1 files changed, 80 insertions, 0 deletions
diff --git a/src/blind-arithm.c b/src/blind-arithm.c
new file mode 100644
index 0000000..ce85287
--- /dev/null
+++ b/src/blind-arithm.c
@@ -0,0 +1,80 @@
+/* See LICENSE file for copyright and license details. */
+#include "stream.h"
+#include "util.h"
+
+#include <fcntl.h>
+#include <math.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+USAGE("right-hand-stream")
+
+/* Because the syntax for a function returning a function pointer is disgusting. */
+typedef void (*process_func)(struct stream *left, struct stream *right, size_t n);
+
+#define LIST_OPERATORS\
+	X(add, *lh += rh)\
+	X(sub, *lh -= rh)\
+	X(mul, *lh *= rh)\
+	X(div, *lh /= rh)\
+	X(exp, *lh = pow(*lh, rh))\
+	X(log, *lh = log(*lh) / log(rh))\
+	X(min, *lh = *lh < rh ? *lh : rh)\
+	X(max, *lh = *lh > rh ? *lh : rh)
+
+#define X(NAME, ALGO)\
+	static void\
+	process_lf_##NAME(struct stream *left, struct stream *right, size_t n)\
+	{\
+		size_t i;\
+		double *lh, rh;\
+		for (i = 0; i < n; i += 4 * sizeof(double)) {\
+			lh = ((double *)(left->buf + i)) + 0, rh = ((double *)(right->buf + i))[0];\
+			ALGO;\
+			lh = ((double *)(left->buf + i)) + 1, rh = ((double *)(right->buf + i))[1];\
+			ALGO;\
+			lh = ((double *)(left->buf + i)) + 2, rh = ((double *)(right->buf + i))[2];\
+			ALGO;\
+			lh = ((double *)(left->buf + i)) + 3, rh = ((double *)(right->buf + i))[3];\
+			ALGO;\
+		}\
+	}
+LIST_OPERATORS
+#undef X
+
+static process_func
+get_lf_process(const char *operation)
+{
+#define X(NAME, ALGO)\
+	if (!strcmp(operation, #NAME)) return process_lf_##NAME;
+LIST_OPERATORS
+#undef X
+	eprintf("algorithm not recognised: %s\n", operation);
+	return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream left, right;
+	process_func process = NULL;
+
+	ENOFLAGS(argc != 1);
+
+	left.file = "<stdin>";
+	left.fd = STDIN_FILENO;
+	einit_stream(&left);
+
+	right.file = argv[1];
+	right.fd = eopen(right.file, O_RDONLY);
+	einit_stream(&right);
+
+	if (!strcmp(left.pixfmt, "xyza"))
+		process = get_lf_process(argv[0]);
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", left.pixfmt);
+
+	process_two_streams(&left, &right, STDOUT_FILENO, "<stdout>", process);
+	return 0;
+}