----------------------------------- Canned Thu Sep 11, 2008 6:52 pm [HELP] Circle to Line Collision ----------------------------------- I know how to do rectangle collision, but how do I detect whether a circle has collided with a line? ----------------------------------- [Gandalf] Thu Sep 11, 2008 8:11 pm RE:[HELP] Circle to Line Collision ----------------------------------- I believe everything you need is included in the [url=http://compsci.ca/v3/viewtopic.php?p=139959]collision detection tutorial by richcash. Take a look on the second page for circle-line collisions. ----------------------------------- evildaddy911 Sun Oct 16, 2011 11:52 am RE:[HELP] Circle to Line Collision ----------------------------------- same problem man, i looked at the tutorial a week ago, and still havent figured out how to do it :idea: im thinking that a good way would be to use the area/circumference formula, and whatdotcolor, but i havent figured out out to do the for loops for that ----------------------------------- Aange10 Sun Oct 16, 2011 12:47 pm Re: [HELP] Circle to Line Collision ----------------------------------- idea im thinking that a good way would be to use the area/circumference formula, and whatdotcolor, but i haven't figured out out to do the for loops for that Yes, there are many ways to do it (: ... For loops can be confusing at first, but once you lean them you'll find out how useful they are(:. But, anyways, I've taken a look at what you all want to do, and I've decided I'll help you all learn how to do it. First and foremost, everything (other than the fors) I used came from http://compsci.ca/v3/viewtopic.php?t=13661&postdays=0&postorder=asc&start=0 (Collision detection tutorial). Sometimes it's easier, though, to learn when you already have a basic gist of things. Anyways, on to yall's problem: I know how to do rectangle collision, but how do I detect whether a circle has collided with a line? The same basic ideas. Lets look step-by-step at what to do. Now, the first thing to do (as always) is to define our variables. Here's my example I'll be using: View.Set ("graphics:maxx;maxy,position:center;center") % Set Screen % Define Variables var circle_radius, circle_x, circle_y : int var line_x1,line_x2,line_y1,line_y2 : int var circle_x_velocity : real := 3.0 circle_radius := 20 circle_x := 20 circle_y := maxy div 2 line_x1 := maxx - (maxx div 2) + 70 line_x2 := maxx - (maxx div 2) - 30 line_y1 := maxy div 2 line_y2 := maxy div 2 % An array so we can check the distance from each point in the line var distance : array 0 .. (line_x1 - line_x2) of real %% Everything is pretty straight forward. We have variables to keep track of the points in the line, and the x,y & radius of the circle. Now, if you don't know what arrays are yet, I suggest you read http://compsci.ca/v3/viewtopic.php?t=14333, before you continue. ... The purpose of this array is so that we can find the distance from our circle to every point in the line (as apposed to just one point of the line). Our next step is to put this array to use, using the equation given to us in the Collision Detection tutorial (the distance formula). % Moves the circle circle_x += round (circle_x_velocity) % Update the distance from the circle to each point of the line for i : 0 .. upper (distance) distance (i) := sqrt (((line_x1 - i) - circle_x) ** 2 + ((line_y1) - circle_y) ** 2) end for Now, the trick here is with the for statement. A for is just an infinite loop that repeats a number of times (x .. y) in this case, (0 .. upper(distance)), now if you read the arrays tutorial, you'll know that upper(distance) is just a pointer to the upper range of the array distance. Which in this case is (line_x1 - line_x2). So, to clarify, we have a for loop i that is repeating its self o .. upper(distance) times. In this situation, upper(distance) is = line_x1 - line_x2 which is = 100. So it's repeating itself 101 times (0 counts as a time!). Each time a for executes its self, it assigns the number of executions to the variable i. So if it's on it's 20th execution, i = 19 (remember, 0 counts as an execution!). ... Now that we have a basic understanding of for loops (if you're still confused I suggest you read http://compsci.ca/v3/viewtopic.php?t=3678 as they can explain it better than I can), we can continue with the code: As I said before, each time the for executes, it assigns i a value. Now by adding i into our distance equation, we effectively check every point on the line. % Draw our objects drawline (line_x1, line_y1, line_x2, line_y2, red) drawfilloval (circle_x, circle_y, circle_radius, circle_radius, blue) % Check for collision at each point for i : 0 .. upper (distance) if distance (i) execute the function -> output the result than it does for it to just do the equation.) ----------------------------------- evildaddy911 Sun Oct 16, 2011 2:39 pm RE:[HELP] Circle to Line Collision ----------------------------------- for now im going to stick to the Math.Distance, thanks for the help! ----------------------------------- Aange10 Sun Oct 16, 2011 2:46 pm RE:[HELP] Circle to Line Collision ----------------------------------- No problem!(: So I take it your program works now? ----------------------------------- evildaddy911 Sun Oct 16, 2011 3:01 pm RE:[HELP] Circle to Line Collision ----------------------------------- not completely, i have to change half the code... ----------------------------------- Aange10 Sun Oct 16, 2011 3:08 pm Re: RE:[HELP] Circle to Line Collision ----------------------------------- not completely, i have to change half the code... Happens =/ ... If you need help feel free to ask EDIT: Just realized A for is just an infinite loop that repeats a number of times ... Oops. Sorry, i meant to say "A for is just a loop that repeats itself a number of times" Sorry 8-) ----------------------------------- evildaddy911 Sun Oct 16, 2011 3:24 pm Re: [HELP] Circle to Line Collision ----------------------------------- yah, im stuck :cry: heres my code, im trying to replace the whatdotcolor for the brightgreen i shoot and the purple that the enemy shoots: [code]View.Set ("graphics:max;max,nobuttonbar") var myx, myy, mousex, mousey, button, cpuhp, myhp, kills, damage, typ, rad, enemyx, enemyy, move, score, dlay : int var mode : string var chars : array char of boolean enemyx := Rand.Int (100, maxx - 100) enemyy := Rand.Int (100, maxy - 100) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % DRAWENEMY proc drawenemy drawfilloval (enemyx, enemyy, 10, 10, white) move := Rand.Int (1, 8) if enemyx > 0 then if move = 1 then enemyx := enemyx + Rand.Int (1, 6) end if end if if enemyy > 0 then if move = 2 then enemyy := enemyy + Rand.Int (1, 6) end if end if if enemyx < maxx then if move = 3 then enemyx := enemyx - Rand.Int (1, 6) end if end if if enemyy < maxy then if move = 4 then enemyy := enemyy - Rand.Int (1, 6) end if end if if enemyy < maxy then if enemyx < maxx then if move = 5 then enemyy := enemyy - Rand.Int (1, 6) enemyx := enemyx - Rand.Int (1, 6) end if end if end if if enemyy < maxy then if enemyx > 0 then if move = 6 then enemyx := enemyx + Rand.Int (1, 6) enemyy := enemyy - Rand.Int (1, 6) end if end if end if if enemyy > 0 then if enemyx > 0 then if move = 7 then enemyx := enemyx + Rand.Int (1, 6) enemyy := enemyy + Rand.Int (1, 6) end if end if end if if enemyy > 0 then if enemyx < maxx then if move = 8 then enemyx := enemyx - Rand.Int (1, 4) enemyy := enemyy + Rand.Int (1, 4) end if end if end if drawfilloval (enemyx, enemyy, 10, 10, black) drawfilloval (enemyx - 2, enemyy, 1, 2, green) drawfilloval (enemyx + 2, enemyy, 1, 2, green) drawline (enemyx - 3, enemyy - 4, enemyx + 3, enemyy - 4, red) end drawenemy % HEALTH proc health if whatdotcolor (enemyx, enemyy) = brightred then cpuhp := cpuhp - 7500 end if if whatdotcolor (enemyx, enemyy) = brightblue then cpuhp := cpuhp - 125 end if if whatdotcolor (enemyx, enemyy) = brightgreen then cpuhp := cpuhp - 3 end if if whatdotcolor (myx, myy) = purple then myhp := myhp - 5 end if if whatdotcolor (myx, myy) = gray then myhp := myhp - 100 end if if whatdotcolor (myx, myy) = brightblue then myhp := myhp - 200 end if put cpuhp put myhp end health % DAMAGE proc dmge for counter : 0 .. 