From 213f68f52654da067b36077784f673ce90a29c03 Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Tue, 5 Jan 2021 23:38:28 -0500
Subject: [PATCH] gr-utils: missing file

---
 utils/gr-utils/png2fourrle.c | 115 +++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 utils/gr-utils/png2fourrle.c

diff --git a/utils/gr-utils/png2fourrle.c b/utils/gr-utils/png2fourrle.c
new file mode 100644
index 00000000..24f8afd2
--- /dev/null
+++ b/utils/gr-utils/png2fourrle.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "loadpng.h"
+
+static int offset=0;
+
+static int print_byte(int byte) {
+
+	if (offset%16==0) {
+		printf(".byte\t");
+	}
+	else {
+		printf(",");
+	}
+
+	printf("$%02X",byte);
+	offset++;
+
+	if (offset%16==0) {
+		printf("\n");
+	}
+	else {
+
+	}
+
+	return 0;
+}
+
+static int print_rle(int color, int run) {
+
+	int ret=0;
+
+	if ((color&0xf)!=((color>>4)&0xf)) {
+		fprintf(stderr,"color not match! %x\n",color);
+		ret=1;
+	}
+	if (run>255) {
+		fprintf(stderr,"Run too big %x\n",run);
+		ret=1;
+	}
+
+	if (run<=14) {
+		print_byte((run<<4)|(color&0xf));
+	}
+	else {
+		print_byte((15<<4)|(color&0xf));
+		print_byte(run);
+	}
+
+
+	return ret;
+}
+
+/* Converts a PNG to 4/4 RLE encoding */
+
+int main(int argc, char **argv) {
+
+	int row=0;
+	int col=0;
+	int color=0,oldcolor=0;
+	int run=0;
+
+	unsigned char *image;
+	int xsize,ysize;
+
+	if (argc<2) {
+		fprintf(stderr,"Usage:\t%s INFILE\n\n",argv[0]);
+		exit(-1);
+	}
+
+	if (loadpng(argv[1],&image,&xsize,&ysize,PNG_WHOLETHING)<0) {
+		fprintf(stderr,"Error loading png!\n");
+		exit(-1);
+	}
+
+	fprintf(stderr,"Loaded image %d by %d\n",xsize,ysize);
+
+	oldcolor=image[0];
+	for(row=0;row<24;row++) {
+		for(col=0;col<40;col++) {
+			color=image[row*xsize+col];
+			if (color!=oldcolor) {
+				if (print_rle(oldcolor,run)) {
+					fprintf(stderr,"at %d, %d\n",col,row);
+				}
+				oldcolor=color;
+				run=0;
+			}
+			if (run>254) {
+				if (print_rle(oldcolor,run)) {
+					fprintf(stderr,"at %d, %d\n",col,row);
+				}
+				oldcolor=color;
+				run=0;
+			}
+
+			run++;
+		}
+	}
+	print_rle(oldcolor,run);
+
+	/* terminate */
+	print_rle(0,0);
+
+	printf("\n");
+
+	return 0;
+}