4.2 inch partial render issues

[bi-ebouchard]

If I use the 4.2 example in RaspberryPi_JetsonNano/c/examples/EPD_4in2_V2_test.c, it works fine on Raspberry pi.

Here is the display that I use: https://www.good-display.com/product/617.html

But if I change the location of the partial render for the clock, I get garbage data rendered. It seems like it has a few sweet spots on partial rendering.
I tried this by rendering a 32x32 black square in random places on the screen, and it seems most of the time I will get bad data on the screen rendered. If I render a 200x50 black square at 80, 200 (like the clock position and size) it works fine (code below)

--- a/RaspberryPi_JetsonNano/c/examples/EPD_4in2_V2_test.c
+++ b/RaspberryPi_JetsonNano/c/examples/EPD_4in2_V2_test.c
@@ -115,7 +115,23 @@ int EPD_4in2_V2_test(void)
        DEV_Delay_ms(2000);
 #endif
 
-#if 1
+ Paint_NewImage(BlackImage, 200, 50, 0, WHITE);
+ Paint_Clear(WHITE);
+
+for (int i = 0; i < 200; i++)
+{
+    for (int j = 0; j < 50; j++)
+    {
+        Paint_SetPixel(i, j, BLACK);
+    }
+}
+            
+
+
+EPD_4IN2_V2_PartialDisplay(BlackImage, 80, 200, 200, 50);
+DEV_Delay_ms(2000);
+
+#if 0

but as soon as i change it from x80, y200 to something slightly different like (x72, y192) or (x56, y176)I get bad data (see imgs, notice the last img is fine, but the other one have a long black line)

Maybe I need to use a different demo?

Also is it possible that Paint_NewImage has an issue with rotation? When I try to rotate, it causes further issues.

@SSYYL I notice you did a commit a while back to fix 4.2 partial render, any ideas?