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#include "../../lv_examples.h"
#if LV_USE_CANVAS && LV_BUILD_EXAMPLES
#define CANVAS_WIDTH 80
#define CANVAS_HEIGHT 40
/**
* Create a transparent canvas with transparency
*/
void lv_example_canvas_2(void)
{
lv_obj_set_style_bg_color(lv_screen_active(), lv_palette_lighten(LV_PALETTE_RED, 5), 0);
/*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);
/*Create a canvas and initialize its palette*/
lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
lv_canvas_set_draw_buf(canvas, &draw_buf);
lv_obj_center(canvas);
/*Red background (There is no dedicated alpha channel in indexed images so LV_OPA_COVER is ignored)*/
lv_canvas_fill_bg(canvas, lv_palette_main(LV_PALETTE_BLUE), LV_OPA_COVER);
/*Create hole on the canvas*/
uint32_t x;
uint32_t y;
for(y = 10; y < 20; y++) {
for(x = 5; x < 75; x++) {
lv_canvas_set_px(canvas, x, y, lv_palette_main(LV_PALETTE_BLUE), LV_OPA_50);
}
}
for(y = 20; y < 30; y++) {
for(x = 5; x < 75; x++) {
lv_canvas_set_px(canvas, x, y, lv_palette_main(LV_PALETTE_BLUE), LV_OPA_20);
}
}
for(y = 30; y < 40; y++) {
for(x = 5; x < 75; x++) {
lv_canvas_set_px(canvas, x, y, lv_palette_main(LV_PALETTE_BLUE), LV_OPA_0);
}
}
}
#endif
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