whatdotcolour Problem

[bharath1000]

I'm trying to use the whatdotcolour command and it is not working for me (Note: first time using this command) and i dont see what is wrong with what i did... im trying to make the character stop when it hits the white block

Turing:

View.Set ("graphics:800;600,offscreenonly,nobuttonbar") %%%%%%%%%%%%%%%%%%%%%%%%%%%VARIABLES%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% var chars : array char of boolean var hossam, hossamm : int var x : int := 10 var y : int := 0 var xsize : int := 23 var ysize : int := 80 var velx : int := 0 var vely : int := 0 var groundheight := 0 const gravity := 1 const runspeed := 5 const jumpspeed := 15 var brickcolour : int := white %%%%%%%%%%%%%%%%%%%%%%%%%%%DECLARATIONS%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% hossam := Pic.FileNew ("hossam.BMP") %%%%%%%%%%%%%%%%%%%%%%%%%%%INITIAL SCREEN%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Pic.Draw (hossam, x, y, picMerge) drawfillbox (500, 0, 510, 80, brickcolour) colourback (black) loop     Pic.Draw (hossam, x, y, picMerge)     drawfillbox (500, 0, 523, 80, brickcolour)     View.Update     delay (10)     cls     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) then         vely := 5     end if     if chars (KEY_LEFT_ARROW) then         velx := -3     elsif chars (KEY_RIGHT_ARROW) then         velx := +3     else         velx := 0     end if     if chars (KEY_UP_ARROW) then         y += vely         vely -= gravity     else         vely := 0     end if     x+=velx     if chars (KEY_LEFT_ARROW) and whatdotcolor (round (x) - xsize - 1, round (y)) = brickcolour then         x -= velx     end if     if chars (KEY_RIGHT_ARROW) and whatdotcolor (round (x) + xsize + 1, round (y)) = brickcolour then         x -= velx     end if end loop

Please specify what version of Turing you are using
Turing 4.1.1

[Insectoid]

code:

round (x) - xsize - 1

Where is this point?

Why do you check again if the left/right arrow keys are pressed before subtracting the velocity?

You're only checking if a 1-pixel-thick line at the top of Hossam's head and twice his width is hitting the brick. Can you figure out why?

[bharath1000]

Thank you.. i got it too work but now there is another problem.... the character sinks through the ground every time he jumps from a certain height . is there any way to fix??

Turing:

View.Set ("graphics:800;600,offscreenonly,nobuttonbar") %%%%%%%%%%%%%%%%%%%%%%%%%%%VARIABLES%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% var chars : array char of boolean var hossam, hossamm : int var x : int := 10 var y : int := 250 var velx : int := 0 var vely : int := 0 var groundheight := false const gravity := 5 const runspeed := 5 const jumpspeed := 40 %%%%%%%%%%%%%%%%%%%%%%%%%%%DECLARATIONS%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% hossam := Pic.FileNew ("hossam.BMP") hossamm := Pic.FileNew ("hossammotion.BMP") %%%%%%%%%%%%%%%%%%%%%%%%%%%INITIAL SCREEN%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% procedure foreground     drawfillbox (0, 0, 150, 150, green)     drawfillbox (303, 0, maxx, 150, green)     drawfillbox (210, 150, 250, 200, green) end foreground Pic.Draw (hossam, x, y, picMerge) foreground View.Update %%%%%%%%%%%%%%%%%%%%%%%%%%%INTERFACE CONTROL%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% loop     Pic.Draw (hossam, x, y, picMerge)     View.Update     cls     if y > 0 then         vely -= gravity         y += vely     end if     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) and groundheight = true then         vely := jumpspeed         y += vely     end if     if chars (KEY_RIGHT_ARROW) and x not= 775 then         velx := runspeed         x += velx     elsif chars (KEY_LEFT_ARROW) and x >= 0 then         velx := -runspeed         x += velx     else         velx := 0     end if     foreground     drawfillbox (400, 150, 500, 200, green)     if View.WhatDotColor (x + 20, y + 20) = green then         velx := 0         velx -= runspeed         x += velx     end if     if View.WhatDotColor (x + 5, y + 20) = green then         velx := 0         velx += runspeed         x += velx     end if     if View.WhatDotColor (x + 5, y + 5) = green then         groundheight := true         vely := 0         vely += gravity         y += vely     else         groundheight := false     end if     delay (50) end loop put "Game Over!"

[/list]

[Insectoid]

If the character is below the ground, what can you do to put him on the ground again?

Also:

code:

vely := 0         vely += gravity         y += vely

You can reduce this part to one line.

[bharath1000]

there is a ground height and it works but eveytime i jump i land a few units below the ground and float back up to the ground height again

[Insectoid]

You do not have a ground height. You have a boolean called ground height, but that does not represent the height of the ground. Ground height should be an integer, and if your character's y value is lower than that integer, you are underground.

code:

if View.WhatDotColor (x + 5, y + 5) = green then         groundheight := true         vely := 0         vely += gravity         y += vely     else         groundheight := false     end if

What is this code doing?

You check if the character is underground, then you set vely to gravity (vely := 0, vely += gravity is equivalent to vely := gravity). Gravity is a positive value (5). Then you add vely (gravity) to y. So if your character is underground, he will float up at 5 pixels per second.

This issue is not easily solved with whatdotcolor. Not as easily as regular collision detection anyway. Actually, whatdotcolor is pretty bad overall. It will take a lot of work to switch over to a better system, but once you've done that everything becomes a lot easier.

[bharath1000]

Can you explain what the better system is? or at least the idea of it?

[Insectoid]

I could, but the Turing Walkthrough already did.

[Raknarg]

I think he's referring to using actual objects for detection rather than colour. So instead of landing on a colour, you land on top of the range of an object. It makes it much more flexible, and you don't have to keep using the same colour.

[Insectoid]

Actually, whatdotcolor doesn't limit your pallet at all. Using View.Update, you draw your simple colors, do all your detection work, then draw the real image on top, then update the screen.

[Raknarg]

So it reads the buffer, not the screen itself? I didn't know that