Determining the color of an object

[Banished_Outlaw]

How can i determine the color of an object i drew? I have a program in which rain drops are falling down. They are in a loop and I cannot use cls to erase the droplets because that erases everything i have in the background. The only other way i could think of is to draw the raindrops again with their color matching the color of the object drawn in the background so that it appears that they have vanished. Can anyone tell me how i can do this?

[Cervantes]

You have two options, as I see it. One is to record the data about what you have drawn. That is, store the colour and position of the rain drops that have already been drawn, then cls and redraw them. The other option is to use whatdotcolour. Without further knowledge of your purpose, I don't think I can decide which is better. The answer to your initial question is whatdotcolour, but I suspect storing the data is better for your purposes.

[Banished_Outlaw]

How do i record the color of the objects i draw? I dont think i can use cls because cls clears everything and i do not want that happening. This is what i have so far:

code:

%BACKGROUND drawfillbox (0, 0, maxx, maxy, 16) %GROUND drawfillbox (0, 0, maxx, round (maxy / 2.5), 6) %STEPHEN LEACOCK var font := Font.New ("comic sans:16:bold,underline") drawfillbox (40, 162, 180, 320, grey) drawfillbox (180, 162, 450, 380, grey) drawfillbox (400, 162, 600, 320, grey) drawbox (40, 162, 180, 320, red) drawbox (180, 162, 450, 380, red) drawbox (450, 162, 600, 320, red) Font.Draw ("SCHOOL NAME", 195, 350, font, brightblue) %FACE drawfilloval (320, 300, 25, 35, white) %LEFT EAR drawfilloval (300, 300, 8, 10, white) %RIGHT EAR drawfilloval (340, 300, 8, 10, white) %NECK drawfillbox (310, 265, 330, 275, white) %STOMACH drawfilloval (320, 200, 30, 70, white) %LEFT THIGH drawfilloval (304, 120, 10, 70, white) %RIGHT THIGH drawfilloval (336, 120, 10, 70, white) %RIGHT HAND drawfilloval (275, 240, 60, 8, white) %LEFT HAND drawfilloval (365, 240, 60, 8, white) %LEFT EYE drawfilloval (308, 305, 8, 5, brightred) %LEFT IRIS drawfilloval (308, 305, 2, 2, white) %LEFT EYEBROW drawarc (308, 298, 10, 20, 25, 150, black) %RIGHT EYE drawfilloval (332, 305, 8, 5, brightred) %RIGHT IRIS drawfilloval (332, 305, 2, 2, white) %RIGHT EYEBROW drawarc (332, 298, 10, 20, 25, 150, black) %NOSE drawfillbox (315, 294, 325, 298, black) %MOUTH drawfilloval (320, 285, 8, 5, black) drawfilloval (320, 215, 30, 60, white) drawfilloval (320, 215, 30, 60, white) drawfilloval (320, 215, 30, 60, white) process bloodrain     var x : int     var y : int := 500     for k : 1 .. 100000         randint (x, 0, maxx)         %randint (y, 0, maxy)         drawfilloval (x, y, 2, 4, brightred)         delay (100)         y := y - 20         if y = 0 then             y := 500         end if     end for end bloodrain process bloodfill     for j : 1 .. 100000         delay (100)         drawfillbox (0, 0, maxx, round (j), brightred)         if j > 72 then             %MOUTH             drawfilloval (320, 282, 10, 8, white)             drawfilloval (320, 285, 9, 7, black)             %RIGHT HAND             drawfilloval (275, 240, 60, 8, grey)             %LEFT HAND             drawfilloval (365, 240, 60, 8, grey)             %STOMACH             drawfilloval (320, 200, 30, 70, white)             %RIGHT HAND             drawfilloval (275, 240, 30, 10, white)             %LEFT HAND             drawfilloval (365, 240, 30, 10, white)             %RIGHT HAND             drawfilloval (250, 272, 8, 40, white)             %LEFT HAND             drawfilloval (390, 272, 8, 40, white)         end if         if j > 140 then             drawfilloval (320, 282, 10, 20, black)             drawfillbox (0, 0, maxx, round (j), brightred)         end if     end for end bloodfill fork bloodrain fork bloodfill

[Cervantes]

I'm saying you record the data, cls, then redraw it.

To record the data, you'd probably want to use a flexible array of records. Check out the [Turing Walkthrough] for links to tutorials on these subjects.

Also, please, don't use processes. It is not necessary for something like this, and there are many downsides to them. Read more here.

[Geostigma]

Why can't you use cls again? have your rain drops in a array and if spawns a drop then have a procedure to make it move x amount of pixels...

[Banished_Outlaw]

But this is supposed to be a fairly easy project where I only have to draw some stuff. A bit of animation is allowed and we also have not covered records yet. I read the walk through and its really helpful but I don't want to spend time making records as it is due tomorrow. But thanks a lot for your help. You guys really know a lot. I'm just probably gonna let the rain drops stay on the screen or remove the rain and make a lightning thing in a process and fork it.

[Cervantes]

As you wish, but that's a really awful way to do it. It hurts my head to consider it.

[Banished_Outlaw]

lol dun worry i got really good marks on the project...just gotta do some more commenting...and a pseudocode...but we have started doing records and two dimensional arrays now..so if i get time i will try making the program better