Merge upstream/main into belt-printer

Brings belt-printer up to main 4b4a261787. Resolutions:

- G-code header (#15897, #15915): main moved the header, config and
  thumbnail block later in _do_export; write_belt_header() moves with it,
  still after the thumbnails and outside the BTT_TFT gate.
- _extrude: first-layer acceleration keeps the per-path first-layer plane
  test with main's cached nozzle index (#16028); main's set_speed out-param
  form (#16108) everywhere else.
- GCodeWriter (#16108): the arc-to-polyline fallback for machine mappings
  that cannot express G2/G3 now runs in the out-param extrude_arc_to_xy,
  which is the overload GCode calls, and appends to the caller's string.
- GCodeProcessorResult: the belt fields join main's forwarding assign.
- Clipper2 (#15969): belt arrange helpers take Slic3r::Point; the tree
  support join types lose their ClipperLib qualifier.
- CLI arrange (#15837): belt printers still reserve no wipe tower.
- Wipe tower options (#15841): the two new sparse-layer toggles are hidden
  for belt printers like the rest of the tower options.
- Keyboard shortcuts (#15706): main's registry replaces the old key switch;
  the belt view toggle is re-registered in the next commit.
- Print::process: the belt purge-plan undo runs before main's SliceStarted
  event.
- scripts/filament_id_snapshot.json: deleted on main (a77209af8f).
- Includes and appended tests: union of both sides.

src/slic3r/GUI/GCodeViewer.hpp

@@ -8,17 +8,31 @@
 #include "GLModel.hpp"
 #include "I18N.hpp"
 
+#include <algorithm>
 #include <boost/iostreams/device/mapped_file.hpp>
 
 #include "LibVGCode/LibVGCodeWrapper.hpp"
 // needed for tech VGCODE_ENABLE_COG_AND_TOOL_MARKERS
+#include "libslic3r/Technologies.hpp"
+#include "libslic3r/Color.hpp"
+#include "libslic3r/Point.hpp"
+#include "libslic3r/BoundingBox.hpp"
+#include <cstddef>
+#include "libslic3r/Config.hpp"
+#include "libvgcode/include/GCodeInputData.hpp"
+#include <iterator>
+#include "libvgcode/include/PathVertex.hpp"
 #include <libvgcode/include/Types.hpp>
 
 #include <array>
 #include <cstdint>
 #include <float.h>
 #include <set>
+#include "slic3r/GUI/MeshUtils.hpp"
+#include <string>
 #include <unordered_set>
+#include <utility>
+#include <vector>
 
 namespace Slic3r {
 
@@ -153,7 +167,10 @@ public:
         GCodeWindow gcode_window;
         float m_scale = 1.0;
         bool m_show_marker = false;
-        void render(const bool has_render_path, float legend_height, const libvgcode::Viewer* viewer, uint32_t gcode_id, int canvas_width, int canvas_height, int right_margin, const libvgcode::EViewType& view_type);
+        // The tool marker at the current move, drawn in 3D.
+        void render_marker(const bool has_render_path, int canvas_width, int canvas_height, const libvgcode::EViewType& view_type);
+        // The marker's position window and the G-code window, both ImGui.
+        void render_overlay(const bool has_render_path, float legend_height, const libvgcode::Viewer* viewer, uint32_t gcode_id, int canvas_width, int canvas_height, int right_margin, const libvgcode::EViewType& view_type);
     };
     struct ExtruderFilament
     {
@@ -226,7 +243,8 @@ private:
     std::vector<libvgcode::EViewType> view_type_items;
     std::vector<std::string> view_type_items_str;
     int       m_view_type_sel = 0;
-    int       m_last_extruder_count_default_applied{0};  // 0=unset, 1=single, 2+=multi
+    // ORCA: which default view type was last applied, see apply_default_view_type(). Empty until the first one is applied.
+    std::string m_applied_default_view_type_key;
     std::vector<EMoveType> options_items;
 
     bool m_legend_visible{ true };
@@ -249,6 +267,8 @@ mutable bool m_no_render_path { false };
                                          // turn off (hotkey B) to inspect the raw machine-frame G-code.
 
