Raycasting

src/game.lua

@@ -58,6 +58,7 @@ local weapons_manager = require(make_path("weapons"))
 local Barrel = require(make_path("barrel"))
 local Strawberry = require(make_path("strawberry"))
 local Box = require(make_path("box"))
+local NPC = require(make_path("npc"))
 
 include(make_path("pgui" .. ".lua"))
 
@@ -115,7 +116,8 @@ actors_db = {
   {name="player",sprite=65,actor=nil},
   {name="box",sprite=4,actor=Box},
   {name="alarm",sprite=19,actor=nil},
-  {name="fan",sprite=16,actor=nil}
+  {name="fan",sprite=16,actor=nil},
+  {name="NPC",sprite=69,actor=NPC}
 }
 
 
@@ -307,3 +309,66 @@ function check_collisions()
 
 end
 
+function raycast(x1, y1, x2, y2, max_distance)
+  local dx = x2 - x1
+  local dy = y2 - y1
+  local step_x = dx > 0 and 1 or -1
+  local step_y = dy > 0 and 1 or -1
+  dx = dx < 0 and -dx or dx
+  dy = dy < 0 and -dy or dy
+  local fraction = dx - dy
+  local x = x1
+  local y = y1
+
+ 
+
+  -- calculate the distance between start and end point
+  local distance = (math.sqrt((x2-x1)^2 + (y2-y1)^2))\1
+
+  local scale = max_distance / distance
+  local px = x1 + (x2 - x1) * scale
+  local py = y1 + (y2 - y1) * scale
+
+  -- limit the maximum distance 
+  if distance > max_distance then
+      --return x2, y2, false
+      return px, py, false
+  end
+
+  -- checking the start point
+  --if map_manager.is_tile_shoot_solid(flr(x / tile_width), flr(y / tile_height)) then
+    if map_manager.is_tile_shoot_solid(x, y) then
+      return x1, y1, false
+  end
+
+  local distance_traveled = 0
+
+  while distance_traveled <= max_distance and (x ~= x2 or y ~= y2) do
+    local prevX = x  -- store previous positions for distance calculation
+      local prevY = y
+      
+      if fraction >= 0 then
+          x += step_x
+          fraction -= dy
+      else
+          y += step_y
+          fraction += dx
+      end
+      
+      -- calculate distance traveled
+      distance_traveled += math.sqrt((x - prevX) ^ 2  + (y - prevY) ^ 2)\1
+      
+      -- return false as soon as a solid tile is hit
+      if map_manager.is_tile_shoot_solid(x, y) then
+          if x==x2 and y==y2 then  -- return true only if hit tile is destination tile
+              return x, y, true
+          else
+              return x, y, false
+          end
+      end
+  end
+
+  -- if the loop is done without hitting a solid tile, return false
+  return x2, y2, true
+end
+

src/npc.lua

@@ -0,0 +1,69 @@
+local Actor = require(make_path("actor2"))
+
+local NPC = Actor:new()
+
+function NPC:new(x,y)
+    local n = Actor:new(x,y)
+
+    n.spriteIndex = 69
+    n.range = 64 + 16
+    
+    n.found = false
+
+    n.enemy_x_debug = 0
+    n.enemy_x_debug = 0
+
+    --n.dir_vec_debug_x = 0
+    --n.dir_vec_debug_y = 0
+
+    n.hit_x = 0
+    n.hit_y = 0
+
+    n.raycast_frames = 0
+    n.raycast_frames_to_wait = 120
+
+    return setmetatable(n, {__index=self})
+end
+
+function NPC:update()
+    local enemy_x = cirnoInstance.x + 8
+    local enemy_y = cirnoInstance.y + 8
+
+    self.enemy_x_debug = enemy_x
+    self.enemy_y_debug = enemy_y
+
+    --local dir_vec = get_direction_vector(self.x, self.y, enemy_x, enemy_y)
+    
+    --self.dir_vec_debug_x = dir_vec.dir_x
+    --self.dir_vec_debug_y = dir_vec.dir_y
+
+    self.raycast_frames += 1
+
+    if (self.raycast_frames % self.raycast_frames_to_wait == 0) then
+        local hit_x, hit_y, hit_status = raycast(self.x, self.y, enemy_x, enemy_y, self.range, 2)
+
+        --if (raycast_hit) then
+            self.hit_x = hit_x
+            self.hit_y = hit_y
+        --end
+    
+        self.found = hit_status == true
+    end
+end
+
+function NPC:draw()
+
+    --circfill(self.x,self.y,self.range,18)
+    local col = 30
+    spr(self.spriteIndex,self.x,self.y)
+    print(string.format("Found: %s", tostring(self.found)),self.x,self.y-16,col)
+    --print(string.format("dir_x: %.2f dir_y: %.2f",self.dir_vec_debug_x, self.dir_vec_debug_y),self.x,self.y-8,28)
+    --print(string.format("hit_x: %.2f dir_y: %.2f", self.hit_x, self.hit_y),self.x, self.y,28)
+
+    --line(self.x,self.y, self.enemy_x_debug, self.enemy_y_debug, 14)
+    line(self.x,self.y, self.hit_x, self.hit_y, col)
+
+end
+
+
+return NPC