How to install opengl for this to run

问题

I am trying following simple code to create a GUI using Fyne package:

// from: https://github.com/fyne-io/fyne
package main
import (
    "fyne.io/fyne/widget"
    "fyne.io/fyne/app"
)
func main() {
    app := app.New()
    w := app.NewWindow("Hello")
    w.SetContent(widget.NewVBox(
        widget.NewLabel("Hello Fyne!"),
        widget.NewButton("Quit", func() {
            app.Quit()
        }),
    ))
    w.ShowAndRun()
}

It compiles and builds executable file without any error or even warning, but on trying to run it gives following error:

I:\>rnfynetest
2019/08/25 12:37:18 Fyne error:  failed to initialise OpenGL
2019/08/25 12:37:18   Cause: glBeginConditionalRender
2019/08/25 12:37:18   At: C:/Users/ABCD/go/src/fyne.io/fyne/internal/driver/gl/window.go:1007
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x2c pc=0x572afd]

goroutine 1 [running, locked to thread]:
fyne.io/fyne/internal/driver/gl.(*window).SetContent(0x0, 0x8fc5e0, 0x1386e0c0)
        C:/Users/ABCD/go/src/fyne.io/fyne/internal/driver/gl/window.go:361 +0x1d
main.main()
        I:/rnfynetest.go:10 +0x1ce

As given on Fyne homepage I need to install OpenGL. From go bindings for OpenGL it seems there are three ways to install it:

go get -u github.com/go-gl/gl/v{3.2,3.3,4.1,4.2,4.3,4.4,4.5,4.6}-{core,compatibility}/gl
go get -u github.com/go-gl/gl/v3.1/gles2
go get -u github.com/go-gl/gl/v2.1/gl

Which of these commands do I need to use? I am working on Windows7 and using go version go1.12.9 windows/386

Thanks for your help.

Edit:

I tried following commands:

go get -u github.com/go-gl/gl/v2.1/gl
go get -u github.com/go-gl/gl/v4.6-core/gl
go get -u github.com/go-gl/gl/v4.6-compatibility/gl

They all install all right but same error is persisting on trying to run built executable.

I also tried gles2 but it does not install rather gives following error:

I:\>go get -u github.com/go-gl/gl/v3.1/gles2
# github.com/go-gl/gl/v3.1/gles2
C:\Users\ABCD\go\src\github.com\go-gl\gl\v3.1\gles2\package.go:38:11: fatal error: KHR/khrplatform.h: No such file or directory
 // #include <KHR/khrplatform.h>
           ^~~~~~~~~~~~~~~~~~~
compilation terminated.

回答1:

The OpenGL libraries typically come from your graphics card drivers, and looks like Fyne-io needs fairly new Graphics Card Drivers. (~~It uses OpenGL 3.2 which was released around 2009~~ It uses OpenGL 2.0). So you can try to:

Use a Software Implementation of OpenGL using the Mesa project, which should be "good enough" for most desktop apps use cases - more details here: https://fdossena.com/?p=mesa/index.frag

Update your Graphics Card drivers - If they are available for your hardware, to get GPU accelerated OpenGL. Definitely try this this if you are planning on making a graphics intensive application).

Edit: Updated the version of the OpenGL context Fyne uses

来源：https://stackoverflow.com/questions/57643992/how-to-install-opengl-for-this-to-run

标签

user-interface

opengl

fyne