1 files changed, 73 insertions, 0 deletions
diff --git a/src/print.c b/src/print.c
new file mode 100644
index 0000000..0a0220c
--- /dev/null
+++ b/src/print.c
@@ -0,0 +1,73 @@
+#include "print.h"
+
+TextOutput createOutput(const int max_row, const int max_column, uint16_t* vid_mem) {
+    // Create a new TextOutput interface
+    TextOutput output;
+    output.max_row = max_row;
+    output.max_column = max_column;
+    output.vid_mem = vid_mem;
+    output.terminal_row = 0;
+    output.terminal_column = 0;
+    return output;
+}
+
+void scrollText(TextOutput* textOutput) {
+    // Move each character up one row
+    for (int y = 0; y < textOutput->max_row; y++) {
+        for (int x = 0; x < textOutput->max_column; x++) {
+            *(textOutput->vid_mem + textOutput->max_column*y + x) = 
+                    *(textOutput->vid_mem + textOutput->max_column*(y+1) + x);
+        }
+    }
+    textOutput->terminal_row--;
+}
+
+void putChar(uint8_t character, uint8_t background, uint8_t foreground, 
+                                                TextOutput* textOutput) {
+    foreground = foreground & 0xF; background = background & 0xF;
+
+    // Handle putting a character to the screen
+    if (textOutput->terminal_row == textOutput->max_row) {
+        scrollText(textOutput);
+    }
+
+    if (character == '\r') {
+        // Delete the character before this \r
+        if (textOutput->terminal_column == 0) {
+            textOutput->terminal_row--;
+            textOutput->terminal_column = 80;
+        }
+        textOutput->terminal_column--;
+        *(textOutput->vid_mem + textOutput->terminal_row*textOutput->max_column
+                + textOutput->terminal_column) = background << 12;
+        return;
+    }
+
+    else if (character == '\n' || textOutput->terminal_column == textOutput->max_column) {
+        // Make a new line
+        for (int i = textOutput->terminal_column; i < textOutput->max_column; i++) {
+            *(textOutput->vid_mem + textOutput->terminal_row*textOutput->max_column
+                   + textOutput->terminal_column) = background << 12;
+            textOutput->terminal_column++;
+        }
+   
+        textOutput->terminal_row++;
+        textOutput->terminal_column = 0;
+    }
+
+    if (character != '\n' && character != '\r') {
+        // Write character to video memory
+        uint16_t entry = (background << 12) | (foreground << 8) | character;
+        *(textOutput->vid_mem + textOutput->terminal_row*textOutput->max_column
+                + textOutput->terminal_column) = entry;
+        textOutput->terminal_column++;
+    }
+}
+
+void print(char* string, uint8_t background, uint8_t foreground, TextOutput* textOutput) {
+    // Print a string
+    for (string; *string; string++) {
+        putChar(*string, background, foreground, textOutput);
+    }
+}
+