Text scrolling optimisation for VGATextOutput

2 files changed, 13 insertions, 0 deletions

diff --git a/Source/Kernel/Devices/Display/VGATextOutput.class.cpp b/Source/Kernel/Devices/Display/VGATextOutput.class.cpp
index 50a57b2..c597696 100644
--- a/Source/Kernel/Devices/Display/VGATextOutput.class.cpp
+++ b/Source/Kernel/Devices/Display/VGATextOutput.class.cpp
@@ -24,6 +24,7 @@ void VGATextOutput::getModes(Vector<mode_t> &to) {
 	m.identifier = 1;
 	m.graphWidth = 0;
 	m.graphHeight = 0;
+	m.graphDepth = 0;
 	m.device = this;
 	to.push(m);
 	m.textCols = 80;
@@ -60,3 +61,13 @@ void VGATextOutput::clear() {
 	u16int* where = (u16int*)RAM_ADDR;
 	for (int i = 0; i < 25 * 80; i++) where[i] = 0;
 }
+
+bool VGATextOutput::textScroll(u16int line, u16int col, u16int height, u16int width, u8int color) {
+	u8int* where = (u8int*)RAM_ADDR;
+	for (u32int i = 1; i < height; i++) {
+		memcpy(where + ((line + i - 1) * (m_cols * 2)) + (col * 2), where + ((line + i) * (m_cols * 2)) + (col * 2), width * 2);
+	}
+	u16int* w = (u16int*)where;
+	memsetw(w + ((line + height - 1) * m_cols) + col, 0x20 | (color << 8), width);
+	return true;
+}
diff --git a/Source/Kernel/Devices/Display/VGATextOutput.class.h b/Source/Kernel/Devices/Display/VGATextOutput.class.h
index 2c72d40..0b0ba94 100644
--- a/Source/Kernel/Devices/Display/VGATextOutput.class.h
+++ b/Source/Kernel/Devices/Display/VGATextOutput.class.h
@@ -18,6 +18,8 @@ class VGATextOutput : public Display {
 	void putChar(u16int line, u16int col, WChar c, u8int color);
 	void moveCursor(u16int line, u16int col);
 	void clear();
+
+	bool textScroll(u16int line, u16int col, u16int height, u16int width, u8int color);
 };
 
 #endif