From dfb8fb16fcdae8bd0235949a78aa6948af817b5e Mon Sep 17 00:00:00 2001
From: Sijmen Schoon <me@sijmenschoon.nl>
Date: Fri, 11 Dec 2020 20:52:57 +0100
Subject: [PATCH] Implement PrintFormat which scrolls the screen when
 overflowing

---
 src/Screen.cpp | 10 ++++++++++
 src/Screen.h   |  1 +
 src/main.cpp   | 15 +++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/src/Screen.cpp b/src/Screen.cpp
index 6118b5d..a4aeb28 100644
--- a/src/Screen.cpp
+++ b/src/Screen.cpp
@@ -188,6 +188,16 @@ void Screen::ScrollArea(u32 x1, u32 y1, u32 x2, u32 y2)
 	}
 }
 
+void Screen::ScrollUp(u32 pixels)
+{
+	memcpy(
+		framebuffer,
+		framebuffer + pixels * 2 * pitch,
+		(height - pixels * 2) * pitch
+	);
+	DrawRectangle(0, height - pixels, width, height, RGBA(0, 0, 0, 0xFF));
+}
+
 void Screen::Clear(RGBA colour)
 {
 	DrawRectangle(0, 0, width, height, colour);
diff --git a/src/Screen.h b/src/Screen.h
index 1e4a8aa..5e7116c 100644
--- a/src/Screen.h
+++ b/src/Screen.h
@@ -36,6 +36,7 @@ public:
 	void Clear(RGBA colour);
 
 	void ScrollArea(u32 x1, u32 y1, u32 x2, u32 y2);
+	void ScrollUp(u32 pixels);
 
 	void WriteChar(bool petscii, u32 x, u32 y, unsigned char c, RGBA colour);
 	u32 PrintText(bool petscii, u32 xPos, u32 yPos, char *ptr, RGBA TxtColour = RGBA(0xff, 0xff, 0xff, 0xff), RGBA BkColour = RGBA(0, 0, 0, 0xFF), bool measureOnly = false, u32* width = 0, u32* height = 0);
diff --git a/src/main.cpp b/src/main.cpp
index 0a1b4cf..e1ac290 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1867,6 +1867,21 @@ void DisplayMessage(int x, int y, bool LCD, const char* message, u32 textColour,
 #endif
 }
 
+int y_pos = 184;
+void PrintFormat(const char* format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	vsnprintf(tempBuffer, tempBufferSize, format, args);
+	va_end(args);
+
+	if (y_pos + 96 >= screenHeight) {
+		screen.ScrollUp(8);
+		y_pos -= 16;
+	}
+	screen.PrintText(false, 0, y_pos+=16, tempBuffer, COLOUR_WHITE, COLOUR_BLACK);
+}
+
 extern "C"
 {
 	void kernel_main(unsigned int r0, unsigned int r1, unsigned int atags)