1 files changed, 149 insertions, 0 deletions
diff --git a/src/vu-to-image.c b/src/vu-to-image.c
new file mode 100644
index 0000000..3b93dd9
--- /dev/null
+++ b/src/vu-to-image.c
@@ -0,0 +1,149 @@
+/* See LICENSE file for copyright and license details. */
+#include "arg.h"
+#include "stream.h"
+#include "util.h"
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static int luma_warning_triggered = 0;
+static int gamut_warning_triggered = 0;
+static int alpha_warning_triggered = 0;
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-d depth]\n", argv0);
+}
+
+static void
+write_pixel(double R, double G, double B, double A, int bytes, unsigned long long int max)
+{
+	unsigned long long int colours[4];
+	unsigned char buf[4 * 8];
+	int i, j, k, bm = bytes - 1;
+	size_t ptr, n;
+	ssize_t r;
+
+	if (R < 0 || G < 0 || B < 0 || R > 1 || G > 1 || B > 1) {
+		if (gamut_warning_triggered) {
+			gamut_warning_triggered = 1;
+			weprintf("warning: out-of-gamut colour detected\n");
+		}
+		; /* TODO gamut */
+		R = R < 0 ? 0 : R > 1 ? 1 : R;
+		G = G < 0 ? 0 : G > 1 ? 1 : G;
+		B = B < 0 ? 0 : B > 1 ? 1 : B;
+	}
+
+	if (A < 0 || A > 1) {
+		if (alpha_warning_triggered) {
+			alpha_warning_triggered = 1;
+			weprintf("warning: alpha values truncated\n");
+		}
+		A = A < 0 ? 0 : 1;
+	}
+
+	colours[0] = srgb_encode(R) * max + 0.5;
+	colours[1] = srgb_encode(G) * max + 0.5;
+	colours[2] = srgb_encode(B) * max + 0.5;
+	colours[3] = A * max + 0.5;
+
+	for (i = k = 0; i < 4; i++) {
+		for (j = 0; j < bytes; j++, k++) {
+			buf[k + bm - j] = (unsigned char)(colours[j]);
+			colours[j] >>= 8;
+		}
+	}
+
+	n = (size_t)bytes * 4;
+	for (ptr = 0; ptr < n; ptr += (size_t)r) {
+		r = write(STDOUT_FILENO, buf + ptr, n - ptr);
+		if (r < 0)
+			eprintf("write <stdout>:");
+	}
+}
+
+static void
+process_xyza(struct stream *stream, size_t n, int bytes, unsigned long long int max)
+{
+	size_t i;
+	double X, Y, Z, A, R, G, B;
+	for (i = 0; i < n; i += stream->pixel_size) {
+		X = ((double *)(stream->buf + i))[0];
+		Y = ((double *)(stream->buf + i))[1];
+		Z = ((double *)(stream->buf + i))[2];
+		A = ((double *)(stream->buf + i))[3];
+
+		if (Y < 0 || Y > 1) {
+			if (luma_warning_triggered) {
+				luma_warning_triggered = 1;
+				weprintf("warning: %s colour detected\n",
+					 Y < 0 ? "subblack" : "superwhite");
+			}
+		}
+
+		srgb_to_ciexyz(X, Y, Z, &R, &G, &B);
+		write_pixel(R, G, B, A, bytes, max);
+	}
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	int depth = 16, bytes;
+	unsigned long long int max;
+	size_t n;
+	void (*process)(struct stream *stream, size_t n, int bytes, unsigned long long int max);
+
+	ARGBEGIN {
+	case 'd':
+		if (toi(EARGF(usage()), 1, 64, &depth))
+			eprintf("argument of -d must be an integer in [1, 64]\n");
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc)
+		usage();
+
+	stream.fd = STDIN_FILENO;
+	stream.file = "<stdin.h>";
+	einit_stream(&stream);
+
+	max = 1ULL << (depth - 1);
+	max |= max - 1;
+	for (bytes = 1; bytes * 8 < depth; bytes++);
+
+	if (!strcmp(stream.pixfmt, "xyza"))
+		process = process_xyza;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
+
+	printf("P7\n"
+	       "WIDTH %zu\n"
+	       "HEIGHT %zu\n"
+	       "DEPTH 4\n" /* Depth actually means channels */
+	       "MAXVAL %llu\n"
+	       "TUPLTYPE RGB_ALPHA\n"
+	       "ENDHDR\n", stream.width, stream.height, max);
+	fflush(stdout);
+	if (ferror(stdout))
+		eprintf("<stdout>:");
+
+	for (;;) {
+		n = stream.ptr;
+		n -= n % stream.pixel_size;
+		process(&stream, n, bytes, max);
+		memmove(stream.buf, stream.buf + n, stream.ptr -= n);
+		if (!eread_stream(&stream, SIZE_MAX))
+			break;
+	}
+
+	return 0;
+}