Mainly destined for kids and youths, this is the second H.urna game dedicated to learning programming without having to write any line of code. In this challenge we use block instructions to guide a robot laser in order to produce lines, patterns and shapes in the same way computers draw vectorial images on the screen.

What will be learnt:

A reminder of fundamental concepts as seen in the previous game (Globo In Mazes):
- Programming using blocks to move forward and backward.
- Getting orientation and making turns.
- Using loops to avoid unnecessary repetition of code.
- Using conditionals instructions to take actions depending on the environment.

Newer concepts introduced:
- Using variables to store and reuse information.
- Using specific angles to make a turn.
- Performing mathematical calculations within the code.
- Using new kind of loops.
- Using nested loops.

Optional concepts to play with:
- Conditional compositions.
- Advanced mathematical operations.
- Loop breakers.
- Random numbers.
- ...

Note : the last levels are difficult enough to be enjoyed by professional developers ; )

We just acquired a new robot laser !
Let us master it to produce wonderful pictures.

Drag block instructions on the right panel to tell the robot laser what to do to produce the shadow figure proposed at each level. A turtle represents the laser position and direction (this is a traditional tribute to Turtle Graphics and the Logo language). Remember: a program is just a series of instructions telling a computer what to do.

Below are the description, the programming concepts covered as well as a solution for each level.

Levels 1 - 3: Warming Ups

Level 1 - From simple instructions to square

Warming up : drag blocks on the right panel to tell the robot how to make a square and click on 'Run'.

H.urna Blocks - Robot Laser - Level 01

Level 01 solution and the generated code :
moveForward();
turnRight();
moveForward();
turnRight();
moveForward();
turnRight();
moveForward();
// turnRight();

Level 2 - Use a 'For' loop to avoid unnecessary repetitions!

The 'For' loop executes some actions a specified number of times.

H.urna Blocks - Robot Laser - Level 02

Solution Level 02 and the Generated code :
for (let i = 0; i < 4; ++i) {
 moveForward();
 turnRight();
}

Level 3 - The moonwalk !

The same square as before, but the turtle (the robot laser) refuses to move forward.

H.urna Blocks - Robot Laser - Level 03

Solution Level 03 and the Generated code :
for (let i = 0; i < 4; ++i) {
 turnLeft();
 moveBackward();
}

Levels 4 - 7: Handling distances and angles

Level 4 - Handling the distance - 4 Squares

Manage the robot distance steps to make those four nested squares (100, 75, ...).
Note: You may duplicate blocks and group of blocks using right click.

H.urna Blocks - Robot Laser - Level 04

Solution Level 04 and the Generated code :
for (let i = 0; i < 4; ++i) {
 moveForward(100);
 turnRight();
}
for (let i = 0; i < 4; ++i) {
 moveForward(75);
 turnRight();
}
for (let i = 0; i < 4; ++i) {
 moveForward(50);
 turnRight();
}
for (let i = 0; i < 4; ++i) {
 moveForward(25);
 turnRight();
}

Level 5 - Handling the angle - Octagon

Stop being stuck with right angle shapes; let's make an Octagon.

H.urna Blocks - Robot Laser - Level 05

Solution Level 05 and the Generated code :
for (let i = 0; i < 8; ++i) {
 moveForward();
 turnRight(45);
}

Level 6 - Polygons everywhere!

Build those polygons using only 16 blocks (Recall: Do not hesitate to use duplicate on right click).

H.urna Blocks - Robot Laser - Level 06

Solution Level 06 and the Generated code :
for (let i = 0; i < 3; ++i) {
 moveForward();
 turnRight(120);
}
for (let i = 0; i < 4; ++i) {
 moveForward();
 turnRight(90);
}
for (let i = 0; i < 6; ++i) {
 moveForward();
 turnRight(60);
}
for (let i = 0; i < 8; ++i) {
 moveForward();
 turnRight(45);
}

Level 7 - Polygon disguises in a circle

Drawing 360 micro lines will look like a perfect circle.
Do not hesitate to change the speed slider to get a faster animation.

H.urna Blocks - Robot Laser - Level 07

Solution Level 07 and the Generated code :
for (let i = 0; i < 360; ++i) {
 moveForward(1);
 turnRight(1);
}

Levels 8 - 11: Using variables to store and reuse information

Until now you have programmed a series of instructions that get executed no matter what, you have learned how to use conditions, to use pre-defined loops (while and for), to handle distances and angles... You have seen a lot. However, now, you will use the memory of the computer! It is a big step up, but do not worry, it is going to be smooth.

Level 8 - The spiral

To create a spiral, we will increase the distance the turtle walks on each step. In order to do so efficiently, we create a variable (a memory) to optimize our efforts.

H.urna Blocks - Robot Laser - Level 08

Solution Level 08 and the Generated code :
let lenght = 10;
for (let i = 0; i < 8; ++i) {
 moveForward(lenght);
 turnRight(90);
 lenght += 10;
}

Level 9 - Remember level 04? Using a variable will avoid repetition.

Two nested loops will be needed for this figure (length from 25 to 100). Do not be afraid; it is still as simple as before. We were doing four times the same thing to build a square; we will only make those things four times to get four squares :).

H.urna Blocks - Robot Laser - Level 09

Solution Level 09 and the Generated code :
let lenght = 25;
for (let i = 0; i < 4; ++i) {
 for (let j = 0; j < 4; ++j) {
  moveForward(lenght);
  turnRight(90);
 }
 lenght += 25;
}

Level 10 - Crisis! We lack blocks!

Be careful, you have a limited amount of blocks to use ! We need to use a variable : no more possible cheat (length from 10 to 80). The solution is almost the same as for the previous level.

H.urna Blocks - Robot Laser - Level 10

Solution Level 10 and the Generated code :
let lenght = 10;
turnRight(45);
for (let i = 0; i < 8; ++i) {
 for (let j = 0; j < 4; ++j) {
  moveForward(lenght);
  turnRight(90);
 }
 lenght += 10;
}

Level 11 - From triangle to a nonperfect circle

Draw those 13 polygons by using a variable to control the loops (Two nested loops will be needed).

H.urna Blocks - Robot Laser - Level 11

Solution Level 11 and the Generated code :
turnLeft(90);
for (let i = 3; i < 16; ++i) {
 for (let j = 0; j < i; ++j) {
  moveForward();
  turnRight(360 / i);
 }
}

Level 12 - Laser on (Pen down) / off (Pen up)!

You may want to stop using the laser while moving from one point to another.

H.urna Blocks - Robot Laser - Level 12

Solution Level 12 and the Generated code :
moveForward();
turnRight();
laser('off');
moveForward();
turnRight();
laser('on');
moveForward();

Level 13 - Final Boss!

Putting everything together! (very advanced).

H.urna Blocks - Robot Laser - Level 13

No solution for the level 13, but some hints
- It's all made of pentagones !
- Except the two pentagones in the middle, the rest can be made with 3 nested loops.
- This figure may be built as a fractal.

Level 14 - Freestyle !

Tons of new functions to play within this 2000 x 2000 free space. Do not hesitate to take a screenshot and share it.

Jump in Hurna Explorer to play and solve yourself those 13 figures using our new robot laser.