I have to learn everything about classes and inheriting..

 

now I've written a little program on my own (similiar to the example on the processing site), but I don't understand whether this is all you can do with this "extends"?

 

and why is it possible not to have a constructor in the AllButton-class? I thought every class has to have at least one constructor?

 

thanks for your help..

I've got an equation that allows to calculate the coordinates of a point if it was rotated around an axis that is given in a space with three angles.. But now, how can I calculate these angles?

 

if I've got a vector.. can I do this with the tan() or how is that possible?

 

thanks for your help....

I've got my own 3d-space without using P3D or something like that..

 

woudl like to program a plane. what's the easiest way?

 

--> take three points? and make a triangle in the space?

 

--> take four points? and make a rect in the space?

 

and make it transparent?

 

--> the shown "size" depends on what the user typed in.

I'm working on a little project and I'm interested as a reference:

 

how long did how many people have to program a famous thing like windows or something like that?

 

does someone have an idea?

I'd like to program the intersection point of two lines..

 

they are given with two points, so that you can write following equation:

 

(xp1,yp1,zp1)=(x1,y1,z1)+s*(u1,v1,w1);

 

and

 

(xp2,yp2,zp2)=(x2,y2,z2)+t*(u2,v2,w2);

 

so now I could write it as three equations, so that I've got s=, s= and s=.

Now I could replace t with the rest and I've got a solution for s and can calculate the point. But if xp1 is 0, there's a mistake..

 

so is there an equation for every case?

hello..

 

I've got a textfield (programmed on my own) where I want users to give in some text. If this text is typed in, it should be shown there but still be changeable.

 

in the textfield class I work with separate characters. When a key is pressed, a new character is added. If the submit-button is pressed, I join these characters to one and give it out. So far no problems..

 

I use the textfield to add new objects for example a point or a triangle. for all the points there are the same two textfields (one for the name, the other for the coordinates--> the coordinates I split by "," and there's no problem).

If the text has been submitted, a new object is added and the text is deleted because the textfield is like I said used for all the other objects as well.

But if I select an object, I'd like the coordinates and the name to be shown.. It isn't stored in the textfield (that's because the values are changeable without typing a number but with dragging it around on the screen). So there has the actual value to be written there, a float or a string value. No problem so far, but hence it should be changeable it has to be splitted by every character. But if I split a string by:
String split1[]=(myString,"");

the program crashes ;)

 

any ideas how to split a string (or a float) by every character??

 

or is there an easier possibility I don't see?

I'm programming a little 3d-software and have got lines there. I want them to be shown as long as the points are in a "virtual" box. So I can find the intersection points of the line and this box. (6 planes) this is no problem and I can display these points. But there's the problem that the lines have more than two intersection points, so you can't say which are the "true" ones. I 'm looking for these points that really are intersection points of this box and not with the whole plane..

 

so is there an easy idea? I solved the problem of finding the points (easily) with the coordinate equation but now I'm stuck..

 

thanks for your answers..

could anyone tell me why this isn't working? it's just displaying a half circle.

 

it's not the whole code (and exactly the right code, but it should be still somehow the same) because this would be too long. Hope you can help me anyway...

 

I'd like to let the user type in an equation. then in a for-loop I want to draw this.

 

so for example:

 

user types: y=2*x+(2*x+1)

 

I split this String with "=" and have the String 2*x+(2*x+1) and can split this again with "".

Then I've got strings 2,*,x,+,(,2, ...

But now how can I calculate with them?

 

for(int x=-200;x<200;x++){

point(x,y);

}

 

and y= the combination of this splitted strings..

 

is there an handier method?

 

(and by the way, do you have an idea how to solve the problem of curve sketching --> deduction) ?

 

thanks for your ideas.. I'm overextended.. :D

is there an easy possibility to load and save files? I talk about searching the file in the folders, is there an easier way than tipping the whole link to the file? (like a file browser?)

 

thanks for the help..