xwlScaling.diff

diff --git a/hw/xwayland/xwayland-output.c b/hw/xwayland/xwayland-output.c
index 7c8ebd49a..0bd8e8957 100644
--- a/hw/xwayland/xwayland-output.c
+++ b/hw/xwayland/xwayland-output.c
@@ -194,6 +194,13 @@ update_screen_size(struct xwl_screen *xwl_screen, int width, int height)
     if (xwl_screen_get_height(xwl_screen) != height)
         xwl_screen->height = height;
 
+    /* In rootless mode, if global_surface_scale is set, we must scale accordingly here */
+    /* This is because xscale is never set if we are not running rootful */
+    if (xwl_screen->rootless && xwl_screen->global_surface_scale > 1) {
+        width *= xwl_screen->global_surface_scale;
+        height *= xwl_screen->global_surface_scale;
+    }
+
     if (xwl_screen->root_clip_mode == ROOT_CLIP_FULL)
         SetRootClip(xwl_screen->screen, ROOT_CLIP_NONE);
 
@@ -617,14 +624,15 @@ maybe_update_fullscreen_state(struct xwl_output *xwl_output)
     }
 }
 
-static void
-apply_output_change(struct xwl_output *xwl_output)
+void
+xwl_output_apply_changes(struct xwl_output *xwl_output)
 {
     struct xwl_screen *xwl_screen = xwl_output->xwl_screen;
     struct xwl_output *it;
     int mode_width, mode_height, count;
     int width = 0, height = 0, has_this_output = 0;
     RRModePtr *randr_modes;
+    int32_t scale = xwl_screen->global_surface_scale;
 
     /* Clear out the "done" received flags */
     xwl_output->wl_output_done = FALSE;
@@ -643,10 +651,10 @@ apply_output_change(struct xwl_output *xwl_output)
     }
     if (xwl_output->randr_output) {
         /* Build a fresh modes array using the current refresh rate */
-        randr_modes = output_get_rr_modes(xwl_output, mode_width, mode_height, &count);
+        randr_modes = output_get_rr_modes(xwl_output, mode_width * scale, mode_height * scale, &count);
         RROutputSetModes(xwl_output->randr_output, randr_modes, count, 1);
         RRCrtcNotify(xwl_output->randr_crtc, randr_modes[0],
-                     xwl_output->x, xwl_output->y,
+                     xwl_output->x * scale, xwl_output->y * scale,
                      xwl_output->rotation, NULL, 1, &xwl_output->randr_output);
         /* RROutputSetModes takes ownership of the passed in modes, so we only
          * have to free the pointer array.
@@ -740,7 +748,7 @@ output_handle_done(void *data, struct wl_output *wl_output)
      */
     if (xwl_output->xdg_output_done || !xwl_output->xdg_output ||
         zxdg_output_v1_get_version(xwl_output->xdg_output) >= 3)
-        apply_output_change(xwl_output);
+        xwl_output_apply_changes(xwl_output);
 }
 
 static void
@@ -808,7 +816,7 @@ xdg_output_handle_done(void *data, struct zxdg_output_v1 *xdg_output)
 
     if (xwl_output->wl_output_done &&
         zxdg_output_v1_get_version(xdg_output) < 3)
-        apply_output_change(xwl_output);
+        xwl_output_apply_changes(xwl_output);
 }
 
 static void
@@ -944,6 +952,8 @@ xwl_output_create(struct xwl_screen *xwl_screen, uint32_t id,
     RROutputSetConnection(xwl_output->randr_output,
                           connected ? RR_Connected : RR_Disconnected);
 
+    xwl_output->scale = 1;
+
     /* We want the output to be in the list as soon as created so we can
      * use it when binding to the xdg-output protocol...
      */
diff --git a/hw/xwayland/xwayland-output.h b/hw/xwayland/xwayland-output.h
index 0d36f459a..123d01380 100644
--- a/hw/xwayland/xwayland-output.h
+++ b/hw/xwayland/xwayland-output.h
@@ -121,4 +121,6 @@ void xwl_output_set_window_randr_emu_props(struct xwl_screen *xwl_screen,
 
 void xwl_screen_init_xdg_output(struct xwl_screen *xwl_screen);
 
