acid-drop

- Hacking the planet from a LilyGo T-Deck using custom firmware
git clone git://git.acid.vegas/acid-drop.git
lv_example_label_4.c (2216B)
      1 #include "../../lv_examples.h"
      2 #if LV_USE_LABEL && LV_USE_CANVAS && LV_BUILD_EXAMPLES && LV_DRAW_COMPLEX
      3 
      4 #define MASK_WIDTH 100
      5 #define MASK_HEIGHT 45
      6 
      7 static void add_mask_event_cb(lv_event_t * e)
      8 {
      9     static lv_draw_mask_map_param_t m;
     10     static int16_t mask_id;
     11 
     12     lv_event_code_t code = lv_event_get_code(e);
     13     lv_obj_t * obj = lv_event_get_target(e);
     14     lv_opa_t * mask_map = lv_event_get_user_data(e);
     15     if(code == LV_EVENT_COVER_CHECK) {
     16         lv_event_set_cover_res(e, LV_COVER_RES_MASKED);
     17     }
     18     else if(code == LV_EVENT_DRAW_MAIN_BEGIN) {
     19         lv_draw_mask_map_init(&m, &obj->coords, mask_map);
     20         mask_id = lv_draw_mask_add(&m, NULL);
     21 
     22     }
     23     else if(code == LV_EVENT_DRAW_MAIN_END) {
     24         lv_draw_mask_free_param(&m);
     25         lv_draw_mask_remove_id(mask_id);
     26     }
     27 }
     28 
     29 /**
     30  * Draw label with gradient color
     31  */
     32 void lv_example_label_4(void)
     33 {
     34     /* Create the mask of a text by drawing it to a canvas*/
     35     static lv_opa_t mask_map[MASK_WIDTH * MASK_HEIGHT];
     36 
     37     /*Create a "8 bit alpha" canvas and clear it*/
     38     lv_obj_t * canvas = lv_canvas_create(lv_scr_act());
     39     lv_canvas_set_buffer(canvas, mask_map, MASK_WIDTH, MASK_HEIGHT, LV_IMG_CF_ALPHA_8BIT);
     40     lv_canvas_fill_bg(canvas, lv_color_black(), LV_OPA_TRANSP);
     41 
     42     /*Draw a label to the canvas. The result "image" will be used as mask*/
     43     lv_draw_label_dsc_t label_dsc;
     44     lv_draw_label_dsc_init(&label_dsc);
     45     label_dsc.color = lv_color_white();
     46     label_dsc.align = LV_TEXT_ALIGN_CENTER;
     47     lv_canvas_draw_text(canvas, 5, 5, MASK_WIDTH, &label_dsc, "Text with gradient");
     48 
     49     /*The mask is reads the canvas is not required anymore*/
     50     lv_obj_del(canvas);
     51 
     52     /* Create an object from where the text will be masked out.
     53      * Now it's a rectangle with a gradient but it could be an image too*/
     54     lv_obj_t * grad = lv_obj_create(lv_scr_act());
     55     lv_obj_set_size(grad, MASK_WIDTH, MASK_HEIGHT);
     56     lv_obj_center(grad);
     57     lv_obj_set_style_bg_color(grad, lv_color_hex(0xff0000), 0);
     58     lv_obj_set_style_bg_grad_color(grad, lv_color_hex(0x0000ff), 0);
     59     lv_obj_set_style_bg_grad_dir(grad, LV_GRAD_DIR_HOR, 0);
     60     lv_obj_add_event_cb(grad, add_mask_event_cb, LV_EVENT_ALL, mask_map);
     61 }
     62 
     63 #endif