Add demo1.0

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

1 files changed, 158 insertions, 0 deletions

diff --git a/demo.c b/demo.c
new file mode 100644
index 0000000..75c0c7d
--- /dev/null
+++ b/demo.c
@@ -0,0 +1,158 @@
+/* See LICENSE file for copyright and license details. */
+#include <arpa/inet.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "libquanta.h"
+
+
+static void
+die(const char *msg)
+{
+	perror(msg);
+	exit(1);
+}
+
+
+static void
+xfread(void *ptr, size_t size, size_t n)
+{
+	if (fread(ptr, size, n, stdin) != n) {
+		if (feof(stdin))
+			fprintf(stderr, "Unexpected EOF\n");
+		else
+			perror("fread");
+		exit(1);
+	}
+}
+
+static uint32_t
+read_be32(void)
+{
+	uint32_t be;
+	xfread(&be, 1, sizeof(be));
+	return ntohl(be);
+}
+
+
+static uint16_t
+read_be16(void)
+{
+	uint16_t be;
+	xfread(&be, 1, sizeof(be));
+	return ntohs(be);
+}
+
+
+static void
+xfwrite(const void *ptr, size_t size, size_t n)
+{
+	if (fwrite(ptr, size, n, stdout) != n)
+		die("fwrite");
+}
+
+
+static void
+write_be32(uint32_t v)
+{
+	uint32_t be = htonl(v);
+	xfwrite(&be, 1, sizeof(be));
+}
+
+static void
+write_be16(uint16_t v)
+{
+	uint16_t be = htons(v);
+	xfwrite(&be, 1, sizeof(be));
+}
+
+
+static size_t
+parse_opt_zu(const char *s, size_t def)
+{
+	char *end = NULL;
+	unsigned long int v;
+	if (!s || !*s)
+		return def;
+	errno = 0;
+	v = strtoul(s, &end, 10);
+	if (errno || end == s || *end || v == 0)
+		return def;
+	return (size_t)v;
+}
+
+
+int
+main(void)
+{
+	size_t max_colours = parse_opt_zu(getenv("QUANTA_COLOURS"), 16);
+	char magic[8];
+	size_t w, h, size, i, j;
+	uint16_t *chimgs[4];
+	struct libquanta_channel chs[4];
+	struct libquanta_palette *pal;
+	struct libquanta_image *img;
+
+	xfread(magic, 1, 8);
+	if (memcmp(magic, "farbfeld", 8)) {
+		fprintf(stderr, "Input is not farbfeld\n");
+		return 1;
+	}
+
+	w = (size_t)read_be32();
+	h = (size_t)read_be32();
+	if (!w || !h) {
+		fprintf(stderr, "Empty image\n");
+		return 1;
+	}
+	if (w > SIZE_MAX / h) {
+		fprintf(stderr, "Image too large\n");
+		return 1;
+	}
+	size = w * h;
+
+	memset(chs, 0, sizeof(chs));
+
+	for (i = 0; i < 4; i++) {
+		chimgs[i] = calloc(size, sizeof(**chimgs));
+		if (!chimgs[i])
+			die("calloc");
+		chs[i].bits_in = 16;
+		chs[i].bits_out = 16;
+		chs[i].image_width = w;
+		chs[i].image_height = h;
+		chs[i].image_row_size = w * sizeof(uint16_t);
+		chs[i].image_cell_size = sizeof(uint16_t);
+		chs[i].image = chimgs[i];
+	}
+
+	for (j = 0; j < size; j++)
+		for (i = 0; i < 4; i++)
+			chimgs[i][j] = read_be16();
+
+	pal = libquanta_malloc_palette(max_colours, 4);
+	if (!pal)
+		die("libquanta_malloc_palette");
+
+	img = libquanta_quantise(pal, &chs[0], &chs[1], &chs[2], &chs[3], NULL);
+	if (!img)
+		die("libquanta_quantise");
+
+	xfwrite("farbfeld", 1, 8);
+	write_be32((uint32_t)w);
+	write_be32((uint32_t)h);
+
+	for (j = 0; j < size; j++)
+		for (i = 0; i < 4; i++)
+			write_be16((uint16_t)pal->palette[img->image[j] * 4 + i]);
+
+	free(img);
+	free(pal);
+	for (i = 4; i--;)
+		free(chimgs[i]);
+
+	fflush(stdout);
+	return 0;
+}