1 files changed, 86 insertions, 0 deletions
diff --git a/src/blind-crop.c b/src/blind-crop.c
new file mode 100644
index 0000000..bf5a930
--- /dev/null
+++ b/src/blind-crop.c
@@ -0,0 +1,86 @@
+/* See LICENSE file for copyright and license details. */
+#include "stream.h"
+#include "util.h"
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+
+USAGE("[-t] width height left top")
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	char *buf, *image, *p;
+	size_t width = 0, height = 0, left = 0, top = 0;
+	size_t off, yoff = 0, x, y, irown, orown, ptr, n, m;
+	int tile = 0;
+
+	ARGBEGIN {
+	case 't':
+		tile = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 4)
+		usage();
+
+	width  = etozu_arg("the width",         argv[0], 1, SIZE_MAX);
+	height = etozu_arg("the height",        argv[1], 1, SIZE_MAX);
+	left   = etozu_arg("the left position", argv[2], 0, SIZE_MAX);
+	top    = etozu_arg("the top position",  argv[3], 0, SIZE_MAX);
+
+	stream.file = "<stdin>";
+	stream.fd = STDIN_FILENO;
+	einit_stream(&stream);
+	if (left + width > stream.width || top + height > stream.height)
+		eprintf("crop area extends beyond original image\n");
+	if (tile) {
+		fprint_stream_head(stdout, &stream);
+	} else {
+		x = stream.width,  stream.width  = width;
+		y = stream.height, stream.height = height;
+		fprint_stream_head(stdout, &stream);
+		stream.width  = x;
+		stream.height = y;
+	}
+	efflush(stdout, "<stdout>");
+
+	echeck_frame_size(stream.width, stream.height, stream.pixel_size, 0, stream.file);
+	n = stream.height * (irown = stream.width * stream.pixel_size);
+	buf = emalloc(n);
+	orown = width * stream.pixel_size;
+	m = tile ? n : height * orown;
+	image = emalloc(m);
+
+	left *= stream.pixel_size;
+	if (!tile) {
+		off = top * irown;
+	} else {
+		off  = (orown  - (left % orown))  % orown;
+		yoff = (height - (top  % height)) % height;
+	}
+
+	memcpy(buf, stream.buf, ptr = stream.ptr);
+	while (eread_frame(&stream, buf, n)) {
+		if (!tile) {
+			for (y = 0; y < height; y++)
+				memcpy(image + y * orown, buf + y * irown + off, orown);
+		} else {
+			for (ptr = y = 0; y < stream.height; y++) {
+				p = buf + ((y + yoff) % height) * irown + left;
+				for (x = 0; x < irown; x++, ptr++)
+					image[ptr++] = p[(x + off) % orown];
+			}
+		}
+		ewriteall(STDOUT_FILENO, image, m, "<stdout>");
+	}
+
+	free(buf);
+	free(image);
+	return 0;
+}