@@ -25,7 +25,7 @@ 
 include( FindPkgConfig )
 include( CheckLibraryExists )
 include( CheckCSourceCompiles )
-pkg_check_modules( X11 REQUIRED x11 xcomposite xdamage xinerama xrender xrandr>=1.3 )
+pkg_check_modules( X11 REQUIRED x11 xcomposite xdamage xinerama xext xrender xrandr>=1.3 )
 pkg_check_modules( PANGOCAIRO REQUIRED pangocairo )
 pkg_check_modules( PANGO REQUIRED pango )
 pkg_check_modules( CAIRO REQUIRED cairo )

@@ -6,6 +6,11 @@ #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xatom.h>
+#include <X11/extensions/XShm.h>
+
 #include "config.h"
 #include "drag_and_drop.h"
 #include "fps_distribution.h"
@@ -193,6 +198,7 @@ server_init_atoms();
     server.screen = DefaultScreen(server.display);
     server.root_win = RootWindow(server.display, server.screen);
     server.desktop = get_current_desktop();
+    server.has_shm = XShmQueryExtension(server.display);
 
     // Needed since the config file uses '.' as decimal separator
     setlocale(LC_ALL, "");

@@ -147,6 +147,7 @@ Colormap colormap32;
     Global_atom atom;
     int xdamage_event_type;
     int xdamage_event_error_type;
+    gboolean has_shm;
 #ifdef HAVE_SN
     SnDisplay *sn_display;
     GTree *pids;

@@ -629,16 +629,15 @@ return;
     double now = get_time();
     if (now - task->thumbnail_last_update < 0.1)
         return;
-    cairo_surface_t *thumbnail = get_window_thumbnail(task->win, panel_config.g_task.thumbnail_width);
+    fprintf(stderr, "tint2: thumbnail for window: %s" RESET "\n", task->title ? task->title : "");
+    cairo_surface_t *thumbnail = get_window_thumbnail(task->win, panel_config.g_task.thumbnail_width, task->current_state == TASK_ACTIVE);
     if (!thumbnail)
         return;
     if (task->thumbnail)
         cairo_surface_destroy(task->thumbnail);
     task->thumbnail = thumbnail;
     task->thumbnail_last_update = get_time();
-    if (task->thumbnail_last_update - now > 0.01) {
-        fprintf(stderr, YELLOW "tint2: %s took %f ms (window: %s)" RESET "\n", __func__, 1000 * (task->thumbnail_last_update - now), task->title ? task->title : "");
-    }
+    fprintf(stderr, YELLOW "tint2: %s took %f ms (window: %s)" RESET "\n", __func__, 1000 * (task->thumbnail_last_update - now), task->title ? task->title : "");
     if (g_tooltip.mapped && (g_tooltip.area == &task->area)) {
         tooltip_update_contents_for(&task->area);
         tooltip_update();

@@ -29,6 +29,10 @@ #include <Imlib2.h>
 #include <cairo.h>
 #include <cairo-xlib.h>
 
+#include <X11/extensions/XShm.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
 #include "common.h"
 #include "window.h"
 #include "server.h"
@@ -357,8 +361,146 @@ XFree(text_property.value);
     return result;
 }
 
