fix screen tearing issue when switch between frames

Author: leonardocavagnis

libraries/Arduino_H7_Video/src/Arduino_H7_Video.cpp

@@ -56,17 +56,13 @@ int Arduino_H7_Video::begin() {
 
   textFont(Font_5x7);
 
-  /* Video controller/bridge init */
-  _shield->init(_edidMode);
-  
   /* Configure SDRAM */
   SDRAM.begin();
 
-  dsi_lcdClear(0); 
+  /* Video controller/bridge init */
+  _shield->init(_edidMode);
 
   #if __has_include("lvgl.h")
-    dsi_getNextFrameBuffer();
-
     /* Initiliaze LVGL library */
     lv_init();
 
@@ -107,17 +103,13 @@ void Arduino_H7_Video::end() {
 void Arduino_H7_Video::beginDraw() {
   ArduinoGraphics::beginDraw();
 
-  #if __has_include("lvgl.h")
-    dsi_getNextFrameBuffer();
-  #endif
-
   dsi_lcdClear(0); 
 }
 
 void Arduino_H7_Video::endDraw() {
   ArduinoGraphics::endDraw();
 
-  dsi_getNextFrameBuffer();
+  dsi_drawCurrentFrameBuffer();
 }
 
 void Arduino_H7_Video::clear(){
@@ -165,7 +157,7 @@ void lvgl_displayFlushing(lv_disp_drv_t * disp, const lv_area_t * area, lv_color
     uint32_t height     = lv_area_get_height(area);
     uint32_t offsetPos  = (area->x1 + (dsi_getDisplayXSize() * area->y1)) * sizeof(uint16_t);
 
-    dsi_lcdDrawImage((void *) color_p, (void *)(dsi_getCurrentFrameBuffer() + offsetPos), width, height, DMA2D_INPUT_RGB565);
+    dsi_lcdDrawImage((void *) color_p, (void *)(dsi_getActiveFrameBuffer() + offsetPos), width, height, DMA2D_INPUT_RGB565);
     lv_disp_flush_ready(disp);         /* Indicate you are ready with the flushing*/
 }
 

libraries/Arduino_H7_Video/src/dsi.cpp

@@ -247,9 +247,9 @@ int dsi_init(uint8_t bus, struct edid *edid, struct display_timing *dt) {
 	HAL_DSI_PatternGeneratorStop(&dsi);
 
 	dsi_lcdClear(0);
-	dsi_getNextFrameBuffer();
+	dsi_drawCurrentFrameBuffer();
 	dsi_lcdClear(0);
-	dsi_getNextFrameBuffer();
+	dsi_drawCurrentFrameBuffer();
 }
 
 void dsi_lcdClear(uint32_t Color) {
@@ -319,18 +319,20 @@ uint32_t dsi_getFramebufferEnd(void) {
 	return (FB_BASE_ADDRESS + 2 * (lcd_x_size * lcd_y_size * BYTES_PER_PIXEL));
 }
 
-uint32_t dsi_getNextFrameBuffer(void) {
+void dsi_drawCurrentFrameBuffer(void) {
 	int fb = pend_buffer++ % 2;
-
+	
 	__HAL_LTDC_LAYER_ENABLE(&(ltdc), fb);
-  	__HAL_LTDC_LAYER_DISABLE(&(ltdc), !fb);
-  	__HAL_LTDC_VERTICAL_BLANKING_RELOAD_CONFIG(&(ltdc));
-
-	return fb ? FB_ADDRESS_0 : FB_ADDRESS_1;
+	__HAL_LTDC_LAYER_DISABLE(&(ltdc), !fb);
+	__HAL_LTDC_VERTICAL_BLANKING_RELOAD_CONFIG(&(ltdc));
 }
 
 uint32_t dsi_getCurrentFrameBuffer() {
-	return pend_buffer ? FB_ADDRESS_0 : FB_ADDRESS_1;
+	return (ltdc.LayerCfg[pend_buffer%2].FBStartAdress);
+}
+
+uint32_t dsi_getActiveFrameBuffer() {
+	return (ltdc.LayerCfg[(pend_buffer+1)%2].FBStartAdress);
 }
 
 uint32_t dsi_getDisplayXSize(){

libraries/Arduino_H7_Video/src/dsi.h

@@ -36,8 +36,9 @@ void		dsi_lcdClear(uint32_t color);
 void		dsi_lcdDrawImage(void *pSrc, void *pDst, uint32_t xSize, uint32_t ySize, uint32_t ColorMode);
 void		dsi_lcdFillArea(void *pDst, uint32_t xSize, uint32_t ySize, uint32_t ColorMode);
 void		dsi_configueCLUT(uint32_t* clut);
-uint32_t	dsi_getNextFrameBuffer(void);
+void		dsi_drawCurrentFrameBuffer(void);
 uint32_t	dsi_getCurrentFrameBuffer(void);
+uint32_t 	dsi_getActiveFrameBuffer(void);
 uint32_t	dsi_getFramebufferEnd(void);
 uint32_t 	dsi_getDisplayXSize(void);
 uint32_t 	dsi_getDisplayYSize(void);