1 files changed, 74 insertions, 0 deletions
diff --git a/src/blind-matrix-translate.c b/src/blind-matrix-translate.c
new file mode 100644
index 0000000..c761a7f
--- /dev/null
+++ b/src/blind-matrix-translate.c
@@ -0,0 +1,74 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-c]")
+
+static int per_channel = 0;
+
+#define PROCESS(TYPE)\
+	do {\
+		typedef TYPE pixel_t[4];\
+		pixel_t matrix[9];\
+		pixel_t buf[2];\
+		int i;\
+		\
+		for (i = 0; i < 4; i++) {\
+			matrix[0][i] = 1, matrix[1][i] = 0, matrix[2][i] = 0;\
+			matrix[3][i] = 0, matrix[4][i] = 1, matrix[5][i] = 0;\
+			matrix[6][i] = 0, matrix[7][i] = 0, matrix[8][i] = 1;\
+		}\
+		\
+		while (eread_frame(stream, buf)) {\
+			if (per_channel) {\
+				for (i = 0; i < 4; i++) {\
+					matrix[2][i] = buf[0][i];\
+					matrix[5][i] = buf[1][i];\
+				}\
+			} else {\
+				matrix[2][3] = matrix[2][2] = matrix[2][1] = matrix[2][0] = buf[0][1] * buf[0][3];\
+				matrix[5][3] = matrix[5][2] = matrix[5][1] = matrix[5][0] = buf[1][1] * buf[1][3];\
+			}\
+			ewriteall(STDOUT_FILENO, matrix, sizeof(matrix), "<stdout>");\
+		}\
+	} while (0)
+
+static void process_lf(struct stream *stream) { PROCESS(double); }
+static void process_f(struct stream *stream) { PROCESS(float); }
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	void (*process)(struct stream *stream);
+
+	ARGBEGIN {
+	case 'c':
+		per_channel = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	eopen_stream(&stream, NULL);
+
+	if (stream.width > 2 || stream.height > 2 || stream.width * stream.height != 2)
+		eprintf("<stdin>: each frame must contain exactly 2 pixels\n");
+
+	stream.width  = 3;
+	stream.height = 3;
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+
+	if (!strcmp(stream.pixfmt, "xyza"))
+		process = process_lf;
+	else if (!strcmp(stream.pixfmt, "xyza f"))
+		process = process_f;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
+
+	process(&stream);
+	return 0;
+}