add basic anti-speed (relative to the star only for now)

spec/engine/vector_spec.cr

@@ -137,7 +137,7 @@ describe Vector do
     Vector[1, 1].magnitude.should eq(Math.sqrt(2))
     Vector[1, 2].magnitude.should eq(Math.sqrt(1**2 + 2**2))
     Vector[2, 2].magnitude.should eq(Math.sqrt(2**2 + 2**2))
-    Vector[2, 2, 2].magnitude.should eq((2**2 + 2**2 + 2**2)**(1.0/3.0))
+    Vector[2, 2, 2].magnitude.should eq((2**2 + 2**2 + 2**2)**(1.0/2.0))
   end
 
   it "normalized vector" do

src/engine/vector.cr

@@ -169,13 +169,16 @@ class Vector(T, N) # should be a struct since it's a simple pointer inside, the
     T
   end
 
-  # I think it's always square root not 1.0/size
   def magnitude : Number
-    reduce(T.zero) { |base, elem| base + elem**2 } ** (1.0 / size)
+    reduce(T.zero) { |base, elem| base + elem**2 } ** (1.0 / 2.0)
+  end
+
+  # put the vector on a trigonomic circle so sqrt(x**2 + y**2) = 1
+  def normalize
+    self / magnitude
   end
 
   def normalize
-    magnitude = self.magnitude
+    self.div!(magnitude)
-    self / magnitude
   end
 end

src/engine/vessel.cr

@@ -139,11 +139,26 @@ class Vessel(N)
   end
 
   class Pilot(N) < Station(N)
-    property low_thrust_save, low_thrust_pressed, computer_input_thurst
+    # these properties handle manual override of trust (either analogic or exact computed)
-    property permanent_mode, temporary_mode
+    property low_thrust_save, low_thrust_pressed, computer_input_thrust
+    # on the interface, the pilot can select a body to create relative vectors
+    property current_selected_body : Gravity::Body(N)?
+    # this is a hard limit for thrust so the pilot can avoid killing all the people aboard
+    property max_thrust
+    # permanent mode is the default mode to apply at all time
+    property permanent_mode
+    # temporary mode must be set at each tick and will be reset each time it is applied
+    property temporary_mode
 
-    @permanent_mode : Symbol?
+    enum Mode
-    @temporary_mode : Symbol?
+      Constant
+      Pulse
+      AntiGrav
+      AntiSpeed
+    end
+
+    @permanent_mode : Mode?
+    @temporary_mode : Mode?
 
     def initialize(*p, **o)
       super
@@ -151,37 +166,53 @@ class Vessel(N)
       @temporary_mode = nil
       @low_thrust_save = 0.0
       @low_thrust_pressed = false
-      @computer_input_thurst = Vector(Float64, N).zero
+      @computer_input_thrust = Vector(Float64, N).zero
+      @max_thrust = 10.0
+      @current_selected_body = nil
     end
 
-    def set_exact_acceleration_axis!(index : Int32, value : Float64)
+    # Modify immediatly one elemnt of the acceleration vector
+    def set_exact_acceleration_axis(index : Int32, value : Float64)
       vessel.gravity_body.acceleration[index] = value
     end
 
-    def set_exact_acceleration_axis!(axis : Vector(Float64, N))
+    # Modify immediatly the acceleration vector
+    def set_exact_acceleration_axis(axis : Vector(Float64, N))
       axis.each_with_index do |value, index|
-        set_exact_acceleration_axis!(index, value)
+        set_exact_acceleration_axis(index, value)
       end
     end
 
-    #     set_exact_acceleration_axis!({0, 23.0}, {1, 11.2}) # to set x;y at once
+    #     set_exact_acceleration_axis({0, 23.0}, {1, 11.2}) # to set x;y at once
-    def set_exact_acceleration_axis!(*tuples : Array(Tuple(Int32, Float64)))
+    def set_exact_acceleration_axis(*tuples : Array(Tuple(Int32, Float64)))
       tuples.each do |tuple|
-        set_exact_acceleration_axis!(*tuple)
+        set_exact_acceleration_axis(*tuple)
       end
     end
 
+    def immediate_mode
+      @temporary_mode || @permanent_mode
+    end
+
     def apply_current_mode
-      if (@permanent_mode == :antigrav && @temporary_mode.nil?) || @temporary_mode == :antigrav
+      if immediate_mode == Mode::AntiGrav
         # somehow it doesn't work as expected... :thinking:
-        set_exact_acceleration_axis!(-vessel.gravity)
+        set_exact_acceleration_axis(-vessel.gravity)
+      elsif immediate_mode == Mode::AntiSpeed
+        if (current_selected_body = @current_selected_body)
+          relative_speed = vessel.gravity_body.speed - current_selected_body.speed
+          if relative_speed.magnitude > @max_thrust
+            relative_speed.normalize.mult!(@max_thrust)
+          end
+          set_exact_acceleration_axis(-relative_speed)
+        end
       end
 
