lvgl/examples/widgets/canvas/lv_example_canvas_4.c

#include "../../lv_examples.h"
#if LV_USE_CANVAS && LV_FONT_MONTSERRAT_18 && LV_BUILD_EXAMPLES

#define CANVAS_WIDTH  50
#define CANVAS_HEIGHT  50

/**
 * Draw a text to the canvas
 */
void lv_example_canvas_4(void)
{
    /*Create a buffer for the canvas*/
    static uint8_t cbuf[LV_CANVAS_BUF_SIZE_TRUE_COLOR(CANVAS_WIDTH, CANVAS_HEIGHT)];

    /*Create a canvas and initialize its palette*/
    lv_obj_t * canvas = lv_canvas_create(lv_scr_act());
    lv_canvas_set_buffer(canvas, cbuf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_COLOR_FORMAT_NATIVE);
    lv_canvas_fill_bg(canvas, lv_color_hex3(0xccc), LV_OPA_COVER);
    lv_obj_center(canvas);

    lv_layer_t layer;
    lv_canvas_init_layer(canvas, &layer);

    lv_draw_label_dsc_t dsc;
    lv_draw_label_dsc_init(&dsc);
    dsc.color = lv_palette_main(LV_PALETTE_RED);
    dsc.font = &lv_font_montserrat_18;
    dsc.decor = LV_TEXT_DECOR_UNDERLINE;
    dsc.text = "Hello";

    lv_area_t coords = {10, 10, 30, 60};

    lv_draw_label(&layer, &dsc, &coords);

    lv_canvas_finish_layer(canvas, &layer);

}
#endif