esp-idf/examples/peripherals/lcd/lvgl/main/lvgl_demo_ui.c

/* LCD LVGL UI example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/

#include <math.h>
#include "lvgl.h"

#ifndef PI
#define PI  (3.14159f)
#endif

// LVGL image declare
LV_IMG_DECLARE(esp_logo)
LV_IMG_DECLARE(esp_text)

static lv_obj_t *arc[3];
static lv_obj_t *img_logo;
static lv_obj_t *img_text;
static lv_color_t arc_color[] = {
    LV_COLOR_MAKE(232, 87, 116),
    LV_COLOR_MAKE(126, 87, 162),
    LV_COLOR_MAKE(90, 202, 228),
};

static void anim_timer_cb(lv_timer_t *timer)
{
    static int32_t count = -90;
    lv_obj_t *scr = (lv_obj_t *) timer->user_data;

    // Play arc animation
    if (count < 90) {
        lv_coord_t arc_start = count > 0 ? (1 - cosf(count / 180.0f * PI)) * 270 : 0;
        lv_coord_t arc_len = (sinf(count / 180.0f * PI) + 1) * 135;

        for (size_t i = 0; i < sizeof(arc) / sizeof(arc[0]); i++) {
            lv_arc_set_bg_angles(arc[i], arc_start, arc_len);
            lv_arc_set_rotation(arc[i], (count + 120 * (i + 1)) % 360);
        }
    }

    // Delete arcs when animation finished
    if (count == 90) {
        for (size_t i = 0; i < sizeof(arc) / sizeof(arc[0]); i++) {
            lv_obj_del(arc[i]);
        }

        // Create new image and make it transparent
        img_text = lv_img_create(scr);
        lv_img_set_src(img_text, &esp_text);
        lv_obj_set_style_img_opa(img_text, 0, 0);
    }

    // Move images when arc animation finished
    if ((count >= 100) && (count <= 180)) {
        lv_coord_t offset = (sinf((count - 140) * 2.25f / 90.0f) + 1) * 20.0f;
        lv_obj_align((lv_obj_t *) timer->user_data, LV_ALIGN_CENTER, 0, -offset);
        lv_obj_align(img_text, LV_ALIGN_CENTER, 0, 2 * offset);
        lv_obj_set_style_img_opa(img_text, offset / 40.0f * 255, 0);
    }

    // Delete timer when all animation finished
    if (++count >= 180) {
        lv_timer_del(timer);
    }
}

void example_lvgl_demo_ui(lv_obj_t *scr)
{
    // Create image
    img_logo = lv_img_create(scr);
    lv_img_set_src(img_logo, &esp_logo);
    lv_obj_center(img_logo);

    // Create arcs
    for (size_t i = 0; i < sizeof(arc) / sizeof(arc[0]); i++) {
        arc[i] = lv_arc_create(scr);

        // Set arc caption
        lv_obj_set_size(arc[i], 220 - 30 * i, 220 - 30 * i);
        lv_arc_set_bg_angles(arc[i], 120 * i, 10 + 120 * i);
        lv_arc_set_value(arc[i], 0);

        // Set arc style
        lv_obj_remove_style(arc[i], NULL, LV_PART_KNOB);
        lv_obj_set_style_arc_width(arc[i], 10, 0);
        lv_obj_set_style_arc_color(arc[i], arc_color[i], 0);

        // Make arc center
        lv_obj_center(arc[i]);
    }

    // Create timer for animation
    lv_timer_create(anim_timer_cb, 20, (void *) scr);
}