From 17f2393679c8c0fd6051e27d6ced8a9af3075f28 Mon Sep 17 00:00:00 2001
From: Joshua Grams <josh@qualdan.com>
Date: Wed, 6 Apr 2005 20:59:31 +0000
Subject: [PATCH 1/1] * pnmoutline.c: actually works now.  Stupid, stupid
 libnetpbm.

---
 pnmoutline.c |   72 +++++++++++++++++++++++++++-------------------------------
 1 file changed, 33 insertions(+), 39 deletions(-)

diff --git a/pnmoutline.c b/pnmoutline.c
index 8a718bb..1315da5 100644
--- a/pnmoutline.c
+++ b/pnmoutline.c
@@ -6,7 +6,7 @@ tuple *inrows[3];
 tuple *outrow;
 
 void
-clear_inrow(struct pam *p, tuple *row)
+row_fill_black(struct pam *p, tuple *row)
 {
 	int i, j;
 	
@@ -15,16 +15,6 @@ clear_inrow(struct pam *p, tuple *row)
 			row[i][j]=0;
 }
 
-void
-clear_outrow(struct pam *p, tuple *row)
-{
-	int i,j;
-
-	for(i=0; i<p->width; i++)
-		for(j=0; j<3; j++)
-			row[i][j]=p->maxval;
-}
-
 int
 is_black(unsigned int row, unsigned int column)
 {
@@ -40,44 +30,52 @@ is_edge(unsigned int column)
 	unsigned int n = 0;
 	if(is_black(0,column)) n++;
 	if(is_black(2,column)) n++;
-	if(is_black(1,column-1)) n++;
-	if(is_black(1,column+1)) n++;
-	return n==2 || n==3;
+	if(column == 0 || is_black(1, column-1)) n++;
+	if(column == outpam.width-1 || is_black(1, column+1)) n++;
+	return n>1 && n<4;
 }
 
 void
-set_white(unsigned int column)
+set_black(unsigned int column)
 {
 	sample *s = outrow[column];
-	s[0]=255; s[1]=255; s[2]=255;
+	s[0]=0; s[1]=0; s[2]=0;
 }
 
 void
-set_black(unsigned int column)
+set_white(unsigned int column)
 {
 	sample *s = outrow[column];
-	s[0]=0; s[1]=0; s[2]=0;
+	s[0]=255; s[1]=255; s[2]=255;
 }
 
 void
-copy_tuple(unsigned int column)
+copy_tuple(sample *dest, sample *src)
 {
-	sample *src, *dest;
-
-	src = inrows[1][column];
-	dest = outrow[column];
 	dest[0] = src[0];
 	dest[1] = src[1];
 	dest[2] = src[2];
 }
 
 void
-read_row(unsigned int q)
+copy_row(struct pam *p, tuple *dest, tuple *src) 
+{
+	int i;
+
+	for(i=0; i<p->width; i++) copy_tuple(dest[i], src[i]);
+}
+
+void
+next_row(unsigned int read)
 {
+	copy_row(&outpam, inrows[0], inrows[1]);
+	copy_row(&outpam, inrows[1], inrows[2]);
+	/*
 	memcpy(inrows[0], inrows[1], outpam.width*sizeof(sample)*3);
 	memcpy(inrows[1], inrows[2], outpam.width*sizeof(sample)*3);
-	if(q) pnm_readpamrow(&inpam, inrows[2]+1);
-	else clear_inrow(&outpam, inrows[2]);
+	*/
+	if(read) pnm_readpamrow(&inpam, inrows[2]+1);
+	else row_fill_black(&outpam, inrows[2]);
 }
 
 
@@ -94,28 +92,24 @@ main(int argc, char **argv)
 	outpam.file = stdout;
 	pnm_writepaminit(&outpam);
 
-	outrow = pnm_allocpamrow(&outpam);
-	for(i=0; i<3; i++) inrows[i] = pnm_allocpamrow(&outpam);
-	for(i=0; i<3; i++) clear_inrow(&outpam, inrows[i]);
+	for(i=0; i<3; i++) {
+		inrows[i] = pnm_allocpamrow(&outpam);
+		row_fill_black(&outpam, inrows[i]);
+	}
 
-	clear_outrow(&outpam, outrow);
-	pnm_writepamrow(&outpam, inrows[0]);
+	outrow = pnm_allocpamrow(&outpam);
 
-	pnm_readpamrow(&inpam, inrows[1]+1);
-	for(row=0; row < inpam.height; row++) {
-		for(column=1; column<=inpam.width; column++) {
+	for(row=0; row < outpam.height; row++) {
+		next_row(row < inpam.height);
+		for(column=0; column<outpam.width; column++) {
 			if(is_black(1,column)) {
 				if(is_edge(column)) set_black(column);
 				else set_white(column);
-			} else copy_tuple(column);
+			} else copy_tuple(outrow[column], inrows[1][column]);
 		}
 		pnm_writepamrow(&outpam, outrow);
-		read_row(row != inpam.height-1);
 	}
 
-	clear_outrow(&outpam, outrow);
-	pnm_writepamrow(&outpam, inrows[2]);
-
 	pnm_freepamrow(outrow);
 	for(i=0; i<3; i++) pnm_freepamrow(inrows[i]);
 	return 0;
-- 
1.7.10.4