kc3-lang/SDL/src/video/x11/SDL_x11framebuffer.c

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• Hash : 76392f4f
  Author :
  Date : 2023-01-11T19:45:01
  

  Handle DPI scaling in SDL_GetWindowSurface Fixes DPI awareness of testdrawchessboard (previously, the surface was being created in points instead of pixels, resulting in the demo app only drawing in a corner of the screen on High-DPI displays) *_CreateWindowFramebuffer()/*_UpdateWindowFramebuffer(): are updated to use SDL_GetWindowSizeInPixels instead of SDL_GetWindowSize() or window->w/window->h. Most of the _CreateWindowFramebuffer backends are untested except for Windows. Fixes #7047 (cherry picked from commit 67c91353e01f6f2c0cc80c17eeddbad6def7cb01)

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• src/video/x11/SDL_x11framebuffer.c

• /*
    Simple DirectMedia Layer
    Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:
  
    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
  */
  #include "../../SDL_internal.h"
  
  #if SDL_VIDEO_DRIVER_X11
  
  #include "SDL_x11video.h"
  #include "SDL_x11framebuffer.h"
  
  #ifndef NO_SHARED_MEMORY
  
  /* Shared memory error handler routine */
  static int shm_error;
  static int (*X_handler)(Display *, XErrorEvent *) = NULL;
  static int shm_errhandler(Display *d, XErrorEvent *e)
  {
      if (e->error_code == BadAccess) {
          shm_error = True;
          return 0;
      }
      return X_handler(d, e);
  }
  
  static SDL_bool have_mitshm(Display *dpy)
  {
      /* Only use shared memory on local X servers */
      return X11_XShmQueryExtension(dpy) ? SDL_X11_HAVE_SHM : SDL_FALSE;
  }
  
  #endif /* !NO_SHARED_MEMORY */
  
  int X11_CreateWindowFramebuffer(_THIS, SDL_Window *window, Uint32 *format,
                                  void **pixels, int *pitch)
  {
      SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
      Display *display = data->videodata->display;
      XGCValues gcv;
      XVisualInfo vinfo;
      int w, h;
  
      SDL_GetWindowSizeInPixels(window, &w, &h);
  
      /* Free the old framebuffer surface */
      X11_DestroyWindowFramebuffer(_this, window);
  
      /* Create the graphics context for drawing */
      gcv.graphics_exposures = False;
      data->gc = X11_XCreateGC(display, data->xwindow, GCGraphicsExposures, &gcv);
      if (!data->gc) {
          return SDL_SetError("Couldn't create graphics context");
      }
  
      /* Find out the pixel format and depth */
      if (X11_GetVisualInfoFromVisual(display, data->visual, &vinfo) < 0) {
          return SDL_SetError("Couldn't get window visual information");
      }
  
      *format = X11_GetPixelFormatFromVisualInfo(display, &vinfo);
      if (*format == SDL_PIXELFORMAT_UNKNOWN) {
          return SDL_SetError("Unknown window pixel format");
      }
  
      /* Calculate pitch */
      *pitch = (((w * SDL_BYTESPERPIXEL(*format)) + 3) & ~3);
  
      /* Create the actual image */
  #ifndef NO_SHARED_MEMORY
      if (have_mitshm(display)) {
          XShmSegmentInfo *shminfo = &data->shminfo;
  
          shminfo->shmid = shmget(IPC_PRIVATE, (size_t)h * (*pitch), IPC_CREAT | 0777);
          if (shminfo->shmid >= 0) {
              shminfo->shmaddr = (char *)shmat(shminfo->shmid, 0, 0);
              shminfo->readOnly = False;
              if (shminfo->shmaddr != (char *)-1) {
                  shm_error = False;
                  X_handler = X11_XSetErrorHandler(shm_errhandler);
                  X11_XShmAttach(display, shminfo);
                  X11_XSync(display, False);
                  X11_XSetErrorHandler(X_handler);
                  if (shm_error) {
                      shmdt(shminfo->shmaddr);
                  }
              } else {
                  shm_error = True;
              }
              shmctl(shminfo->shmid, IPC_RMID, NULL);
          } else {
              shm_error = True;
          }
          if (!shm_error) {
              data->ximage = X11_XShmCreateImage(display, data->visual,
                                                 vinfo.depth, ZPixmap,
                                                 shminfo->shmaddr, shminfo,
                                                 w, h);
              if (!data->ximage) {
                  X11_XShmDetach(display, shminfo);
                  X11_XSync(display, False);
                  shmdt(shminfo->shmaddr);
              } else {
                  /* Done! */
                  data->ximage->byte_order = (SDL_BYTEORDER == SDL_BIG_ENDIAN) ? MSBFirst : LSBFirst;
                  data->use_mitshm = SDL_TRUE;
                  *pixels = shminfo->shmaddr;
                  return 0;
              }
          }
      }
  #endif /* not NO_SHARED_MEMORY */
  
