make this arrays / for loop easier (use value as array name)

Programming Questions

martijnbac

make this arrays / for loop easier (use value as array name)

in Programming Questions • 1 year ago

Hello,

I try to find a more compact way for creating a custom 'pixel' font (because I need to process a whole alphabet this way).

When i select a character ( c='a') I want to loop the corresponding array with the for loop. Now I have a seperate rect for each character, because I don't know how to use the value of c as the name of the array (so I can say if value of c[i][j]{}).

Is this possible?

the 'problem' part:

if (c=='a') {
if (a[i][j]==1) {
rect(x+j*40, i*40, 20, 20);
}
}

full code:

c = 'a';
int[][] a = {
{0,0,0,0,0},
{0,0,0,0,0},
{0,1,1,1,0},
{0,0,0,0,1},
{0,1,1,1,1},
{1,0,0,0,1},
{0,1,1,1,1},
{0,0,0,0,0},
{0,0,0,0,0}
};
int[][] b = {
{1,0,0,0,0},
{1,0,0,0,0},
{1,1,1,1,0},
{1,0,0,0,1},
{1,0,0,0,1},
{1,0,0,0,1},
{1,1,1,1,0},
{0,0,0,0,0},
{0,0,0,0,0}
};
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if (c=='a') {
if (a[i][j]==1) {
rect(x+j*40, i*40, 20, 20);
}
}
if (c=='b') {
if (b[i][j]==1) {
rect(x+j*40, i*40, 20, 20);
}
}
}
}

Replies(6)

PhiLho

Re: make this arrays / for loop easier (use value as array name)

1 year ago

int[][][] chars = { a, b, c, ... };
perhaps...
Then
if (chars[i][j][c - 'a') rect(...);

Or
int[][][] chars =
{
{
    {0,0,0,0,0},
    {0,0,0,0,0},
    {0,1,1,1,0},
    {0,0,0,0,1},
    {0,1,1,1,1},
    {1,0,0,0,1},
    {0,1,1,1,1},
    {0,0,0,0,0},
    {0,0,0,0,0}
},
{
    {1,0,0,0,0},
    {1,0,0,0,0},
    {1,1,1,1,0},
    {1,0,0,0,1},
    {1,0,0,0,1},
    {1,0,0,0,1},
    {1,1,1,1,0},
    {0,0,0,0,0},
    {0,0,0,0,0}
},
// Etc.
}

martijnbac

Re: make this arrays / for loop easier (use value as array name)

1 year ago

Thanks for your help!

It looks like I need some kind of 3d array. I get the idea, but don't know how to do this exactly.

This is what I tried, but this doesn't work of course :-)

void drawChar() {
int[][][] chars = { a, b };
chars[][][a] = {
{0,0,0,0,0},
{0,0,0,0,0},
{0,1,1,1,0},
{0,0,0,0,1},
{0,1,1,1,1},
{1,0,0,0,1},
{1,0,0,0,1},
{0,1,1,1,1},
{0,0,0,0,0},
{0,0,0,0,0},
};
chars[][][b] = {
{1,0,0,0,0},
{1,0,0,0,0},
{1,1,1,1,0},
{1,0,0,0,1},
{1,0,0,0,1},
{1,0,0,0,1},
{1,0,0,0,1},
{1,1,1,1,0},
{0,0,0,0,0},
{0,0,0,0,0},
};
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if (chars[i][j][c]) {
rect(x+j*40, i*40, 20, 20);
}
}
}
}

PhiLho

Re: make this arrays / for loop easier (use value as array name)

1 year ago

Trying some kind of creative syntax?

OK, to be honest, my answer had an error (the char index must be first), but I wasn't suggesting to change the syntax of a and b.
I won't point out all the errors you made (one of the prominent ones is to use a and b before defining them), it would take some time, so I just made a little test code around the base of your code.

void setup() {
  size(1000, 500);
  String word = "abba";
  for (int l = 0; l < word.length(); l++) {
    int c = word.charAt(l) - 'a';
    drawChar(c, 250 * l);
  }
}

int[][] a = {   
  {0,0,0,0,0},
  {0,0,0,0,0},
  {0,1,1,1,0},
  {0,0,0,0,1},
  {0,1,1,1,1},
  {1,0,0,0,1},
  {1,0,0,0,1},
  {0,1,1,1,1},
  {0,0,0,0,0},
  {0,0,0,0,0},
};
int[][] b = {   
  {1,0,0,0,0},
  {1,0,0,0,0},
  {1,1,1,1,0},
  {1,0,0,0,1},
  {1,0,0,0,1},
  {1,0,0,0,1},
  {1,0,0,0,1},
  {1,1,1,1,0},
  {0,0,0,0,0},
  {0,0,0,0,0},
};

int[][][] chars = { a, b };

void drawChar(int c, int x) {
  for (int i = 0; i < 9; i++) {
    for (int j = 0; j < 5; j++) {
      if (chars[c][i][j] == 1) {
        rect(x+j*40, i*40, 20, 20);
      }
    }
  }
}

martijnbac

Re: make this arrays / for loop easier (use value as array name)

1 year ago

I'm more of a creative person, not a programmer. I know creative programming is a bad combination, haha.

But thanks, this is really, really helpful!

One last question though. Now I try to add other characters. a,b,c,d,e,f,etc. is no problem, but what if I want to add things like punctuation? That's also the part of the code I don't fully understand. You convert the chars to ints?

PhiLho

Re: make this arrays / for loop easier (use value as array name)

1 year ago

Note: you might have an issue with class size if you put a full char set in it. Perhaps it is easier to define the data in a text file (lines of strings, just 0 and 1, no separators) and to read the file in setup().

And, yes, chars are actually just numbers (the Ascii code of the letters, or more exactly, the Unicode code point of the character), so you can make some arithmetic out of them...

martijnbac

Re: make this arrays / for loop easier (use value as array name)

1 year ago

Thank you, it's working great now. No problems with the class size at this point, maybe I convert it to a text file later, good idea.

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