From b85f779355b784675d2e948c1b92a32794554dc6 Mon Sep 17 00:00:00 2001
From: Nathan Letwory <nathan@letworyinteractive.com>
Date: Fri, 1 Oct 2010 08:12:37 +0000
Subject: [PATCH] Add distance check in lasso generation to get a smoother
 lasso.

Hopefully this helps with lasso select troubles [#21179].
---
 source/blender/editors/mesh/editmesh_mods.c    |  2 +-
 .../windowmanager/intern/wm_operators.c        | 18 ++++++++++++++----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/source/blender/editors/mesh/editmesh_mods.c b/source/blender/editors/mesh/editmesh_mods.c
index 5a33d60b00e..f8018c686f5 100644
--- a/source/blender/editors/mesh/editmesh_mods.c
+++ b/source/blender/editors/mesh/editmesh_mods.c
@@ -284,7 +284,7 @@ int EM_mask_init_backbuf_border(ViewContext *vc, short mcords[][2], short tot, s
 	
 	/* yah, opengl doesn't do concave... tsk! */
 	ED_region_pixelspace(vc->ar);
-	 draw_triangulated(mcords, tot);	
+	draw_triangulated(mcords, tot);
 	
 	glBegin(GL_LINE_LOOP);	/* for zero sized masks, lines */
 	for(a=0; a<tot; a++) glVertex2s(mcords[a][0], mcords[a][1]);
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 2831e9a0535..b880dab2ee6 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -2435,11 +2435,21 @@ int WM_gesture_lasso_modal(bContext *C, wmOperator *op, wmEvent *event)
 			}
 
 			{
+				short x, y;
 				short *lasso= gesture->customdata;
-				lasso += 2 * gesture->points;
-				lasso[0] = event->x - sx;
-				lasso[1] = event->y - sy;
-				gesture->points++;
+				
+				lasso += (2 * gesture->points - 2);
+				x = (event->x - sx - lasso[0]);
+				y = (event->y - sy - lasso[1]);
+				
+				/* make a simple distance check to get a smoother lasso
+				   add only when at least 2 pixels between this and previous location */
+				if((x*x+y*y) > 4) {
+					lasso += 2;
+					lasso[0] = event->x - sx;
+					lasso[1] = event->y - sy;
+					gesture->points++;
+				}
 			}
 			break;