Debounce key queue: suppress duplicate printable chars within ~80ms (key-repeat)

Co-authored-by: Chris Garrett <chris@chrisg.com>

Author: omiq

basic.c

@@ -5009,11 +5009,14 @@ static void statement_locate(char **p)
 }
 
 #ifdef GFX_VIDEO
-/* Read a line from gfx key queue; echo to screen; handle backspace (20). */
+/* Read a line from gfx key queue; echo to screen; handle backspace (20).
+ * Debounce: ignore same printable char within ~80ms (key-repeat suppression). */
 static int gfx_read_line(char *buf, int size)
 {
     int len = 0;
     uint8_t b;
+    uint8_t last_printable = 0;
+    uint32_t last_tick = 0;
     buf[0] = '\0';
     if (size <= 0) return 0;
     while (len < size - 1) {
@@ -5029,9 +5032,16 @@ static int gfx_read_line(char *buf, int size)
                     buf[len] = '\0';
                     gfx_put_byte((unsigned char)b);
                 }
+                last_printable = 0;
                 continue;
             }
             if (b >= 32 && b <= 126) {
+                if (gfx_vs && last_printable == b && (gfx_vs->ticks60 - last_tick) < 5) {
+                    /* Debounce: same char within ~80ms, skip (key repeat) */
+                    continue;
+                }
+                last_printable = b;
+                last_tick = gfx_vs ? gfx_vs->ticks60 : 0;
                 buf[len++] = (char)b;
                 buf[len] = '\0';
                 gfx_put_byte((unsigned char)b);

gfx/gfx_raylib.c

@@ -664,8 +664,18 @@ static void keyq_push(GfxVideoState *vs, uint8_t b)
     uint8_t next = (uint8_t)(vs->key_q_tail + 1);
     if (next >= (uint8_t)sizeof(vs->key_queue)) next = 0;
     if (next == vs->key_q_head) {
-        /* full: drop */
-        return;
+        return;  /* full: drop */
+    }
+    /* Debounce: suppress key-repeat for printable chars within ~80ms */
+    if (b >= 32 && b <= 126) {
+        static uint8_t last_b = 0;
+        static uint32_t last_tick = 0;
+        uint32_t t = vs->ticks60;
+        if (last_b == b && (t - last_tick) < 5) {
+            return;  /* same char too soon, skip */
+        }
+        last_b = b;
+        last_tick = t;
     }
     vs->key_queue[vs->key_q_tail] = b;
     vs->key_q_tail = next;