[Tutorial] whatdotcolor

[Cuzty]

Ok mister whatdotcolor master guy.. umm i was wondering if you can make the bullet kill the ball that comes down. And i apologize for the crappy code.. i'm not very good at this turing stuff so plz bear with me .

code:

setscreen ("offscreenonly") var m, x, a, b, ymouse, xmouse, button : int %The Plane procedure plane     drawline (xmouse - 4, 5, xmouse, 40, 4)     drawline (xmouse - 3, 5, xmouse, 40, 4)     drawline (xmouse - 2, 5, xmouse, 40, 4)     drawline (xmouse - 1, 5, xmouse, 40, 4)     drawline (xmouse, 5, xmouse, 40, 4)     drawline (xmouse + 1, 5, xmouse, 40, 4)     drawline (xmouse + 2, 5, xmouse, 40, 4)     drawline (xmouse + 3, 5, xmouse, 40, 4)     drawline (xmouse + 4, 5, xmouse, 40, 4) end plane %The falling ball process nme     loop         cls         randint (m, 10, maxx - 10)         for decreasing i : maxy .. 1 by 7             drawfilloval (m, i, 10, 10, 4)             delay (10)         end for     end loop end nme %Your Plane process you     loop         mousewhere (xmouse, ymouse, button)         cls         plane         View.Update         %The Bullet         if button = 1 then             a := xmouse             b := ymouse             for i : 40 .. 400 by 5                 cls                 mousewhere (xmouse, ymouse, button)                 plane                 drawline (a - 1, i, a - 1, i + 40, 7)                 drawline (a, i, a, i + 40, 7)                 drawline (a + 1, i, a + 1, i + 40, 7)                 View.Update             end for         end if     end loop end you fork nme fork you

Oh, and if possible.. can you make the ball stop flickering? Thanks so much in advance, sir.

[Leny]

Ok so you can do anything with whatdotcolour so help me then how do i do what dot coulr in a circular pattern

i.e. in my curling game i need to do the scoreing at the end by checking which rocks are closer to the center

so if there are two blue rocks closer then the first red rock then the score becomes two blue or one red rock cloest to the center then a blue one closer then the next red one then the score is one red

how would i do that?

[Tony]

Leny : don't make things complicated and just use Math.Distance()

[Leny]

our school computers can't do that i've tried it as well as others and it wont work for anyone including the teach who knows what she's doing

[Tony]

Leny : Math.Distance is a v4.0.5 feature. If you don't have the latest version of turing installed, you can write this function yourself

code:

function distance (x1, y1, x2, y2 : int) : real     result sqrt ((x2 - x1) ** 2 + (y2 - y1) ** 2) end distance %example put distance (0, 0, 3, 4)

[Leny]

so how would i use this math.distance thingger then? is there a tutorial on it?

or maybe a basic program with it to look at

[Tony]

leny : there is a tutorial now

[Leny]

thanks man if i have any trouble i'ma ask ya more about it but i should figure it out

[theanimator]

this whatdotcolour makes no sense to me at all. Bare with me i am just a beginner.

[TokenHerbz]

code:

(x1,xy)  <-----TOP RIGHT OF SQUARE     %%%%%%%     %     %     %     %     %%%%%%%             (x,y)           <<---  BOTTOM LEFT OF SQUARE!    whatdotcolor takes the 2 varibles, say (x,y) and looks on the background  of your program, and sees which colour it is on...

heres an example!

code:

%%Example. setscreen("Graphics:max;max,offscreenonly") var x,y: int var x1,y1: int x:= 50 y := 50 x1:= x+50 y1 := y+20 loop     cls     x += 1     x1+= 1     drawfillbox(225,25,175,75,black)     %%this is BIG BLACK BOX!     if whatdotcolor(x,y) = 7 then  %%IF x,y SEE BLACK!         exit    %%LEAVES THE LOOP!     end if     drawbox(x,y,x1,y1,red)     View.Update     delay(20) end loop put "Done"

If you run that, you will see it stops only when x,y get hit...

Now if we refer to the top diagram i shows, x1,y1 need to be in play aswell.! this way it will stop at the front.