+void xwl_output_apply_changes(struct xwl_output *xwl_output);
+
 #endif /* XWAYLAND_OUTPUT_H */
diff --git a/hw/xwayland/xwayland-present.c b/hw/xwayland/xwayland-present.c
index 4d2410568..2ebe166cf 100644
--- a/hw/xwayland/xwayland-present.c
+++ b/hw/xwayland/xwayland-present.c
@@ -911,6 +911,7 @@ xwl_present_flip(present_vblank_ptr vblank, RegionPtr damage)
 
     /* We can flip directly to the main surface (full screen window without clips) */
     wl_surface_attach(xwl_window->surface, buffer, 0, 0);
+    wl_surface_set_buffer_scale(xwl_window->surface, xwl_window->xwl_screen->global_surface_scale);
 
     if (xorg_list_is_empty(&xwl_present_window->frame_callback_list)) {
         xorg_list_add(&xwl_present_window->frame_callback_list,
diff --git a/hw/xwayland/xwayland-screen.c b/hw/xwayland/xwayland-screen.c
index 287fe8b06..c9f0c9da6 100644
--- a/hw/xwayland/xwayland-screen.c
+++ b/hw/xwayland/xwayland-screen.c
@@ -124,6 +124,12 @@ xwl_screen_has_resolution_change_emulation(struct xwl_screen *xwl_screen)
     return xwl_screen->rootless && xwl_screen_has_viewport_support(xwl_screen);
 }
 
+int
+xwl_scale_to(struct xwl_screen *xwl_screen, int value)
+{
+    return value / (double)xwl_screen->global_surface_scale + 0.5;
+}
+
 /* Return the output @ 0x0, falling back to the first output in the list */
 struct xwl_output *
 xwl_screen_get_first_output(struct xwl_screen *xwl_screen)
@@ -721,8 +727,14 @@ void xwl_surface_damage(struct xwl_screen *xwl_screen,
 {
     if (wl_surface_get_version(surface) >= WL_SURFACE_DAMAGE_BUFFER_SINCE_VERSION)
         wl_surface_damage_buffer(surface, x, y, width, height);
-    else
+    else {
+        x = xwl_scale_to(xwl_screen, x);
+        y = xwl_scale_to(xwl_screen, y);
+        width = xwl_scale_to(xwl_screen, width);
+        height = xwl_scale_to(xwl_screen, height);
+
         wl_surface_damage(surface, x, y, width, height);
+    }
 }
 
 void
@@ -854,6 +866,18 @@ xwl_screen_update_global_surface_scale(struct xwl_screen *xwl_screen)
     return (xwl_screen->global_surface_scale != old_scale);
 }
 
+void
+xwl_screen_set_global_scale( struct xwl_screen *xwl_screen, int32_t scale)
+{
+    struct xwl_output *it;
+    xwl_screen->global_surface_scale = scale;
+
+    /* change randr resolutions and positions */
+    xorg_list_for_each_entry(it, &xwl_screen->output_list, link) {
+        xwl_output_apply_changes(it);
+    }
+}
+
 Bool
 xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
 {
@@ -894,6 +918,7 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
 #ifdef XWL_HAS_GLAMOR
     xwl_screen->glamor = XWL_GLAMOR_DEFAULT;
 #endif
+    xwl_screen->global_surface_scale = 1;
 
     for (i = 1; i < argc; i++) {
         if (strcmp(argv[i], "-rootless") == 0) {
diff --git a/hw/xwayland/xwayland-screen.h b/hw/xwayland/xwayland-screen.h
index 0800fb392..a49813a16 100644
--- a/hw/xwayland/xwayland-screen.h
+++ b/hw/xwayland/xwayland-screen.h
@@ -181,5 +181,7 @@ int xwl_screen_get_next_output_serial(struct xwl_screen * xwl_screen);
 void xwl_screen_lost_focus(struct xwl_screen *xwl_screen);
 Bool xwl_screen_update_global_surface_scale(struct xwl_screen *xwl_screen);
 Bool xwl_screen_should_use_fractional_scale(struct xwl_screen *xwl_screen);
+int xwl_scale_to(struct xwl_screen *xwl_screen, int value);
+void xwl_screen_set_global_scale( struct xwl_screen *xwl_screen, int32_t scale);
 
