Add "from_existing_window" function to the _sdl2.Window

[yunline]

Add "from_existing_window" function to the _sdl2.Window

This PR is cloned from pygame/pygame#3685.

2023-02-06T21:59:19Z yunline wrote:

from_existing_window(hwnd: int) -> Window

With this function, pygame window could be inserted into another window (Tk/Qt/MFC/...) .
Here is an example based on Tkinter：

import tkinter
import threading

root=tkinter.Tk()
root.geometry("640x480")
btn=tkinter.Button(root,text="HelloWorld\n你好世界")
btn.pack()
cv=tkinter.Canvas(root)
cv.pack()

off=0
def pg_loop(hwnd):
    import pygame
    from pygame._sdl2 import video

    pygame.display.init()

    win=video.Window.from_existing_window(hwnd)
    
    win.focus()         # focus/restore is available
    #win.grab=1         # grab is available
    #win.opacity=0.5    # opacity is available
    #win.hide()         # hide/show is availabe
    #win.resizable=1    # available but works weirdly

    ren=video.Renderer(win)

    pos=(20,20)
    while not off:
        ren.draw_color=(0,0,0,0)
        ren.clear()
        ren.draw_color=(255,0,0,0)
        ren.fill_rect((*pos,10,10))
        ren.present()

        for event in pygame.event.get():
            if event.type==1024:#MOUSEMOTION
                pos=event.pos
            else:
                print(event)


if __name__ == "__main__":
    #hwnd=int(root.frame(),16)  # get the handle of the root window
    hwnd=cv.winfo_id()          # get the handle of the canvas widget

    p=threading.Thread(target=pg_loop,args=(hwnd,))

    p.start()
    root.mainloop()
    off=1

2023-01-27T19:18:18Z MyreMylar wrote:

Related Stale PR: pygame/pygame#2981

To reference when reviewing

2023-01-29T02:43:50Z yunline wrote:

Since the environment variable SDL_WINDOWID was no longer used in SDL2, I added a new hwnd argument to the set_mode() function to embed the pygame window to another window. I also wrote an example here

import tkinter
import threading

root=tkinter.Tk()
root.geometry("640x480")
cv=tkinter.Canvas(root,width=400,height=400)
cv.pack()

off=0
def pg_loop(hwnd):
    import pygame
    pygame.display.init()

    sf=pygame.display.set_mode(hwnd=hwnd)

    while not off:
        sf.fill((0,0,0))
        pygame.draw.rect(sf,(255,0,0),(10,10,10,10))
        pygame.display.update()

