Optimize hot loops with direct access, LUTs, and closed-form formulas

1 files changed, 25 insertions, 0 deletions

diff --git a/src/core.c b/src/core.c
index 12daa72..01218cc 100644
--- a/src/core.c
+++ b/src/core.c
@@ -14,7 +14,19 @@
 
 static uint16_t cluster_presentation(const uint32_t *cps, int len)
 {
+    if (len <= 1)
+        return 0;
     bool pictographic = unicode_extended_pictographic(cps[0]);
+    if (len == 2) {
+        uint32_t c1 = cps[1];
+        if (c1 == 0xFE0F) return CELL_EMOJI;
+        if (c1 == 0xFE0E) return CELL_TEXT;
+        if (c1 == 0x20E3 || grapheme_regional_indicator(c1) ||
+            (pictographic && (c1 == 0x200D || grapheme_emoji_modifier(c1) ||
+                             (c1 >= 0xE0020 && c1 <= 0xE007F))))
+            return CELL_EMOJI;
+        return 0;
+    }
     bool emoji = false;
     for (int i = 1; i < len; i++) {
         if (cps[i] == 0xFE0F)
@@ -320,6 +332,19 @@ void term_sc_tab(struct term *t, int n)
     int dir = n >= 0 ? 1 : -1;
     int count = n >= 0 ? n : -n;
     if (count > t->cols) count = t->cols;
+    if (!t->custom_tabs) {
+        if (dir > 0) {
+            int next = ((t->cursor_x / 8) + count) * 8;
+            t->cursor_x = next < t->cols ? next : t->cols - 1;
+        } else {
+            int prev = t->cursor_x > 0 ? (((t->cursor_x - 1) / 8 - (count - 1)) * 8) : 0;
+            t->cursor_x = prev > 0 ? prev : 0;
+        }
+        t->pending_wrap = false;
+        struct srow *cur = term_row(t, t->cursor_y);
+        if (cur) cur->version++;
+        return;
+    }
     while (count-- > 0) {
         int x = t->cursor_x + dir;
         while (x > 0 && x < t->cols - 1 && !t->tabs[x])