slightly better curved line joins, needs more tests

polyline.c

@@ -120,5 +120,5 @@ i_polyline_dump(const i_polyline_t *poly) {
   printf("Points: %d (%d allocated)\n", poly->point_count,
 	 poly->point_alloc);
   for (i = 0; i < poly->point_count; ++i)
-    printf(" %4d: (%g,%g)\n", i, poly->x[i], poly->y[i]);
+    printf(" %4d: (%.3f,%.3f) (%d, %d)\n", i, poly->x[i], poly->y[i], (int)(poly->x[i]+0.5), (int)(poly->y[i]+0.5));
 }

t/t22thick.t

@@ -5,22 +5,25 @@ use Imager;
 use Imager::Fill;
 
 use_ok('Imager::Pen::Thick');
-my $im = Imager->new(xsize => 100, ysize => 100);
+my $im = Imager->new(xsize => 200, ysize => 200);
 {
   #my $pen = Imager::Pen::Thick->new(thickness => 5, color => '#888');
   my $pen = Imager::Pen::Thick->new
     (
-     thickness => 9, 
-     fill => Imager::Fill->new(solid => '#888', combine => 'normal'), 
+     thickness => 17, 
+     fill => Imager::Fill->new(solid => '#880', combine => 'normal'), 
      front => 'round', 
      back => 'round',
      corner => 'round',
     );
 
-  my $line = Imager::Polyline->new(0, 10, 10, 90, 10, 10, 90, 90, 90);#, 10, 90);
+  my @pts = ( [ 20, 20 ], [ 180, 20 ], [ 20, 180 ], [ 180, 180 ]);#, [ 10, 90 ]);
+  my $line = Imager::Polyline->new(0, map @$_, @pts);
   ok($line, "made a polyline object");
   ok($pen->draw(image => $im, lines => [ $line ]), "draw it");
-  $im->setpixel(x => [ 10, 90, 90 ], 'y' => [10,10,90], color => '#00f');
+  $im->setpixel(x => [ map $_->[0], @pts ], 
+		'y' => [ map $_->[1], @pts], 
+		color => '#00f');
   #my $line2 = Imager::Polyline->new(0, 20, 20, 80, 80);
   #my $pen2 = Imager::Pen::Thick->new(thickness => 5, color => 'red');
   #ok($pen2->draw(image => $im, lines => [ $line2 ]), "draw another");

thickline.c

@@ -422,7 +422,7 @@ make_poly_round(thick_seg *segs, int seg_count, int closed,
       if (i) { /* if not the first point */
 	/* curve to the new point */
 	double start_angle = atan2(-segs[i-1].cos_slope, -segs[i-1].sin_slope);
-	double end_angle = atan2(-segs[i].cos_slope, -segs[i-1].sin_slope);
+	double end_angle = atan2(-segs[i].cos_slope, segs[i].sin_slope);
 	double angle;
 	double cx = (seg->left.a.x + seg->right.b.x) / 2.0;
 	double cy = (seg->left.a.y + seg->right.b.y) / 2.0;
@@ -607,7 +607,7 @@ thick_draw_line(i_img *im, i_pen_thick_t *thick, const i_polyline_t *line) {
 
 #if 1
   if (poly->point_count) {
-#if 0
+#if 1
     {
       i_color red;
       int i;
@@ -617,13 +617,13 @@ thick_draw_line(i_img *im, i_pen_thick_t *thick, const i_polyline_t *line) {
       red.rgba.g = red.rgba.b = 0;
 
       for (i = 0; i < poly->point_count-1; ++i) {
-	i_line(im, x[i], y[i], x[i+1], y[i+1], &red, 0);
+	i_line(im, x[i]+0.5, y[i]+0.5, x[i+1]+0.5, y[i+1]+0.5, &red, 0);
       }
-      i_line(im, x[poly->point_count-1], y[poly->point_count-1], x[0], y[0], &red, 0);
+      i_line(im, x[poly->point_count-1]+0.5, y[poly->point_count-1]+0.5, x[0]+0.5, y[0]+0.5, &red, 0);
     }
 #endif
 
-#if 1
+#if 0
     {
       int i;
       i_color white;
@@ -648,7 +648,10 @@ thick_draw(i_pen_t *pen, i_img *im, int line_count, const i_polyline_t **lines)
 
   for (i = 0; i < line_count; ++i) {
     i_polyline_t *poly = thick_draw_line(im, thick, lines[i]);
+    //i_polyline_dump(poly);
+#if 0
     i_poly_aa_cfill(im, poly->point_count, poly->x, poly->y, thick->fill);
+#endif
     i_polyline_delete(poly);
   }