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
+