compsitor-x11: Report more accurate dimension of outputs

We use the X screen DPI to compute the X11 compositor output size,
which gives us a more accurate and useful value in the wl_output
geometry event.

diff --git a/src/compositor-x11.c b/src/compositor-x11.c
index ce1c071..56b3228 100644 (file)
--- a/src/compositor-x11.c
+++ b/src/compositor-x11.c
@@ -761,7 +761,7 @@ x11_compositor_create_output(struct x11_compositor *c, int x, int y,
        xcb_screen_iterator_t iter;
        struct wm_normal_hints normal_hints;
        struct wl_event_loop *loop;
-       int output_width, output_height;
+       int output_width, output_height, width_mm, height_mm;
        int ret;
        uint32_t mask = XCB_CW_EVENT_MASK | XCB_CW_CURSOR;
        xcb_atom_t atom_list[1];
@@ -876,8 +876,12 @@ x11_compositor_create_output(struct x11_compositor *c, int x, int y,
        if (configured_name)
                output->base.name = strdup(configured_name);
 
+       width_mm = width * c->screen->width_in_millimeters /
+               c->screen->width_in_pixels;
+       height_mm = height * c->screen->height_in_millimeters /
+               c->screen->height_in_pixels;
        weston_output_init(&output->base, &c->base,
-                          x, y, width, height, transform, scale);
+                          x, y, width_mm, height_mm, transform, scale);
 
        if (c->use_pixman) {
                if (x11_output_init_shm(c, output,