imagefile -> farbfeld

 - Rename the format
 - Change the format specification
 - Drop old tools waiting to be fixed on a later date, just keep
   fixed png for now
 - Simplify other stuff

This is a direct consequence of my slcon2-talk on this topic.
At first I planned to have 64 bits per channel, but this is
overkill.

1 files changed, 75 insertions, 0 deletions

diff --git a/png2ff.c b/png2ff.c
new file mode 100644
index 0000000..52f1781
--- /dev/null
+++ b/png2ff.c
@@ -0,0 +1,75 @@
+/* See LICENSE file for copyright and license details. */
+#include <endian.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <png.h>
+
+#include "arg.h"
+
+char *argv0;
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage:%s\n", argv0);
+	exit(1);
+}
+
+int
+main(int argc, char *argv[])
+{
+	png_structp png_struct_p;
+	png_infop png_info_p;
+	png_bytepp png_row_p;
+	int depth, color, interlace;
+	uint32_t width, height, png_row_len, tmp32, r, i;
+	uint16_t tmp16;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND
+
+	if (argc)
+		usage();
+
+	/* load png */
+	png_struct_p = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+	                                      NULL, NULL);
+	png_info_p = png_create_info_struct(png_struct_p);
+
+	if (!png_struct_p || !png_info_p || setjmp(png_jmpbuf(png_struct_p))) {
+		fprintf(stderr, "failed to initialize libpng\n");
+		return 1;
+	}
+	png_init_io(png_struct_p, stdin);
+	png_set_add_alpha(png_struct_p, 255, PNG_FILLER_AFTER);
+	png_set_gray_to_rgb(png_struct_p);
+	png_read_png(png_struct_p, png_info_p, PNG_TRANSFORM_STRIP_16 |
+	             PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND, NULL);
+	png_get_IHDR(png_struct_p, png_info_p, &width, &height, &depth,
+	             &color, &interlace, NULL, NULL);
+	png_row_len = png_get_rowbytes(png_struct_p, png_info_p);
+	png_row_p = png_get_rows(png_struct_p, png_info_p);
+
+	/* write header */
+	fprintf(stdout, "farbfeld");
+	tmp32 = htobe32(width);
+	fwrite(&tmp32, sizeof(uint32_t), 1, stdout);
+	tmp32 = htobe32(height);
+	fwrite(&tmp32, sizeof(uint32_t), 1, stdout);
+
+	/* write data */
+	/* TODO: allow 16 bit PNGs to be converted losslessly */
+	for (r = 0; r < height; ++r) {
+		for (i = 0; i < png_row_len; i++) {
+			tmp16 = htobe16((uint16_t)png_row_p[r][i]);
+			fwrite(&tmp16, sizeof(uint16_t), 1, stdout);
+		}
+	}
+
+	/* cleanup */
+	png_destroy_read_struct(&png_struct_p, &png_info_p, NULL);
+	return 0;
+}