vtgl

Commit: 0940841f6decc5c9eeaca2997a06ad5eb4aa2438
Parent: 9f1013ae9084c9abe499a2b58e108731b196cea5
Author: Randy Palamar
Date:   Sun,  7 Jul 2024 09:38:43 -0600

handle case when line buf wraps around

Diffstat:
M
terminal.c
 | 
16
++++++++++++----

1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/terminal.c b/terminal.c
@@ -662,15 +662,22 @@ push_line(Term *t, Line *line)
 	}
 }
 
+static size
+get_line_idx(LineBuf *lb, size off)
+{
+	ASSERT(-off <= lb->filled);
+	size result = lb->widx + off;
+	if (result < 0)
+		result += lb->filled;
+	return result;
+}
+
 static void
 blit_lines(Term *t)
 {
 	size line_count = t->size.h;
 	if (line_count > t->log_lines.filled)
 		line_count = t->log_lines.filled;
-	/* TODO: handle case where widx has wrapped around */
-	ASSERT(t->log_lines.widx >= line_count);
-	size line_off = t->log_lines.widx - line_count;
 
 	/* TODO: Performance!!! */
 	fb_clear_region(t, 0, t->size.h, 0, t->size.w);
@@ -679,6 +686,7 @@ blit_lines(Term *t)
 	t->cursor.row = 0;
 	t->cursor.col = 0;
 	for (size i = 0; i <= line_count; i++) {
-		push_line(t, t->log_lines.buf + line_off + i);
+		size line_idx = get_line_idx(&t->log_lines, -line_count + i);
+		push_line(t, t->log_lines.buf + line_idx);
 	}
 }