refactor(viewer): make viewport grid overlay a built-in capability

Drop BUILD_VIEWPORT_GRID_OVERLAY cmake option and remove all #ifdef
guards — the feature is now always compiled into realsense-viewer.
Rename draw_2d_grid to draw_crosshair per review request.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Evgeni Raikhel

CMake/lrs_options.cmake

@@ -63,4 +63,3 @@ option(USE_EXTERNAL_LZ4 "Use externally build LZ4 library instead of building an
 option(BUILD_ASAN "Enable AddressSanitizer" OFF)
 option(BUILD_ROSBAG2 "Build and use rosbag2 recording system" ON) # temporary flag, should be removed when deprecated ROSBAG1 recording system is removed
 mark_as_advanced(BUILD_ASAN)
-option(BUILD_VIEWPORT_GRID_OVERLAY "Build 2D viewport grid overlay for realsense-viewer (configurable via the per-user realsense-config.json)" OFF)

common/device-model.h

@@ -150,7 +150,6 @@ namespace rs2
             static const char* lpc_point_size{ "viewer_model.lpc_point_size" };
             static const char* show_safety_zones_3d{ "viewer_model.show_safety_zones_3d" };
             static const char* show_safety_zones_2d{ "viewer_model.show_safety_zones_2d" };
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
             namespace viewport_grid
             {
                 static const char* horizontal_lines{ "viewer_model.grid.horizontal_lines" };
@@ -160,7 +159,6 @@ namespace rs2
                 static const char* line_color_g    { "viewer_model.grid.line_color_g"      };
                 static const char* line_color_b    { "viewer_model.grid.line_color_b"      };
             }
-#endif
         }
         namespace window
         {

common/stream-model.cpp

@@ -30,7 +30,6 @@ namespace rs2
             configurations::viewer::show_stream_details, false);
         show_safety_zones_2d = config_file::instance().get_or_default(
             configurations::viewer::show_safety_zones_2d, true);
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
         {
             namespace cfg = configurations::viewer::viewport_grid;
             auto& cf = config_file::instance();
@@ -46,7 +45,6 @@ namespace rs2
             if ( r >= 0 && r <= 255 && g >= 0 && g <= 255 && b >= 0 && b <= 255 )
             { grid_color_r = r; grid_color_g = g; grid_color_b = b; }
         }
-#endif
     }
 
     std::shared_ptr<texture_buffer> stream_model::upload_frame(frame&& f)
@@ -150,9 +148,8 @@ namespace rs2
         glPopAttrib();
     }
 
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
-    static void draw_2d_grid(const rect& r, int h_lines, int v_lines, int line_width,
-                              int cr, int cg, int cb)
+    static void draw_crosshair(const rect& r, int h_lines, int v_lines, int line_width,
+                               int cr, int cg, int cb)
     {
         glPushAttrib(GL_ENABLE_BIT | GL_LINE_BIT | GL_COLOR_BUFFER_BIT | GL_CURRENT_BIT);
         glLineWidth(static_cast<GLfloat>(line_width));
@@ -176,8 +173,6 @@ namespace rs2
         glPopAttrib();
     }
 
-#endif
-
     bool stream_model::is_stream_visible() const
     {
         if (dev &&
@@ -460,9 +455,7 @@ namespace rs2
         if (RS2_STREAM_DEPTH == profile.stream_type()) ++num_of_buttons; // Color map ruler button
         if (RS2_FORMAT_MOTION_XYZ32F == profile.format()) ++num_of_buttons; // Motion graph button
         if (RS2_STREAM_OCCUPANCY == profile.stream_type() && _normalized_zoom.w == 1) ++num_of_buttons; // Safety zones button
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
         ++num_of_buttons; // Grid overlay button
-#endif
 
         RsImGui_ScopePushFont(font);
         ImGui::PushStyleColor(ImGuiCol_Text, light_grey);
@@ -598,7 +591,6 @@ namespace rs2
         }
         ImGui::SameLine();
 
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
         label = rsutils::string::from() << textual_icons::grid << "##Grid " << profile.unique_id();
         if (show_grid)
         {
@@ -622,7 +614,6 @@ namespace rs2
                 RsImGui::CustomTooltip("Show grid overlay");
         }
         ImGui::SameLine();
-#endif
 
 
         if (RS2_STREAM_DEPTH == profile.stream_type())
@@ -2114,11 +2105,9 @@ namespace rs2
 
             update_ae_roi_rect(stream_rect, g, error_message);
 
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
             if (show_grid)
-                draw_2d_grid(stream_rect, grid_h_lines, grid_v_lines, grid_line_width,
-                             grid_color_r, grid_color_g, grid_color_b);
-#endif
+                draw_crosshair(stream_rect, grid_h_lines, grid_v_lines, grid_line_width,
+                               grid_color_r, grid_color_g, grid_color_b);
 
         }
         texture->show_preview(stream_rect, _normalized_zoom);

common/stream-model.h

@@ -106,15 +106,13 @@ namespace rs2
         bool show_metadata = false;
         bool show_safety_zones_2d = true;
 
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
         bool show_grid     = false;
         int  grid_h_lines  = 1;
         int  grid_v_lines  = 1;
         int  grid_line_width = 1;
         int  grid_color_r  = 255;
         int  grid_color_g  = 255;
         int  grid_color_b  = 255;
-#endif
 
         std::shared_ptr<graph_model> graph;
         bool show_graph = false;

common/ux-window.cpp

@@ -87,7 +87,6 @@ namespace rs2
         config_file::instance().set_default(configurations::viewer::commands_xml, "./Commands.xml");
         config_file::instance().set_default(configurations::viewer::hwlogger_xml, "./HWLoggerEvents.xml");
 
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
         if( config_file::instance().is_empty() )
         {
             namespace cfg = configurations::viewer::viewport_grid;
@@ -99,7 +98,6 @@ namespace rs2
             cf.set_nested_default( cfg::line_color_g,     255 );
             cf.set_nested_default( cfg::line_color_b,     255 );
         }
-#endif
 
         std::string path;
         try

common/viewer.cpp

@@ -2983,7 +2983,6 @@ namespace rs2
                     {
                         reload_required = true;
                         temp_cfg = config_file();
-#ifdef BUILD_VIEWPORT_GRID_OVERLAY
                         {
                             namespace cfg = configurations::viewer::viewport_grid;
                             temp_cfg.set_nested_default( cfg::horizontal_lines, 1   );
@@ -2993,7 +2992,6 @@ namespace rs2
                             temp_cfg.set_nested_default( cfg::line_color_g,     255 );
                             temp_cfg.set_nested_default( cfg::line_color_b,     255 );
                         }
-#endif
                     }
                     ImGui::SameLine();
                     if (ImGui::Button(" Export Settings "))

tools/realsense-viewer/CMakeLists.txt

@@ -241,11 +241,6 @@ if(OPENVINO_NGRAPH)
     target_compile_definitions(realsense-viewer PRIVATE OPENVINO_NGRAPH)
 endif()
 
-if(BUILD_VIEWPORT_GRID_OVERLAY)
-    message(STATUS "Viewport grid overlay enabled for realsense-viewer")
-    target_compile_definitions(realsense-viewer PRIVATE BUILD_VIEWPORT_GRID_OVERLAY)
-endif()
-
 source_group("SW-Update" FILES ${SW_UPDATE_FILES})
 
 include_directories(