From a754c0af4088aaa7d1799351db1d03b9250a0d2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20T=C3=B6nne?= <lukas.toenne@gmail.com>
Date: Thu, 13 Nov 2014 16:05:17 +0100
Subject: [PATCH] Another fix for off-by-one hair grid resolution errors.

---
 source/blender/editors/space_view3d/drawobject.c | 12 ++++++------
 source/blender/physics/intern/hair_volume.cpp    | 12 ++++++------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index da075419890..109dc10bcab 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -5255,22 +5255,22 @@ static void draw_new_particle_system(Scene *scene, View3D *v3d, RegionView3D *rv
 						UI_ThemeColorShadeAlpha(TH_WIRE, 0, -100);
 					glEnable(GL_BLEND);
 					glBegin(GL_LINES);
-					for (i = 1; i < res[0]; ++i) {
-						float f = interpf(b[0], a[0], (float)i / (float)(res[0]));
+					for (i = 1; i < res[0]-1; ++i) {
+						float f = interpf(b[0], a[0], (float)i / (float)(res[0]-1));
 						glVertex3f(f, a[1], a[2]); glVertex3f(f, b[1], a[2]);
 						glVertex3f(f, b[1], a[2]); glVertex3f(f, b[1], b[2]);
 						glVertex3f(f, b[1], b[2]); glVertex3f(f, a[1], b[2]);
 						glVertex3f(f, a[1], b[2]); glVertex3f(f, a[1], a[2]);
 					}
-					for (i = 1; i < res[1]; ++i) {
-						float f = interpf(b[1], a[1], (float)i / (float)(res[1]));
+					for (i = 1; i < res[1]-1; ++i) {
+						float f = interpf(b[1], a[1], (float)i / (float)(res[1]-1));
 						glVertex3f(a[0], f, a[2]); glVertex3f(b[0], f, a[2]);
 						glVertex3f(b[0], f, a[2]); glVertex3f(b[0], f, b[2]);
 						glVertex3f(b[0], f, b[2]); glVertex3f(a[0], f, b[2]);
 						glVertex3f(a[0], f, b[2]); glVertex3f(a[0], f, a[2]);
 					}
-					for (i = 1; i < res[2]; ++i) {
-						float f = interpf(b[2], a[2], (float)i / (float)(res[2]));
+					for (i = 1; i < res[2]-1; ++i) {
+						float f = interpf(b[2], a[2], (float)i / (float)(res[2]-1));
 						glVertex3f(a[0], a[1], f); glVertex3f(b[0], a[1], f);
 						glVertex3f(b[0], a[1], f); glVertex3f(b[0], b[1], f);
 						glVertex3f(b[0], b[1], f); glVertex3f(a[0], b[1], f);
diff --git a/source/blender/physics/intern/hair_volume.cpp b/source/blender/physics/intern/hair_volume.cpp
index daf362d1f55..5dadd45c154 100644
--- a/source/blender/physics/intern/hair_volume.cpp
+++ b/source/blender/physics/intern/hair_volume.cpp
@@ -794,18 +794,18 @@ HairGrid *BPH_hair_volume_create_vertex_grid(float cellsize, const float gmin[3]
 	
 	sub_v3_v3v3(extent, gmax, gmin);
 	for (i = 0; i < 3; ++i) {
-		resmin[i] = (int)(gmin[i] * scale);
-		resmax[i] = (int)(gmax[i] * scale) + 1;
+		resmin[i] = floor_int(gmin[i] * scale);
+		resmax[i] = floor_int(gmax[i] * scale) + 1;
 		
 		/* add margin of 1 cell */
 		resmin[i] -= 1;
 		resmax[i] += 1;
 		
-		res[i] = resmax[i] - resmin[i];
+		res[i] = resmax[i] - resmin[i] + 1;
 		/* sanity check: avoid null-sized grid */
-		if (res[i] < 3) {
-			res[i] = 3;
-			resmax[i] = resmin[i] + 3;
+		if (res[i] < 4) {
+			res[i] = 4;
+			resmax[i] = resmin[i] + 4;
 		}
 		/* sanity check: avoid too large grid size */
 		if (res[i] > MAX_HAIR_GRID_RES) {