From 38239f09e3ea889aab14cc6c6bc2d6a27013981d Mon Sep 17 00:00:00 2001
From: tamasmeszaros <meszaros.q@gmail.com>
Date: Tue, 2 Jun 2020 17:28:46 +0200
Subject: [PATCH] Fix remove_bottom_points function

---
 src/libslic3r/SLA/SupportPoint.hpp          |  4 ++--
 src/libslic3r/SLA/SupportPointGenerator.cpp | 11 ++++------
 src/libslic3r/SLA/SupportPointGenerator.hpp |  2 +-
 src/libslic3r/SLAPrintSteps.cpp             | 23 ++++++++++-----------
 4 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/src/libslic3r/SLA/SupportPoint.hpp b/src/libslic3r/SLA/SupportPoint.hpp
index 202a614c3..455962cc4 100644
--- a/src/libslic3r/SLA/SupportPoint.hpp
+++ b/src/libslic3r/SLA/SupportPoint.hpp
@@ -29,13 +29,13 @@ struct SupportPoint
                  float pos_y,
                  float pos_z,
                  float head_radius,
-                 bool  new_island)
+                 bool  new_island = false)
         : pos(pos_x, pos_y, pos_z)
         , head_front_radius(head_radius)
         , is_new_island(new_island)
     {}
     
-    SupportPoint(Vec3f position, float head_radius, bool new_island)
+    SupportPoint(Vec3f position, float head_radius, bool new_island = false)
         : pos(position)
         , head_front_radius(head_radius)
         , is_new_island(new_island)
diff --git a/src/libslic3r/SLA/SupportPointGenerator.cpp b/src/libslic3r/SLA/SupportPointGenerator.cpp
index 78c2ced35..b598439ca 100644
--- a/src/libslic3r/SLA/SupportPointGenerator.cpp
+++ b/src/libslic3r/SLA/SupportPointGenerator.cpp
@@ -523,15 +523,12 @@ void SupportPointGenerator::uniformly_cover(const ExPolygons& islands, Structure
     }
 }
 
-void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double tolerance)
+void remove_bottom_points(std::vector<SupportPoint> &pts, float lvl)
 {
     // get iterator to the reorganized vector end
-    auto endit =
-        std::remove_if(pts.begin(), pts.end(),
-                       [tolerance, gnd_lvl](const sla::SupportPoint &sp) {
-        double diff = std::abs(gnd_lvl -
-                               double(sp.pos(Z)));
-        return diff <= tolerance;
+    auto endit = std::remove_if(pts.begin(), pts.end(), [lvl]
+                                (const sla::SupportPoint &sp) {
+        return sp.pos.z() <= lvl;
     });
 
     // erase all elements after the new end
diff --git a/src/libslic3r/SLA/SupportPointGenerator.hpp b/src/libslic3r/SLA/SupportPointGenerator.hpp
index 2fe8e11fc..172923056 100644
--- a/src/libslic3r/SLA/SupportPointGenerator.hpp
+++ b/src/libslic3r/SLA/SupportPointGenerator.hpp
@@ -214,7 +214,7 @@ private:
     std::mt19937 m_rng;
 };
 
-void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double tolerance);
+void remove_bottom_points(std::vector<SupportPoint> &pts, float lvl);
 
 }} // namespace Slic3r::sla
 
diff --git a/src/libslic3r/SLAPrintSteps.cpp b/src/libslic3r/SLAPrintSteps.cpp
index e421e9c1d..ea016d5bb 100644
--- a/src/libslic3r/SLAPrintSteps.cpp
+++ b/src/libslic3r/SLAPrintSteps.cpp
@@ -360,18 +360,6 @@ void SLAPrint::Steps::support_points(SLAPrintObject &po)
         // removed them on purpose. No calculation will be done.
         po.m_supportdata->pts = po.transformed_support_points();
     }
-
-    // If the zero elevation mode is engaged, we have to filter out all the
-    // points that are on the bottom of the object
-    if (is_zero_elevation(po.config())) {
-        double tolerance = po.config().pad_enable.getBool() ?
-                               po.m_config.pad_wall_thickness.getFloat() :
-                               po.m_config.support_base_height.getFloat();
-
-        remove_bottom_points(po.m_supportdata->pts,
-                             po.m_supportdata->emesh.ground_level(),
-                             tolerance);
-    }
 }
 
 void SLAPrint::Steps::support_tree(SLAPrintObject &po)
@@ -382,6 +370,17 @@ void SLAPrint::Steps::support_tree(SLAPrintObject &po)
     
     if (pcfg.embed_object)
         po.m_supportdata->emesh.ground_level_offset(pcfg.wall_thickness_mm);
+
+    // If the zero elevation mode is engaged, we have to filter out all the
+    // points that are on the bottom of the object
+    if (is_zero_elevation(po.config())) {
+        double discard = po.config().pad_enable.getBool() ?
+                             po.m_config.pad_wall_height.getFloat() :
+                             po.m_config.support_base_height.getFloat() ;
+
+        remove_bottom_points(po.m_supportdata->pts,
+                             float(po.m_supportdata->emesh.ground_level() + discard));
+    }
     
     po.m_supportdata->cfg = make_support_cfg(po.m_config);
 //    po.m_supportdata->emesh.load_holes(po.transformed_drainhole_points());