blind

commit 431e28b386fe4b63fd530e68b7d6b53d3c98b786
parent 5692bb59cb4b4aea4991d475c0f7aa978b6a1008
Author: Mattias Andrée <maandree@kth.se>
Date:   Fri, 20 Jan 2017 01:59:37 +0100

Add blind-time-blur

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

Diffstat:
M
Makefile
 | 
1
+
A
src/blind-time-blur.c
 | 
79
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 80 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -27,6 +27,7 @@ BIN =\
 	blind-single-colour\
 	blind-split\
 	blind-stack\
+	blind-time-blur\
 	blind-to-image\
 	blind-to-text\
 	blind-to-video\
diff --git a/src/blind-time-blur.c b/src/blind-time-blur.c
@@ -0,0 +1,79 @@
+/* See LICENSE file for copyright and license details. */
+#include "stream.h"
+#include "util.h"
+
+#include <string.h>
+#include <unistd.h>
+
+USAGE("alpha-stream")
+
+static int first = 1;
+
+static void
+process_xyza(char *output, char *restrict cbuf, char *restrict abuf,
+	     struct stream *colour, struct stream *alpha, size_t cn, size_t an)
+{
+	typedef double pixel_t[4];
+	pixel_t *restrict clr = (pixel_t *)cbuf;
+	pixel_t *restrict alf = (pixel_t *)abuf;
+	pixel_t *img = (pixel_t *)output;
+	size_t i, n = cn / sizeof(pixel_t);
+	double a1, a2;
+
+	if (first) {
+		memcpy(output, cbuf, cn);
+		first = 0;
+		return;
+	}
+
+	for (i = 0; i < n; i++, clr++, alf++, img++) {
+		a1 = (*img)[3];
+		a2 = (*clr)[3] * (*alf)[1] * (*alf)[3];
+		a1 *= (1 - a2);
+		(*img)[0] = (*img)[0] * a1 + (*clr)[0] * a2;
+		(*img)[1] = (*img)[1] * a1 + (*clr)[1] * a2;
+		(*img)[2] = (*img)[2] * a1 + (*clr)[2] * a2;
+		(*img)[3] = a1 + a2;
+	}
+
+	(void) colour;
+	(void) alpha;
+	(void) an;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream colour, alpha;
+	void (*process)(char *restrict output, char *restrict cbuf, char *restrict abuf,
+			struct stream *colour, struct stream *alpha, size_t cn, size_t an);
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 1)
+		usage();
+
+	colour.file = "<stdin>";
+	colour.fd = STDIN_FILENO;
+	einit_stream(&colour);
+
+	alpha.file = argv[0];
+	alpha.fd = eopen(alpha.file, O_RDONLY);
+	einit_stream(&alpha);
+
+	if (!strcmp(colour.pixfmt, "xyza"))
+		process = process_xyza;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", colour.pixfmt);
+
+	echeck_compat(&colour, &alpha);
+
+	fprint_stream_head(stdout, &colour);
+	efflush(stdout, "<stdout>");
+	process_each_frame_two_streams(&colour, &alpha, STDOUT_FILENO, "<stdout>", process);
+
+	return 0;
+}