Add gradients

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

1 files changed, 101 insertions, 0 deletions

diff --git a/src/blind-triangular-wave.c b/src/blind-triangular-wave.c
new file mode 100644
index 0000000..923c74b
--- /dev/null
+++ b/src/blind-triangular-wave.c
@@ -0,0 +1,101 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-es]")
+
+static int equal = 0;
+static int spiral = 0;
+
+
+#define PROCESS(TYPE, SUFFIX)\
+	static void\
+	process_##SUFFIX(struct stream *stream)\
+	{\
+		size_t i, n;\
+		TYPE x, y, z, a;\
+		do {\
+			n = stream->ptr / stream->pixel_size;\
+			if (equal) {\
+				for (i = 0; i < n; i++) {\
+					a = ((TYPE *)(stream->buf))[4 * i + 3];\
+					a = posmod(a, (TYPE)2);\
+					a = a > 1 ? 2 - a : a;\
+					if (spiral)\
+						a = (a > 0.5 ? 1 - a : a) * 2;\
+					((TYPE *)(stream->buf))[4 * i + 0] = a;\
+					((TYPE *)(stream->buf))[4 * i + 1] = a;\
+					((TYPE *)(stream->buf))[4 * i + 2] = a;\
+					((TYPE *)(stream->buf))[4 * i + 3] = a;\
+				}\
+			} else {\
+				for (i = 0; i < n; i++) {\
+					x = ((TYPE *)(stream->buf))[4 * i + 0];\
+					y = ((TYPE *)(stream->buf))[4 * i + 1];\
+					z = ((TYPE *)(stream->buf))[4 * i + 2];\
+					a = ((TYPE *)(stream->buf))[4 * i + 3];\
+					x = posmod(x, (TYPE)2);\
+					y = posmod(y, (TYPE)2);\
+					z = posmod(z, (TYPE)2);\
+					a = posmod(a, (TYPE)2);\
+					x = x > 1 ? 2 - x : x;\
+					y = y > 1 ? 2 - y : y;\
+					z = z > 1 ? 2 - z : z;\
+					a = a > 1 ? 2 - a : a;\
+					if (spiral) {\
+						x = (x > 0.5 ? 1 - x : x) * 2;\
+						y = (y > 0.5 ? 1 - y : y) * 2;\
+						z = (z > 0.5 ? 1 - z : z) * 2;\
+						a = (a > 0.5 ? 1 - a : a) * 2;\
+					}\
+					((TYPE *)(stream->buf))[4 * i + 0] = x;\
+					((TYPE *)(stream->buf))[4 * i + 1] = y;\
+					((TYPE *)(stream->buf))[4 * i + 2] = z;\
+					((TYPE *)(stream->buf))[4 * i + 3] = a;\
+				}\
+			}\
+			n *= stream->pixel_size;\
+			ewriteall(STDOUT_FILENO, stream->buf, n, "<stdout>");\
+			memmove(stream->buf, stream->buf + n, stream->ptr -= n);\
+		} while (eread_stream(stream, SIZE_MAX));\
+		if (stream->ptr)\
+			eprintf("%s: incomplete frame\n", stream->file);\
+	}
+
+PROCESS(double, lf)
+PROCESS(float, f)
+
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	void (*process)(struct stream *stream);
+
+	ARGBEGIN {
+	case 'e':
+		equal = 1;
+		break;
+	case 's':
+		spiral = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	eopen_stream(&stream, NULL);
+
+	if (!strcmp(stream.pixfmt, "xyza"))
+		process = process_lf;
+	else if (!strcmp(stream.pixfmt, "xyza f"))
+		process = process_f;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
+
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+	process(&stream);
+	return 0;
+}