     libvgcode::Viewer m_viewer;
+    // ORCA: section view, as the viewer has it. What it cuts away casts no shadow.
+    std::array<float, 4> m_clipping_plane{ 0.0f, 0.0f, 0.0f, 1.0f };
     bool m_loaded_as_preview{ false };
 
 public:
@@ -278,7 +298,20 @@ public:
     //BBS: add all plates filament statistics
     void render_all_plates_stats(const std::vector<const GCodeProcessorResult*>& gcode_result_list, bool show = true) const;
     //BBS: GUI refactor: add canvas width and height
-    void render(int canvas_width, int canvas_height, int right_margin);
+    // Shells, toolpaths and the sequential marker, drawn in 3D.
+    void render_scene(int canvas_width, int canvas_height);
+    // Legend, sliders, the marker's position window and the G-code window, all ImGui.
+    void render_overlay(int canvas_width, int canvas_height, int right_margin);
+    // ORCA: realistic view. Depth-only pass drawing the toolpaths as the light sees them, into
+    // the shadow map the caller has bound, and the map they sample back in render_scene.
+    void render_shadow_casters(const Transform3d& light_view_matrix, const Transform3d& light_projection_matrix, const Vec3d& light_position);
+    void set_shadow_map(int texture_unit, const Transform3d& light_view_projection, float intensity, float texel_size);
+    // ORCA: tone applied to the shaded toolpaths, paying back the light the lighting term,
+    // the shadow and the SSAO pass each take off. 1.0/1.0 is a no-op.
+    void set_tone(float exposure, float saturation);
+    // ORCA: section view
+    void set_clipping_plane(const ClippingPlane& plane);
+    void set_light_top_dir(const Vec3d& direction);
     //BBS
     // void _render_calibration_thumbnail_internal(ThumbnailData& thumbnail_data, const ThumbnailsParams& thumbnail_params, PartPlateList& partplate_list, OpenGLManager& opengl_manager);
     // void _render_calibration_thumbnail_framebuffer(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, const ThumbnailsParams& thumbnail_params, PartPlateList& partplate_list, OpenGLManager& opengl_manager);
@@ -302,6 +335,10 @@ public:
     std::vector<float> get_layers_times() const { return m_viewer.get_layers_estimated_times(); }
 
     const std::array<size_t,2> &get_layers_z_range() const { return m_viewer.get_layers_view_range(); }
+    size_t get_vertices_count() const { return m_viewer.get_vertices_count(); }
+    size_t get_layers_count() const { return m_viewer.get_layers_count(); }
+    // ORCA: realistic view. Changes whenever the toolpaths casting shadows do.
+    size_t shadow_casters_signature() const;
 
     const SequentialView& get_sequential_view() const { return m_sequential_view; }
     void update_sequential_view_current(unsigned int first, unsigned int last);
@@ -325,6 +362,16 @@ public:
     void set_view_type(libvgcode::EViewType type) {
         m_viewer.set_view_type(type);
     }
+    // ORCA: select a view type in the preview combo box and apply it
+    void select_view_type(libvgcode::EViewType type);
+    // ORCA: apply the "preview_default_view_type" preference, see the definition for the supported values
+    void apply_default_view_type();
+
+    // ORCA: stable, locale independent name of a view type, as stored in the application config
+    static std::string view_type_to_config_name(libvgcode::EViewType type);
+    static bool view_type_from_config_name(const std::string& name, libvgcode::EViewType& type);
+    // ORCA: (config value, translated label) pairs for the "preview_default_view_type" preference combo box
+    static std::vector<std::pair<std::string, std::string>> default_view_type_choices();
     void reset_visible(libvgcode::EViewType type) {
         if (type == libvgcode::EViewType::FeatureType) {
             auto roles = m_viewer.get_extrusion_roles();
@@ -374,6 +421,8 @@ public:
 private:
     //BBS: always load shell at preview
     //void load_shells(const Print& print);
+    // Canvas height minus the room the horizontal slider takes.
+    int sequential_view_height(int canvas_height) const;
     void render_toolpaths();
     void render_shells(int canvas_width, int canvas_height);