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#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "../libleds.h"
#include "chars.h"
#include "space.xbm"
#include "0.xbm"
#include "1.xbm"
#include "2.xbm"
#include "3.xbm"
#include "4.xbm"
#include "5.xbm"
#include "6.xbm"
#include "7.xbm"
#include "8.xbm"
#include "9.xbm"
static unsigned char *get_char_bits(char c) {
switch (c) {
case ' ':
return cspace_bits;
case '0':
return c0_bits;
case '1':
return c1_bits;
case '2':
return c2_bits;
case '3':
return c3_bits;
case '4':
return c4_bits;
case '5':
return c5_bits;
case '6':
return c6_bits;
case '7':
return c7_bits;
case '8':
return c8_bits;
case '9':
return c9_bits;
default:
return NULL;
}
}
static char is_active(unsigned char const *bits, unsigned int const i)
{
/*
* The first led is in the top left corner.
* After that it goes down the column, then up the next and so on.
*
* This means all columns with an even index count down.
* Those with an odd index count up.
*
*
* With a height of 8 the led numbers would look like this:
*
* 00 0F 10 1F 20 ...
* 01 0E 11 1E 21 ...
* 02 0D 12 1D ...
* 03 0C 13 1C ...
* 04 0B 14 1B ...
* 05 0A 15 1A ...
* 06 09 16 19 ...
* 07 08 17 18 ...
*/
unsigned int const bytes_per_row = ceil(char_width / 8.0);
unsigned int col = i / char_height;
unsigned int row = i % char_height;
if (col % 2)
row = char_height - 1 - row;
// calculate byte to access
unsigned int byte = row * bytes_per_row;
byte += col / 8;
unsigned char data = bits[byte];
unsigned char mask = 1<<(col % 8);
return data & mask;
}
static char leds_write_char(const struct led_color color, char c, struct led_color *buf)
{
unsigned char *bits = get_char_bits(c);
if (bits == NULL)
return 0;
for (unsigned int i = 0; i < char_length; i++) {
if (is_active(bits, i))
buf[i] = color;
else
buf[i] = (struct led_color){0, 0, 0};
}
return 1;
}
struct led_color *leds_text(struct led_color const color, const char *text)
{
unsigned int const len = strlen(text);
struct led_color *buf = calloc(
sizeof(struct led_color), len * char_length
);
for (unsigned int i = 0; i < len; i++) {
if (!leds_write_char(color, text[i], buf + i*char_length)) {
// Invalid char
free(buf);
return NULL;
}
}
return buf;
}
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