From e05f047185c2e3e396fcb2ca3d426d3f4df9af71 Mon Sep 17 00:00:00 2001
From: Juha Aatrokoski <jha@iki.fi>
Date: Thu, 4 Jul 2019 10:50:33 +0300
Subject: [PATCH] Add pixelated option to desktop zoom

Add the option (disabled by default) to have the desktop zoom feature
always use the "nearest" filter, with 2x zoom increments (as otherwise
the nearest filter would horrible). While it can be used as an
accessibility feature like the standard desktop zoom, it is not really
meant as such, but rather as a "pixel inspector": to see what pixels
are actually rendered on the screen.

Signed-off-by: Juha Aatrokoski <jha@iki.fi>
---
 defaults/defaults |  1 +
 src/compositor.c  | 27 ++++++++++++++++++++++-----
 src/settings.c    |  7 +++++++
 src/settings.h    |  1 +
 4 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/defaults/defaults b/defaults/defaults
index 38d34704..7deda18a 100644
--- a/defaults/defaults
+++ b/defaults/defaults
@@ -77,3 +77,4 @@ wrap_resistance=10
 wrap_windows=true
 wrap_workspaces=false
 zoom_desktop=true
+zoom_desktop_pixelated=false
diff --git a/src/compositor.c b/src/compositor.c
index 165601f3..fa75ce7f 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -3283,7 +3283,8 @@ recenter_zoomed_area (ScreenInfo *screen_info, int x_root, int y_root)
         screen_info->transform.matrix[1][2] = (yp << 16);
     }
 
-    if (zf > (1 << 14) && zf < (1 << 16))
+    if (!screen_info->params->zoom_desktop_pixelated
+        && zf > (1 << 14) && zf < (1 << 16))
     {
 #ifdef HAVE_EPOXY
         if (screen_info->use_glx)
@@ -4172,8 +4173,16 @@ void
 compositorZoomIn (ScreenInfo *screen_info, XfwmEventButton *event)
 {
 #ifdef HAVE_COMPOSITOR
-    screen_info->transform.matrix[0][0] -= 4096;
-    screen_info->transform.matrix[1][1] -= 4096;
+    if (screen_info->params->zoom_desktop_pixelated)
+    {
+        screen_info->transform.matrix[0][0] >>= 1;
+        screen_info->transform.matrix[1][1] >>= 1;
+    }
+    else
+    {
+        screen_info->transform.matrix[0][0] -= 4096;
+        screen_info->transform.matrix[1][1] -= 4096;
+    }
 
     if (screen_info->transform.matrix[0][0] < (1 << 10))
     {
@@ -4208,8 +4217,16 @@ compositorZoomOut (ScreenInfo *screen_info, XfwmEventButton *event)
     /* don't do anything if the user disabled the zoom feature */
     if (screen_info->zoomed)
     {
-        screen_info->transform.matrix[0][0] += 4096;
-        screen_info->transform.matrix[1][1] += 4096;
+        if (screen_info->params->zoom_desktop_pixelated)
+        {
+            screen_info->transform.matrix[0][0] <<= 1;
+            screen_info->transform.matrix[1][1] <<= 1;
+        }
+        else
+        {
+            screen_info->transform.matrix[0][0] += 4096;
+            screen_info->transform.matrix[1][1] += 4096;
+        }
 
         if (screen_info->transform.matrix[0][0] >= (1 << 16))
         {
diff --git a/src/settings.c b/src/settings.c
index ccb14319..2c23c2ca 100644
--- a/src/settings.c
+++ b/src/settings.c
@@ -746,6 +746,7 @@ loadSettings (ScreenInfo *screen_info)
         {"wrap_windows", NULL, G_TYPE_BOOLEAN, TRUE},
         {"wrap_workspaces", NULL, G_TYPE_BOOLEAN, TRUE},
         {"zoom_desktop", NULL, G_TYPE_BOOLEAN, TRUE},
+        {"zoom_desktop_pixelated", NULL, G_TYPE_BOOLEAN, TRUE},
         {NULL, NULL, G_TYPE_INVALID, FALSE}
     };
 
@@ -850,6 +851,8 @@ loadSettings (ScreenInfo *screen_info)
         getBoolValue ("wrap_workspaces", rc);
     screen_info->params->zoom_desktop =
         getBoolValue ("zoom_desktop", rc);
+    screen_info->params->zoom_desktop_pixelated =
+        getBoolValue ("zoom_desktop_pixelated", rc);
 
     screen_info->params->wrap_layout =
         getBoolValue ("wrap_layout", rc);
@@ -1301,6 +1304,10 @@ cb_xfwm4_channel_property_changed(XfconfChannel *channel, const gchar *property_
                 {
                     screen_info->params->zoom_desktop = g_value_get_boolean (value);
                 }
+                else if (!strcmp (name, "zoom_desktop_pixelated"))
+                {
+                    screen_info->params->zoom_desktop_pixelated = g_value_get_boolean (value);
+                }
                 else if (!strcmp (name, "wrap_windows"))
                 {
                     screen_info->params->wrap_windows = g_value_get_boolean (value);
diff --git a/src/settings.h b/src/settings.h
index f20c6db4..e359ddd7 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -245,6 +245,7 @@ struct _XfwmParams
     gboolean wrap_windows;
     gboolean wrap_workspaces;
     gboolean zoom_desktop;
+    gboolean zoom_desktop_pixelated;
 };
 
 gboolean                 loadSettings                           (ScreenInfo *);
-- 
2.21.0