renderdoc/util/test/demos/linux/linux_window.cpp

/******************************************************************************
 * The MIT License (MIT)
 *
 * Copyright (c) 2019-2025 Baldur Karlsson
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * THE SOFTWARE.
 ******************************************************************************/

#include "linux_window.h"

static Display *display = NULL;
static xcb_connection_t *connection = NULL;
static xcb_screen_t *screen = NULL;
static xcb_intern_atom_reply_t *atom_wm_delete_window = NULL;

void X11Window::Init()
{
  display = XOpenDisplay(NULL);
  connection = XGetXCBConnection(display);

  XSetEventQueueOwner(display, XCBOwnsEventQueue);

  int scr = DefaultScreen(display);

  const xcb_setup_t *setup = xcb_get_setup(connection);
  xcb_screen_iterator_t iter = xcb_setup_roots_iterator(setup);
  while(scr-- > 0)
    xcb_screen_next(&iter);

  screen = iter.data;

  xcb_intern_atom_cookie_t cookie2 = xcb_intern_atom(connection, 0, 16, "WM_DELETE_WINDOW");
  atom_wm_delete_window = xcb_intern_atom_reply(connection, cookie2, 0);
}

Display *X11Window::GetDisplay()
{
  return display;
}

X11Window::X11Window(int width, int height, int visualid_override, const char *title)
    : GraphicsWindow(title)
{
  uint32_t value_mask, value_list[32];

  xcb_window_t window = xcb_generate_id(connection);

  value_mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
  value_list[0] = screen->black_pixel;
  value_list[1] =
      XCB_EVENT_MASK_KEY_RELEASE | XCB_EVENT_MASK_EXPOSURE | XCB_EVENT_MASK_STRUCTURE_NOTIFY;

  xcb_visualid_t visual = screen->root_visual;

  if(visualid_override)
  {
    visual = (xcb_visualid_t)visualid_override;

    value_mask |= XCB_CW_COLORMAP;
    value_list[2] = xcb_generate_id(connection);
    xcb_create_colormap(connection, XCB_COLORMAP_ALLOC_NONE, value_list[2], screen->root, visual);
  }

  xcb_create_window(connection, XCB_COPY_FROM_PARENT, window, screen->root, 0, 0, width, height, 0,
                    XCB_WINDOW_CLASS_INPUT_OUTPUT, visual, value_mask, value_list);

  /* Magic code that will send notification when window is destroyed */
  xcb_intern_atom_cookie_t cookie = xcb_intern_atom(connection, 1, 12, "WM_PROTOCOLS");
  xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(connection, cookie, 0);

  if(title)
  {
    xcb_change_property(connection, XCB_PROP_MODE_REPLACE, window, XCB_ATOM_WM_NAME,
                        XCB_ATOM_STRING, 8, strlen(title), title);
  }

  xcb_change_property(connection, XCB_PROP_MODE_REPLACE, window, (*reply).atom, 4, 32, 1,
                      &(*atom_wm_delete_window).atom);
  free(reply);

  if(title)
  {
    xcb_map_window(connection, window);
  }

  xlib.display = display;
  xlib.window = (Drawable)window;
  xcb.connection = connection;
  xcb.window = window;

  xcb_flush(connection);
}

X11Window::~X11Window()
{
}

void X11Window::Resize(int width, int height)
{
  const static uint32_t values[] = {(uint32_t)width, (uint32_t)height};

  xcb_configure_window(xcb.connection, xcb.window,
                       XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT, values);
}

bool X11Window::Update()
{
  xcb_generic_event_t *event;

  event = xcb_poll_for_event(xcb.connection);
  if(event)
  {
    switch(event->response_type & 0x7f)
    {
      case XCB_EXPOSE: break;
      case XCB_CLIENT_MESSAGE:
        if((*(xcb_client_message_event_t *)event).data.data32[0] == (*atom_wm_delete_window).atom)
        {
          return false;
        }
        break;
      case XCB_KEY_RELEASE:
      {
        const xcb_key_release_event_t *key = (const xcb_key_release_event_t *)event;

        if(key->detail == 0x9)
          return false;
      }
      break;
      case XCB_DESTROY_NOTIFY: return false;
      default: break;
    }
    free(event);
  }

  return true;
}