feat: geo helpers enemy_start_position start_position

Enemy start position was nested deeply and not friendly.
Own start position relies on checking your own main hq, which might be dead. Using camera start position on frame 0 instead.

docs/QUICK_REFERENCE.md

@@ -288,7 +288,7 @@ Here's an example using Protoss `warp` for five stalkers. We use the unit group
 ```ruby
 
 def on_step
-  enemy_main = game_info.start_raw.start_locations.first
+  enemy_main = geo.enemy_start_position
 
   if can_afford?(unit_type_id: Api::UnitTypeId::STALKER, quantity: 5)
 

docs/README.md

@@ -194,8 +194,7 @@ require "sc2ai"
 class MyCleverBot < Sc2::Player::Bot
   def on_step
     if game_loop == 0
-      enemy_start_pos = game_info.start_raw.start_locations.first
-      units.workers.attack(target: enemy_start_pos)
+      units.workers.attack(target: geo.enemy_start_position)
     end
 
     # If your attack fails, "good game" and exit
@@ -232,9 +231,9 @@ bundle exec ruby --yjit run_example_match.rb
 
 **The replay** is auto-saved as `replays/autosave-#{botname}.SC2Replay` for casual review.  
 
-If the code scares you, especially that `game_info.start_raw.start_locations.first` part, fear not.   
-The syntax is generally quite friendly while also forcibly teaching you the API.  
-We have some extremely useful tutorials ahead once you're done skimming the next two sections.
+While the code might seem foreign right now, fear not!  
+The syntax is generally quite friendly while also forcibly teaching you the API.    
+We have some extremely useful tutorials ahead once you're done skimming the next two sections.  
 
 ## Competing on the ladder
 
@@ -333,7 +332,7 @@ Or even how is ANY OF THIS possible?
 Let's go through all of the above in byte sized chunks with the tutorials which follows.
 The README is over, but check out [Acknowledgements](#label-Acknowledgements) below which answers one of these questions.
 
-Onwards, {file:docs/QUICK_REFERENCE.md to the tutorials!}
+Onwards, {file:docs/QUICK_REFERENCE.md to the tutorials! ➡️}
 
 ## Development
 

lib/sc2ai/player.rb

@@ -490,6 +490,8 @@ def prepare_start
     def started
       # Calculate expansions
       geo.expansions
+      # Set our start position base on camera
+      geo.start_position
     end
 
     # Moves emulation ahead and calls back #on_step

lib/sc2ai/player/geometry.rb

@@ -402,6 +402,19 @@ def divide_grid(input_grid, length)
         output_grid
       end
 
+      # Returns own 2d start position as set by initial camera
+      # This differs from position of first base structure
+      # @return [Api::Point2D]
+      def start_position
+        @start_position ||= bot.observation.raw_data.player.camera
+      end
+
+      # Returns the enemy 2d start position
+      # @return [Api::Point2D]
+      def enemy_start_position
+        bot.game_info.start_raw.start_locations.first
+      end
+
       # Gets expos and surrounding minerals
       # The index is a build location for an expo and the value is a UnitGroup, which has minerals and geysers
       # @example
@@ -506,13 +519,14 @@ def expansion_points
       end
 
       # Returns a slice of #expansions where a base hasn't been built yet
+      # The has index is a build position and the value is a UnitGroup of resources for the base
       # @example
       #   # Lets find the nearest unoccupied expo
       #   expo_pos = expansions_unoccupied.keys.min { |p2d| p2d.distance_to(structures.hq.first) }
       #   # What minerals/geysers does it have?
       #   puts expansions_unoccupied[expo_pos].minerals # or expansions[expo_pos]... => UnitGroup
       #   puts expansions_unoccupied[expo_pos].geysers # or expansions[expo_pos]... => UnitGroup
-      # @return [Hash<Api::Point2D], UnitGroup] Location => UnitGroup of resources (minerals+geysers)
+      # @return [Hash<Api::Point2D, UnitGroup>] Location => UnitGroup of resources (minerals+geysers)
       def expansions_unoccupied
         taken_bases = bot.structures.hq.map { |hq| hq.pos.to_p2d } + bot.enemy.structures.hq.map { |hq| hq.pos.to_p2d }
         remaining_points = expansion_points - taken_bases

lib/templates/new/my_bot.rb.tt

@@ -10,8 +10,7 @@ class <%= @classname %> < Sc2::Player::Bot
 
   def on_step
     if game_loop == 0
-      enemy_start_pos = game_info.start_raw.start_locations.first
-      units.workers.attack(target: enemy_start_pos)
+      units.workers.attack(target: geo.enemy_start_position)
     end
 
     # If your attack fails, "good game" and exit