Access to lv palette colors

[jonsmirl]

Introduce the problem

Would need these three API and some constants.

lv_palette_main(LV_PALETTE_...) lv_palette_lighten(LV_PALETTE_..., v) lv_palette_darken(LV_PALETTE_..., v)

Proposal

No response

[jonsmirl]

I put this into constants.c, not sure of your naming conventions.

  lua_pushcfunction(L, luavgl_palette);
  lua_setfield(L, -2, "Palette");

  lua_pushcfunction(L, luavgl_palette_light);
  lua_setfield(L, -2, "PaletteLight");

  lua_pushcfunction(L, luavgl_palette_dark);
  lua_setfield(L, -2, "PaletteDark");

static int luavgl_palette(lua_State *L)
{
  int palette = luaL_checkinteger(L, 1);

  int color = lv_color_to32(lv_palette_main(palette));

  lua_pushinteger(L, color);
  return 1;
}

static int luavgl_palette_light(lua_State *L)
{
  int palette = luaL_checkinteger(L, 1);
  int light = luaL_checkinteger(L, 2);

  int color = lv_color_to32(lv_palette_lighten(palette, light));

  lua_pushinteger(L, color);
  return 1;
}

static int luavgl_palette_dark(lua_State *L)
{
  int palette = luaL_checkinteger(L, 1);
  int dark = luaL_checkinteger(L, 2);

  int color = lv_color_to32(lv_palette_darken(palette, dark));

  lua_pushinteger(L, color);
  return 1;
}

[XuNeo]

Thank you. You can use luavgl_tocolor to convert other supported color format to lv_color_t, such as color in format of "#FFF".

not sure of your naming conventions.

I wanted to preserve name of the directly mapped APIs from lvgl C functions and convert those widget names to Widget. For constants, it's always uppercase.