       @temporary_mode = nil # each time we apply the temporary_mode, reset it
     end
 
     def accelerate_current_vector!(coef : Float64)
-      set_exact_acceleration_axis!(vessel.gravity_body.speed * coef)
+      set_exact_acceleration_axis(vessel.gravity_body.speed * coef)
     end
   end
 

src/tests/physics_sandbox.cr

@@ -175,7 +175,7 @@ class Game
     end
 
     if joystick_moved_modified == :vector
-      @vessel.pilot.set_exact_acceleration_axis!(@joystick_moved)
+      @vessel.pilot.set_exact_acceleration_axis(@joystick_moved)
     elsif joystick_moved_modified == :accelerate
       # can double the vector each second
       Log.debug "accelerate #{@joystick_moved}"

src/tests/physics_sandbox/draw.cr

@@ -59,8 +59,8 @@ module PhysicsSandboxDraw
             ),
           ) do |value|
             @vessel.pilot.order(priority: 10, group: :acceleration_x) do
-              @vessel.pilot.set_exact_acceleration_axis!(0, value)
+              @vessel.pilot.set_exact_acceleration_axis(0, value)
-              @vessel.pilot.permanent_mode = :constant
+              @vessel.pilot.permanent_mode = Vessel::Pilot::Mode::Constant
               @vessel.pilot.low_thrust_pressed = false
               @vessel.pilot.low_thrust_save = value
             end
@@ -75,8 +75,8 @@ module PhysicsSandboxDraw
             ),
           ) do |value|
             @vessel.pilot.order(priority: 10, group: :acceleration_y) do
-              @vessel.pilot.set_exact_acceleration_axis!(1, value)
+              @vessel.pilot.set_exact_acceleration_axis(1, value)
-              @vessel.pilot.permanent_mode = :constant
+              @vessel.pilot.permanent_mode = Vessel::Pilot::Mode::Constant
               @vessel.pilot.low_thrust_pressed = false
               @vessel.pilot.low_thrust_save = value
             end
@@ -94,12 +94,12 @@ module PhysicsSandboxDraw
             data: @vessel.gravity_body.acceleration[0],
           ) do |value|
             @vessel.pilot.order(priority: 10, group: :maneuvers) do
-              @vessel.pilot.temporary_mode = :pulse
+              @vessel.pilot.temporary_mode = Vessel::Pilot::Mode::Pulse
               if !@vessel.pilot.low_thrust_pressed
                 @vessel.pilot.low_thrust_save = @vessel.gravity_body.acceleration[0]
               end
               @vessel.pilot.low_thrust_pressed = true
-              @vessel.pilot.set_exact_acceleration_axis!(0, value)
+              @vessel.pilot.set_exact_acceleration_axis(0, value)
               lock_callback = @ui_events_handler.add(SF::Event::KeyPressed) do |callback, event|
                 if event.as(SF::Event::KeyPressed).code == SF::Keyboard::Key::L
                   @vessel.pilot.low_thrust_save = value
@@ -109,7 +109,7 @@ module PhysicsSandboxDraw
                 @ui_events_handler.remove(SF::Event::MouseButtonReleased, callback)
                 @ui_events_handler.remove(SF::Event::MouseButtonReleased, lock_callback)
                 @vessel.pilot.low_thrust_pressed = false
-                @vessel.pilot.set_exact_acceleration_axis!(0, @vessel.pilot.low_thrust_save)
+                @vessel.pilot.set_exact_acceleration_axis(0, @vessel.pilot.low_thrust_save)
               end
             end
           end
@@ -120,12 +120,12 @@ module PhysicsSandboxDraw
             data: @vessel.gravity_body.acceleration[1],
           ) do |value|
             @vessel.pilot.order(priority: 10, group: :maneuvers) do
-              @vessel.pilot.temporary_mode = :pulse
+              @vessel.pilot.temporary_mode = Vessel::Pilot::Mode::Pulse
               if !@vessel.pilot.low_thrust_pressed
                 @vessel.pilot.low_thrust_save = @vessel.gravity_body.acceleration[1]
               end
               @vessel.pilot.low_thrust_pressed = true
-              @vessel.pilot.set_exact_acceleration_axis!(1, value)
+              @vessel.pilot.set_exact_acceleration_axis(1, value)
               lock_callback = @ui_events_handler.add(SF::Event::KeyPressed) do |callback, event|
                 if event.as(SF::Event::KeyPressed).code == SF::Keyboard::Key::L
                   @vessel.pilot.low_thrust_save = value
@@ -135,7 +135,7 @@ module PhysicsSandboxDraw
                 @ui_events_handler.remove(SF::Event::MouseButtonReleased, callback)
                 @ui_events_handler.remove(SF::Event::MouseButtonReleased, lock_callback)
                 @vessel.pilot.low_thrust_pressed = false
-                @vessel.pilot.set_exact_acceleration_axis!(1, @vessel.pilot.low_thrust_save)
+                @vessel.pilot.set_exact_acceleration_axis(1, @vessel.pilot.low_thrust_save)
               end
             end
           end
@@ -148,65 +148,94 @@ module PhysicsSandboxDraw
         ->{
           draw_input(
             label: "###acceleration_digit_x",
-            data: @vessel.pilot.computer_input_thurst[0],
+            data: @vessel.pilot.computer_input_thrust[0],
