Scratch

Heybrian wrote:

Hey Scratch makers, (people who helped program the scratch blocks) how did you program a block that we use for other programming? becuase heres my question:
you have to program the block to do stuff right? so id be like this

                   <move(  )steps>

                To program that block id say somehting. what does it say?

That one isn't too hard to make and I made a demo of how to make it with trig functions.

and the code is,

change x by sin of direction
change y by cos of direction

This will make a sprite move 1 unit.

The distance to block was created using the Pythagorean theorem.

In this example I will find the distance between spriteA and spriteB

distance= square root of ( (x position of spriteA - x position of spriteB)^2 +  (y position of spriteA - y position of spriteB)^2)


And the point to block was probably made using the atan2 math function

I will make spriteA point to spriteB

angle = Math.atan2( -(y of spriteA - y of spriteB),(y of spriteA - y of spriteB))
rotation = 270-angle

Thats the way I would program things.

Last edited by archmage (2008-01-27 23:20:57)

No, I am pretty sure the blocks are programmed in the squeak language.

I mentioned some of the ways that could be used to program some of the blocks in my above post. The programming I mentioned could also be applied to blocks (except point to because it requires atan2).

Last edited by archmage (2008-01-27 23:47:51)

Squeak is the language that scratch was programmed in. If you know squeak you could program your own blocks in the open source version of scratch.

Scratch was meant to be a simple language that anyone could easily pick up. It is easy to learn but you can use it to make complex programs if you wanted.

In other languages you have to ype the commands - every mistake is a bug. Scratch is a "new" way of programming - you drag blocks together instead of typing code.

an example:

this is (easy!) flash action script code:

sprite1.onRelease = function() {
  for (i=0; i<360; i++) {
    this.direction = this.direction + 1
  }
}

This is (almost) the same thing, but in scratch:

code wrote:

---
[blocks]
<when[ sprite 1 ]clicked>
<repeat( 360
<turn cw( 1 )degrees>
<end>
[/blocks]
---

What do you think is the most easyest?

to jso, I THINK SCRATCH IS EASEIR LOL! that looks so hard! to blob, its called squeak.