Add libfonts_{get,unget}_subpixel_order_class

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 41 insertions, 0 deletions

diff --git a/libfonts_get_subpixel_order_class.c b/libfonts_get_subpixel_order_class.c
new file mode 100644
index 0000000..577b0f0
--- /dev/null
+++ b/libfonts_get_subpixel_order_class.c
@@ -0,0 +1,41 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+enum libfonts_subpixel_order_class
+libfonts_get_subpixel_order_class(enum libfonts_subpixel_order order,
+                                  enum libfonts_subpixel_colour *cell1p,
+                                  enum libfonts_subpixel_colour *cell2p,
+                                  enum libfonts_subpixel_colour *cell3p)
+{
+	enum libfonts_subpixel_colour c1, c2, c3;
+	enum libfonts_subpixel_order_class layout;
+	int i; /* RGB, RBG, GRB, GBR, BRG, BGR */
+
+	if (order >= LIBFONTS_SUBPIXEL_ORDER_RGB && order <= LIBFONTS_SUBPIXEL_ORDER_G_R_B) {
+		layout = ((order - LIBFONTS_SUBPIXEL_ORDER_RGB) & 1) + LIBFONTS_SUBPIXEL_ORDER_CLASS_123;
+		i = (order - LIBFONTS_SUBPIXEL_ORDER_RGB) / 2;
+		i = ((int []){0, 5, 3, 1, 4, 2})[i];
+
+	} else if (order >= LIBFONTS_SUBPIXEL_ORDER_RR_GB && order <= LIBFONTS_SUBPIXEL_ORDER_BALANCED_BR_BG) {
+		layout = ((order - LIBFONTS_SUBPIXEL_ORDER_RR_GB) & 3) + LIBFONTS_SUBPIXEL_ORDER_CLASS_11_23;
+		if (order >= LIBFONTS_SUBPIXEL_ORDER_BALANCED_RR_GB)
+			layout += 4;
+		i = (order - LIBFONTS_SUBPIXEL_ORDER_RR_GB) / 4 % 6;
+
+	} else {
+		layout = LIBFONTS_SUBPIXEL_ORDER_CLASS_OTHER;
+		i = 0;
+	}
+
+	c1 = i / 2;
+	c2 = (i + 1 + i / 3) % 3;
+	c3 = 3 - c1 - c2;
+	if (cell1p)
+		*cell1p = c1;
+	if (cell2p)
+		*cell2p = c2;
+	if (cell3p)
+		*cell3p = c3;
+	return layout;
+}