1 files changed, 91 insertions, 0 deletions
diff --git a/src/blind-vector-projection.c b/src/blind-vector-projection.c
new file mode 100644
index 0000000..199e01f
--- /dev/null
+++ b/src/blind-vector-projection.c
@@ -0,0 +1,91 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-r | -s] plane-stream")
+
+static int level = 1;
+
+#if defined(__GNUC__) && !defined(__clang__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wunsafe-loop-optimizations"
+#endif
+
+#define PROCESS(TYPE, SUFFIX)\
+	static void\
+	process_##SUFFIX(struct stream *left, struct stream *right, size_t n)\
+	{\
+		size_t i;\
+		TYPE *lx, *ly, *lz, *la, rx, ry, rz, ra, x, y, z, a, norm;\
+		for (i = 0; i < n; i += 4 * sizeof(TYPE)) {\
+			lx = ((TYPE *)(left->buf + i)) + 0, rx = ((TYPE *)(right->buf + i))[0];\
+			ly = ((TYPE *)(left->buf + i)) + 1, ry = ((TYPE *)(right->buf + i))[1];\
+			lz = ((TYPE *)(left->buf + i)) + 2, rz = ((TYPE *)(right->buf + i))[2];\
+			la = ((TYPE *)(left->buf + i)) + 3, ra = ((TYPE *)(right->buf + i))[3];\
+			norm = rx * rx + ry * ry + rz * rz + ra * ra;\
+			norm = sqrt(norm);\
+			x = y = z = a = *lx * rx + *ly * ry + *lz * rz + *la * ra;\
+			if (level) {\
+				x *= rx;\
+				y *= ry;\
+				z *= rz;\
+				a *= rz;\
+				if (level > 1) {\
+					x = *lx - x;\
+					y = *ly - y;\
+					z = *lz - z;\
+					a = *la - a;\
+				}\
+			}\
+			*lx = x;\
+			*ly = y;\
+			*lz = z;\
+			*la = a;\
+		}\
+	}
+
+PROCESS(double, lf)
+PROCESS(float, f)
+
+#if defined(__GNUC__) && !defined(__clang__)
+# pragma GCC diagnostic pop
+#endif
+
+int
+main(int argc, char *argv[])
+{
+	struct stream left, right;
+	void (*process)(struct stream *left, struct stream *right, size_t n);
+
+	ARGBEGIN {
+	case 'r':
+		if (level == 0)
+			usage();
+		level = 2;
+		break;
+	case 's':
+		if (level == 2)
+			usage();
+		level = 0;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 2)
+		usage();
+
+	eopen_stream(&left, NULL);
+	eopen_stream(&right, argv[1]);
+
+	if (!strcmp(left.pixfmt, "xyza"))
+		process = process_lf;
+	else if (!strcmp(left.pixfmt, "xyza f"))
+		process = process_f;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", left.pixfmt);
+
+	fprint_stream_head(stdout, &left);
+	efflush(stdout, "<stdout>");
+	process_two_streams(&left, &right, STDOUT_FILENO, "<stdout>", process);
+	return 0;
+}