So we just modify this here...

code:

if whatdotcolor(x,y) = 7 or  %%IF x,y SEE BLACK!         whatdotcolor(x1,y1) = black then    %%7 and black are the same thing.         exit    %%LEAVES THE LOOP!     end if

run it...

BUT, lets see, change y to this ...

code:

y:= 65

Run that, now you will see that the x1,y1 position is missed, and its not a detection collition at all, so we have to think hard cause programming not easy. For effective collotioning/ useing whatdotcolor, you must cover all angles, i trust you learned a bit??? Well Gl with this! i ll let you try some stuff now


EDIT::

So, we need to be creative (which i am not) and make a simple code what checks all of the obsticle, or at least.. the border of it.

um somthing like??

code:

%%Example. setscreen("Graphics:max;max,offscreenonly") var x,y: int var x1,y1: int var endgame: boolean := false x:= 50 y := 65 x1:= x+50 y1 := y+20 loop     if endgame = true then         exit     end if     cls     x += 1     x1+= 1     drawfillbox(225,25,175,75,black)     %%this is BIG BLACK BOX!     for i: x .. x1         for j: y .. y1             if whatdotcolor(i,j) = 7 then  %%IF x,y SEE BLACK!                 endgame := true    %%SETS END GAME!                 exit             end if         end for         if endgame = true then             exit         end if     end for     drawbox(x,y,x1,y1,red)     View.Update     delay(20) end loop put "Done"

Notice how slow it moves, its not efficiant, cause its checking the INSIDE of the rectangle, when we only need it to check the borders, so ill let you think about it, and work with that... Bye!


EDIT:::

Well again i wish to help you think on how to visualize getting a border..

if we think a 5*5 square..

its,

code:

x,y: int := 0 drawbox(x,y,x+5,y+5,black)

lets look at the *structure* of this

NOTE::: The 1st numbers are x axis numbers, 2nd are the y axis.

code:

1,5  2,5  3,5  4,5  5,5 1,4  2,4  3,4  4,4  5,4 1,3  2,3  3,3  4,3  5,3 1,2  2,2  3,2  4,2  5,2 1,1  2,1  3,1  4,1  5,1

So with that there, Try to code a patter which checks essentailly only these numbers.

code:

1,5  2,5  3,5  4,5  5,5 1,4                 5,4 1,3                 5,3 1,2                 5,2 1,1  2,1  3,1  4,1  5,1

Now, to make it a bit easier for you to get which variables are which..

code:

x,y+4 | x+1,y+4 | x+2,y+4 | x+3,y+4 | x+4,y+4 x,y+3                                 x+4,y+3 x,y+2                                 x+4,y+2 x,y+1                                 x+4,y+1 x,y   | x+1,y   |  x+2,y  |  x+3,y  |  x+4,y

Now you wouldn't want to enter in all the possible variables for a big square, so image if you could have a counter??

of course then, you could replayce all the numbers with i(for x axis) and j(for y axis)

The code gets a little complex, and ill post it later if you dont get it

i think i tend to make thinks more complex then they should :S

[BenLi]

i have a question, why would you use whatdotcolor for things that can probably be done easier with other methods? its a total waste of time

[md]

Because it works for very simple cases and doesn't require consious thought.

Really using math to do collisions is only easy if you know the (admittedly basic) math and are familiar enough with things like records to keep track of everythign easily.

[HellblazerX]

Whatdotcolor is not useless. In fact, it's quite useful in collision detection. Normally, you would use coordinates and calculate whether or not one object is within another, but with whatdotcolor, you can easily determine whether or not the objects have collided by checking the colors of a particular point. Also, if you use coordinates, collision detection becomes more and more difficult when more objects are placed on the field, and the objects themselves become more complicated in their shapes. With whatdotcolor, it doesn't get that much more difficult.

[Andy]

cornflakes! you're such a blasphemer! how dare you say that about whatdotcolour? haha jk..

my obsession with whatdotcolour has nothing to do with "taking the easy way" but rather thinking abstractly. collision detection whatdotcolor is for noobs... unless you're talking about masking irregular shapes

[BenLi]

Though for the example above, it'd be much better to use Math.Distance for the circle