From 4634d859e9a5f0b9251debb6b1fcc0f1ae5dad79 Mon Sep 17 00:00:00 2001
From: Dmitry Karasik <dmitry.karasik@teliacompany.com>
Date: Wed, 31 Jul 2024 22:54:35 +0200
Subject: [PATCH] harmonize +/-1 conditions some more

---
 img/aafill.c       | 10 +++++++---
 img/polyfill.c     |  7 ++-----
 img/region.c       |  2 +-
 include/img_conv.h |  2 +-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/img/aafill.c b/img/aafill.c
index 617e11ee..662ac69b 100644
--- a/img/aafill.c
+++ b/img/aafill.c
@@ -60,7 +60,7 @@ skipto( ScanlinePtr* scan, int x, Bool subsample_last_pixel)
 
 			if ( subsample_last_pixel) {
 				register int x1 = p->x;
-				register int x2 = p[1].x;
+				register int x2 = p[1].x - 1;
 				if ( x1 <= x_to && x2 >= x_from ) {
 					if ( x1 < x_from ) x1 = x_from;
 					if ( x2 > x_to   ) x2 = x_to;
@@ -248,7 +248,11 @@ aafill_init( NPoint *pts, int n_pts, int rule, Rect clip, PAAFillRec ctx)
 
 	clip.left   *= AAX;
 	clip.bottom *= AAY;
-	clip.right  = (clip.right + 1) * AAX - 1; /* convert to exclusive-inclusive coordinates */
+	/* convert to exclusive-inclusive coordinates, however, add extra pixel to the right
+	because poly_poly2points always returns that extra pixel since it is may be needed
+	for superimpose_outline() later on.
+	*/
+	clip.right  = (clip.right + 1) * AAX - 1 + 1;
 	clip.top    = (clip.top   + 1) * AAY - 1;
 	if ( !intersect(&aa_extents, &clip)) {
 		free( pXpts );
@@ -262,7 +266,7 @@ aafill_init( NPoint *pts, int n_pts, int rule, Rect clip, PAAFillRec ctx)
 
 	DEBUG("EXTENTS %d-%d/%d-%d = %d-%d = %d\n", aa_extents.left, aa_extents.right, aa_extents.bottom, aa_extents.top, ctx->x, xmax_px , ctx->maplen);
 
-	ctx->block = poly_poly2points(pXpts, n_pts, rule, &clip);
+	ctx->block = poly_poly2points(pXpts, n_pts, rule & fmWinding, &clip);
 	free( pXpts );
 	if ( ctx->block == NULL )
 		return 0;
diff --git a/img/polyfill.c b/img/polyfill.c
index 654e469d..d3b32c3b 100644
--- a/img/polyfill.c
+++ b/img/polyfill.c
@@ -747,7 +747,7 @@ PolyPointBlock*
 poly_poly2points(
 	Point     *Pts,                  /* the pts                 */
 	int       Count,                 /* number of pts           */
-	int       rule,                  /* winding and outline     */
+	Bool      winding,
 	PRect     clip
 ) {
 	register EdgeTableEntry *pAET;   /* Active Edge Table       */
@@ -762,12 +762,9 @@ poly_poly2points(
 	ScanLineListBlock SLLBlock;      /* header for scanlinelist */
 	int fixWAET = 0;
 	PolyPointBlock *ret;
-	Bool outline, winding;
 	unsigned long curr_max_size;
 
-	outline = (rule & fmOverlay) ? 1 : 0;
-	winding = (rule & fmWinding) ? 1 : 0;
-	DEBUG("init: %s %s\n", winding ? "wind" : "alt", outline ? "outl" : "raw");
+	DEBUG("init: %s\n", winding ? "wind" : "alt");
 
 	if ( Count < 2 )
 		return NULL;
diff --git a/img/region.c b/img/region.c
index edf8a11a..e63909af 100644
--- a/img/region.c
+++ b/img/region.c
@@ -1122,7 +1122,7 @@ img_region_polygon( Point *pts, int count, int rule)
 		return rect_region(&single);
 	}
 
-	if (( pt_block = poly_poly2points(pts, count, rule, NULL)) == NULL )
+	if (( pt_block = poly_poly2points(pts, count, rule & fmWinding, NULL)) == NULL )
 		return NULL;
 	region = points2region(pt_block, outline);
 	free( pt_block );
diff --git a/include/img_conv.h b/include/img_conv.h
index 31c51e36..a2671392 100644
--- a/include/img_conv.h
+++ b/include/img_conv.h
@@ -388,7 +388,7 @@ typedef struct {
 	unsigned long size;
 	Point pts[1];
 } PolyPointBlock;
-extern PolyPointBlock* poly_poly2points(Point *pts, int count, int rule, PRect clip);
+extern PolyPointBlock* poly_poly2points(Point *pts, int count, Bool winding, PRect clip);
 
 /* istXXX function */
 typedef double FilterFunc( const double x );