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lvgl/examples/widgets/canvas/lv_example_canvas_9.c
Benign X 62291fa174
feat(draw): add lv_draw_letter support (#7490)
Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
2025-01-16 10:42:30 +08:00

69 lines
1.9 KiB
C

#include "../../lv_examples.h"
#if LV_USE_CANVAS && LV_BUILD_EXAMPLES
#define CANVAS_WIDTH 300
#define CANVAS_HEIGHT 200
static void timer_cb(lv_timer_t * timer)
{
static int32_t counter = 0;
const char * string = "lol~ I'm wavvvvvvving~>>>";
const int16_t string_len = lv_strlen(string);
lv_obj_t * canvas = lv_timer_get_user_data(timer);
lv_layer_t layer;
lv_canvas_init_layer(canvas, &layer);
lv_canvas_fill_bg(canvas, lv_color_white(), LV_OPA_COVER);
lv_draw_letter_dsc_t letter_dsc;
lv_draw_letter_dsc_init(&letter_dsc);
letter_dsc.color = lv_color_hex(0xff0000);
letter_dsc.font = lv_font_default();
{
#define CURVE2_X(t) (t * 2 + 10)
#define CURVE2_Y(t) (lv_trigo_sin((t) * 5) * 40 / 32767 + CANVAS_HEIGHT / 2)
int32_t pre_x = CURVE2_X(-1);
int32_t pre_y = CURVE2_Y(-1);
for(int16_t i = 0; i < string_len; i++) {
const int32_t angle = i * 5;
const int32_t x = CURVE2_X(angle);
const int32_t y = CURVE2_Y(angle + counter / 2);
letter_dsc.unicode = (uint32_t)string[i % string_len];
letter_dsc.rotation = lv_atan2(y - pre_y, x - pre_x) * 10;
letter_dsc.color = lv_color_hsv_to_rgb(i * 10, 100, 100);
lv_draw_letter(&layer, &letter_dsc, &(lv_point_t) {
.x = x, .y = y
});
pre_x = x;
pre_y = y;
}
}
lv_canvas_finish_layer(canvas, &layer);
counter++;
}
void lv_example_canvas_9(void)
{
/*Create a buffer for the canvas*/
LV_DRAW_BUF_DEFINE_STATIC(draw_buf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_COLOR_FORMAT_ARGB8888);
LV_DRAW_BUF_INIT_STATIC(draw_buf);
lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
lv_obj_set_size(canvas, CANVAS_WIDTH, CANVAS_HEIGHT);
lv_obj_center(canvas);
lv_canvas_set_draw_buf(canvas, &draw_buf);
lv_timer_create(timer_cb, 16, canvas);
}
#endif