English How to do image collision detection?

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FishyFinThing
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Hi there it's me again for another scripting question.

Apparently, I think Gradius is cool and I want to implement the Option thingy into CS2D. You know the glowing orb that follow player and shoot right?

So far I can make the image follow me smoothly. I can also make them shot snowball too.

But I think snowball and rocket are boring so I make a custom bullet.

But the problem is I don't know how to do collision detection for that bullet. If anyone know how, please let me know.

Updated: The collision detection is working now. However, there a bug I still don't know why. When the bullet collide somewhere near the drone, all the next bullets range get shorten. I can't shot any further until I stop holding right mouse button for a while.

I guess it have something to do with the freeimage timer on line 97.
But without it, the bullet won't disappear.


Here is the code that I use to make bullet. Sorry for posting a long code. If you want to see where the problem is, just skip to line 80 - 146:
Code:
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bullet_speedDam = 1 --bullet speed dam -- more mean slower

--create bullet
drone_id = {}
drone_x = {}
drone_y = {}

--player last positions
drone_player_lastx = {} 
drone_player_lasty = {}

drone_player_index_use = 1 --at which pos drone is tracing
drone_player_index_write = 1 --at which index player last pos got update

drone_update = false --check when player last pos should be updated
drone_moving = false --check when drone should start chasing player

drone_chain_length = 5 --drone chain's length
drone_chain_distance = 0 --extra distance between each drone

bullet_speedDam = 3--bullet speed dam -- more mean slower
bullet_id = {}
bullet_id_max = 3200
bullet_id_index = 1
bullet_id_lifespand = {}

--key check variables and key bind
key_hold_w = false
key_hold_a = false
key_hold_s = false
key_hold_d = false
key_hold_mouse1 = false

addbind("W")
addbind("A")
addbind("S")
addbind("D")
addbind("mouse1")

--create drone
function make_drone(d_id)
  drone_id[d_id] = image("gfx/sprites/flare1.bmp",player(1,"x"),player(1,"y"),0)
  imagecolor(drone_id[d_id],255,100,0)
  imageblend(drone_id[d_id],1)
  tween_animate(drone_id[d_id],100,4)
end

function drone_follow()
     if(key_hold_w or key_hold_a or key_hold_s or key_hold_d) then
          drone_player_lastx[drone_player_index_write] = player(1,"x")
          drone_player_lasty[drone_player_index_write] = player(1,"y")
          drone_player_index_write = drone_player_index_write + 1
          if(drone_player_index_write > drone_chain_length) then
            drone_player_index_write = 1
            drone_moving = true
          end

          if(drone_moving) then
               drone_player_index_use = drone_player_index_use + 1
               if(drone_player_index_use > drone_chain_length) then
                    drone_player_index_use = 1
               end
               
               for i = 0, 1 do
                    if(drone_player_index_use - i - drone_chain_distance>= 1) then
                         drone_x[i+1] = drone_player_lastx[drone_player_index_use - i - drone_chain_distance]
                         drone_y[i+1] = drone_player_lasty[drone_player_index_use - i - drone_chain_distance]
                         tween_move(drone_id[i+1],100,drone_x[i+1],drone_y[i+1])
                    else
                         drone_x[i+1] = drone_player_lastx[drone_chain_length + (drone_player_index_use - i - drone_chain_distance)]
                         drone_y[i+1] = drone_player_lasty[drone_chain_length + (drone_player_index_use - i - drone_chain_distance)]
                         tween_move(drone_id[i+1],100,drone_x[i+1],drone_y[i+1])
                    end
                    
               end
          end
     end
end

--create bullet
function spawn_bullet(id,x,y,dir,dis)
     local lifespand
     local i_id
     
     if(x ~= nil and y ~= nil) then
          i_id = image("gfx/sprites/raindrop.bmp",x,y,0)
          
          dir = (dir - 90) --direction
          imagecolor(i_id,100,100,255)
          imageblend(i_id,1)
          imagepos(i_id,x,y,dir - 90)
          
          --make bullet move toward the destination
          tween_move(i_id,bullet_speedDam * dis, x + dis * math.cos(math.rad(dir)), y + dis * math.sin(math.rad(dir)), dir - 90)
          
          --free bullet when it's reach max distance
          timer(bullet_speedDam * dis,"freeimage",i_id)
          
          --collition detection call -- when to call this using timer?
          image_collision(i_id,lifespand)
     end
end

function image_collision(i_id,lifespand) --how should I do this?
     local x
     local y
     local hitbox
     local hitList
     local hitWall = false
     local tile_property
     
     --msg(type(lifespand))
     
     if(imageparam(i_id,"x") and imageparam(i_id,"y")) then
          x = imageparam(i_id,"x") + 16 * math.cos(math.rad(imageparam(i_id,"rot") + 90))
          y = imageparam(i_id,"y") + 16 * math.sin(math.rad(imageparam(i_id,"rot") + 90))
          --local hitbox = image("gfx/sprites/flare1.bmp",x,y,0)
          --imagecolor(hitbox,255,0,0)
          --imageblend(hitbox,1)
          --tween_animate(hitbox,100,4)
          
          hitList = closeplayers(x,y,16,1)
          tile_property = tile((x - 16)/ 32,(y - 16) / 32,"property")
          
          if(tile_property == 1 or tile_property == 3 or tile_property == 5) then
               hitWall = true
          end
          
          if(hitWall) then
               msg("hit wall")
               freeimage(i_id)
          --     freeimage(hitbox)
          else
               if (hitList[1] ~= nil) then
                    msg("hit player id: "..hitList[1].." at index"..1)
                    freeimage(i_id)
               --     freeimage(hitbox)
               else
                    --set up next function call
               --     timer(10,"freeimage",hitbox)
                    --life = life - 10
                    timer(10,"image_collision",i_id,life)
               end
          end
     end
end

--make drone on spawn
addhook("spawn","hook_spawn")
function hook_spawn(id)
     --make drone for player 1
  if (id == 1) then
    make_drone(1)
     make_drone(2)
     --make_drone(3)
     --make_drone(4)
  end
end

--key check
addhook("key","hook_key")
function hook_key(id,key,state)
     if(id == 1) then
          if(key == 'W') then
               if(state == 1) then
                    key_hold_w = true
               elseif(state == 0) then
                    key_hold_w = false
               end
          elseif(key == 'A') then
               if(state == 1) then
                    key_hold_a = true
               elseif(state == 0) then
                    key_hold_a = false
               end
          elseif(key == 'S') then
               if(state == 1) then
                    key_hold_s = true
               elseif(state == 0) then
                    key_hold_s = false
               end
          elseif(key == 'D') then
               if(state == 1) then
                    key_hold_d = true
               elseif(state == 0) then
                    key_hold_d = false
               end
          elseif(key == "mouse1") then
               if(state == 1) then
                    key_hold_mouse1 = true
               elseif(state == 0) then
                    key_hold_mouse1 = false
               end
          end
     end
end


addhook("ms100","hook_ms100")
function hook_ms100()
     --make drone follow player 1
     drone_follow()
     
      
     --rapid fire mode
     if(key_hold_mouse1) then
          for i = 1, 4 do
               --parse("spawnprojectile "..id.." 75 "..drone_x[i].." "..drone_y[i].." 360 "..player(1,"rot")) --shot snowball
               spawn_bullet(1,drone_x[i],drone_y[i],player(1,"rot"),360)
          end
     end
     
end


addhook("attack","hook_attack")
function hook_attack(id)
     --attack fire mode
     if(id == 1) then
          for i = 1, 2 do
               --parse("spawnprojectile "..id.." 75 "..drone_x[i].." "..drone_y[i].." 360 "..player(1,"rot"))
               --spawn_bullet(1,drone_x[i],drone_y[i],player(1,"rot"),360)
          end
     end
end


addhook("die","hook_die")
function hook_die(id)
     --free drone when die
     if(id == 1) then
          for i = 1, 2 do
               freeimage(drone_id[i])
          end
     end
end
edited 2×, last 22.10.19 08:15:08 am
file cs2d Fishyfinthing's Zombie Mod v0.1.2 (2) Join my server at "142.11.240.170". I hope you will have a good time. Please give some feedback.
22.10.19 09:01:29 am
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TrialAndError
User
Offline Off
Because you are using a timer in the spawn_bullet function, that timer will still get executed even after you remove the image in the image_collision function. Because you remove it and spawn another image, that image might have the same ID as the previous one and the timer that went gets executed and removes the image.

To fix it, you need to stop the execution of the timer when you remove the image.

Added freetimer to line 29 and 35 in the following code:

Code:
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function image_collision(i_id,lifespand) --how should I do this?
     local x
     local y
     local hitbox
     local hitList
     local hitWall = false
     local tile_property
     
     --msg(type(lifespand))
     
     if(imageparam(i_id,"x") and imageparam(i_id,"y")) then
          x = imageparam(i_id,"x") + 16 * math.cos(math.rad(imageparam(i_id,"rot") + 90))
          y = imageparam(i_id,"y") + 16 * math.sin(math.rad(imageparam(i_id,"rot") + 90))
          --local hitbox = image("gfx/sprites/flare1.bmp",x,y,0)
          --imagecolor(hitbox,255,0,0)
          --imageblend(hitbox,1)
          --tween_animate(hitbox,100,4)
          
          hitList = closeplayers(x,y,16,1)
          tile_property = tile((x - 16)/ 32,(y - 16) / 32,"property")
          
          if(tile_property == 1 or tile_property == 3 or tile_property == 5) then
               hitWall = true
          end
          
          if(hitWall) then
               msg("hit wall")
               freeimage(i_id)
               freetimer("freeimage",i_id)
          --     freeimage(hitbox)
          else
               if (hitList[1] ~= nil) then
                    msg("hit player id: "..hitList[1].." at index"..1)
                    freeimage(i_id)
                    freetimer("freeimage",i_id)
               --     freeimage(hitbox)
               else
                    --set up next function call
               --     timer(10,"freeimage",hitbox)
                    --life = life - 10
                    timer(10,"image_collision",i_id,life)
               end
          end
     end
end
22.10.19 09:41:17 am
Up
FishyFinThing
User
Offline Off
Thank for help, the bug is fixed!

I will finish the code soon. Let's hope there won't be anymore problem that I can't solve.
file cs2d Fishyfinthing's Zombie Mod v0.1.2 (2) Join my server at "142.11.240.170". I hope you will have a good time. Please give some feedback.
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