Begin ANSI Escape Sequence support

This commit is contained in:
Jenny Curle 2019-04-02 22:46:37 +01:00
parent 96ed9e6785
commit 94c1eb2279

View File

@ -43,6 +43,7 @@ void term_putentryat (char c, uint8_t color, size_t x, size_t y) {
void term_putchar(char c) {
unsigned char uc = c;
//Handle escaped characters, such as newline, and crtn.
switch (uc) {
case '\n':
terminal_column = 0;
@ -57,15 +58,69 @@ void term_putchar(char c) {
{
terminal_column = 0;
if(++terminal_row == TERM_HEIGHT){
term_scroll();
term_scroll(false);
terminal_row = 0;
}
}
}
void term_write(const char* data, size_t size) {
for(size_t i = 0; i < size; i++)
for(size_t i = 0; i < size; i++) {
//Begin handling ANSI escape codes.
if(data[i] == 0x1B) { //The current character is ESC - the start of ANSI codes.
term_writes("ANSI Code encountered: ");
bool string_terminated = false; //Flag used in some of the escape codes
switch(data[i+1]) {
case 0x9b/*[*/: //CSI - Control Sequence Introducer (The most common one, hence it comes first)
char* controlSequence;
if(data[i+2] == NULL) {
controlSequence = '\0';
for(size_t j = 0; j < (strlen(data) - (i+2); j++) {
if(data[j] == ' ')
break;
controlSequence += data[j];
}
handleControlSequence(controlSequence); //Send it off to our handler function to keep this part clean
break;
//Single shifts are not handled, so just print them and exit
case 0x8e/*N*/: //SS2 - Single Shift Two
term_writes("Single Shift Two\n");
break;
case 0x8f/*O*/: //SS3 - Single Shift Three
term_writes("Single Shift Three\n");
break;
//Control Strings
case 0x90/*P*/: //DCS - Device Control String
term_writes("Device Control String");
string_terminated = false;
break;
case 0x9c/*\*/: //ST - String Terminator
term_writes("String Terminator\n");
string_terminated = true;
break;
case 0x9d/*]*/: //OSC - Operating System Command
term_writes("Operating System Command\n");
string_terminated = false;
break;
case 0x98/*X*/: //SOS - Start Of String
term_writes("Start of String");
string_terminated = false;
break;
case 0x9e/*^*/: //PM - Privacy Message
term_writes("Privacy Message\n");
break;
case 0x9f/*_*/: //APC - Application Program Command
term_writes("Application Program Command\n");
break;
}
}
term_putchar(data[i]);
}
}
void term_writes(const char* data) {
@ -77,25 +132,163 @@ void puts(const char* string) {
term_putchar('\n');
}
void term_scroll() {
int current_pos = 160; //Start of the second line.
void handleControlSequence(const char* sequence) {
//Check for our failsafes
if(sequence) {
if(sequence != '\0') {
int n = 0; //Default of the flag used for a few items
bool nPresent = false;
bool terminated = false;
for(size_t i = 0; i < strlen(sequence); i++) {
if(isDigit(sequence[i])) {
nPresent = true;
n = (n*10) + sequence[i];
} else if(n > 80) {
n = 80;
break;
}
}
if(n == 0)
n = 1;
switch(sequence[i]) {
case ';':
terminated = true;
int m = 0;
for(size_t j = 0; j < strlen(sequence - i); j++) {
if(sequence[j] == 'H' ||sequence[j] == 'f')
break;
if(isDigit(sequence[j])) {
m = (m*10) + sequence[j];
} else if(j > 80) break;
}
if(m == 0)
m = 1;
cursor_pos(n, m);
break;
case 'A': //CUU - Cursor Up
//cursor_pos(x, y)
cursor_pos(terminal_column, terminal_row + n);
break;
case 'B': //CUD - Cursor Down
cursor_pos(terminal_column, terminal_row - n);
break;
case 'C': //CUF - Cursor Forward
cursor_pos(terminal_column + n, terminal_row);
break;
case 'D': //CUB - Cursor Back
cursor_pos(terminal_column - n, terminal_row);
break;
case 'E': //CNL - Cursor Next Line
cursor_pos(0, terminal_row + n);
break;
case 'F': //CPL - Cursor Previous Line
cursor_pos(0, terminal_row - n);
break;
case 'G': //CHA - Cursor Horizontal Absolute
cursor_pos(n, terminal_row);
case 'J': //ED - Erase in Display
//current cursor pos = y * width + x
int pos = terminal_row * 80 + terminal_column;
if(!nPresent) {
for(pos < (25 * 80); pos++) {
vga_buffer[pos] = '\0';
}
n = 0;
} else if(nPresent && n == 1) {
for(pos > 0; pos--) {
vga_buffer[pos] = '\0';
}
} else if(n == 2 || n == 3) {
for(int i = 0; i < (25*80); i++) {
vga_buffer[0] = '\0';
}
}
break;
case 'K': //EL - Erase in Line
int pos = terminal_row * 80 + terminal_column;
if(!nPresent) { //From cursor to end of line
int endPos = (terminal_row + 1) * 80 - 1; //End of line = current row + 25 columns = current row + 1
for(pos < endPos; pos++) {
vga_buffer[pos] = '\0';
}
} else if(nPresent && n == 1) { //From cursor to start of line
int endPos = terminal_row * 80; //Start of line = end of previous line + 1 == current line
for(pos > endPos; pos--) {
vga_buffer[pos] = '\0';
}
} else if(nPresent && n == 2) { //Entire current line
pos = terminal_row * 80;
int endPos = (terminal_row + 1) * 80 - 1;
for(pos < endPos; pos++) {
vga_buffer[pos] = '\0';
}
}
break;
case 'S': //SU - Scroll Up
term_scroll(true);
break;
case 'T': //SD - Scroll Down
term_scroll(false);
break;
}
}
}
}
}
bool isDigit(const char c) {
return c == '0' || c == '1' || c == '2' || c == '3' ||
c == '4' || c == '5' || c == '6' || c == '7' ||
c == '8' || c == '9';
}
void term_scroll(bool down) {
int current_pos;
if(down) {
current_pos = 25 * 80; //Start of the last line.
} else {
current_pos = 160; //Start of the second line.
}
unsigned char* term_buffer = (unsigned char*) vga_buffer;
if(down) { //To scroll down, move every character into the one below it, or "pull" every character down
while(current_pos > 80) {
term_buffer[current_pos + 160] = vga_buffer[current_pos];
term_buffer[current_pos + 159] = vga_buffer[current_pos - 1];
current_pos -= 2;
} else {
while (current_pos <= 4000) {
term_buffer[current_pos - 160 /*The character immediately below it*/] = vga_buffer[current_pos]; //Move each character up a line
term_buffer[current_pos - 159 /*The color of the character below*/] = vga_buffer[current_pos + 1]; //As well as its color
current_pos += 2; //Move to next char
}
}
current_pos = 3840; //Start of the last line
int i; //Offset for framebuffer
if(down) {
current_pos = 0; //Start of first line
for(current_pos < 80; current_pos++) {
term_buffer[current_pos] = '\0';
current_pos += 2;
} else {
; //Start of the last line
//Wipe out the bottom line
for(i = 1920; i <= 2000; i++) {
for(current_pos = 3840; current_pos <= 3920; i++) {
term_buffer[current_pos] = 0;
current_pos += 2;
}
}
i = 3840;
terminal_row = 24; //Prepare the screen to scroll
terminal_row = 24; //Start writing on the last line
terminal_column = 0;
}