Need help with "shooting a projectile" and a "password menu"

[Alex C.]

What is it you are trying to achieve?

1) Have a image fire a projectile vertically
2) Create a password entry area (for cheats and such unlockables =D)


What is the problem you are having?

I have no knowledge on either of those topics... =(


Describe what you have tried to solve this problem



Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)
<Answer Here>

Turing:

View.Set ("nobuttonbar,offscreenonly") var x, y : int x := 100 y := 100 var chars : array char of boolean loop     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) then         y := y + 3     end if     if chars (KEY_RIGHT_ARROW) then         x := x + 3     end if     if chars (KEY_LEFT_ARROW) then         x := x - 3     end if     if chars (KEY_DOWN_ARROW) then         y := y - 3     end if     if chars (/*SHOOTING KEY*/) then        %SHOOTING CODE     end if     drawfilloval (x, y, 40, 40, 56)     delay (10)     put "Use the arrow keys to move the ball, and press ESC to exit"     View.Update     cls end loop

for a password screen... yeah no clue

Please specify what version of Turing you are using

um... it's 4.1.1

[chipanpriest]

You seem to already know how to shoot a projectile given your code. For the password thing, you can do a simple get code. Do something like:

Turing:

var answer : string get answer : * if answer = whateverthepasswordis then cheat := true end if

[Alex C.]

alright, but when I try to shoot the projectile & move, the shot follows the character...

[Tony]

things like

code:

var x, y : int

are ambiguous. Use descriptive names, such as

code:

var character_x, character_y : int

If you find yourself drawing projectiles using the values of character_x, then that is a problem.

[Alex C.]

thanks!

[Velocity]

instead of y := y + 5

Write y += 5 its the same thing, its more advanced, saves you .5 milliseconds and it looks pro. You can do it for any operator. For the password... Seems like you have knowlendge of arrays so make an array say a max 3 range, and call each variable from the array and declare that variable with a password. Any text that u decide
And then make a put and get statement and write if password say (1) of your array = true then .... Whatever the password does. Oh and do you still need help with shooting projectiles?.

[Tony]

Velocity @ Wed Jan 11, 2012 12:18 am wrote:

instead of y := y + 5

Write y += 5 its the same thing

It's almost the same thing. Fun exercise -- find a case where the difference matters. (For most practical purposes, this difference doesn't matter).

[chipanpriest]

Your shot probably follows your player because you are using the same variables for the coordinates of your player and the coordinates of the shot. In order to make the shot not follow your player, you would need separate variables for the player and the shot; for example,

Turing:

if chars (/*SHOOTING KEY*/) then        %This would need a separate x and y variable than the ones you are using such as bulletx and bullety     end if

[Velocity]

tony, in which case would you use one over the other ? Ima look around

[tg851]

chipanpriest @ Tue Jan 10, 2012 9:32 pm wrote:

You seem to already know how to shoot a projectile given your code. For the password thing, you can do a simple get code. Do something like:

Turing:

var answer : string get answer : * if answer = whateverthepasswordis then cheat := true end if

its actually

Turing:

var answer : string get answer : * if answer = "whateverthepasswordis" then cheat := true end if

otherwise it will look for a nonexistent variable, instead of checking the string
also

Tony @ Wed Jan 11, 2012 1:09 am wrote:

Velocity @ Wed Jan 11, 2012 12:18 am wrote:

instead of y := y + 5

Write y += 5 its the same thing

It's almost the same thing. Fun exercise -- find a case where the difference matters. (For most practical purposes, this difference doesn't matter).

x= instead of x:= makes the argument flimsy if x go a change from floor or another command that changes it to something other that int(like from int to true)the error module will throw a fit(I think)

[Tony]

Velocity @ Wed Jan 11, 2012 8:40 am wrote:

tony, in which case would you use one over the other ? Ima look around

When the following behaviour difference matters

code:

#include <iostream> int foo = 0; int& var() {         std::cout << "eval var" << std::endl;         return foo; } int main() {         std::cout << "TEST +" << std::endl;         foo = 1;         var() = var() + 5;         std::cout << "result: " << foo << std::endl;         std::cout << std::endl << "TEST +=" << std::endl;         foo = 1;         var() += 5;         std::cout << "result: " << foo << std::endl;                 return 0; }

[DemonWasp]

Given that the context is a Turing Help thread, this may be a more pertinent example:

Turing:

fcn modify ( var v : int ) : int     v := v + 1     result v end modify var a : int := 1 % Depending on which line you uncomment, the result changes. %a := a + modify(a)     % puts 3 %a += modify(a)         % puts 3 %a := modify(a) + a     % puts 4 put a

[Tony]

@DemonWasp this looks like an order-of-operation difference, rather than assignment operators. The modify() function is equivalent to ++v.

The important difference with += is that the evaluation takes place only once. This shouldn't even matter for simple variables, as I'd expect a good compiler to rewrite that in whichever version is faster (I'm expecting speed difference to be on the order of ++a vs. a++). This difference could matter if the variable comes from an expression. Here's a Turing example:

code:

var list : array 1 .. 10 of int := init(1,2,3,4,5,6,7,8,9,10) list[Rand.Int(1,10)] := list[Rand.Int(1,10)] + 1 % vs list[Rand.Int(1,10)] += 1

[DemonWasp]

Apparently I'd forgotten just how C-like Turing really can be. Here's your example, translated:

Turing:

% I couldn't find any syntax to allow me to get a pointer to an existing int % var in 5 minutes, so I gave up. This works alright, even if it gets messy. var foo : ^ int new foo % varr because "var" is a reserved keyword fcn varr() : ^int     put "eval varr"         result foo end varr % main... ^foo := 1 ^(varr()) := ^(varr()) + 5; put "result: ", ^foo ^foo := 1 ^(varr()) += 5 put "result: ", ^foo

In any case, both of these are relatively benign: you have to explicitly say that you wanted something done twice. They only become evil if you start defining macros so that they look like plain variables:

code:

#define RANDOM_ENTRY list[randint(LIST_SIZE)] // Yes: RANDOM_ENTRY += 5; // Whoops: RANDOM_ENTRY = RANDOM_ENTRY + 5;

[Velocity]

oooh, okay but tony, i was just talking about how the y+=5 would be better than y := y + 5 in this case