      *pixels = SDL_malloc((size_t)h * (*pitch));
      if (*pixels == NULL) {
          return SDL_OutOfMemory();
      }
  
      data->ximage = X11_XCreateImage(display, data->visual,
                                      vinfo.depth, ZPixmap, 0, (char *)(*pixels),
                                      w, h, 32, 0);
      if (!data->ximage) {
          SDL_free(*pixels);
          return SDL_SetError("Couldn't create XImage");
      }
      data->ximage->byte_order = (SDL_BYTEORDER == SDL_BIG_ENDIAN) ? MSBFirst : LSBFirst;
      return 0;
  }
  
  int X11_UpdateWindowFramebuffer(_THIS, SDL_Window *window, const SDL_Rect *rects,
                                  int numrects)
  {
      SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
      Display *display = data->videodata->display;
      int i;
      int x, y, w, h;
      int window_w, window_h;
  
      SDL_GetWindowSizeInPixels(window, &window_w, &window_h);
  
  #ifndef NO_SHARED_MEMORY
      if (data->use_mitshm) {
          for (i = 0; i < numrects; ++i) {
              x = rects[i].x;
              y = rects[i].y;
              w = rects[i].w;
              h = rects[i].h;
  
              if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
                  /* Clipped? */
                  continue;
              }
              if (x < 0) {
                  x += w;
                  w += rects[i].x;
              }
              if (y < 0) {
                  y += h;
                  h += rects[i].y;
              }
              if (x + w > window_w) {
                  w = window_w - x;
              }
              if (y + h > window_h) {
                  h = window_h - y;
              }
  
              X11_XShmPutImage(display, data->xwindow, data->gc, data->ximage,
                               x, y, x, y, w, h, False);
          }
      } else
  #endif /* !NO_SHARED_MEMORY */
      {
          for (i = 0; i < numrects; ++i) {
              x = rects[i].x;
              y = rects[i].y;
              w = rects[i].w;
              h = rects[i].h;
  
              if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
                  /* Clipped? */
                  continue;
              }
              if (x < 0) {
                  x += w;
                  w += rects[i].x;
              }
              if (y < 0) {
                  y += h;
                  h += rects[i].y;
              }
              if (x + w > window_w) {
                  w = window_w - x;
              }
              if (y + h > window_h) {
                  h = window_h - y;
              }
  
              X11_XPutImage(display, data->xwindow, data->gc, data->ximage,
                            x, y, x, y, w, h);
          }
      }
  
      X11_XSync(display, False);
  
      return 0;
  }
  
  void X11_DestroyWindowFramebuffer(_THIS, SDL_Window *window)
  {
      SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
      Display *display;
  
      if (data == NULL) {
          /* The window wasn't fully initialized */
          return;
      }
  
      display = data->videodata->display;
  
      if (data->ximage) {
          XDestroyImage(data->ximage);
  
  #ifndef NO_SHARED_MEMORY
          if (data->use_mitshm) {
              X11_XShmDetach(display, &data->shminfo);
              X11_XSync(display, False);
              shmdt(data->shminfo.shmaddr);
              data->use_mitshm = SDL_FALSE;
          }
  #endif /* !NO_SHARED_MEMORY */
  
          data->ximage = NULL;
      }
      if (data->gc) {
          X11_XFreeGC(display, data->gc);
          data->gc = NULL;
      }
  }
  
  #endif /* SDL_VIDEO_DRIVER_X11 */
  
  /* vi: set ts=4 sw=4 expandtab: */
  

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