add a few more doxygen comments. PR comments are all addressed

Author: soheilshahrouz

vpr/src/draw/draw.cpp

@@ -570,11 +570,8 @@ void free_draw_structs() {
 #endif /* NO_GRAPHICS */
 }
 
-void init_draw_coords(float width_val, const BlkLocRegistry& blk_loc_registry) {
+void init_draw_coords(float clb_width, const BlkLocRegistry& blk_loc_registry) {
 #ifndef NO_GRAPHICS
-    /* Load the arrays containing the left and bottom coordinates of the clbs   *
-     * forming the FPGA.  tile_width_val sets the width and height of a drawn    *
-     * clb.                                                                     */
     t_draw_state* draw_state = get_draw_state_vars();
     t_draw_coords* draw_coords = get_draw_coords_vars();
     const auto& device_ctx = g_vpr_ctx.device();
@@ -598,7 +595,7 @@ void init_draw_coords(float width_val, const BlkLocRegistry& blk_loc_registry) {
             draw_state->draw_rr_node[inode].node_highlighted = false;
         }
     }
-    draw_coords->tile_width = width_val;
+    draw_coords->tile_width = clb_width;
     draw_coords->pin_size = 0.3;
     for (const auto& type : device_ctx.physical_tile_types) {
         auto num_pins = type.num_pins;

vpr/src/draw/draw.h

@@ -44,8 +44,14 @@ extern ezgl::application application;
 
 void update_screen(ScreenUpdatePriority priority, const char* msg, enum pic_type pic_on_screen_val, std::shared_ptr<SetupTimingInfo> timing_info);
 
-//Initializes the drawing locations.
 //FIXME: Currently broken if no rr-graph is loaded
+/**
+ * @brief Load the arrays containing the left and bottom coordinates of the clbs.
+ * forming the FPGA.
+ *
+ * @param clb_width The width and height of a drawn clb.
+ * @param blk_loc_registry A reference to placement location information.
+ */
 void init_draw_coords(float clb_width, const BlkLocRegistry& blk_loc_registry);
 
 /* Sets the static show_graphics and gr_automode variables to the    *

vpr/src/draw/draw_global.cpp

@@ -28,6 +28,8 @@ static t_draw_coords draw_coords;
 
 /**
  * @brief Stores a reference to a PlaceLocVars to be used in the graphics code.
+ * @details This reference let us pass in a currently-being-optimized placement state,
+ * rather than using the global placement state in placement context that is valid only once placement is done
  */
 static std::optional<std::reference_wrapper<const BlkLocRegistry>> blk_loc_registry_ref;
 

vpr/src/timing/VprTimingGraphResolver.h

@@ -37,6 +37,7 @@ class VprTimingGraphResolver : public tatum::TimingGraphNameResolver {
     const AnalysisDelayCalculator& delay_calc_;
     e_timing_report_detail detail_level_ = e_timing_report_detail::NETLIST;
     bool is_flat_;
+    ///@brief contains information about the placement of clustered blocks.
     const BlkLocRegistry& blk_loc_registry_;
 };