(ctx Functions, prog Program, name string) Uniform {
 	loc := ctx.GetUniformLocation(prog, name)
 	if !loc.Valid() {
 		panic(fmt.Errorf("uniform %s not found", name))
@@ -60,7 +60,7 @@ func createShader(ctx Functions, typ Enum, src string) (Shader, error) {
 	return sh, nil
 }
 
-func parseGLVersion(glVer string) ([2]int, error) {
+func ParseGLVersion(glVer string) ([2]int, error) {
 	var ver [2]int
 	if _, err := fmt.Sscanf(glVer, "OpenGL ES %d.%d", &ver[0], &ver[1]); err == nil {
 		return ver, nil