Reduce color allocation/query traffic in the TrueColor case.

When working with an X visual with TrueColor class, pixel values can
be generated from the RGB values according to mask value provided by
the server on connection.  Some of the image-handling code was already
doing this.

* src/xterm.h (x_make_truecolor_pixel): New function; code taken from
lookup_rgb_color.
(x_mutable_colormap): New function.
* src/image.c (lookup_rgb_color): Move pixel composition code to
x_make_truecolor_pixel.
(x_kill_gs_process): Call x_mutable_colormap.
* src/xfaces.c (x_free_colors, x_free_dpy_colors): Call
x_mutable_colormap.
* src/xftfont.c (xftfont_get_colors): Call x_query_colors.
* src/xterm.c (x_query_colors): For a TrueColor display, decompose the
pixel value into RGB values directly, and don't send a request to the
server.
(x_alloc_nearest_color): For a TrueColor display, construct the pixel
value with x_make_truecolor_pixel.
(x_copy_color): For an immutable color map, just return the provided
pixel value.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/xfaces.c b/src/xfaces.c
index 8cf0b427799..a3d122fbf46 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -454,11 +454,9 @@ DEFUN ("dump-colors", Fdump_colors, Sdump_colors, 0, 0, 0,
 void
 x_free_colors (struct frame *f, unsigned long *pixels, int npixels)
 {
-  int class = FRAME_DISPLAY_INFO (f)->visual->class;
-
   /* If display has an immutable color map, freeing colors is not
      necessary and some servers don't allow it.  So don't do it.  */
-  if (class != StaticColor && class != StaticGray && class != TrueColor)
+  if (x_mutable_colormap (FRAME_X_VISUAL (f)))
     {
 #ifdef DEBUG_X_COLORS
       unregister_colors (pixels, npixels);
@@ -471,7 +469,7 @@ x_free_colors (struct frame *f, unsigned long *pixels, int npixels)
 
 #ifdef USE_X_TOOLKIT
 
-/* Free colors used on frame F.  PIXELS is an array of NPIXELS pixel
+/* Free colors used on display DPY.  PIXELS is an array of NPIXELS pixel
    color values.  Interrupt input must be blocked when this function
    is called.  */
 
@@ -480,11 +478,10 @@ x_free_dpy_colors (Display *dpy, Screen *screen, Colormap cmap,
 		   unsigned long *pixels, int npixels)
 {
   struct x_display_info *dpyinfo = x_display_info_for_display (dpy);
-  int class = dpyinfo->visual->class;
 
   /* If display has an immutable color map, freeing colors is not
      necessary and some servers don't allow it.  So don't do it.  */
-  if (class != StaticColor && class != StaticGray && class != TrueColor)
+  if (x_mutable_colormap (dpyinfo->visual))
     {
 #ifdef DEBUG_X_COLORS
       unregister_colors (pixels, npixels);