 #endif /* XWAYLAND_SCREEN_H */
diff --git a/hw/xwayland/xwayland-window.c b/hw/xwayland/xwayland-window.c
index 05f45e16f..56e4338be 100644
--- a/hw/xwayland/xwayland-window.c
+++ b/hw/xwayland/xwayland-window.c
@@ -1317,7 +1317,8 @@ xwl_create_root_surface(struct xwl_window *xwl_window)
     }
 
     wl_region_add(region, 0, 0,
-                  window->drawable.width, window->drawable.height);
+                      xwl_scale_to(xwl_screen, window->drawable.width),
+                      xwl_scale_to(xwl_screen, window->drawable.height));
     wl_surface_set_opaque_region(xwl_window->surface, region);
     wl_region_destroy(region);
 
@@ -1955,6 +1956,7 @@ xwl_window_attach_buffer(struct xwl_window *xwl_window)
     }
 
     wl_surface_attach(xwl_window->surface, buffer, 0, 0);
+    wl_surface_set_buffer_scale(xwl_window->surface, xwl_screen->global_surface_scale);
 
     /* Arbitrary limit to try to avoid flooding the Wayland
      * connection. If we flood it too much anyway, this could
diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c
index cbd2437d6..0d0587b74 100644
--- a/hw/xwayland/xwayland.c
+++ b/hw/xwayland/xwayland.c
@@ -333,6 +333,18 @@ xwl_log_handler(const char *format, va_list args)
 #ifdef XWL_HAS_XWAYLAND_EXTENSION
 #include <X11/extensions/xwaylandproto.h>
 
+// Custom extensions for xwl for setting scale
+#define X_XwlSetScale  	1
+
+typedef struct {
+    CARD8	reqType;		    /* always XwaylandReqCode */
+    CARD8	xwaylandReqType;	/* always X_XwaylandSetScale */
+    CARD16	length;
+    CARD16	screen;
+    CARD16	scale;
+} xXwaylandSetScaleReq;
+#define sz_xXwaylandSetScaleReq	8
+
 Bool noXwaylandExtension = FALSE;
 
 static int
@@ -386,6 +398,28 @@ SProcXwlQueryVersion(ClientPtr client)
     return ProcXwlQueryVersion(client);
 }
 
+static int
+ProcXwlSetScale(ClientPtr client)
+{
+    REQUEST(xXwaylandSetScaleReq);
+    REQUEST_SIZE_MATCH(xXwaylandSetScaleReq);
+
+    if (stuff->screen >= screenInfo.numScreens)
+        return BadValue;
+    ScreenPtr pScreen = screenInfo.screens[stuff->screen];
+
+    struct xwl_screen* xwl_screen = xwl_screen_get(pScreen);
+    if (xwl_screen == NULL)
+        return BadImplementation;
+
+    if (stuff->scale < 1)
+        return BadValue;
+
+    xwl_screen_set_global_scale(xwl_screen, stuff->scale);
+
+    return Success;
+}
+
 static int
 ProcXwaylandDispatch(ClientPtr client)
 {
@@ -394,6 +428,8 @@ ProcXwaylandDispatch(ClientPtr client)
     switch (stuff->data) {
     case X_XwlQueryVersion:
         return ProcXwlQueryVersion(client);
+    case X_XwlSetScale:
+        return ProcXwlSetScale(client);
     }
     return BadRequest;
 }