Some new x helper functions

They should be useful for the refactored backends.

Renamed x_create_picture to x_create_picture_with_pictfmt.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/render.c

@@ -211,7 +211,7 @@ void paint_one(session_t *ps, win *w, const region_t *reg_paint) {
 	// Invert window color, if required
 	if (bkend_use_xrender(ps) && w->invert_color) {
 		xcb_render_picture_t newpict =
-		    x_create_picture(ps, wid, hei, w->pictfmt, 0, NULL);
+		    x_create_picture_with_pictfmt(ps, wid, hei, w->pictfmt, 0, NULL);
 		if (newpict) {
 			// Apply clipping region to save some CPU
 			if (reg_paint) {
@@ -684,7 +684,8 @@ xr_blur_dst(session_t *ps, xcb_render_picture_t tgt_buffer, int x, int y, int wi
 
 	// Directly copying from tgt_buffer to it does not work, so we create a
 	// Picture in the middle.
-	xcb_render_picture_t tmp_picture = x_create_picture(ps, wid, hei, NULL, 0, NULL);
+	xcb_render_picture_t tmp_picture =
+	    x_create_picture_with_pictfmt(ps, wid, hei, NULL, 0, NULL);
 
 	if (!tmp_picture) {
 		log_error("Failed to build intermediate Picture.");
@@ -991,7 +992,7 @@ void paint_all(session_t *ps, region_t *region, const region_t *region_real, win
 			// Then we create a new picture, and copy content to it
 			xcb_render_pictforminfo_t *pictfmt =
 			    x_get_pictform_for_visual(ps, ps->vis);
-			xcb_render_picture_t new_pict = x_create_picture(
+			xcb_render_picture_t new_pict = x_create_picture_with_pictfmt(
 			    ps, ps->root_width, ps->root_height, pictfmt, 0, NULL);
 			xcb_render_composite(ps->c, XCB_RENDER_PICT_OP_SRC,
 			                     ps->tgt_buffer.pict, None, new_pict, 0, 0, 0,

src/x.c

@@ -188,7 +188,7 @@ x_create_picture_with_standard_and_pixmap(
  * Create an picture.
  */
 xcb_render_picture_t
-x_create_picture(session_t *ps, int wid, int hei,
+x_create_picture_with_pictfmt(session_t *ps, int wid, int hei,
   xcb_render_pictforminfo_t *pictfmt, unsigned long valuemask,
   const xcb_render_create_picture_value_list_t *attr)
 {
@@ -214,6 +214,15 @@ x_create_picture(session_t *ps, int wid, int hei,
   return picture;
 }
 
+xcb_render_picture_t
+x_create_picture_with_visual(session_t *ps, int w, int h,
+  xcb_visualid_t visual, unsigned long valuemask,
+  const xcb_render_create_picture_value_list_t *attr)
+{
+  xcb_render_pictforminfo_t *pictfmt = x_get_pictform_for_visual(ps, visual);
+  return x_create_picture_with_pictfmt(ps, w, h, pictfmt, valuemask, attr);
+}
+
 bool x_fetch_region(session_t *ps, xcb_xfixes_region_t r, pixman_region32_t *res) {
   xcb_generic_error_t *e = NULL;
   xcb_xfixes_fetch_region_reply_t *xr = xcb_xfixes_fetch_region_reply(ps->c,
@@ -263,6 +272,19 @@ void x_set_picture_clip_region(session_t *ps, xcb_render_picture_t pict,
   return;
 }
 
+void x_clear_picture_clip_region(session_t *ps, xcb_render_picture_t pict) {
+  xcb_render_change_picture_value_list_t v = {
+    .clipmask = None
+  };
+  xcb_generic_error_t *e =
+    xcb_request_check(ps->c, xcb_render_change_picture(ps->c, pict,
+      XCB_RENDER_CP_CLIP_MASK, &v));
+  if (e)
+    log_error("failed to clear clip region");
+  free(e);
+  return;
+}
+
 /**
  * X11 error handler function.
  *
@@ -390,3 +412,38 @@ x_validate_pixmap(session_t *ps, xcb_pixmap_t pxmap) {
   return XGetGeometry(ps->dpy, pxmap, &rroot, &rx, &ry,
         &rwid, &rhei, &rborder, &rdepth) && rwid && rhei;
 }
+/// Names of root window properties that could point to a pixmap of
+/// background.
+static const char *background_props_str[] = {
+  "_XROOTPMAP_ID",
+  "_XSETROOT_ID",
+  0,
+};
+
+xcb_pixmap_t x_get_root_back_pixmap(session_t *ps) {
+  xcb_pixmap_t pixmap = XCB_NONE;
+
+  // Get the values of background attributes
+  for (int p = 0; background_props_str[p]; p++) {
+    xcb_atom_t prop_atom = get_atom(ps, background_props_str[p]);
+    winprop_t prop =
+      wid_get_prop(ps, ps->root, prop_atom, 1, XCB_ATOM_PIXMAP, 32);
+    if (prop.nitems) {
+      pixmap = *prop.p32;
+      free_winprop(&prop);
+      break;
+    }
+    free_winprop(&prop);
+  }
+
+  return pixmap;
+}
+
+bool x_atom_is_background_prop(session_t *ps, xcb_atom_t atom) {
+  for (int p = 0; background_props_str[p]; p++) {
+    xcb_atom_t prop_atom = get_atom(ps, background_props_str[p]);
+    if (prop_atom == atom)
+      return true;
+  }
+  return false;
+}

src/x.h

@@ -116,16 +116,23 @@ attr_nonnull(1);
  * Create an picture.
  */
 xcb_render_picture_t
-x_create_picture(session_t *ps, int wid, int hei,
+x_create_picture_with_pictfmt(session_t *ps, int wid, int hei,
   xcb_render_pictforminfo_t *pictfmt, unsigned long valuemask,
   const xcb_render_create_picture_value_list_t *attr);
 
+xcb_render_picture_t
+x_create_picture_with_visual(session_t *ps, int w, int h,
+  xcb_visualid_t visual, unsigned long valuemask,
+  const xcb_render_create_picture_value_list_t *attr);
+
 /// Fetch a X region and store it in a pixman region
 bool x_fetch_region(session_t *ps, xcb_xfixes_region_t r, region_t *res);
 
 void x_set_picture_clip_region(session_t *ps, xcb_render_picture_t,
   int clip_x_origin, int clip_y_origin, const region_t *);
 
+void x_clear_picture_clip_region(session_t *ps, xcb_render_picture_t pict);
+
 /**
  * X11 error handler function.
  *
@@ -154,3 +161,9 @@ free_winprop(winprop_t *pprop) {
   pprop->r = NULL;
   pprop->nitems = 0;
 }
+/// Get the back pixmap of the root window
+xcb_pixmap_t x_get_root_back_pixmap(session_t *ps);
+
+/// Return true if the atom refers to a property name that is used for the
+/// root window background pixmap
+bool x_atom_is_background_prop(session_t *ps, xcb_atom_t atom);