Creating a layered Window

[qb-0]

Im trying to create a layered (fully transparent Window) on Windows and I'm facing two issues:

1. Is there some way to get the Pixel Window hwnd?
2. If I use the hwnd manually it won't get layered aswell. Are my parameters correct?

Is there maybe something already build in to draw on a transparent Window?

package main

import (
    "github.com/Sann0/w32"
    "github.com/faiface/pixel"
    "github.com/faiface/pixel/pixelgl"
    "golang.org/x/image/colornames"
    "syscall"
)

var (
    moduser32                      = syscall.NewLazyDLL("user32.dll")
    procSetLayeredWindowAttributes = moduser32.NewProc("SetLayeredWindowAttributes")
)

func SetLayeredAttributes(hwnd w32.HWND, cr w32.COLORREF, alpha byte, flags uint32) bool {
    r0, _, _ := syscall.Syscall6(procSetLayeredWindowAttributes.Addr(), 4, uintptr(hwnd), uintptr(cr), uintptr(alpha), uintptr(flags), 0, 0)
    return r0 != 0
}

func initWindow() {
    cfg := pixelgl.WindowConfig{
        Title:  "Pixel",
        Bounds: pixel.R(0, 0, 1024, 768),
        VSync:  true,
        // Undecorated: true,
        // AlwaysOnTop: true,
    }
    win, err := pixelgl.NewWindow(cfg)
    if err != nil {
        panic(err)
    }
    // win.SetCursorDisabled()
    /*
    result := w32.SetWindowLong(w32.HWND(handle), w32.GWL_EXSTYLE, uint32(w32.GetWindowLong(w32.HWND(handle), w32.GWL_EXSTYLE)) | 0x00080000)
    fmt.Println(result)
    // (135, 206, 345) colornames.Skyblue
    result2 := SetLayeredAttributes(w32.HWND(handle), w32.COLORREF(uint32(135) | uint32(206) | uint32(235)), 0, 0x00000001)
    fmt.Println(result2)
    */
    mainLoop(win)
}

func mainLoop(win *pixelgl.Window) {
    for !win.Closed() {
        win.Clear(colornames.Skyblue)
        win.Update()
    }
}

func main() {
    pixelgl.Run(initWindow)
}

[qb-0]

I got it finally running with calling EnumWindows from the win32 api. Anyway I would prefer a native pixel way.

[delp]

I'm not sure what would be involved in doing this but I'll tag it as a feature request :)

[fgrosse]

I think #234 implements the requested feature. At least it allows you to make the window fully (or partially) transparent which I think it what you want?

[delp]

@Sann0 could you take a look at https://github.com/faiface/pixel/pull/234 and see if it resolves your issue?

[qb-0]

234 is great and works how it should be but a win32 layered window lets you interact through the window itself. Example

Not sure if thats something which glfw supports aswell.

[delp]

You could make a pretty good Bonzi Buddy with that

[delp]

@Sann0 so check this out.

Try making a window with these settings. You should see the effect you're looking for. This could be animated obviously. I'm going to close this issue because the feature is implemented now. You can follow up if you like.

    cfg := pixelgl.WindowConfig{
        Title:                  "Pixel Rocks!",
        Bounds:                 pixel.R(0, 0, 1024, 768),
        VSync:                  true,
        TransparentFramebuffer: true,
        Undecorated:            true,
    }

[delp]

Oh wait...I see what you mean. You can click on things through the window. I'm not sure if that's possible right now. That requires more investigation.