pixel-formats: Added pixel_format_get_info_shm() helper for printing SHM buffers

In current form SHM buffers pixel format can only be printed as 0 and 1.
With the help of this helper we align with DRM_FORMAT_ pixel format.

Signed-off-by: Marius Vlad <marius.vlad0@gmail.com>

libweston/pixel-formats.c

@@ -32,6 +32,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <drm_fourcc.h>
+#include <wayland-client-protocol.h>
 
 #include "helpers.h"
 #include "wayland-util.h"
@@ -375,6 +376,17 @@ static const struct pixel_format_info pixel_format_table[] = {
 	},
 };
 
+WL_EXPORT const struct pixel_format_info *
+pixel_format_get_info_shm(uint32_t format)
+{
+	if (format == WL_SHM_FORMAT_XRGB8888)
+		return pixel_format_get_info(DRM_FORMAT_XRGB8888);
+	else if (format == WL_SHM_FORMAT_ARGB8888)
+		return pixel_format_get_info(DRM_FORMAT_ARGB8888);
+	else
+		return pixel_format_get_info(format);
+}
+
 WL_EXPORT const struct pixel_format_info *
 pixel_format_get_info(uint32_t format)
 {

libweston/pixel-formats.h

@@ -115,6 +115,19 @@ struct pixel_format_info {
 const struct pixel_format_info *
 pixel_format_get_info(uint32_t format);
 
+/**
+ * Get pixel format information for a SHM format code
+ *
+ * Given a SHM format code, return a DRM pixel format info structure describing
+ * the properties of that format.
+ *
+ * @param format SHM format code to get info for.
+ * @returns A pixel format structure (must not be freed), or NULL if the
+ *          format could not be found.
+ */
+const struct pixel_format_info *
+pixel_format_get_info_shm(uint32_t format);
+
 /**
  * Get pixel format information for a named DRM format
  *