compositor: Use weston_head transform for output default

If the output only has a single weston_head attached to it, take its
declared transform as the default transform.

With the previous patches, this allows a device declaring the KMS 'panel
orientation' property (e.g. through DeviceTree) to autoconfigure to the
correct display rotation when running Weston.

Signed-off-by: Daniel Stone <daniels@collabora.com>

diff --git a/compositor/main.c b/compositor/main.c
index 799ab83..c9002bf 100644 (file)
--- a/compositor/main.c
+++ b/compositor/main.c
@@ -1700,6 +1700,7 @@ drm_backend_output_configure(struct weston_output *output,
        const struct weston_drm_output_api *api;
        enum weston_drm_backend_output_mode mode =
                WESTON_DRM_BACKEND_OUTPUT_PREFERRED;
+       uint32_t transform = WL_OUTPUT_TRANSFORM_NORMAL;
        char *s;
        char *modeline = NULL;
        char *gbm_format = NULL;
@@ -1731,9 +1732,13 @@ drm_backend_output_configure(struct weston_output *output,
        }
        free(modeline);
 
+       if (count_remaining_heads(output, NULL) == 1) {
+               struct weston_head *head = weston_output_get_first_head(output);
+               transform = weston_head_get_transform(head);
+       }
+
        wet_output_set_scale(output, section, 1, 0);
-       if (wet_output_set_transform(output, section,
-                                    WL_OUTPUT_TRANSFORM_NORMAL,
+       if (wet_output_set_transform(output, section, transform,
                                     UINT32_MAX) < 0) {
                return -1;
        }