-cairo_surface_t *get_window_thumbnail(Window win, int size)
+void smooth_thumbnail(cairo_surface_t *image_surface)
+{
+    u_int32_t *data = (u_int32_t *)cairo_image_surface_get_data(image_surface);
+    const size_t tw = cairo_image_surface_get_width(image_surface);
+    const size_t th = cairo_image_surface_get_height(image_surface);
+    const size_t rmask = 0xff0000;
+    const size_t gmask = 0xff00;
+    const size_t bmask = 0xff;
+    for (size_t i = 0; i < tw * (th - 1) - 1; i++) {
+        u_int32_t c1 = data[i];
+        u_int32_t c2 = data[i+1];
+        u_int32_t c3 = data[i+tw];
+        u_int32_t b = (6 * (c1 & bmask) + (c2 & bmask) + (c3 & bmask)) / 8;
+        u_int32_t g = (6 * (c1 & gmask) + (c2 & gmask) + (c3 & gmask)) / 8;
+        u_int32_t r = (6 * (c1 & rmask) + (c2 & rmask) + (c3 & rmask)) / 8;
+        data[i] = (r & rmask) | (g & gmask) | (b & bmask);
+    }
+}
+
+cairo_surface_t *screenshot(Window win, size_t size)
+{
+    cairo_surface_t *result = NULL;
+    XWindowAttributes wa;
+    if (!XGetWindowAttributes(server.display, win, &wa) || wa.width <= 0 || wa.height <= 0)
+        goto err0;
+
+    size_t w, h;
+    w = (size_t)wa.width;
+    h = (size_t)wa.height;
+    size_t tw, th, fw;
+    size_t ox, oy;
+    tw = size;
+    th = h * tw / w;
+    if (th > tw * 0.618) {
+        th = (size_t)(tw * 0.618);
+        fw = w * th / h;
+        ox = (tw - fw) / 2;
+        oy = 0;
+    } else {
+        fw = tw;
+        ox = oy = 0;
+    }
+
+    XShmSegmentInfo shminfo;
+    XImage *ximg = XShmCreateImage(server.display,
+                                   wa.visual,
+                                   (unsigned)wa.depth,
+                                   ZPixmap,
+                                   NULL,
+                                   &shminfo,
+                                   (unsigned)wa.width,
+                                   (unsigned)wa.height);
+    if (!ximg) {
+        fprintf(stderr, "tint2: !ximg\n");
+        goto err0;
+    }
+    shminfo.shmid = shmget(IPC_PRIVATE, (size_t)(ximg->bytes_per_line * ximg->height), IPC_CREAT | 0777);
+    if (shminfo.shmid < 0) {
+        fprintf(stderr, "tint2: !shmget\n");
+        goto err1;
+    }
+    shminfo.shmaddr = ximg->data = (char *)shmat(shminfo.shmid, 0, 0);
+    if (!shminfo.shmaddr) {
+        fprintf(stderr, "tint2: !shmat\n");
+        goto err2;
+    }
+    shminfo.readOnly = False;
+    if (!XShmAttach(server.display, &shminfo)) {
+        fprintf(stderr, "tint2: !xshmattach\n");
+        goto err3;
+    }
+    if (!XShmGetImage(server.display, win, ximg, 0, 0, AllPlanes)) {
+        fprintf(stderr, "tint2: !xshmgetimage\n");
+        goto err4;
+    }
+
+    result = cairo_image_surface_create(CAIRO_FORMAT_RGB24, (int)tw, (int)th);
+    u_int32_t *data = (u_int32_t *)cairo_image_surface_get_data(result);
+    memset(data, 0, tw * th);
+
+    const size_t xstep = w / fw;
+    const size_t ystep = h / th;
+    const size_t offset_x1 = xstep / 4;
+    const size_t offset_y1 = ystep / 4;
+    const size_t offset_x2 = 3 * xstep / 4;
+    const size_t offset_y2 = ystep / 4;
+    const size_t offset_x3 = xstep / 4;
+    const size_t offset_y3 = 3 * ystep / 4;
+    const size_t offset_x4 = 3 * xstep / 4;
+    const size_t offset_y4 = ystep / 4;
+    const size_t offset_x5 = xstep / 2;
+    const size_t offset_y5 = ystep / 2;
+    const size_t offset_x6 = 5 * xstep / 8;
+    const size_t offset_y6 = 3 * ystep / 16;
+    const size_t offset_x7 = 3 * xstep / 16;
+    const size_t offset_y7 = 5 * ystep / 8;
+    const size_t rmask = 0xff0000;
+    const size_t gmask = 0xff00;
+    const size_t bmask = 0xff;
+    for (size_t yt = 0, y = 0; yt < th; yt++, y += ystep) {
+        for (size_t xt = 0, x = 0; xt < fw; xt++, x += xstep) {
+            size_t j = yt * tw + ox + xt;
+            u_int32_t c1 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x1), (int)(y + offset_y1));
+            u_int32_t c2 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x2), (int)(y + offset_y2));
+            u_int32_t c3 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x3), (int)(y + offset_y3));
+            u_int32_t c4 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x4), (int)(y + offset_y4));
+            u_int32_t c5 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x5), (int)(y + offset_y5));
+            u_int32_t c6 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x6), (int)(y + offset_y6));
+            u_int32_t c7 = (u_int32_t)XGetPixel(ximg, (int)(x + offset_x7), (int)(y + offset_y7));
+            u_int32_t b = ((c1 & bmask) + (c2 & bmask) + (c3 & bmask) + (c4 & bmask) + (c5 & bmask) * 2 + (c6 & bmask) +
+                           (c7 & bmask)) /
+                          8;
+            u_int32_t g = ((c1 & gmask) + (c2 & gmask) + (c3 & gmask) + (c4 & gmask) + (c5 & gmask) * 2 + (c6 & gmask) +
+                           (c7 & gmask)) /
+                          8;
+            u_int32_t r = ((c1 & rmask) + (c2 & rmask) + (c3 & rmask) + (c4 & rmask) + (c5 & rmask) * 2 + (c6 & rmask) +
+                           (c7 & rmask)) /
+                          8;
+            data[j] = (r & rmask) | (g & gmask) | (b & bmask);
+        }
+    }
+
+    // 2nd pass
+    smooth_thumbnail(result);
+
+err4:
+    XShmDetach(server.display, &shminfo);
+err3:
+    shmdt(shminfo.shmaddr);
+err2:
+    shmctl(shminfo.shmid, IPC_RMID, NULL);
+err1:
+    XDestroyImage(ximg);
+err0:
+    return result;
+}
+
+cairo_surface_t *get_window_thumbnail_cairo(Window win, int size)
 {
+    static cairo_filter_t filter = CAIRO_FILTER_BEST;
     XWindowAttributes wa;
     if (!XGetWindowAttributes(server.display, win, &wa))
         return NULL;
@@ -373,40 +515,81 @@ tw = size;
     th = h * tw / w;
     if (th > tw * 0.618) {
         th = (int)(tw * 0.618);
-        sy = th/(double)h;
+        sy = th / (double)h;
         double fw = w * th / h;
         sx = fw / w;
         ox = (tw - fw) / 2;
         oy = 0;
     } else {
-        sx = tw/(double)w;
-        sy = th/(double)h;
+        sx = tw / (double)w;
+        sy = th / (double)h;
         ox = oy = 0;
     }
 
