57 lines
1.9 KiB
C
57 lines
1.9 KiB
C
#include "../../lv_examples.h"
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#if LV_USE_LABEL && LV_FONT_MONTSERRAT_24 && LV_USE_CANVAS && LV_BUILD_EXAMPLES && LV_DRAW_SW_COMPLEX
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#define MASK_WIDTH 150
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#define MASK_HEIGHT 60
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static void generate_mask(uint8_t * mask, int32_t w, int32_t h, const char * txt)
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{
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/*Create a "8 bit alpha" canvas and clear it*/
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lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
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lv_canvas_set_buffer(canvas, mask, w, h, LV_COLOR_FORMAT_L8);
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lv_canvas_fill_bg(canvas, lv_color_black(), LV_OPA_TRANSP);
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lv_layer_t layer;
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lv_canvas_init_layer(canvas, &layer);
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/*Draw a label to the canvas. The result "image" will be used as mask*/
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lv_draw_label_dsc_t label_dsc;
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lv_draw_label_dsc_init(&label_dsc);
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label_dsc.color = lv_color_white();
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label_dsc.align = LV_TEXT_ALIGN_CENTER;
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label_dsc.text = txt;
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label_dsc.font = &lv_font_montserrat_24;
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lv_area_t a = {0, 0, w - 1, h - 1};
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lv_draw_label(&layer, &label_dsc, &a);
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lv_canvas_finish_layer(canvas, &layer);
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lv_obj_delete(canvas);
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}
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/**
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* Draw label with gradient color
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*/
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void lv_example_label_4(void)
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{
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/* Create the mask of a text by drawing it to a canvas*/
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static uint8_t mask[MASK_WIDTH * MASK_HEIGHT];
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generate_mask(mask, MASK_WIDTH, MASK_HEIGHT, "Text with gradient");
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static lv_draw_buf_t draw_buf;
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lv_draw_buf_init(&draw_buf, MASK_WIDTH, MASK_HEIGHT, LV_COLOR_FORMAT_A8, LV_STRIDE_AUTO, mask, sizeof(mask));
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/* Create an object from where the text will be masked out.
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* Now it's a rectangle with a gradient but it could be an image too*/
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lv_obj_t * grad = lv_obj_create(lv_screen_active());
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lv_obj_set_size(grad, MASK_WIDTH, MASK_HEIGHT);
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lv_obj_center(grad);
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lv_obj_set_style_bg_color(grad, lv_color_hex(0xff0000), 0);
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lv_obj_set_style_bg_grad_color(grad, lv_color_hex(0x0000ff), 0);
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lv_obj_set_style_bg_grad_dir(grad, LV_GRAD_DIR_HOR, 0);
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lv_obj_set_style_bitmap_mask_src(grad, &draw_buf, 0);
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}
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#endif
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