Add basic selector and relative speed

src/engine/projectable.cr

@@ -6,6 +6,15 @@ require "./gravity"
 class Projectable(N)
   property :gravity_body, :color, :size, :outline_color, :outline_size
 
+  @@hook_new : Proc(Projectable(2), Nil) = ->(obj : Projectable(2)) { nil }
+  def self.set_hook_new(hook_proc : Proc(Projectable(2), Nil))
+    @@hook_new = hook_proc
+  end
+
+  def trigger_hook_new
+    @@hook_new.call(self)
+  end
+
   def initialize(
     @gravity_body : Gravity::Body(N),
     @color : Tuple(Int32, Int32, Int32),
@@ -13,6 +22,7 @@ class Projectable(N)
     @outline_color : Tuple(Int32, Int32, Int32) = {0, 0, 0},
     @outline_size : Int32 = 0
      )
+    trigger_hook_new
   end
 
   def position

src/tests/physics_sandbox.cr

@@ -24,6 +24,7 @@ class Game
   @screen_center_position : Vector(Float64, 2)
   @center_position : Vector(Float64, 2)
   @joystick_moved : Vector(Float64, 2)
+  @selected_body : Gravity::Body(2)
 
   SECOND_IN_NANO = 1_000_000_000
   DEFAULT_ZOOM = 5/16
@@ -85,6 +86,11 @@ class Game
     # # What's the current position of the Y axis on joystick #0?
     # position = SF::Joystick.get_axis_position(0, SF::Joystick::Y)
 
+    @projectables = Array(Projectable(2)).new
+    Projectable(2).set_hook_new ->(projectable : Projectable(2)) {
+      @projectables << projectable
+    }
+
     sun_offset = Vector[3*10.0**11, 3*10.0**11]
     @bodies = {
       vessel: Gravity::MovingBody(2).new(mass: 1.0, g: 0.1, position: Vector[10.0, 10.0]),
@@ -124,9 +130,10 @@ class Game
       color: {50, 150, 50},
       size: 10,
     )
-    @projectables = {
+    # @projectables = {
-      @star, @pla1, @pla2, @pla3, @star, @vessel_p,
+    #   @star, @pla1, @pla2, @pla3, @star, @vessel_p,
-    }
+    # }
+    @selected_body = @bodies[:vessel]
     @g = Gravity::Field(2).new(@gravited)
     @vessel = Vessel(2).new(name: "Starbird", gravity_body: @bodies[:vessel], gravity_field: @g)
     @vessel.navigation.zoom_ratio = DEFAULT_ZOOM
@@ -148,6 +155,10 @@ class Game
         Log.debug "KeyPressed #{event}"
       when SF::Event::MouseMoved
       when SF::Event::MouseButtonEvent
+        click_coord = @window.map_pixel_to_coords({event.x, event.y}, @view)
+        # mmhhhh it does not work as expected, bugged
+        nearest_proj = @projectables.sort_by { |proj| (proj.position - Vector[event.x, event.y]).magnitude }.first
+        @selected_body = nearest_proj.gravity_body
         Log.debug "MouseButtonEvent #{event}"
       when SF::Event::JoystickButtonPressed
         @joystick_moved.zero!              # reset 0

src/tests/physics_sandbox/draw.cr

@@ -36,7 +36,8 @@ module PhysicsSandboxDraw
       label: "Set timescale###set_timescale",
       data: @timescale,
       min: 0.1,
-      max: 3600 * 24 * 7,
+      max: 60,
+      # max: 3600 * 24 * 7,
       flags: (
         ImGui::ImGuiSliderFlags::Logarithmic
       ),
@@ -295,15 +296,22 @@ module PhysicsSandboxDraw
 
   def draw_navigation(gravity_field)
     # ImGui.text "Total Accele is  : [#{acceleration[0].round(4)}, #{acceleration[1].round(4)}] m/s²"
-    ImGui.text "Pulse Accele is  : [#{@vessel.gravity_body.acceleration[0].round(4)}, #{@vessel.gravity_body.acceleration[1].round(4)}] m/s²"
+    draw_table(title: "Applied forces", headers: {"Name", "X", "Y", "unit"}) do
-    ImGui.text "GraviticBody is  : [#{gravity_field[0].round(4)}, #{gravity_field[1].round(4)}] m/s²"
+      draw_table_line "Pulse Accele", "#{@vessel.gravity_body.acceleration[0].round(4)}", "#{@vessel.gravity_body.acceleration[1].round(4)}", "m/s²"
-    ImGui.text "Current speed is : #{@vessel.gravity_body.speed.magnitude.round(4)} m/s"
+      draw_table_line "Gravitic Field", "#{gravity_field[0].round(4)}", "#{gravity_field[1].round(4)}", "m/s²"
+    end
+    ImGui.text "Current speed #{@vessel.gravity_body.speed.magnitude.round(4)} m/s"
+    ImGui.text ""
 
+    relative_speed = @vessel.gravity_body.speed - @selected_body.speed
     draw_table(title: "Actual vectors", headers: {"Name", "X", "Y", "unit"}) do
       draw_table_line "Position", @vessel.gravity_body.position[0].round(3).to_s, @vessel.gravity_body.position[1].round(3).to_s, "m"
       draw_table_line "Speed", @vessel.gravity_body.speed[0].round(3).to_s, @vessel.gravity_body.speed[1].round(3).to_s, "m/s"
       draw_table_line "Acceleration", @vessel.gravity_body.acceleration[0].round(3).to_s, @vessel.gravity_body.acceleration[1].round(3).to_s, "m/s²"
+      draw_table_line "Selected body", "#{@selected_body.position[0].round(4)}", "#{@selected_body.position[1].round(4)}", "m"
+      draw_table_line "Relative speed", "#{relative_speed[0].round(4)}", "#{relative_speed[1].round(4)}", "m/s"
     end
+    ImGui.text ""
 
     ImGui.text "Zoom on"
     ImGui.radio_button("vessel##navigation_zoom", pointerof(@vessel.navigation.zoom_select), 0)
@@ -336,7 +344,6 @@ module PhysicsSandboxDraw
   end
 
   def draw_bridge(gravity_field)
-
     if ImGui.begin("Bridge")
       if ImGui.tree_node_ex("Captain", ImGui::ImGuiTreeNodeFlags.new(ImGui::ImGuiTreeNodeFlags::DefaultOpen))
         draw_captain