From 0ecc95fd555f143eabd5a972a261cf9dcc351fcc Mon Sep 17 00:00:00 2001
From: Maeyanie <me@maeyanie.com>
Date: Fri, 30 Jan 2026 20:44:16 -0500
Subject: [PATCH] Implement a Preferences option to set Draco position
 quantization bits

---
 src/libslic3r/AppConfig.cpp    |  6 ++++++
 src/libslic3r/Format/DRC.hpp   |  5 +++++
 src/slic3r/GUI/Plater.cpp      |  9 ++++++++-
 src/slic3r/GUI/Preferences.cpp | 11 +++++++++++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/libslic3r/AppConfig.cpp b/src/libslic3r/AppConfig.cpp
index c9ce68e3e0..79ae5d3001 100644
--- a/src/libslic3r/AppConfig.cpp
+++ b/src/libslic3r/AppConfig.cpp
@@ -1,5 +1,6 @@
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Utils.hpp"
+#include "libslic3r/Format/DRC.hpp"
 #include "AppConfig.hpp"
 //BBS
 #include "Preset.hpp"
@@ -124,6 +125,8 @@ void AppConfig::set_defaults()
 #ifdef _WIN32
         if (get("associate_3mf").empty())
             set_bool("associate_3mf", false);
+        if (get("associate_drc").empty())
+            set_bool("associate_drc", false);
         if (get("associate_stl").empty())
             set_bool("associate_stl", false);
         if (get("associate_step").empty())
@@ -234,6 +237,9 @@ void AppConfig::set_defaults()
     if (get("enable_multi_machine").empty())
         set_bool("enable_multi_machine", false);
 
+    if (get("drc_bits").empty())
+        set("drc_bits", DRC_BITS_DEFAULT_STR);
+
     if (get("show_gcode_window").empty())
         set_bool("show_gcode_window", true);
 
diff --git a/src/libslic3r/Format/DRC.hpp b/src/libslic3r/Format/DRC.hpp
index 22c0d1f000..7286dd9bf7 100644
--- a/src/libslic3r/Format/DRC.hpp
+++ b/src/libslic3r/Format/DRC.hpp
@@ -3,6 +3,11 @@
 
 namespace Slic3r {
 
+#define DRC_BITS_MIN 0
+#define DRC_BITS_MAX 30
+#define DRC_BITS_DEFAULT 16
+#define DRC_BITS_DEFAULT_STR "16"
+
 class TriangleMesh;
 class ModelObject;
 class Model;
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index e81d343f36..89adf490de 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -14877,8 +14877,15 @@ void Plater::export_drc(bool extended, bool selection_only, bool multi_drcs)
     if (p->model.objects.empty()) { return; }
 
     wxString path;
-    int bits = 16;
+    int bits = 0;
     int speed = 0;
+
+    AppConfig* app_config = wxGetApp().app_config;
+    if (app_config) bits = stoi(app_config->get("drc_bits"));
+
+    if (bits < DRC_BITS_MIN) bits = DRC_BITS_MIN;
+    if (bits > DRC_BITS_MAX) bits = DRC_BITS_MAX;
+
     if (multi_drcs) {
         wxDirDialog dlg(this, _L("Choose a directory"), from_u8(wxGetApp().app_config->get_last_dir()),
                         wxDD_DEFAULT_STYLE | wxDD_DIR_MUST_EXIST);
diff --git a/src/slic3r/GUI/Preferences.cpp b/src/slic3r/GUI/Preferences.cpp
index ffbcea2723..6d07f401a9 100644
--- a/src/slic3r/GUI/Preferences.cpp
+++ b/src/slic3r/GUI/Preferences.cpp
@@ -6,6 +6,7 @@
 #include "MsgDialog.hpp"
 #include "I18N.hpp"
 #include "libslic3r/AppConfig.hpp"
+#include "libslic3r/Format/DRC.hpp"
 #include <wx/language.h>
 #include "OG_CustomCtrl.hpp"
 #include "wx/graphics.h"
@@ -1314,6 +1315,16 @@ void PreferencesDialog::create_items()
     g_sizer->Add(item_pop_up_filament_map_dialog);
 #endif
 
+    auto item_draco_position_bits = create_item_input(_L("Draco quantization bits\n(Note: Affects dimensional accuracy)"), _L("(0 for no quantization)"), _L("More bits results in better quality and dimensional accuracy but larger file size.\n0 disables quantization, producing a nearly lossless file. ~16 bits is visually lossless but can introduce small dimensional errors over longer distances."), "drc_bits", [=](wxString value) {
+            long drcBits = DRC_BITS_DEFAULT;
+            if (value.ToLong(&drcBits)) {
+                if (drcBits < DRC_BITS_MIN) drcBits = DRC_BITS_MIN;
+                if (drcBits > DRC_BITS_MAX) drcBits = DRC_BITS_MAX;
+                app_config->set("drc_bits", std::to_string(drcBits));
+            }
+    });
+    g_sizer->Add(item_draco_position_bits);
+
     g_sizer->AddSpacer(FromDIP(10));
     sizer_page->Add(g_sizer, 0, wxEXPAND);