After thinking for a while, I decided to add a new ability to the player’s character. It can drop from the current block to a lower one. Because I have planned for the player’s character to obtain new skills after winning each boss. This post will focus on the ability to drop from the current block to the lower one.

The game will change from one-button game to two-buttons game. 🙂

It required to add a variable to keep which block that it will ignore for checking the ground and a function for detecting pressing a button.

ignore_block = nil

In this function. If the player presses the button. It will set value for “ignore_block” with the “current_block”‘s value.

function player_drop_down()
   if btnp(5) and player.ground == true and 
      current_block != nil and 
      ignore_block == nil then
         
      ignore_block = current_block
   end
end

In the “change_current_block()” function. we add condition to clear value in “ignore_block” variable when player change to the new block.

function change_current_block(b)
   
   current_block = b

   if current_block != ignore_block then
      ignore_block = nil
   end

   local d = distance(camera_data.target_x + 64, camera_data.target_y + 64, current_block.x + current_block.w/2, current_block.y - current_block.h/2)
   _debug = d
   if d > 12 then
      set_camera_target(current_block)
   end
end

In “player_apply_gravity()” function. we will add a condition to skip setting the ground value when the player’s character stays inside “ignore_block”.

function player_apply_gravity()
   local next_py = player.y
   if player.ground == false then
      
      if player.jump_counter <= 0 then
         next_py += 1
         if  is_inside_block(player.x, player.y, current_block) == true and 
            is_inside_block(player.x, next_py, current_block) == false and 
            current_block.floor == true
            then

               if current_block != ignore_block then
                  next_py = player.y
                  player.ground = true
               end
         end
      end
   else
      if is_inside_block(player.x, player.y, current_block) == false or current_block == ignore_block then
         player.ground = false
      end
   end

   player.y = next_py
end

player = {x=64,y=64,di=1,jump_counter=0,ground=true}

ignore_block = nil
current_block = nil
block_list = {}

function create_block(x,y,w,h,left_wall,right_wall, floor)
   return {x=x,y=y,w=w,h=h,obstacles={},left_wall=left_wall,right_wall=right_wall,floor=floor}
end

function draw_block(b,c)
   if (b == nil) return

   if b.floor == true then
      line(b.x,b.y,b.x+b.w,b.y,c)
   end

   
   if b.left_wall == true then
      line(b.x,b.y,b.x,b.y-b.h,c)
   end
   if b.right_wall == true then
      line(b.x+b.w,b.y,b.x+b.w,b.y-b.h,c)
   end
   
   for obs in all(b.obstacles) do
      print("✽", b.x + (b.w*obs.value), b.y - 6, 8)
   end
end

function distance(x1,y1,x2,y2)
   local dx = x1-x2
   local dy = y1-y2
   local distance = sqrt(dx*dx+dy*dy)

   return distance
end

function change_current_block(b)
   
   current_block = b

   if current_block != ignore_block then
      ignore_block = nil
   end

   local d = distance(camera_data.target_x + 64, camera_data.target_y + 64, current_block.x + current_block.w/2, current_block.y - current_block.h/2)
   _debug = d
   if d > 12 then
      set_camera_target(current_block)
   end
end

function add_obstacle(b,v)
   if (b == nil) return
   add(b.obstacles, {value=v})
end

function is_inside_block(x,y,b)

   if (b == nil) return

   if x >= b.x and x < b.x + b.w then

      if y <= b.y and y > b.y - b.h then
          return true
      end
   end
   return false 
end

function player_running()
   local next_px = player.x + player.di
   if is_inside_block(player.x, player.y, current_block) == true and 
      is_inside_block(next_px, player.y, current_block) == false then

      if player.di == 1 and current_block.right_wall == false then

      elseif player.di == -1 and current_block.left_wall == false then

      else
         player.di = player.di * -1
         next_px = player.x + player.di
      end
   end

   player.x = next_px
end

function player_jumping()
   if btnp(4) then
      if player.jump_counter == 0 and player.ground == true then
         player.jump_counter = 20
         player.ground = false
      end
   end

   local next_py = player.y
   if player.jump_counter > 0 then
      player.jump_counter -= 1

      if player.jump_counter > 10 then
         next_py = player.y - 1  
      else
         next_py = player.y
      end
   end
   player.y = next_py
end

function player_drop_down()
   if btnp(5) and player.ground == true and 
      current_block != nil and 
      ignore_block == nil then
         
      ignore_block = current_block
   end
end

function player_apply_gravity()
   local next_py = player.y
   if player.ground == false then
      
      if player.jump_counter <= 0 then
         next_py += 1
         if  is_inside_block(player.x, player.y, current_block) == true and 
            is_inside_block(player.x, next_py, current_block) == false and 
            current_block.floor == true
            then

               if current_block != ignore_block then
                  next_py = player.y
                  player.ground = true
               end
         end
      end
   else
      if is_inside_block(player.x, player.y, current_block) == false or current_block == ignore_block then
         player.ground = false
      end
   end

   player.y = next_py
end


function player_find_new_current_block()
   if player.ground == false and 
      is_inside_block(player.x, player.y, current_block) == false then

      for b in all(block_list) do
         if is_inside_block(player.x, player.y, b) == true then
            change_current_block(b)
            break
         end
      end
   end
end

function player_hit_obstacle(b)
   if b == nil then return false end
   if is_inside_block(player.x, player.y, current_block) == false  then return false end

   for o in all(b.obstacles) do
      local d = distance(player.x, player.y, (b.x + b.w * o.value), b.y)

      if d < 3 then
         return true
      end
   end
end

function player_reset()
   player = {x=64,y=64,di=1,jump_counter=0,ground=true}
   change_current_block(block_list[1])
end

camera_data = {x=0,y=0,target_x=0,target_y=0}

function set_camera_target(b)
   if b == nil then return end

   local block_center_x = b.x + b.w/2
   local block_center_y = b.y - b.h/2

   camera_data.target_x = block_center_x - 64
   camera_data.target_y = block_center_y - 64
end

function update_camera()
   if camera_data.x > camera_data.target_x then
      camera_data.x -= 1
   elseif camera_data.x < camera_data.target_x then
      camera_data.x += 1
   end

   if camera_data.y > camera_data.target_y then
      camera_data.y -= 1
   elseif camera_data.y < camera_data.target_y then
      camera_data.y += 1
   end

   camera(camera_data.x, camera_data.y)
end

function _init()
   add(block_list, create_block(16,64,96,8,true ,true , true))
   add(block_list, create_block(16,56,96,8,true ,false, true))
   add(block_list, create_block(16,48,96,8,false,false , true))
   add(block_list, create_block(16,40,96,8,true,true , false))
   player_reset()

end

function _update60()
   player_running()
   player_jumping()
   player_drop_down()
   player_apply_gravity()
   player_find_new_current_block()
   local hit_result = player_hit_obstacle(current_block)
   if hit_result == true then
      player_reset()
   end

   update_camera()
end

function _draw()
   cls(0)
   print("웃", player.x-3, player.y - 5, 7)
   
   for b in all(block_list) do
     draw_block(b, 7)
   end

end