100 if whatdotcolor (counter, 100) = brightred then damage := damage + 125 score := score + 125 end if if whatdotcolor (100, counter) = brightred then damage := damage + 125 score := score + 125 end if if whatdotcolor (counter, 100) = brightblue then damage := damage + 2 score := score + 2 end if if whatdotcolor (100, counter) = brightblue then damage := damage + 2 score := score + 2 end if if whatdotcolor (counter, 100) = brightgreen then damage := damage + 1 score := score + 1 end if if whatdotcolor (100, counter) = brightgreen then damage := damage + 1 score := score + 1 end if end for if whatdotcolor (myx, myy) = purple then damage := damage * (1 div 100) end if if whatdotcolor (myx, myy) = gray then damage := damage - 300 end if if whatdotcolor (myx, myy) = brightblue then damage := damage - 750 end if put damage end dmge % GRENADE proc grenade (l, m : int) if mode = "KILLS" then drawfilloval (Rand.Int (l - 50, l + 50), Rand.Int (m - 10, m + 10), 15, 15, brightblue) health elsif mode = "DAMAGE" then drawfilloval (Rand.Int (l - 125, l + 125), Rand.Int (m - 10, m + 10), 15, 15, brightblue) dmge end if delay (250) cls end grenade % SHOT proc shot (q, w, e, r, clr : int) drawline (q + 1, w, 1000 * (e - q) + e + 1, 1000 * (r - w) + r, clr) drawline (q, w, 1000 * (e - q) + e, 1000 * (r - w) + r, clr) drawline (q - 1, w, 1000 * (e - q) + e - 1, 1000 * (r - w) + r, clr) drawline (q, w + 1, 1000 * (e - q) + e, 1000 * (r - w) + r + 1, clr) drawline (q, w - 1, 1000 * (e - q) + e, 1000 * (r - w) + r - 1, clr) if mode = "KILLS" then health elsif mode = "DAMAGE" then dmge end if delay (10) cls end shot % ATTK proc attk (a, b : int) typ := Rand.Int (0, 5) if typ < 3 then if mode = "KILLS" then for counter : 1 .. 100 drawline (a, b, Rand.Int (0, maxx), Rand.Int (0, maxy), purple) end for elsif mode = "DAMAGE" then for counter : 1 .. Rand.Int (500, 2000) drawline (a, b, 2 * Rand.Int (-5, maxx), 2 * Rand.Int (-5, maxy), purple) end for end if health delay (20) cls elsif typ = 3 then myhp := myhp - 1 damage := damage - 100 elsif typ = 4 then if mode = "DAMAGE" then drawfilloval (a, b, maxy div 2, maxy div 2, gray) dmge end if delay (20) cls elsif typ = 5 then if mode = "DAMAGE" then for qwe : 1 .. Rand.Int (15, 50) drawfilloval (Rand.Int (100, maxx), Rand.Int (100, maxy), 25, 25, brightblue) end for elsif mode = "KILLS" then drawfilloval (Rand.Int (0, maxx), Rand.Int (0, maxy), 40, 40, brightblue) health end if delay (10) cls end if end attk % BUTTONS proc buttons % MOVEMENT if myy < maxy then if chars ('w') then drawfilloval (myx, myy, 10, 10, white) myy := myy + 5 end if end if if myx < maxx - 1 then if chars ('d') then drawfilloval (myx, myy, 10, 10, white) myx := myx + 5 end if end if if myx > 0 then if chars ('a') then drawfilloval (myx, myy, 10, 10, white) myx := myx - 5 end if end if if myy > 0 then if chars ('s') then drawfilloval (myx, myy, 10, 10, white) myy := myy - 5 end if end if % ATTACKS if chars (chr (ORD_SPACE)) then grenade (mousex, mousey) end if if chars ('f') then for i : 1 .. 