[PATCH v3 6/8] winewayland.drv: Use surface geometry to satisfy state size constraints.

[Alexandros Frantzis]

From: Alexandros Frantzis

The maximized and fullscreen states disallow surface contents that are
larger than the configured size. However, if we have a larger surface,
and only part of the surface contains useful client data, we can inform
the compositor using xdg_surface_set_geometry, so that only the
specified region is considered for compositor-side positioning and
state constraints.

We use the geometry to support the presentation of windows that insist
on particular positions and sizes which may not match the compositor's
requested size (e.g., fullscreen but may overshoot a few pixels outside
the monitor boundary).
---
 dlls/winewayland.drv/wayland_surface.c | 92 ++++++++++++++++++++++++--
 1 file changed, 85 insertions(+), 7 deletions(-)

diff --git a/dlls/winewayland.drv/wayland_surface.c b/dlls/winewayland.drv/wayland_surface.c
index 124d15821bf..b581cec1b46 100644
--- a/dlls/winewayland.drv/wayland_surface.c
+++ b/dlls/winewayland.drv/wayland_surface.c
@@ -334,21 +334,97 @@ static BOOL wayland_surface_configure_is_compatible(struct wayland_surface_confi
     /* We require the same state. */
     if ((state & mask) != (conf->state & mask)) return FALSE;

-    /* The maximized state requires the configured size. */
+    /* The maximized state requires the configured size. During surface
+     * reconfiguration we can use surface geometry to provide smaller areas
+     * from larger sizes, so only smaller sizes are incompatible. */
     if ((conf->state & WAYLAND_SURFACE_CONFIG_STATE_MAXIMIZED) &&
-        (width != conf->width || height != conf->height))
+        (width < conf->width || height < conf->height))
     {
         return FALSE;
     }

-    /* The fullscreen state requires at most the configured size. */
-    if ((conf->state & WAYLAND_SURFACE_CONFIG_STATE_FULLSCREEN) &&
-        (width > conf->width || height > conf->height))
+    /* The fullscreen state requires a size smaller or equal to the configured
+     * size. If we have a larger size, we can use surface geometry during
+     * surface reconfiguration to provide the smaller size, so we are always
+     * compatible with a fullscreen state. */
+
+    return TRUE;
+}
+
+/**********************************************************************
+ *          wayland_surface_get_rect_in_monitor
+ *
+ * Gets the largest rectangle within a surface's window (in window coordinates)
+ * that is visible in a monitor.
+ */
+static void wayland_surface_get_rect_in_monitor(struct wayland_surface *surface,
+                                                RECT *rect)
+{
+    HMONITOR hmonitor;
+    MONITORINFO mi;
+
+    mi.cbSize = sizeof(mi);
+    if (!(hmonitor = NtUserMonitorFromRect(&surface->window.rect, 0)) ||
+        !NtUserGetMonitorInfo(hmonitor, (MONITORINFO *)&mi))
     {
-        return FALSE;
+        SetRectEmpty(rect);
+        return;
     }

-    return TRUE;
+    intersect_rect(rect, &mi.rcMonitor, &surface->window.rect);
+    OffsetRect(rect, -surface->window.rect.left, -surface->window.rect.top);
+}
+
+/**********************************************************************
+ *          wayland_surface_reconfigure_geometry
+ *
+ * Sets the xdg_surface geometry
+ */
+static void wayland_surface_reconfigure_geometry(struct wayland_surface *surface)
+{
+    int width, height;
+    RECT rect;
+
+    width = surface->window.rect.right - surface->window.rect.left;
+    height = surface->window.rect.bottom - surface->window.rect.top;
+
+    /* If the window size is bigger than the current state accepts, use the
+     * largest visible (from Windows' perspective) subregion of the window. */
+    if ((surface->current.state & (WAYLAND_SURFACE_CONFIG_STATE_MAXIMIZED |
+                                   WAYLAND_SURFACE_CONFIG_STATE_FULLSCREEN)) &&
+        (width > surface->current.width || height > surface->current.height))
+    {
+        wayland_surface_get_rect_in_monitor(surface, &rect);
+
+        /* If the window rect in the monitor is smaller than required,
+         * fall back to an appropriately sized rect at the top-left. */
+        if ((surface->current.state & WAYLAND_SURFACE_CONFIG_STATE_MAXIMIZED) &&
+            (rect.right - rect.left < surface->current.width ||
+             rect.bottom - rect.top < surface->current.height))
+        {
+            SetRect(&rect, 0, 0, surface->current.width, surface->current.height);
+        }
+        else
+        {
+            rect.right = min(rect.right, rect.left + surface->current.width);
+            rect.bottom = min(rect.bottom, rect.top + surface->current.height);
+        }
+        TRACE("Window is too large for Wayland state, using subregion\n");
+    }
+    else
+    {
+        SetRect(&rect, 0, 0, width, height);
+    }
+
+    TRACE("hwnd=%p geometry=%s\n", surface->hwnd, wine_dbgstr_rect(&rect));
+
+    if (!IsRectEmpty(&rect))
+    {
+        xdg_surface_set_window_geometry(surface->xdg_surface,
+                                        rect.left, rect.top,
+                                        rect.right - rect.left,
+                                        rect.bottom - rect.top);
+    }
 }

/**********************************************************************
@@ -403,6 +479,8 @@ BOOL wayland_surface_reconfigure(struct wayland_surface *surface)
         return FALSE;
     }

+    wayland_surface_reconfigure_geometry(surface);
+
     return TRUE;
 }