From 63179fb3f56637c4ec6a6f8cd7338349c7ef4404 Mon Sep 17 00:00:00 2001
From: CrispyPin <crispin@tasa.se>
Date: Fri, 12 Apr 2024 22:36:16 +0200
Subject: [PATCH] clear screen on startup

---
 ch32_decoder/bad_apple.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/ch32_decoder/bad_apple.c b/ch32_decoder/bad_apple.c
index 7497819..ea86c6e 100644
--- a/ch32_decoder/bad_apple.c
+++ b/ch32_decoder/bad_apple.c
@@ -16,6 +16,7 @@
 
 void decode_next_frame();
 void refresh_screen();
+void clear_screen();
 u32 reader = 0;
 
 u32 frame[WIDTH];
@@ -33,6 +34,7 @@ int main()
 	uint8_t *cmd_list = (uint8_t *)ssd1306_init_array;
 	while (*cmd_list != SSD1306_TERMINATE_CMDS)
 		ssd1306_cmd(*cmd_list++);
+	clear_screen();
 
 	while (1)
 	{
@@ -77,6 +79,18 @@ void refresh_screen()
 	}
 }
 
+void clear_screen()
+{
+	ssd1306_cmd(SSD1306_COLUMNADDR);
+	ssd1306_cmd(0);	  // Column start address (0 = reset)
+	ssd1306_cmd(127); // Column end address (127 = reset)
+	ssd1306_cmd(SSD1306_PAGEADDR);
+	ssd1306_cmd(0); // Page start address (0 = reset)
+	ssd1306_cmd(7); // Page end address
+	for (u32 i = 0; i < 32 * 8; i++)
+		ssd1306_data(frame, SSD1306_PSZ);
+}
+
 u8 next_byte()
 {
 	u8 byte = video[reader];