-    cairo_surface_t *x11_surface =
-        cairo_xlib_surface_create(server.display, win, wa.visual, w, h);
-    cairo_surface_t *image_surface = cairo_surface_create_similar_image(x11_surface, CAIRO_FORMAT_ARGB32, tw, th);
+    cairo_surface_t *x11_surface = cairo_xlib_surface_create(server.display, win, wa.visual, w, h);
 
+    cairo_surface_t *full_surface = cairo_surface_create_similar_image(x11_surface, CAIRO_FORMAT_ARGB32, w, h);
+    cairo_t *cr0 = cairo_create(full_surface);
+    cairo_set_source_surface(cr0, x11_surface, 0, 0);
+    cairo_paint(cr0);
+    cairo_destroy(cr0);
+
+    cairo_surface_t *image_surface = cairo_surface_create_similar_image(full_surface, CAIRO_FORMAT_ARGB32, tw, th);
+
+    double start_time = get_time();
     cairo_t *cr = cairo_create(image_surface);
     cairo_translate(cr, ox, oy);
     cairo_scale(cr, sx, sy);
-    cairo_set_source_surface(cr, x11_surface, 0, 0);
-    cairo_pattern_set_filter(cairo_get_source(cr), CAIRO_FILTER_GAUSSIAN);
+    cairo_set_source_surface(cr, full_surface, 0, 0);
+    cairo_pattern_set_filter(cairo_get_source(cr), filter);
     cairo_paint(cr);
     cairo_destroy(cr);
     cairo_surface_destroy(x11_surface);
+    if (filter == CAIRO_FILTER_FAST)
+        smooth_thumbnail(image_surface);
+    double end_time = get_time();
 
+    if (end_time - start_time > 0.030)
+        filter = CAIRO_FILTER_FAST;
+    else if (end_time - start_time < 0.010)
+        filter = CAIRO_FILTER_BEST;
+
+    return image_surface;
+}
+
+gboolean cairo_surface_is_blank(cairo_surface_t *image_surface)
+{
     uint32_t *pixels = (uint32_t *)cairo_image_surface_get_data(image_surface);
     gboolean empty = TRUE;
-    for (int i = 0; empty && i < tw * th; i += 4) {
+    int size = cairo_image_surface_get_width(image_surface) * cairo_image_surface_get_height(image_surface);
+    for (int i = 0; empty && i < size; i++) {
         if (pixels[i] & 0xffFFff)
             empty = FALSE;
     }
-    if (empty) {
-        cairo_surface_destroy(image_surface);
-        return NULL;
+    return empty;
+}
+
+cairo_surface_t *get_window_thumbnail(Window win, int size, gboolean active)
+{
+    cairo_surface_t *image_surface = NULL;
+    if (server.has_shm && server.composite_manager) {
+        image_surface = screenshot(win, (size_t)size);
+        if (cairo_surface_is_blank(image_surface)) {
+            cairo_surface_destroy(image_surface);
+            image_surface = NULL;
+        }
+    }
+
+    if (!image_surface) {
+        image_surface = get_window_thumbnail_cairo(win, size);
+        if (cairo_surface_is_blank(image_surface)) {
+            cairo_surface_destroy(image_surface);
+            image_surface = NULL;
+        }
     }
+
+    if (!image_surface)
+        return NULL;
 
     return image_surface;
 }

@@ -34,6 +34,6 @@ int get_icon_count(gulong *data, int num);
 gulong *get_best_icon(gulong *data, int icon_count, int num, int *iw, int *ih, int best_icon_size);
 
 char *get_window_name(Window win);
-cairo_surface_t *get_window_thumbnail(Window win, int size);
+cairo_surface_t *get_window_thumbnail(Window win, int size, gboolean active);
 
 #endif