Add helpers that compare two pixel-format descriptions against
each other.
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
Reviewed-by: Javier Martinez Canillas <javi...@redhat.com>
---
include/video/pixel_format.h | 58 ++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/include/video/pixel_format.h b/include/video/pixel_format.h
index b5104b2a3a13..c57019cd6ea8 100644
--- a/include/video/pixel_format.h
+++ b/include/video/pixel_format.h
@@ -38,4 +38,62 @@ struct pixel_format {
#define PIXEL_FORMAT_XRGB2101010 \
{ 32, false, { .alpha = {0, 0}, .red = {20, 10}, .green = {10, 10},
.blue = {0, 10} } }
+#define __pixel_format_cmp_field(lhs, rhs, name) \
+ { \
+ int ret = ((lhs)->name) - ((rhs)->name); \
+ if (ret) \
+ return ret; \
+ }
+
+#define __pixel_format_cmp_bitfield(lhs, rhs, name) \
+ { \
+ __pixel_format_cmp_field(lhs, rhs, name.offset); \
+ __pixel_format_cmp_field(lhs, rhs, name.length); \
+ }
+
+/**
+ * pixel_format_cmp - Compares two pixel-format descriptions
+ *
+ * @lhs: a pixel-format description
+ * @rhs: a pixel-format description
+ *
+ * Compares two pixel-format descriptions for their order. The semantics
+ * are equivalent to memcmp().
+ *
+ * Returns:
+ * 0 if both arguments describe the same pixel format, less-than-zero if lhs <
rhs,
+ * or greater-than-zero if lhs > rhs.
+ */
+static inline int pixel_format_cmp(const struct pixel_format *lhs, const
struct pixel_format *rhs)
+{
+ __pixel_format_cmp_field(lhs, rhs, bits_per_pixel);
+ __pixel_format_cmp_field(lhs, rhs, indexed);
+
+ if (lhs->indexed) {
+ __pixel_format_cmp_bitfield(lhs, rhs, index);
+ } else {
+ __pixel_format_cmp_bitfield(lhs, rhs, alpha);
+ __pixel_format_cmp_bitfield(lhs, rhs, red);
+ __pixel_format_cmp_bitfield(lhs, rhs, green);
+ __pixel_format_cmp_bitfield(lhs, rhs, blue);
+ }
+
+ return 0;
+}
+
+/**
+ * pixel_format_equal - Compares two pixel-format descriptions for equality
+ *
+ * @lhs: a pixel-format description
+ * @rhs: a pixel-format description
+ *
+ * Returns:
+ * True if both arguments describe the same pixel format, or false otherwise.
+ */
+static inline bool pixel_format_equal(const struct pixel_format *lhs,
+ const struct pixel_format *rhs)
+{
+ return !pixel_format_cmp(lhs, rhs);
+}
+
#endif
--
2.50.0