25 drawoval (myx, myy, i, i, brightred) delay (30) end for if mode = "KILLS" then health elsif mode = "DAMAGE" then dmge end if cls end if if button = 1 then shot (myx, myy, mousex, mousey, brightgreen) end if end buttons %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% loop loop put "Welcome to my game." put "The objective is to destroy the enemy using lasers, grenades and melee attacks." : 10 put "" put "Use the arrow keys to move your character, a small red ball." put "Click the mouse to shoot a laser, press Space to use a grenade, or press F to perform a melee attack." put "Pressing M will end the game and P will pause." put "WARNING: grenades will hurt you too" put "The enemy will be a black square in the bottom corner. It will randomly shoot purple lasers across the screen, and will sometimes use a melee attack, in the form of a gray circle." put "Type KILLS or DAMAGE to begin, or QUIT to quit" get mode exit when mode = "KILLS" exit when mode = "DAMAGE" if mode = "QUIT" then Window.Close (defWinID) end if delay (250) cls end loop myx := Rand.Int (maxy div 2, maxx) myy := Rand.Int (maxy div 2, maxy) cpuhp := 200 myhp := 500 kills := 0 damage := 100 score := 0 %%%%%%%%%%%%%%%%%%%%%%%%%% if mode = "KILLS" then %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% loop %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% drawenemy %%%%%draws enemy Mouse.Where (mousex, mousey, button) Input.KeyDown (chars) exit when chars ('m') for dly : 1 .. 20 if dly = 1 then attk (enemyx, enemyy) end if end for % MOVEMENT buttons % PAUSE if chars ('p') then loop Mouse.Where (mousex, mousey, button) drawfilloval (enemyx, enemyy, 10, 10, black) drawfilloval (enemyx - 2, enemyy, 1, 2, green) drawfilloval (enemyx + 2, enemyy, 1, 2, green) drawline (enemyx - 3, enemyy - 4, enemyx + 3, enemyy - 4, red) drawfilloval (myx, myy, 10, 10, red) put "GAME PAUSED" put "ENEMY:", cpuhp, " YOU:", myhp, " KILLS:", kills put "press L to resume" Input.KeyDown (chars) if chars ('l') then exit end if delay (250) cls end loop end if % KILLS if cpuhp < 0 then put "KILL" kills := kills + 1 cpuhp := 200 + 10 * kills myhp := myhp + 2 * kills enemyx := Rand.Int (100, maxx - 100) enemyy := Rand.Int (100, maxy - 100) delay (1000) end if exit when myhp < 0 drawfilloval (myx, myy, 10, 10, red) delay (20) end loop end if %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% if mode = "DAMAGE" then %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% loop %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% drawfillbox (0, 0, 100, 100, black) %%%%%draws enemy Mouse.Where (mousex, mousey, button) Input.KeyDown (chars) exit when chars ('m') dlay := Rand.Int (1, 10) if dlay = 1 then attk (50, 50) end if % MOVEMENT buttons % PAUSE if chars ('p') then loop drawfillbox (0, 0, 100, 100, black) put "GAME PAUSED" put "DAMAGE:", damage put "press L to resume" Input.KeyDown (chars) if chars ('l') then exit end if delay (250) cls end loop end if exit when damage < 0 drawfilloval (myx, myy, 10, 10, red) delay (20) end loop end if put "GAME OVER. Restart game" if mode = "KILLS" then put "KILLS:", kills elsif mode = "DAMAGE" then put "SCORE:", score end if delay (100) put "" put "" end loop [/code] can you help? ----------------------------------- Aange10 Sun Oct 16, 2011 3:46 pm RE:[HELP] Circle to Line Collision ----------------------------------- I'm sure I can. But first you need to clean up a bit. 1. You need to do more commenting on your code. For example, what is the purpose of each line. When you finish commenting that, not only can other people fully understand it, but you might figure out what's wrong as well. 2. typ,rad,dly ... What do these variables mean? and 3. I suggest you make some variables like var player_laser, player_gernade, player_mele, cpu_laser : int player_laser := brightred . . That away it'll be easier to see what the whatdot colors are looking for. Instead of seeing "brightpurple" everywhere, we could see "enemy laser" ----------------------------------- evildaddy911 Mon Oct 17, 2011 7:00 am RE:[HELP] Circle to Line Collision ----------------------------------- ok... ill work on it