ANSI Escape Code Handling

Better handling of ANSI Escape Code Handling

cowterm.c

@@ -365,35 +365,16 @@ static void draw_terminal(Display *display, Window window) {
   if (!terminal_buffer || !color_buffer || !attr_buffer)
     return;
 
-  if (buffer_pixmap == None)
+  XSetForeground(display, gc, current_bg_color);
-    buffer_pixmap = XCreatePixmap(
+  XFillRectangle(display, buffer_pixmap, gc, 0, 0, term_cols * CHAR_WIDTH,
-        display, DefaultRootWindow(display), term_cols * CHAR_WIDTH,
+                 term_rows * CHAR_HEIGHT);
-        term_rows * CHAR_HEIGHT, DefaultDepth(display, DefaultScreen(display)));
 
-  if (needs_refresh) {
+  // Draw all characters
-    int start_y = scroll_top ? scroll_top - 1 : 0;
-    int end_y = scroll_bottom ? scroll_bottom : term_rows;
-
-    if (end_y > term_rows) {
-      end_y = term_rows;
-    }
-
-    if (scroll_top == 0 && scroll_bottom == 0) {
-      // Full screen refresh
   for (int y = 0; y < term_rows; y++) {
     for (int x = 0; x < term_cols; x++) {
       draw_char(display, buffer_pixmap, x, y);
     }
   }
-    } else {
-      // Only refresh scroll region
-      for (int y = start_y; y < end_y; y++) {
-        for (int x = 0; x < term_cols; x++) {
-          draw_char(display, buffer_pixmap, x, y);
-        }
-      }
-    }
-  }
 