           ) do |value|
             @vessel.pilot.order(priority: 9, group: :maneuvers) do
-              @vessel.pilot.computer_input_thurst[0] = value
+              @vessel.pilot.computer_input_thrust[0] = value
             end
           end
         },
         ->{
           draw_input(
             label: "###acceleration_digit_y",
-            data: @vessel.pilot.computer_input_thurst[1],
+            data: @vessel.pilot.computer_input_thrust[1],
           ) do |value|
             @vessel.pilot.order(priority: 9, group: :maneuvers) do
-              @vessel.pilot.computer_input_thurst[1] = value
+              @vessel.pilot.computer_input_thrust[1] = value
             end
           end
         },
         "m/s²",
       )
+      # Manual reset
       draw_table_line(
         "",
         ->{
           if ImGui.button("Comfirm")
             @vessel.pilot.order(priority: 100, group: :maneuvers) do
-              @vessel.pilot.permanent_mode = :constant
+              @vessel.pilot.permanent_mode = Vessel::Pilot::Mode::Constant
-              @vessel.pilot.set_exact_acceleration_axis!(@vessel.pilot.computer_input_thurst)
+              @vessel.pilot.set_exact_acceleration_axis(@vessel.pilot.computer_input_thrust)
-              # @vessel.pilot.set_exact_acceleration_axis!(0, @vessel.pilot.computer_input_thurst[0])
+              # @vessel.pilot.set_exact_acceleration_axis(0, @vessel.pilot.computer_input_thrust[0])
-              # @vessel.pilot.set_exact_acceleration_axis!(1, @vessel.pilot.computer_input_thurst[1])
+              # @vessel.pilot.set_exact_acceleration_axis(1, @vessel.pilot.computer_input_thrust[1])
             end
           end
+        },
+        ->{
           if ImGui.button("Reset")
             @vessel.pilot.order(priority: 100, group: :prepare) do
-              @vessel.pilot.set_exact_acceleration_axis!(@vessel.pilot.computer_input_thurst)
+              @vessel.pilot.set_exact_acceleration_axis(@vessel.pilot.computer_input_thrust)
-              # @vessel.pilot.computer_input_thurst[0] = @vessel.gravity_body.acceleration[0]
+              # @vessel.pilot.computer_input_thrust[0] = @vessel.gravity_body.acceleration[0]
-              # @vessel.pilot.computer_input_thurst[1] = @vessel.gravity_body.acceleration[1]
+              # @vessel.pilot.computer_input_thrust[1] = @vessel.gravity_body.acceleration[1]
             end
           end
         },
         ->{
           if ImGui.button("Zero")
             @vessel.pilot.order(priority: 10, group: :prepare) do
-              @vessel.pilot.computer_input_thurst[0] = 0.0
+              @vessel.pilot.computer_input_thrust[0] = 0.0
-              @vessel.pilot.computer_input_thurst[1] = 0.0
+              @vessel.pilot.computer_input_thrust[1] = 0.0
             end
           end
         },
+      )
+      draw_table_line(
+        "",
+        # AntiGrav
         ->{
-          if @vessel.pilot.permanent_mode != :antigrav
+          if @vessel.pilot.permanent_mode != Vessel::Pilot::Mode::AntiGrav
             if ImGui.button("Anti-grav")
               @vessel.pilot.order(priority: 10, group: :fly_mode) do
-                @vessel.pilot.permanent_mode = :antigrav
+                @vessel.pilot.permanent_mode = Vessel::Pilot::Mode::AntiGrav
-                @vessel.gravity_body.acceleration[0] = @vessel.gravity[0]
+                # @vessel.gravity_body.acceleration[0] = @vessel.gravity[0]
-                @vessel.gravity_body.acceleration[1] = @vessel.gravity[1]
+                # @vessel.gravity_body.acceleration[1] = @vessel.gravity[1]
               end
             end
           else
             if ImGui.button("Disable anti-grav")
               @vessel.pilot.order(priority: 11, group: :fly_mode) do
-                if @vessel.pilot.permanent_mode == :antigrav
+                if @vessel.pilot.permanent_mode == Vessel::Pilot::Mode::AntiGrav
+                  @vessel.pilot.permanent_mode = nil
+                end
+              end
+            end
+          end
+        },
+
+        # AntiSpeed
+        ->{
+          if @vessel.pilot.permanent_mode != Vessel::Pilot::Mode::AntiSpeed
+            if ImGui.button("Anti-speed")
+              @vessel.pilot.order(priority: 10, group: :fly_mode) do
+                @vessel.pilot.permanent_mode = Vessel::Pilot::Mode::AntiSpeed
+                @vessel.pilot.current_selected_body = @star.gravity_body
+                # @vessel.antispeed[0] = @vessel.speed[0]
+                # @vessel.antispeed[1] = @vessel.speed[1]
+              end
+            end
+          else
+            if ImGui.button("Disable anti-speed")
+              @vessel.pilot.order(priority: 11, group: :fly_mode) do
+                if @vessel.pilot.permanent_mode == Vessel::Pilot::Mode::AntiSpeed
                   @vessel.pilot.permanent_mode = nil
                 end
               end