image recoloring for little vGL

• 定义slider的宽度

  #define SLIDER_WIDTH 40

• 变量定义

  static lv_obj_t* red_slider, * green_slider, * blue_slider, * intense_slider, * img1;
  static lv_style_t img_style;

• slider滑动回调函数

  
  static void slider_event_callback(lv_obj_t* obj, lv_event_t event)
  {
      if (event == LV_EVENT_VALUE_CHANGED)
      {
          /*Recolor the image based on the sliders' values*/
          img_style.image.color = lv_color_make(lv_slider_get_value(red_slider), lv_slider_get_value(green_slider),
              lv_slider_get_value(blue_slider));
          img_style.image.intense = lv_slider_get_value(intense_slider);
          lv_img_set_style(img1, LV_IMG_STYLE_MAIN, &img_style);
      }
  }

• 图片数据引用及声明

  LV_IMG_DECLARE(my_jumper)
  

      图片资源下载地址

       链接：https://pan.baidu.com/s/1_Wk7PH93_bIh29pHsaOVRA         提取码：qq3b 

• 创建R,G,B,intense等slider

  static void create_sliders(void)
  {
      /*Create a set of RGB sliders*/
      /*Use the red one as a base for all the settings*/
      red_slider = lv_slider_create(lv_scr_act(), NULL);
      lv_slider_set_range(red_slider, 0, 255);
      lv_obj_set_size(red_slider, SLIDER_WIDTH, 200);
  
      lv_obj_set_event_cb(red_slider, slider_event_callback);
  
      /*Create the intensity slider first,as it does not use any custom styles*/
      intense_slider = lv_slider_create(lv_scr_act(), red_slider);
      lv_slider_set_range(intense_slider, LV_OPA_TRANSP, LV_OPA_COVER);
      /*Create the slider knob and fill styles*/
      /*Fill styles are initialized with a gradient between black and the slider's respective color.*/
      /*Knob styles are simply filled with the slider's respective color.*/
  
      static lv_style_t slider_red_fill_style, slider_red_knob_style;
      lv_style_copy(&slider_red_fill_style, lv_slider_get_style(red_slider, LV_SLIDER_STYLE_INDIC));
      lv_style_copy(&slider_red_knob_style, lv_slider_get_style(red_slider, LV_SLIDER_STYLE_KNOB));
  
      slider_red_fill_style.body.main_color = lv_color_make(255, 0, 0);
      slider_red_fill_style.body.grad_color = LV_COLOR_BLACK;
  
      slider_red_knob_style.body.main_color = slider_red_fill_style.body.main_color;
      slider_red_knob_style.body.grad_color = slider_red_fill_style.body.main_color;
  
      static lv_style_t slider_green_fill_style, slider_green_knob_style;
      lv_style_copy(&slider_green_fill_style, &slider_red_fill_style);
      lv_style_copy(&slider_green_knob_style, &slider_red_knob_style);
  
      slider_green_fill_style.body.main_color = lv_color_make(0, 255, 0);
      slider_green_knob_style.body.main_color = slider_green_fill_style.body.main_color;
      slider_green_knob_style.body.grad_color = slider_green_fill_style.body.main_color;
  
      static lv_style_t slider_blue_fill_style, slider_blue_knob_style;
      lv_style_copy(&slider_blue_fill_style, &slider_red_fill_style);
      lv_style_copy(&slider_blue_knob_style, &slider_red_knob_style);
      slider_blue_fill_style.body.main_color = lv_color_make(0, 0, 255);
      slider_blue_knob_style.body.main_color = slider_blue_fill_style.body.main_color;
      slider_blue_knob_style.body.grad_color = slider_blue_fill_style.body.main_color;
      /*Set the red slider*/
      lv_slider_set_style(red_slider, LV_SLIDER_STYLE_INDIC, &slider_red_fill_style);
      lv_slider_set_style(red_slider, LV_SLIDER_STYLE_KNOB, &slider_red_knob_style);
  
      /*Copy it for the other two sliders*/
      green_slider = lv_slider_create(lv_scr_act(), red_slider);
      lv_slider_set_style(green_slider, LV_SLIDER_STYLE_INDIC, &slider_green_fill_style);
      lv_slider_set_style(green_slider, LV_SLIDER_STYLE_KNOB, &slider_green_knob_style);
  
      blue_slider = lv_slider_create(lv_scr_act(), red_slider);
      lv_slider_set_style(blue_slider, LV_SLIDER_STYLE_INDIC, &slider_blue_fill_style);
      lv_slider_set_style(blue_slider, LV_SLIDER_STYLE_KNOB, &slider_blue_knob_style);
  
      lv_obj_align(red_slider, NULL, LV_ALIGN_IN_LEFT_MID, 10, 0);
  
      lv_obj_align(green_slider, red_slider, LV_ALIGN_OUT_RIGHT_MID, 10, 0);
  
      lv_obj_align(blue_slider, green_slider, LV_ALIGN_OUT_RIGHT_MID, 10, 0);
  
      lv_obj_align(intense_slider, blue_slider, LV_ALIGN_OUT_RIGHT_MID, 10, 0);
  
  }

• 图片着色处理实现

void image_recoloring_demo(void)
{
    /*Create 4 sliders to adjust RGB color and re-color intensity*/
    create_sliders();

    /*Now create the actual image*/
    img1 = lv_img_create(lv_scr_act(), NULL);
    lv_img_set_src(img1, &my_jumper);
    lv_obj_align(img1, intense_slider, LV_ALIGN_OUT_RIGHT_MID, 10, 0);

    /*Create a message box for information*/

    static const char* btns[] = { "OK","" };
    lv_obj_t* mbox = lv_mbox_create(lv_scr_act(), NULL);

    lv_mbox_set_text(mbox, "Welcome to the image recoloring demo!\nThe first \
three sliders control the RGB value of the recoloring.\n\
        The last slider controls the intensity.");
    lv_mbox_add_btns(mbox, btns);
    lv_obj_align(mbox, NULL, LV_ALIGN_CENTER, 0, 0);
    lv_style_copy(&img_style, lv_img_get_style(img1, LV_IMG_STYLE_MAIN));
}

• 运行效果图