First working version of the OpenCV demo

- Getting the camera image
- Creating an OpenCV Mat object with it
- Creating an lv_img_dsc_t LVGL object
- Displaying it on the screen

esp32/examples/ttgo_demo/main/main.cpp

@@ -30,6 +30,67 @@ void app_main(void);
 
 extern CEspLcd *tft;
 
+static lv_obj_t *lvCameraImage; // Camera image object
+
+void gui_boot_screen() {
+    lv_obj_t *scr = lv_disp_get_scr_act(nullptr);
+
+    lv_obj_t *label1 = lv_label_create(scr, nullptr);
+    lv_label_set_text(label1, "Hello World!");
+    lv_obj_align(label1, nullptr, LV_ALIGN_CENTER, 0, 0);
+
+}
+
+void gui_init() {
+    // Create screen
+    lv_obj_t *scr = lv_obj_create(nullptr, nullptr);
+    lv_scr_load(scr);
+
+    // Init camera image Lvgl object
+    lvCameraImage = lv_img_create(lv_disp_get_scr_act(nullptr), nullptr);
+    lv_obj_set_hidden(lvCameraImage, true);
+    lv_obj_move_foreground(lvCameraImage);
+}
+
+esp_err_t updateCameraImage(const cv::Mat &img) {
+    // static variables because they must still be available when lv_task_handler() is called
+    static Mat imgCopy;
+    static lv_img_dsc_t my_img_dsc;
+
+    if(img.empty()) {
+        ESP_LOGW(TAG, "Can't display empty image");
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    // convert image to bgr565 if needed
+    if(img.type() == CV_8UC1) {         // grayscale image
+        cvtColor(img, imgCopy, COLOR_GRAY2BGR565, 1);
+    }
+    else if(img.type() == CV_8UC3) {    // BGR888 image
+        cvtColor(img, imgCopy, COLOR_BGR2BGR565, 1);
+    }
+    else if(img.type() == CV_8UC2) {    // BGR565 image
+        img.copyTo(imgCopy);
+    }
+
+    my_img_dsc.header.always_zero = 0;
+    my_img_dsc.header.w = imgCopy.cols;
+    my_img_dsc.header.h = imgCopy.rows;
+    my_img_dsc.header.cf = LV_IMG_CF_TRUE_COLOR;
+    my_img_dsc.data_size = imgCopy.size().width * imgCopy.size().height;
+    my_img_dsc.data = imgCopy.ptr<uchar>(0);
+
+    if(lv_obj_get_hidden(lvCameraImage))
+        lv_obj_set_hidden(lvCameraImage, false);
+    lv_obj_move_foreground(lvCameraImage);
+
+    lv_img_set_src(lvCameraImage, &my_img_dsc);  /* Set the created file as image */
+    lv_obj_set_pos(lvCameraImage, -40, 0);
+
+    return ESP_OK;
+}
+//#endif
+
 /**
  * Task doing the demo: Getting image from camera, processing it with opencv depending on the displayMode and
  * displaying it on the lcd
@@ -40,6 +101,9 @@ void demo_task(void *arg) {
     // Display memory infos
     disp_infos();
 
+    tft->setRotation(2);        // rotation needed if camera is on the back of the device
+    sensor_t *s = esp_camera_sensor_get();
+
     while(true) {
         auto start = esp_timer_get_time();
 
@@ -48,18 +112,18 @@ void demo_task(void *arg) {
         if (!fb) {
             ESP_LOGE(TAG, "Camera capture failed");
         } else {
+            if(s->pixformat == PIXFORMAT_JPEG) {
                 TFT_jpg_image(CENTER, CENTER, 0, -1, NULL, fb->buf, fb->len);
                 esp_camera_fb_return(fb);
                 fb = NULL;
             }
-
+            else {  // RGB565 pixformat
-        ESP_LOGI(TAG, "time taken: %lld ms", (esp_timer_get_time() - start) / 1000);
+                Mat inputImage(fb->height, fb->width, CV_8UC2, fb->buf);      // rgb565 is 2 channels of 8-bit unsigned
+                updateCameraImage(inputImage);
 
 #if 0   // TODO: next step..
-        Mat inputImage(fb->height, fb->width, CV_8UC2, fb->buf);      // rgb565 is 2 channels of 8-bit unsigned
                 Mat outputImage;
 
-
                 if(currentDisplayMode == DisplayMode::RGB) {
                 }
                 else if(currentDisplayMode == DisplayMode::GRAYSCALE) {
@@ -88,10 +152,14 @@ void demo_task(void *arg) {
 
                 // Diplay image on LCD
                 setImage(inputImage);
-
 #endif
+            }
+        }
+
+        ESP_LOGI(TAG, "time taken: %lld ms", (esp_timer_get_time() - start) / 1000);
 
         wait_msec(25);
+        lv_task_handler();  // tells LVGL to handle its tasks
     }
 }
 
@@ -102,6 +170,11 @@ void app_main()
     /* initializations */
     app_camera_init();
     lvgl_init();
+    gui_init();
+
+    /* display boot screen */
+    gui_boot_screen();
+    wait_msec(1500);
 
     /* Display memory infos */
     disp_infos();