blob: 1afc5f8efe27c98aa754bda9a496871610193ad7 [file] [log] [blame]
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gl
import (
"archive/tar"
"compress/gzip"
"debug/pe"
"fmt"
"io"
"io/ioutil"
"log"
"net/http"
"os"
"path/filepath"
"runtime"
)
var debug = log.New(ioutil.Discard, "gl: ", log.LstdFlags)
func downloadDLLs() (path string, err error) {
url := "https://dl.google.com/go/mobile/angle-bd3f8780b-" + runtime.GOARCH + ".tgz"
debug.Printf("downloading %s", url)
resp, err := http.Get(url)
if err != nil {
return "", fmt.Errorf("gl: %v", err)
}
defer func() {
err2 := resp.Body.Close()
if err == nil && err2 != nil {
err = fmt.Errorf("gl: error reading body from %v: %v", url, err2)
}
}()
if resp.StatusCode != http.StatusOK {
err := fmt.Errorf("gl: error fetching %v, status: %v", url, resp.Status)
return "", err
}
r, err := gzip.NewReader(resp.Body)
if err != nil {
return "", fmt.Errorf("gl: error reading gzip from %v: %v", url, err)
}
tr := tar.NewReader(r)
var bytesGLESv2, bytesEGL, bytesD3DCompiler []byte
for {
header, err := tr.Next()
if err == io.EOF {
break
}
if err != nil {
return "", fmt.Errorf("gl: error reading tar from %v: %v", url, err)
}
switch header.Name {
case "angle-" + runtime.GOARCH + "/libglesv2.dll":
bytesGLESv2, err = ioutil.ReadAll(tr)
case "angle-" + runtime.GOARCH + "/libegl.dll":
bytesEGL, err = ioutil.ReadAll(tr)
case "angle-" + runtime.GOARCH + "/d3dcompiler_47.dll":
bytesD3DCompiler, err = ioutil.ReadAll(tr)
default: // skip
}
if err != nil {
return "", fmt.Errorf("gl: error reading %v from %v: %v", header.Name, url, err)
}
}
if len(bytesGLESv2) == 0 || len(bytesEGL) == 0 || len(bytesD3DCompiler) == 0 {
return "", fmt.Errorf("gl: did not find all DLLs in %v", url)
}
writeDLLs := func(path string) error {
if err := ioutil.WriteFile(filepath.Join(path, "libglesv2.dll"), bytesGLESv2, 0755); err != nil {
return fmt.Errorf("gl: cannot install ANGLE: %v", err)
}
if err := ioutil.WriteFile(filepath.Join(path, "libegl.dll"), bytesEGL, 0755); err != nil {
return fmt.Errorf("gl: cannot install ANGLE: %v", err)
}
if err := ioutil.WriteFile(filepath.Join(path, "d3dcompiler_47.dll"), bytesD3DCompiler, 0755); err != nil {
return fmt.Errorf("gl: cannot install ANGLE: %v", err)
}
return nil
}
// First, we attempt to install these DLLs in LOCALAPPDATA/Shiny.
//
// Traditionally we would use the system32 directory, but it is
// no longer writable by normal programs.
os.MkdirAll(appdataPath(), 0775)
if err := writeDLLs(appdataPath()); err == nil {
return appdataPath(), nil
}
debug.Printf("DLLs could not be written to %s", appdataPath())
// Second, install in GOPATH/pkg if it exists.
gopath := os.Getenv("GOPATH")
gopathpkg := filepath.Join(gopath, "pkg")
if _, err := os.Stat(gopathpkg); err == nil && gopath != "" {
if err := writeDLLs(gopathpkg); err == nil {
return gopathpkg, nil
}
}
debug.Printf("DLLs could not be written to GOPATH")
// Third, pick a temporary directory.
tmp := os.TempDir()
if err := writeDLLs(tmp); err != nil {
return "", fmt.Errorf("gl: unable to install ANGLE DLLs: %v", err)
}
return tmp, nil
}
func appdataPath() string {
return filepath.Join(os.Getenv("LOCALAPPDATA"), "GoGL", runtime.GOARCH)
}
func containsDLLs(dir string) bool {
compatible := func(name string) bool {
file, err := pe.Open(filepath.Join(dir, name))
if err != nil {
return false
}
defer file.Close()
switch file.Machine {
case pe.IMAGE_FILE_MACHINE_AMD64:
return "amd64" == runtime.GOARCH
case pe.IMAGE_FILE_MACHINE_ARM:
return "arm" == runtime.GOARCH
case pe.IMAGE_FILE_MACHINE_I386:
return "386" == runtime.GOARCH
}
return false
}
return compatible("libglesv2.dll") && compatible("libegl.dll") && compatible("d3dcompiler_47.dll")
}
func chromePath() string {
// dlls are stored in:
// <BASE>/<VERSION>/libglesv2.dll
var installdirs = []string{
// Chrome User
filepath.Join(os.Getenv("LOCALAPPDATA"), "Google", "Chrome", "Application"),
// Chrome System
filepath.Join(os.Getenv("ProgramFiles(x86)"), "Google", "Chrome", "Application"),
// Chromium
filepath.Join(os.Getenv("LOCALAPPDATA"), "Chromium", "Application"),
// Chrome Canary
filepath.Join(os.Getenv("LOCALAPPDATA"), "Google", "Chrome SxS", "Application"),
}
for _, installdir := range installdirs {
versiondirs, err := ioutil.ReadDir(installdir)
if err != nil {
continue
}
for _, versiondir := range versiondirs {
if !versiondir.IsDir() {
continue
}
versionpath := filepath.Join(installdir, versiondir.Name())
if containsDLLs(versionpath) {
return versionpath
}
}
}
return ""
}
func findDLLs() (err error) {
load := func(path string) (bool, error) {
if path != "" {
// don't try to start when one of the files is missing
if !containsDLLs(path) {
return false, nil
}
LibD3DCompiler.Name = filepath.Join(path, filepath.Base(LibD3DCompiler.Name))
LibGLESv2.Name = filepath.Join(path, filepath.Base(LibGLESv2.Name))
LibEGL.Name = filepath.Join(path, filepath.Base(LibEGL.Name))
}
if err := LibGLESv2.Load(); err == nil {
if err := LibEGL.Load(); err != nil {
return false, fmt.Errorf("gl: loaded libglesv2 but not libegl: %v", err)
}
if err := LibD3DCompiler.Load(); err != nil {
return false, fmt.Errorf("gl: loaded libglesv2, libegl but not d3dcompiler: %v", err)
}
if path == "" {
debug.Printf("DLLs found")
} else {
debug.Printf("DLLs found in: %q", path)
}
return true, nil
}
return false, nil
}
// Look in the system directory.
if ok, err := load(""); ok || err != nil {
return err
}
// Look in the AppData directory.
if ok, err := load(appdataPath()); ok || err != nil {
return err
}
// Look for a Chrome installation
if dir := chromePath(); dir != "" {
if ok, err := load(dir); ok || err != nil {
return err
}
}
// Look in GOPATH/pkg.
if ok, err := load(filepath.Join(os.Getenv("GOPATH"), "pkg")); ok || err != nil {
return err
}
// Look in temporary directory.
if ok, err := load(os.TempDir()); ok || err != nil {
return err
}
// Download the DLL binary.
path, err := downloadDLLs()
if err != nil {
return err
}
debug.Printf("DLLs written to %s", path)
if ok, err := load(path); !ok || err != nil {
return fmt.Errorf("gl: unable to load ANGLE after installation: %v", err)
}
return nil
}