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#include "print.h"
#define FOREGROUND 0x0
#define BACKGROUND 0xF
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
while (*string) {
putChar(*string, background, foreground, textOutput);
string++;
}
}
void PrintWithScreenFill(char* string, TextOutput* output_stream) {
// Print a string and fill the screen
print(string, BACKGROUND, FOREGROUND, output_stream);
int row = output_stream->terminal_row;
while (output_stream->terminal_row < output_stream->max_row) {
putChar('\n', BACKGROUND, FOREGROUND, output_stream);
}
output_stream->terminal_row = row;
}
inline void swap(char *x, char *y) {
char t = *x; *x = *y; *y = t;
}
int abs(int value) {
return (value < 0 ? -value : value);
}
// function to reverse buffer[i..j]
char* reverse(char *buffer, int i, int j)
{
while (i < j)
swap(&buffer[i++], &buffer[j--]);
return buffer;
}
// Iterative function to implement itoa() function in C
char* itoa(int value, char* buffer, int base)
{
if (base < 2 || base > 32)
return buffer;
int n = abs(value);
int i = 0;
while (n)
{
int r = n % base;
if (r >= 10)
buffer[i++] = 65 + (r - 10);
else
buffer[i++] = 48 + r;
n = n / base;
}
if (i == 0)
buffer[i++] = '0';
if (value < 0 && base == 10)
buffer[i++] = '-';
buffer[i] = '\0';
return reverse(buffer, 0, i - 1);
}
int haveFilledScreen = 0;
void printToMonitor(char* string) {
if (!haveFilledScreen) {
monitor = createOutput(25, 80, (uint16_t*)(0xB8000));
PrintWithScreenFill(string, &monitor);
haveFilledScreen = 1;
}
else
print(string, BACKGROUND, FOREGROUND, &monitor);
}
void printIntToMonitor(int num, int base) {
char* buffer;
printToMonitor(itoa(num, buffer, base));
}
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