1 files changed, 98 insertions, 0 deletions
diff --git a/src/blind-transition.c b/src/blind-transition.c
new file mode 100644
index 0000000..8463575
--- /dev/null
+++ b/src/blind-transition.c
@@ -0,0 +1,98 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-ir] [-s softness-stream]")
+
+static size_t fm;
+static double fm_double;
+static float fm_float;
+static int reverse = 0;
+static int invert = 0;
+static const char *softness_file = NULL;
+static struct stream softness;
+
+#define PROCESS(TYPE)\
+	do {\
+		size_t i, j = 0;\
+		TYPE a, s, t = fm ? (TYPE)(reverse ? fm - f : f) / fm_##TYPE : 0.5;\
+		if (!softness_file) {\
+			for (i = 0; i < n; i += stream->pixel_size) {\
+				a = ((TYPE *)(stream->buf + i))[1];\
+				if (invert)\
+					a = (TYPE)1 - a;\
+				a = (TYPE)(a >= t);\
+				((TYPE *)(stream->buf + i))[0] = a * (TYPE)D65_XYZ_X;\
+				((TYPE *)(stream->buf + i))[1] = a;\
+				((TYPE *)(stream->buf + i))[2] = a * (TYPE)D65_XYZ_Z;\
+				((TYPE *)(stream->buf + i))[3] = 1;\
+			}\
+		} else {\
+			for (i = 0; i < n; i += stream->pixel_size, j += softness.pixel_size) {\
+				while (j + softness.pixel_size > softness.ptr) {\
+					memmove(softness.buf, softness.buf + j, softness.ptr -= j);\
+					j = 0;\
+					if (!eread_stream(&softness, SIZE_MAX))\
+						return;\
+				}\
+				s  = ((TYPE *)(softness.buf + j))[1];\
+				s *= ((TYPE *)(softness.buf + j))[3];\
+				a  = ((TYPE *)(stream->buf + i))[1];\
+				if (invert)\
+					a = (TYPE)1 - a;\
+				a = (a / (1 + 2 * s) + s - t) / s;\
+				a = a < 0 ? (TYPE)0 : a > 1 ? (TYPE)1 : a;\
+				((TYPE *)(stream->buf + i))[0] = a * (TYPE)D65_XYZ_X;\
+				((TYPE *)(stream->buf + i))[1] = a;\
+				((TYPE *)(stream->buf + i))[2] = a * (TYPE)D65_XYZ_Z;\
+				((TYPE *)(stream->buf + i))[3] = 1;\
+			}\
+		}\
+	} while (0)
+
+static void process_lf(struct stream *stream, size_t n, size_t f) {PROCESS(double);}
+static void process_f (struct stream *stream, size_t n, size_t f) {PROCESS(float);}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	void (*process)(struct stream *stream, size_t n, size_t f);
+
+	ARGBEGIN {
+	case 'i':
+		invert = 1;
+		break;
+	case 'r':
+		reverse = 1;
+		break;
+	case 's':
+		softness_file = UARGF();
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	eopen_stream(&stream, NULL);
+	if (softness_file) {
+		eopen_stream(&softness, softness_file);
+		echeck_compat(&stream, &softness);
+	}
+
+	if (stream.encoding == DOUBLE)
+		process = process_lf;
+	else
+		process = process_f;
+
+	if (!stream.frames)
+		eprintf("video's length is not recorded");
+
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+	fm_double = (double)(fm = stream.frames - 1);
+	fm_float = (float)fm_double;
+	process_each_frame_segmented(&stream, STDOUT_FILENO, "<stdout>", process);
+	return 0;
+}