threading.Thread(target=pg_loop,args=(cv.winfo_id(),)).start()
root.mainloop()
off=1
```  > This script runs well.
However, it seems this feature is not compatible with OpenGL. When I try to embed the glcube into a tkinter window, it raises an exception like this: `pygame.error: The specified window isn't an OpenGL window`. I’m not sure if it is a bug.  

2023-01-29T17:55:31Z MyreMylar wrote:

This script runs well. However, it seems this feature is not compatible with OpenGL. When I try to embed the glcube into a tkinter window, it raises an exception like this: pygame.error: The specified window isn't an OpenGL window. I’m not sure if it is a bug.

It is not a bug. You need an OpenGL enabled window to do any openGL rendering. You can create an OpenGL tkinter window with this library I believe:

https://pypi.org/project/pyopengltk/
https://github.com/jonwright/pyopengltk

There is also the SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT to consider.

2023-01-30T08:50:24Z yunline wrote:

https://github.com/juyanith/Win32Host/blob/422833d3b77e58135ae9d493964902690774844f/samples/Sdl2Example/Sdl2Window.cs
https://gamedev.stackexchange.com/questions/110205/context-is-null-with-sdl-createwindowfrom-win32/119903#119903
These might be good references.

2023-01-30T08:46:03Z yunline wrote:

It is not a bug. You need an OpenGL enabled window to do any openGL rendering. You can create an OpenGL tkinter window with this library I believe:

https://pypi.org/project/pyopengltk/ https://github.com/jonwright/pyopengltk

There is also the SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT to consider.

Thank you! This helps a lot. I modified the code and managed to run the glcube in a Tk window.
Here is an example of Pygame glcube embeded in a Tk window.

import tkinter
from OpenGL.GL import *
from OpenGL.GLU import *
from pyopengltk import OpenGLFrame
import pygame
from pygame.locals import *

# Define the vertices. usually a cube contains 8 vertices
vertices=( (1/2, -1/2, -1/2),
    (1/2, 1/2, -1/2),
    (-1/2, 1/2, -1/2),
    (-1/2, -1/2, -1/2),
    (1/2, -1/2, 1/2),
    (1/2, 1/2, 1/2),
    (-1/2, -1/2, 1/2),
    (-1/2, 1/2, 1/2))
# Define 12 edges for the body
edges = (
    (0,1),(0,3),
    (0,4),(2,1),
    (2,3),(2,7),
    (6,3),(6,4),
    (6,7),(5,1),
    (5,4),(5,7)
    )
# Define function to draw the cube
def Cube():
    glBegin(GL_LINES)
    for edge in edges:
        for index in edge:
            glVertex3fv(vertices[index])
    glEnd()

# Get Tk window and OpenGLFrame widget.
class AppOgl(OpenGLFrame):
    def initgl(self):pass
    def redraw(self):pass
root=tkinter.Tk()
root.geometry("640x640")
opengl_frame=AppOgl(root,width=600,height=600)
opengl_frame.pack()
off=0
def on_closing():
    global off
    root.destroy()
    off=1
root.protocol("WM_DELETE_WINDOW",on_closing)

# Main
def main():
    pygame.init()
    display=(600,600)

    pygame.display.set_mode(display, DOUBLEBUF | OPENGL, hwnd=opengl_frame.winfo_id())
    gluPerspective(45, (display[0] / display[1]), 0.1, 50.0)
    glTranslatef(0.0, 0.0, -5)
    while not off:
        root.update() # update tk window
        glRotatef(1,3,1,1)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        Cube()
        pygame.display.flip()
        pygame.time.wait(10)
        
main()

2023-01-30T19:39:51Z MyreMylar wrote:

I think that the new hwnd parameter could use a little bit of documentation in the display module docs for set_mode().
This file:
https://github.com/pygame/pygame/blob/main/docs/reST/ref/display.rst

It is possible we might want to re-create the old SDL_WINDOWID variable for backwards compatability (we could potentially add it even though it doesn't exist in SDL anymore, it would just be a little confusing) - but I'm not 100% convinced by that logic. We have now gone a pretty long time with SDL2 without recreating it, and honestly, it was a kind of clunky way to do it in Pygame 1. I personally prefer your new API with a parameter for set_mode() to achieve the same thing in a cleaner way.

2023-02-02T11:15:04Z yunline wrote:

OpenGL_Window is added to video module. Now we are able to create a window with OpenGL context created.

class OpenGL_Window(Window):
    def gl_flip() ->None : ...

By calling the gl_flip(), the window will be updated.

2023-02-02T12:31:43Z yunline wrote:

I merged some code from #3695 to pass the check.

2023-02-04T01:25:29Z chimosky wrote:

Tested this in sugar and it works as expected, the test activity starts and runs like it should.

2023-02-06T21:59:19Z Mega-JC wrote:

It's great to finally have this kind of functionality in pygame again.

One small remark: OpenGL_Window is a pretty non-standard way of naming classes in Python (mixing PascalCase with snake_case), especially if exposed to the end user. OpenGLWindow is just as clear and doesn't have that issue.

[MyreMylar]

I've just noticed:

SDL_HINT_VIDEO_FOREIGN_WINDOW_OPENGL 

Was recently added since SDL 2.0.22 which may solve this issue a bit more smoothly on very recent versions of SDL.

You can use:

#if SDL_VERSION_ATLEAST(2, 0, 22)
    // new code here
#else 
    // current code here
#endif

To make this possible.

I'm guessing it would be something like:

if (flags & PGS_OPENGL) {
    // Create window with SDL_CreateWindowFrom() and OpenGL
#if SDL_VERSION_ATLEAST(2, 0, 22)
    SDL_SetHint(SDL_HINT_VIDEO_FOREIGN_WINDOW_OPENGL, "1" );
    win = SDL_CreateWindowFrom(hwnd);
    SDL_SetHint(SDL_HINT_VIDEO_FOREIGN_WINDOW_OPENGL, "0" );
#else 
    // See https://gamedev.stackexchange.com/a/119903
    dummy = SDL_CreateWindow(
        "OpenGL Dummy", 0, 0, 1, 1,
        SDL_WINDOW_OPENGL | SDL_WINDOW_HIDDEN);
    sprintf(dummy_id_str, "%p", dummy);
    SDL_SetHint(SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT,
                dummy_id_str);
    
    win = SDL_CreateWindowFrom(hwnd);
    
    SDL_SetHint(SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT,
                "");
#endif
}

[MyreMylar]

As above. It would be good to get a neater version of the fix in for the far future when we eventually are able to drop support for pre-2.0.24 versions of sdl.

[MyreMylar]

This has developed a merge conflict after recent merges.

[yunline]

OpenGLWindow should be another PR

[yunline]

Now SDL_WINDOWID is supported.
If the hwnd parameter is not passed, the SDL_WINDOWID will be checked.
Test code:

import tkinter
import threading
import os

root=tkinter.Tk()
root.geometry("640x480")
btn=tkinter.Button(root,text="HelloWorld\n你好世界")
btn.pack()
cv=tkinter.Canvas(root)
cv.pack()

off=0
def pg_loop(hwnd):
    import pygame
    from pygame._sdl2 import video

    os.environ['SDL_WINDOWID']=str(hwnd)

    pygame.display.init()

    sf=pygame.display.set_mode()

    pos=(20,20)
    while not off:
        sf.fill((0,0,0))
        pygame.draw.rect(sf,(255,0,0),(*pos,10,10))
        pygame.display.update()

        for event in pygame.event.get():
            if event.type==1024:#MOUSEMOTION
                pos=event.pos
            else:
                print(event)

if __name__ == "__main__":
    hwnd=cv.winfo_id()          # get the handle of the canvas widget

    p=threading.Thread(target=pg_loop,args=(hwnd,))

    p.start()
    root.mainloop()
    off=1
    

[yunline]

#1954