First, make sure you use blocks mode, it is easier. If you need help with a specific block, put your mouse over the block, and help will pop up. Then check out the help page
How do I share my duck with my friends?
Click "Save" in the lower right corner. Once it loads, copy the battle code you get. Your friends can go to the battle page to try your duck.
My duck dies as soon as I run the program. How do I stop this?
You probably have an error in your code. Make sure you set all of your variables before you use them; this can cause errors.
My duck does nothing.
Click Stop, click reset, and then click run. Sometimes the code doesn't update right away.
How do I set a variable to a specific value?
This is a known bug. Try using the addition block. For example, if you need to set a variable to 0, use set variable to 0 + 0
It says my duck is not found. Why?
Battle codes are case-sensitive, so make sure you type it in right.
This page just documents moving your duck and battling with your duck. For a reference of JavaScript, try this, or try hovering over over the block for basic help.
Moving your duck
You can make your duck move with the swim block, or the swim(angle); command. This takes an angle as an input.
Stopping your duck
You can stop your duck with the stop block, or the stop(); command. It may take a moment for your duck to completely slow down.
Getting your duck's position
You can stop your duck with the x position and y position blocks, or the getX() and getY() commands. X is horizontal, and Y is vertical.
Getting your duck's speed
You can stop your duck with the speed block, or the speed() command. 0 is stopped, and 100 is full speed.
Shooting a cannon
You can shoot a cannon with the shoot cannon block, or the cannon(angle,distance); command. It takes 2 inputs, the angle to shoot at, and the distance to shoot. The distance cannot be over 70. In JavaScript, I highly reccomend you set it up like this: cannon(angle,scan(angle)).
Scanning the radar
You can scan the radar with the scan radar block or the scan(angle,range) command. This takes one input, the angle to scan the radar. You can also set a second, optional input for the range of the radar, from 1 (skinny) to 20 (wide). I don't reccomend you change this.
Looking for ducks
You can use the any ducks at and any ducks in firing range at blocks to find ducks. These take one input, the angle to search at. This is not supported in JavaScript, instead use scan(angle) < 71 or scan(angle) < Infinity
Checking your health
You can use the health block or the health() command to get your health. 0 is dead, and 100 is no damage. This is useful for checking if you are shot.
/* counter *//* scan in a counter-clockwise direction (increasing degrees) *//* moves when hit */var range;var last_dir=0;var res=2;var d=damage();var angle=Math.random() * 360;while (true){while ((range=scan(angle, res)) !=Infinity){if (range > 70){/* out of range, head toward it */ drive(angle, 50); var i=1; while (i++ < 50) /* use a counter to limit move time */ ; drive (angle, 0); if (d !=damage()){d=damage(); run();}angle -=3;}else{while (!cannon(angle, range)) ; if (d !=damage()){d=damage(); run();}angle -=15;}}if (d !=damage()){d=damage(); run();}angle +=res; angle %=360;}/* run moves around the center of the field */function run(){var i=0; var x=getX(); var y=getY(); if (last_dir==0){last_dir=1; if (y > 51){drive(270, 100); while (y - 10 < getY() && i++ < 50) ; drive(270, 0);}else{drive(90, 100); while (y + 10 > getY() && i++ < 50) ; drive(90, 0);}}else{last_dir=0; if (x > 51){drive(180, 100); while (x - 10 < getX() && i++ < 50) ; drive(180, 0);}else{drive(0, 100); while (x + 10 > getX() && i++ < 50) ; drive(0, 0);}}}