   XCopyArea(display, buffer_pixmap, window, gc, 0, 0, term_cols * CHAR_WIDTH,
             term_rows * CHAR_HEIGHT, 0, 0);
@@ -745,6 +726,19 @@ static unsigned long get_bright_ansi_color(int index) {
 // P.S. yes I had to google this up
 static void parse_ansi_code(const char *buf, int *idx, int max_len,
                             Window window) {
+  if (*idx + 1 < max_len) {
+    // Skip CSI sequences that we don't need to process
+    if (buf[*idx] == '\033' && buf[*idx + 1] == '(') {
+      *idx += 2;
+      return;
+    }
+    // Skip other common terminal sequences
+    if (buf[*idx] == '\033' && strchr("=>", buf[*idx + 1])) {
+      *idx += 2;
+      return;
+    }
+  }
+
   char num_buf[32] = {0};
   int params[32] = {0};
   size_t num_idx = 0;
@@ -911,15 +905,76 @@ static void parse_ansi_code(const char *buf, int *idx, int max_len,
     }
   } break;
   case 'K': // Clear line
-    for (int i = cursor_x; i < term_cols; i++) {
+    switch (params[0]) {
-      terminal_buffer[cursor_y][i] = ' ';
+    case 0: // Clear from cursor to end of line
-      color_buffer[cursor_y][i] = current_color;
+      for (int x = cursor_x; x < term_cols; x++) {
-      attr_buffer[cursor_y][i] = current_attr;
+        terminal_buffer[cursor_y][x] = ' ';
-      bg_color_buffer[cursor_y][i] = current_bg_color;
+        color_buffer[cursor_y][x] = current_color;
+        attr_buffer[cursor_y][x] = current_attr;
+        bg_color_buffer[cursor_y][x] = current_bg_color;
       }
       break;
+    case 1: // Clear from cursor to beginning of line
+      for (int x = 0; x <= cursor_x; x++) {
+        terminal_buffer[cursor_y][x] = ' ';
+        color_buffer[cursor_y][x] = current_color;
+        attr_buffer[cursor_y][x] = current_attr;
+        bg_color_buffer[cursor_y][x] = current_bg_color;
+      }
+      break;
+    case 2: // Clear entire line
+      memset(terminal_buffer[cursor_y], ' ', term_cols);
+      for (int x = 0; x < term_cols; x++) {
+        color_buffer[cursor_y][x] = current_color;
+        attr_buffer[cursor_y][x] = current_attr;
+        bg_color_buffer[cursor_y][x] = current_bg_color;
+      }
+      break;
+    }
+    needs_refresh = 1;
+    break;
   case 'J': // Clear screen
-    if (params[0] == 2) {
+    switch (params[0]) {
+    case 0: // Clear from cursor to end of screen
+      // Clear current line from cursor
+      for (int x = cursor_x; x < term_cols; x++) {
+        terminal_buffer[cursor_y][x] = ' ';
+        color_buffer[cursor_y][x] = current_color;
+        attr_buffer[cursor_y][x] = current_attr;
+        bg_color_buffer[cursor_y][x] = current_bg_color;
+      }
+      // Clear all lines below cursor
+      for (int y = cursor_y + 1; y < term_rows; y++) {
+        memset(terminal_buffer[y], ' ', term_cols);
+        for (int x = 0; x < term_cols; x++) {
+          color_buffer[y][x] = current_color;
+          attr_buffer[y][x] = current_attr;
+          bg_color_buffer[y][x] = current_bg_color;
+        }
+      }
+      needs_refresh = 1;
+      break;
+    case 1: // Clear from cursor to beginning of screen
+      // Clear current line up to cursor
+      for (int x = 0; x <= cursor_x; x++) {
+        terminal_buffer[cursor_y][x] = ' ';
+        color_buffer[cursor_y][x] = current_color;
+        attr_buffer[cursor_y][x] = current_attr;
+        bg_color_buffer[cursor_y][x] = current_bg_color;
+      }
+      // Clear all lines above cursor
+      for (int y = 0; y < cursor_y; y++) {
+        memset(terminal_buffer[y], ' ', term_cols);
+        for (int x = 0; x < term_cols; x++) {
+          color_buffer[y][x] = current_color;
+          attr_buffer[y][x] = current_attr;
+          bg_color_buffer[y][x] = current_bg_color;
+        }
+      }
+      needs_refresh = 1;
+      break;
+    case 2: // Clear entire screen
+    case 3: // Clear entire screen and scrollback (treat same as 2)
       current_color = XWhitePixel(display, DefaultScreen(display));
       current_bg_color = XBlackPixel(display, DefaultScreen(display));
       current_attr = 0;
@@ -932,6 +987,7 @@ static void parse_ansi_code(const char *buf, int *idx, int max_len,
         }
       }
       needs_refresh = 1;
+      break;
     }
     break;
   case 'r': // Set scrolling region
@@ -1051,10 +1107,34 @@ static int master_cb(int fd, void *data, Window window) {
   if (n <= 0)
     return 1;
   for (int i = 0; i < n; i++) {
-    if (buf[i] == '\033' && i + 1 < n && buf[i + 1] == '[') {
+    if (buf[i] == '\033') {
+      if (i + 1 < n && buf[i + 1] == '[') {
         parse_ansi_code(buf, &i, n, window);
         continue;
       }
+      if (i + 1 < n && (buf[i + 1] == '(' || buf[i + 1] == ')')) {
+        if (i + 2 < n) {
+          i += 2; // Skip ESC, (, and the character set identifier
+        }
+        continue;
+      }
+      // Handle other simple escape sequences
+      if (i + 1 < n) {
+        switch (buf[i + 1]) {
+        case '=': // Application keypad
+        case '>': // Normal keypad
+        case '7': // Save cursor position
+        case '8': // Restore cursor position
+        case 'E': // Next line
+        case 'M': // Reverse line feed
+          i++;    // Skip the command character
+          continue;
+        }
+      }
+      continue;
+    }
+    if ((buf[i] >= 32 && buf[i] <= 126) || buf[i] == '\n' || buf[i] == '\r' ||
+        buf[i] == '\b' || buf[i] == '\t') {
       switch (buf[i]) {
       case '\n':
         cursor_x = 0;
@@ -1086,7 +1166,7 @@ static int master_cb(int fd, void *data, Window window) {
       default:
         if (cursor_y >= term_rows || cursor_x >= term_cols)
           break;
-      if (buf[i] >= 32 && buf[i] <= 126) {
+        if ((buf[i] >= 32 && buf[i] <= 126) || buf[i] == '\t') {
           terminal_buffer[cursor_y][cursor_x] = buf[i];
           color_buffer[cursor_y][cursor_x] = current_color;
           attr_buffer[cursor_y][cursor_x] = current_attr;
@@ -1103,6 +1183,7 @@ static int master_cb(int fd, void *data, Window window) {
         break;
       }
     }
+  }
   cursor_visible = 1;
   if (needs_refresh)
     check_refresh(ctx->display, ctx->window);