From 159c19a671b603f58806f1e3c7688a9cf49e1ea6 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 11 Dec 2023 17:39:27 +0900
Subject: [PATCH] text: cache metrics

---
 text/cache.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/text/cache.go b/text/cache.go
index fd2caa088..713562e23 100644
--- a/text/cache.go
+++ b/text/cache.go
@@ -38,7 +38,8 @@ type kernCacheKey struct {
 }
 
 type faceWithCache struct {
-	f font.Face
+	f       font.Face
+	metrics font.Metrics
 
 	glyphBoundsCache  map[rune]glyphBoundsCacheValue
 	glyphAdvanceCache map[rune]glyphAdvanceCacheValue
@@ -126,5 +127,9 @@ func (f *faceWithCache) Kern(r0, r1 rune) fixed.Int26_6 {
 }
 
 func (f *faceWithCache) Metrics() font.Metrics {
-	return f.f.Metrics()
+	if f.metrics != (font.Metrics{}) {
+		return f.metrics
+	}
+	f.metrics = f.f.Metrics()
+	return f.metrics
 }