/* rook.r - scans the battlefield like a rook, i.e., only 0,90,180,270 *//* move horizontally only, but looks horz and vertically *//* move to center of board */if (getY() < 50){while (getY() < 40) /* stop near center */ drive(90, 100); /* start moving */}else{while (getY() > 60) /* stop near center */ drive(270, 100); /* start moving */}drive(0, 0);while (speed() > 0) ;/* initialize starting parameters */var d=damage();var course=0;var boundary=99;drive(course, 30);/* main loop */while(true){/* look all directions */ look(0); look(90); look(180); look(270); /* if near end of battlefield, change directions */ if (course==0){if (getX() > boundary || speed()==0) change();}else{if (getX() < boundary || speed()==0) change();}}/* look somewhere, and fire cannon repeatedly at in-range target */function look(deg){var range; while ((range=scan(deg, 4)) <=70){drive(course, 0); cannon(deg, range); if (d + 20 !=damage()){d=damage(); change();}}}function change(){if (course==0){boundary=1; course=180;}else{boundary=99; course=0;}drive(course, 30);}
/* sniper *//* strategy: since a scan of the entire battlefield can be done in 90 *//* degrees from a corner, sniper can scan the field quickly. *//* external variables, that can be used by any function */var corner=0; /* current corner 0, 1, 2, or 2 */var sc=0; /* current scan start */var range; /* range to target *//* initialize the corner info *//* x and y location of a corner, and starting scan degree */var c1x=2, c1y=2, s1=0;var c2x=2, c2y=98, s2=270;var c3x=98, c3y=98, s3=180;var c4x=98, c4y=2, s4=90;var closest=Infinity;new_corner(); /* start at a random corner */var d=damage(); /* get current damage */var dir=sc; /* starting scan direction */while (true){/* loop is executed forever */ while (dir < sc + 90){/* scan through 90 degree range */ range=scan(dir, 2); /* look at a direction */ if (range <=70){while (range > 0){/* keep firing while in range */ closest=range; /* set closest flag */ cannon(dir, range); /* fire! */ range=scan(dir, 1); /* check target again */ if (d + 15 > damage()) /* sustained several hits, */ range=0; /* goto new corner */}dir -=10; /* back up scan, in case */}dir +=2; /* increment scan */ if (d !=damage()){/* check for damage incurred */ new_corner(); /* we're hit, move now */ d=damage(); dir=sc;}}if (closest==Infinity){/* check for any targets in range */ new_corner(); /* nothing, move to new corner */ d=damage(); dir=sc;}else{/* targets in range, resume */ dir=sc;}closest=Infinity;}/* new corner function to move to a different corner */function new_corner(){var x, y; var rand=Math.floor(Math.random() * 4); /* pick a random corner */ if (rand==corner) /* but make it different than the */ corner=(rand + 1) % 4;/* current corner */ else corner=rand; if (corner==0){/* set new x,y and scan start */ x=c1x; y=c1y; sc=s1;}if (corner==1){x=c2x; y=c2y; sc=s2;}if (corner==2){x=c3x; y=c3y; sc=s3;}if (corner==3){x=c4x; y=c4y; sc=s4;}/* find the heading we need to get to the desired corner */ var angle=plot_course(x,y); /* start drive train, full speed */ /* keep traveling until we are within 15 meters */ /* speed is checked in case we run into wall, other robot */ /* not terribly great, since were are doing nothing while moving */ while (distance(getX(), getY(), x, y) > 15) drive(angle, 100); /* cut speed, and creep the rest of the way */ while (distance(getX(), getY(), x, y) > 1) drive(angle, 20); /* stop drive, should coast in the rest of the way */ drive(angle, 0);}/* end of new_corner *//* classical pythagorean distance formula */function distance(x1, y1, x2, y2){var x=x1 - x2; var y=y1 - y2; return Math.sqrt((x * x) + (y * y));}/* plot course function, return degree heading to *//* reach destination x, y; uses atan() trig function */function plot_course(xx, yy){var d; var x,y; var curx, cury; curx=getX(); /* get current location */ cury=getY(); x=curx - xx; y=cury - yy; /* atan only returns -90 to +90, so figure out how to use */ /* the atan() value */ if (x==0){/* x is zero, we either move due north or south */ if (yy > cury) d=90; /* north */ else d=270; /* south */}else{if (yy < cury){if (xx > curx) d=360 + Math.atan_deg(y / x); /* south-east, quadrant 4 */ else d=180 + Math.atan_deg(y / x); /* south-west, quadrant 3 */}else{if (xx > curx) d=Math.atan_deg(y / x); /* north-east, quadrant 1 */ else d=180 + Math.atan_deg(y / x); /* north-west, quadrant 2 */}}return d;}
