From c7f5de6d63fbaa59c3d95aea90f2a1d0f549cca8 Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pekka.paalanen@collabora.com>
Date: Fri, 2 Sep 2022 14:43:56 +0300
Subject: [PATCH] libweston: add pixel_format_get_shm_format()

This will be useful for client code that wants to create a wl_shm buffer
with a DRM format code.

The test suite will be using this.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
---
 libweston/pixel-formats.c | 16 ++++++++++++++++
 libweston/pixel-formats.h |  9 +++++++++
 2 files changed, 25 insertions(+)

diff --git a/libweston/pixel-formats.c b/libweston/pixel-formats.c
index fc33997d..3da4b5e2 100644
--- a/libweston/pixel-formats.c
+++ b/libweston/pixel-formats.c
@@ -760,3 +760,19 @@ pixel_format_get_modifier(uint64_t modifier)
 
 	return mod_str;
 }
+
+WL_EXPORT uint32_t
+pixel_format_get_shm_format(const struct pixel_format_info *info)
+{
+	/* Only these two format codes differ between wl_shm and DRM fourcc */
+	switch (info->format) {
+	case DRM_FORMAT_ARGB8888:
+		return WL_SHM_FORMAT_ARGB8888;
+	case DRM_FORMAT_XRGB8888:
+		return WL_SHM_FORMAT_XRGB8888;
+	default:
+		break;
+	}
+
+	return info->format;
+}
diff --git a/libweston/pixel-formats.h b/libweston/pixel-formats.h
index 849cc8a2..7a9e0902 100644
--- a/libweston/pixel-formats.h
+++ b/libweston/pixel-formats.h
@@ -345,3 +345,12 @@ pixel_format_height_for_plane(const struct pixel_format_info *format,
  */
 char *
 pixel_format_get_modifier(uint64_t modifier);
+
+/**
+ * Return the wl_shm format code
+ *
+ * @param info Pixel format info structure
+ * @returns The wl_shm format code for this pixel format.
+ */
+uint32_t
+pixel_format_get_shm_format(const struct pixel_format_info *info);