Use custom key structs, instead of raw hashes for the Label3D and TextMesh, to avoid potential hash collisions.

2 files changed, 33 insertions, 14 deletions

diff --git a/scene/resources/primitive_meshes.cpp b/scene/resources/primitive_meshes.cpp
index f4fd81b25f..9fa483bf36 100644
--- a/scene/resources/primitive_meshes.cpp
+++ b/scene/resources/primitive_meshes.cpp
@@ -2190,12 +2190,12 @@ RibbonTrailMesh::RibbonTrailMesh() {
 /*  TextMesh                                                             */
 /*************************************************************************/
 
-void TextMesh::_generate_glyph_mesh_data(uint32_t p_hash, const Glyph &p_gl) const {
-	if (cache.has(p_hash)) {
+void TextMesh::_generate_glyph_mesh_data(const GlyphMeshKey &p_key, const Glyph &p_gl) const {
+	if (cache.has(p_key)) {
 		return;
 	}
 
-	GlyphMeshData &gl_data = cache[p_hash];
+	GlyphMeshData &gl_data = cache[p_key];
 
 	Dictionary d = TS->font_get_glyph_contours(p_gl.font_rid, p_gl.font_size, p_gl.index);
 	Vector2 origin = Vector2(p_gl.x_off, p_gl.y_off) * pixel_size;
@@ -2437,11 +2437,9 @@ void TextMesh::_create_mesh_array(Array &p_arr) const {
 			continue;
 		}
 		if (glyphs[i].font_rid != RID()) {
-			uint32_t hash = hash_one_uint64(glyphs[i].font_rid.get_id());
-			hash = hash_murmur3_one_32(glyphs[i].index, hash);
-
-			_generate_glyph_mesh_data(hash, glyphs[i]);
-			GlyphMeshData &gl_data = cache[hash];
+			GlyphMeshKey key = GlyphMeshKey(glyphs[i].font_rid.get_id(), glyphs[i].index);
+			_generate_glyph_mesh_data(key, glyphs[i]);
+			GlyphMeshData &gl_data = cache[key];
 
 			p_size += glyphs[i].repeat * gl_data.triangles.size() * ((has_depth) ? 2 : 1);
 			i_size += glyphs[i].repeat * gl_data.triangles.size() * ((has_depth) ? 2 : 1);
@@ -2496,10 +2494,9 @@ void TextMesh::_create_mesh_array(Array &p_arr) const {
 			continue;
 		}
 		if (glyphs[i].font_rid != RID()) {
-			uint32_t hash = hash_one_uint64(glyphs[i].font_rid.get_id());
-			hash = hash_murmur3_one_32(glyphs[i].index, hash);
-
-			const GlyphMeshData &gl_data = cache[hash];
+			GlyphMeshKey key = GlyphMeshKey(glyphs[i].font_rid.get_id(), glyphs[i].index);
+			_generate_glyph_mesh_data(key, glyphs[i]);
+			const GlyphMeshData &gl_data = cache[key];
 
 			int64_t ts = gl_data.triangles.size();
 			const Vector2 *ts_ptr = gl_data.triangles.ptr();
diff --git a/scene/resources/primitive_meshes.h b/scene/resources/primitive_meshes.h
index 38cc7db5fe..a6d8978c2d 100644
--- a/scene/resources/primitive_meshes.h
+++ b/scene/resources/primitive_meshes.h
@@ -475,6 +475,7 @@ private:
 			sharp = p_sharp;
 		};
 	};
+
 	struct ContourInfo {
 		real_t length = 0.0;
 		bool ccw = true;
@@ -484,6 +485,27 @@ private:
 			ccw = p_ccw;
 		}
 	};
+
+	struct GlyphMeshKey {
+		uint64_t font_id;
+		uint32_t gl_id;
+
+		bool operator==(const GlyphMeshKey &p_b) const {
+			return (font_id == p_b.font_id) && (gl_id == p_b.gl_id);
+		}
+
+		GlyphMeshKey(uint64_t p_font_id, uint32_t p_gl_id) {
+			font_id = p_font_id;
+			gl_id = p_gl_id;
+		}
+	};
+
+	struct GlyphMeshKeyHasher {
+		_FORCE_INLINE_ static uint32_t hash(const GlyphMeshKey &p_a) {
+			return hash_murmur3_buffer(&p_a, sizeof(GlyphMeshKey));
+		}
+	};
+
 	struct GlyphMeshData {
 		Vector<Vector2> triangles;
 		Vector<Vector<ContourPoint>> contours;
@@ -491,7 +513,7 @@ private:
 		Vector2 min_p = Vector2(INFINITY, INFINITY);
 		Vector2 max_p = Vector2(-INFINITY, -INFINITY);
 	};
-	mutable HashMap<uint32_t, GlyphMeshData> cache;
+	mutable HashMap<GlyphMeshKey, GlyphMeshData, GlyphMeshKeyHasher> cache;
 
 	RID text_rid;
 	String text;
@@ -517,7 +539,7 @@ private:
 	mutable bool dirty_font = true;
 	mutable bool dirty_cache = true;
 
-	void _generate_glyph_mesh_data(uint32_t p_hash, const Glyph &p_glyph) const;
+	void _generate_glyph_mesh_data(const GlyphMeshKey &p_key, const Glyph &p_glyph) const;
 	void _font_changed();
 
 protected: