moving and shooting

[msimard8]

Hello

How do you move a object and shoot something out of it ...and have the bullet moving while your moving aswell.

ya i know that question may be hard to understand. The code is part of what I have done, and you will see what i mean. I freeze until the bullet stops moving.

code:

setscreen ("graphics:649;479") var gx, gy : int := 20 var key : array char of boolean var ly : int := 20 var lx : int := 30 var weaponex : int := 370 proc background     drawfillbox (0, 0, 500, maxy, black) end background proc scoreboard     drawfillbox (501, 0, 649, 479, 12) end scoreboard %checks input keys proc press         if key (KEY_UP_ARROW)                 then             gy := gy + 1             ly := ly + 1         end if         if key (KEY_LEFT_ARROW)                 then             gx := gx - 1             lx := lx - 1             weaponex := weaponex + 1         end if         if key (KEY_DOWN_ARROW)                 then             gy := gy - 1             ly := ly - 1         end if         if key (KEY_RIGHT_ARROW)                 then             gx := gx + 1             weaponex := weaponex - 1             lx := lx + 1         end if         if gx < -80 then             weaponex := 480         elsif gx > 389 then             weaponex := 0         end if end press %.........fireing bullet animation proc gun     setscreen ("nooffscreenonly")     for c : 1 .. weaponex             scoreboard         background         drawfilloval (100 + gx, 100 + gy, 10, 10, red)         drawfilloval (100 + lx + c, 100 + ly, 2, 2, yellow)             setscreen ("offscreenonly")           View.Update       end for end gun %.......allows guy to move around and activates weapon proc good     loop               background         scoreboard                 delay (5)         Input.KeyDown (key)         drawfilloval (100 + gx, 100 + gy, 10, 10, red)    setscreen ("offscreenonly") press         if key ('a') or key ('s') or key ('d') or key ('w')                 then             gun         end if         View.Update         cls end loop end good good

[Cervantes]

This will require you to learn some new concepts.
Turing Walkthrough -> Arrays -> Flexible Arrays
In the flexible array tutorial, there is an example of this very thing.
It would also be good to know how to use records to keep things organized and to same you some code when you have to remove a bullet.

[msimard8]

I dont understand how to incorperate flexible arrays and records to solve this problem

thanks

[Cervantes]

Have you read my tutorial and looked at the source code?

Make a flexible array of bullets:

code:

var bullet : flexible array 1 .. 0 of    record       x, y, vx, vy : real    end record

When you hit the fire button (via Input.KeyDown), incriment the flexible array.

code:

new bullet, upper (bullet) + 1 bullet (upper (bullet)).x := player.x bullet (upper (bullet)).y := player.y %3 + player.velocity represents the velocity of the bullet bullet (upper (bullet)).vx := cosd (player.angle) * (3 + player.velocity)  bullet (upper (bullet)).vy := sind (player.angle) * (3 + player.velocity)

Notice how I added that 3 + player.velocity. Remember we're not shooting beams of light here.

Movement of the bullet is like such:

code:

bullet.x += bullet.vx bullet.y += bullet.vy

When you want to delete the bullet (it has collided with something or gone passed its range):

code:

bullet (bulletToDelete) := bullet (upper (bullet)) new bullet, upper (bullet) - 1

See here we are copying the upper bullet to the position of the one we want to delete and then deleting the original upper bullet. If you want to keep the bullets in "order", you'll need a for loop:

code:

for i : bulletToRemove + 1 .. upper (bullet)     bullet (i - 1) := bullet (i) end for new bullet, upper (bullet) - 1

Hope that helps