2. The Cell

The core building block of Trig is the cell. A cell is mainly comprised of 2 32-bit words, which will eventually be displayed on a 8x8 grid. The topmost word holds the data, the other will hold the command.

<<typedefs>>=

typedef struct trig_cell trig_cell;

<<structs>>=

struct trig_cell {
   uint32_t cmd;
   uint32_t data;
};

Get these values directly with trig_cell_cmd and trig_cell_data.

<<funcdefs>>=

uint32_t trig_cell_cmd(trig_cell *c);
uint32_t trig_cell_data(trig_cell *c);

<<funcs>>=

uint32_t trig_cell_cmd(trig_cell *c)
{
    return c->cmd;
}

uint32_t trig_cell_data(trig_cell *c)
{
    return c->data;
}

The main way to program cells is to set bits. This is done by determining the word and the local XY position. Word 0 is the top word. Word 1 is the bottom word. This is how programming will be done on the monome (bit-by-bit, literally).

<<funcdefs>>=

void trig_cell_set(trig_cell *c, int w, int pos, int s);

<<funcs>>=

void trig_cell_set(trig_cell *c, int w, int pos, int s)
{
    uint32_t *x;
    if (w) {
        x = &c->data;
    } else {
        x = &c->cmd;
    }

    if (s) {
        *x |= 1 << pos;
    } else {
        *x &= ~(1 << pos);
    }
}

In practice, bits will be toggled, not set. Do this with trig_cell_tog. It's similar to trig_cell_set, except that the state value isn't supplied.

<<funcdefs>>=

void trig_cell_tog(trig_cell *c, int w, int pos);

<<funcs>>=

void trig_cell_tog(trig_cell *c, int w, int pos)
{
    uint32_t *x;

    if (w) {
        x = &c->data;
    } else {
        x = &c->cmd;
    }

    *x ^= 1 << pos;
}

Printing a cell is useful for debugging. It will also provide a good preview for what a cell will look like displayed on a monome.

<<funcdefs>>=

void trig_cell_print(trig_cell *c);

<<funcs>>=

void trig_cell_print(trig_cell *c)
{
    int i;

    for (i = 0; i < 64; i++) {
        int s;
        uint32_t byte;
        int pos;

        if (i < 32) {
            byte = c->cmd;
            pos = i;
        } else {
            byte = c->data;
            pos = i - 32;
        }

        if (i == 32) {
            printf("\n");
        }

        s = (byte >> pos) & 1;

        if (s) {
            printf("#");
        } else {
            printf("-");
        }

        if (((i + 1) % 8) == 0) {
            printf("\n");
        }
    }

    printf("\n");
}

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