colors

commit af50be4d25c2e20eb12440aea13f222545a9793e
parent 6a0fbbf686b592065bccf2a319f6d450df5f91f1
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sun,  5 Nov 2017 13:41:33 +0100

ff.c: farbeld support

detect PNG or farbfeld depending on the first byte:

ff first byte is 'f'
PNG first byte is 137

Diffstat:
M
Makefile
 | 
3
++-
M
colors.c
 | 
7
++++++-
M
colors.h
 | 
3
++-
A
ff.c
 | 
45
+++++++++++++++++++++++++++++++++++++++++++++
M
png.c
 | 
2
+-

5 files changed, 56 insertions(+), 4 deletions(-)
diff --git a/Makefile b/Makefile
@@ -6,7 +6,7 @@ MANPREFIX = $(PREFIX)/man
 CPPFLAGS = -I/usr/local/include
 CFLAGS = -Wall -O3
 LDFLAGS = -L/usr/local/lib -lpng
-OBJ = colors.o png.o
+OBJ = colors.o ff.o png.o
 BIN = colors
 
 all: $(BIN)
@@ -15,6 +15,7 @@ $(BIN): $(OBJ)
 	$(CC) $(CFLAGS) $(CPPFLAGS) -o $@ $(OBJ) $(LDFLAGS)
 
 colors.o: arg.h colors.h tree.h
+ff.o: colors.h
 png.o: colors.h
 
 install: all
diff --git a/colors.c b/colors.c
@@ -319,6 +319,7 @@ int
 main(int argc, char *argv[])
 {
 	char *e;
+	int c;
 
 	ARGBEGIN {
 	case 'e':
@@ -351,8 +352,12 @@ main(int argc, char *argv[])
 	if (argc != 0)
 		usage();
 
+	if ((c = getc(stdin)) == EOF || ungetc(c, stdin) == EOF)
+		return 1;
+
 	RB_INIT(&pointhead);
-	parseimg(stdin, fillpoints);
+
+	(c == 'f' ? parseimg_ff : parseimg_png)(stdin, fillpoints);
 
 	initcluster = initcluster_greyscale;
 	initspace = 256;
diff --git a/colors.h b/colors.h
@@ -1,2 +1,3 @@
 /* See LICENSE file for copyright and license details. */
-void parseimg(FILE *, void (*)(int, int, int));
+void parseimg_ff(FILE *, void (*)(int, int, int));
+void parseimg_png(FILE *, void (*)(int, int, int));
diff --git a/ff.c b/ff.c
@@ -0,0 +1,45 @@
+/* See LICENSE file for copyright and license details. */
+#include <arpa/inet.h>
+#include <sys/types.h>
+
+#include <err.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "colors.h"
+
+void
+parseimg_ff(FILE *fp, void (*fn)(int, int, int))
+{
+	uint32_t hdr[4], width, height;
+	uint16_t *row;
+	size_t rowlen, i, j;
+
+	if (fread(hdr, sizeof(*hdr), 4, fp) != 4)
+		err(1, "fread");
+	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1))
+		errx(1, "invalid magic value");
+
+	width = ntohl(hdr[2]);
+	height = ntohl(hdr[3]);
+
+	if (!(row = reallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(uint16_t))))
+		err(1, "reallocarray");
+	rowlen = width * (sizeof("RGBA") - 1);
+
+	for (i = 0; i < height; ++i) {
+		if (fread(row, sizeof(uint16_t), rowlen, fp) != rowlen) {
+			if (ferror(fp))
+				err(1, "fread");
+			else
+				errx(1, "unexpected end of file");
+		}
+		for (j = 0; j < rowlen; j += 4) {
+			if (!row[j + 3])
+				continue;
+			fn(row[j] / 257, row[j+1] / 257, row[j+2] / 257);
+		}
+	}
+}
diff --git a/png.c b/png.c
@@ -6,7 +6,7 @@
 #include "colors.h"
 
 void
-parseimg(FILE *fp, void (*fn)(int, int, int))
+parseimg_png(FILE *fp, void (*fn)(int, int, int))
 {
 	png_structp png_struct_p;
 	png_infop png_info_p;