fix(thorvg): support rendering in draw events (#6406)

Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

demos/lv_demos.c

@@ -64,7 +64,11 @@ static const demo_entry_info_t demos_entry_info[] = {
 #endif
 
 #if LV_USE_DEMO_VECTOR_GRAPHIC && LV_USE_VECTOR_GRAPHIC
-    { "vector_graphic", .entry_cb = lv_demo_vector_graphic },
+    { "vector_graphic_buffered", .entry_cb = lv_demo_vector_graphic_buffered },
+#endif
+
+#if LV_USE_DEMO_VECTOR_GRAPHIC && LV_USE_VECTOR_GRAPHIC
+    { "vector_graphic_not_buffered", .entry_cb = lv_demo_vector_graphic_not_buffered },
 #endif
 
 #if LV_USE_DEMO_BENCHMARK

demos/vector_graphic/lv_demo_vector_graphic.c

@@ -245,6 +245,13 @@ static void delete_event_cb(lv_event_t * e)
     lv_draw_buf_destroy(draw_buf);
 }
 
+static void event_cb(lv_event_t * e)
+{
+    lv_layer_t * layer = lv_event_get_layer(e);
+
+    draw_vector(layer);
+}
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -257,7 +264,12 @@ static void delete_event_cb(lv_event_t * e)
  *   GLOBAL FUNCTIONS
  **********************/
 
-void lv_demo_vector_graphic(void)
+void lv_demo_vector_graphic_not_buffered(void)
+{
+    lv_obj_add_event_cb(lv_screen_active(), event_cb, LV_EVENT_DRAW_MAIN, NULL);
+}
+
+void lv_demo_vector_graphic_buffered(void)
 {
     lv_draw_buf_t * draw_buf = lv_draw_buf_create(WIDTH, HEIGHT, LV_COLOR_FORMAT_ARGB8888, LV_STRIDE_AUTO);
     lv_draw_buf_clear(draw_buf, NULL);
@@ -278,7 +290,15 @@ void lv_demo_vector_graphic(void)
  **********************/
 #else
 
-void lv_demo_vector_graphic(void)
+void lv_demo_vector_graphic_not_buffered(void)
+{
+    /*fallback for online examples*/
+    lv_obj_t * label = lv_label_create(lv_screen_active());
+    lv_label_set_text(label, "Vector graphics is not enabled");
+    lv_obj_center(label);
+}
+
+void lv_demo_vector_graphic_buffered(void)
 {
     /*fallback for online examples*/
     lv_obj_t * label = lv_label_create(lv_screen_active());

demos/vector_graphic/lv_demo_vector_graphic.h

@@ -27,7 +27,18 @@ extern "C" {
 /**********************
  * GLOBAL PROTOTYPES
  **********************/
-void lv_demo_vector_graphic(void);
+
+/**
+ * Draw many vector based shapes and paths to canvas.
+ * It requires a large amount of RAM for the buffer of the canvas
+ */
+void lv_demo_vector_graphic_buffered(void);
+
+/**
+ * Draw many vector based shapes and paths to canvas directly to the screen.
+ * It's slower as the graphics needs to rendered on each rendering cycle.
+ */
+void lv_demo_vector_graphic_not_buffered(void);
 
 /**********************
  *      MACROS

src/libs/thorvg/tvgSwRenderer.cpp

@@ -443,11 +443,7 @@ bool SwRenderer::target(pixel_t* data, uint32_t stride, uint32_t w, uint32_t h,
 
 bool SwRenderer::preRender()
 {
-#if LV_USE_DRAW_VG_LITE && LV_USE_VG_LITE_THORVG
-	return true;
-#else
-    return rasterClear(surface, 0, 0, surface->w, surface->h);
-#endif
+    return true;
 }
 
 

src/widgets/lottie/lv_lottie.c

@@ -219,14 +219,8 @@ static void lottie_update(lv_lottie_t * lottie, int32_t v)
 
     lv_draw_buf_t * draw_buf = lv_canvas_get_draw_buf(obj);
     if(draw_buf) {
-#if LV_USE_DRAW_VG_LITE && LV_USE_VG_LITE_THORVG
-        /**
-         * Since the buffer clearing operation in the SwRenderer::preRender
-         * function is removed when the VG-Lite simulator is enabled, the canvas
-         * buffer must be manually cleared here.
-         */
         lv_draw_buf_clear(draw_buf, NULL);
-#endif
+
         /*Drop old cached image*/
         lv_image_cache_drop(lv_image_get_src(obj));
     }

tests/src/test_cases/draw/test_draw_vector.c

@@ -240,6 +240,8 @@ static void canvas_draw(const char * name, void (*draw_cb)(lv_layer_t *))
     lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
     lv_draw_buf_t * draw_buf = lv_draw_buf_create(640, 480, LV_COLOR_FORMAT_ARGB8888, LV_STRIDE_AUTO);
     TEST_ASSERT_NOT_NULL(draw_buf);
+
+    lv_draw_buf_clear(draw_buf, NULL);
     lv_canvas_set_draw_buf(canvas, draw_buf);
 
     lv_layer_t layer;
@@ -297,4 +299,38 @@ void test_draw_shapes(void)
 {
     canvas_draw("draw_shapes", draw_shapes);
 }
+
+
+static void event_cb(lv_event_t * e)
+{
+    lv_layer_t * layer = lv_event_get_layer(e);
+    lv_obj_t * obj = lv_event_get_current_target_obj(e);
+
+    lv_vector_dsc_t * dsc = lv_vector_dsc_create(layer);
+    lv_vector_path_t * path = lv_vector_path_create(LV_VECTOR_PATH_QUALITY_MEDIUM);
+
+    lv_fpoint_t pts[] = {{10, 10}, {130, 130}, {10, 130}};
+    lv_vector_path_move_to(path, &pts[0]);
+    lv_vector_path_line_to(path, &pts[1]);
+    lv_vector_path_line_to(path, &pts[2]);
+    lv_vector_path_close(path);
+
+    lv_vector_dsc_translate(dsc, obj->coords.x1, obj->coords.y1);
+    lv_vector_dsc_set_fill_color(dsc, lv_color_make(0x00, 0x80, 0xff));
+    lv_vector_dsc_add_path(dsc, path);
+
+    lv_draw_vector(dsc);
+    lv_vector_path_delete(path);
+    lv_vector_dsc_delete(dsc);
+}
+
+void test_draw_during_rendering(void)
+{
+    lv_obj_t * obj = lv_obj_create(lv_screen_active());
+    lv_obj_center(obj);
+    lv_obj_add_event_cb(obj, event_cb, LV_EVENT_DRAW_MAIN, NULL);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("draw/vector_draw_during_rendering.png");
+}
+
 #endif