qmk-dactyl-manuform-a/keyboards/helix/rev2/keymaps/edvorakjp/oled.c

#include <string.h>
#include "oled.h"

static void render_logo(struct CharacterMatrix *matrix) {

  static char logo[] = {
    0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,0x90,0x91,0x92,0x93,0x94,
    0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,0xb0,0xb1,0xb2,0xb3,0xb4,
    0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,0xd0,0xd1,0xd2,0xd3,0xd4,
    0};
  matrix_write(matrix, logo);
}

void matrix_update(struct CharacterMatrix *dest,
                   const struct CharacterMatrix *source) {
  if (memcmp(dest->display, source->display, sizeof(dest->display))) {
    memcpy(dest->display, source->display, sizeof(dest->display));
    dest->dirty = true;
  }
}

void render_status(struct CharacterMatrix *matrix) {

  // Render to mode icon
  static char logo[][2][3] = {{{0x95,0x96,0},{0xb5,0xb6,0}},{{0x97,0x98,0},{0xb7,0xb8,0}}};
  int mode_number = get_enable_kc_lang() ? 0 : 1;
  matrix_write(matrix, logo[mode_number][0]);
  matrix_write(matrix, "\n");
  matrix_write(matrix, logo[mode_number][1]);

  // Define layers here, Have not worked out how to have text displayed for each layer. Copy down the number you see and add a case for it below
  char buf[40];
  snprintf(buf,sizeof(buf), "Undef-%ld", layer_state);
  matrix_write_P(matrix, PSTR("\nLayer: "));
  switch (biton32(layer_state)) {
    case L_BASE:
      matrix_write_P(matrix, PSTR("Default"));
      break;
    case _RAISE:
      matrix_write_P(matrix, PSTR("Raise"));
      break;
    case _LOWER:
      matrix_write_P(matrix, PSTR("Lower"));
      break;
    default:
      matrix_write(matrix, buf);
  }

  // Host Keyboard LED Status
  char led[40];
  snprintf(led, sizeof(led), "\n%s %s %s",
      (host_keyboard_leds() & (1<<USB_LED_NUM_LOCK)) ? "NMLK" : "    ",
      (host_keyboard_leds() & (1<<USB_LED_CAPS_LOCK)) ? "CAPS" : "    ",
      (host_keyboard_leds() & (1<<USB_LED_SCROLL_LOCK)) ? "SCLK" : "    ");
  matrix_write(matrix, led);
}

void iota_gfx_task_user(void) {
  struct CharacterMatrix matrix;

#if DEBUG_TO_SCREEN
  if (debug_enable) { return; }
#endif

  matrix_clear(&matrix);
  if (is_master) {
    render_status(&matrix);
  } else {
    render_logo(&matrix);
  }
  matrix_update(&display, &matrix);
}