1 files changed, 2 insertions, 2 deletions
diff --git a/src/o3d/vertex_data.cpp b/src/o3d/vertex_data.cpp
index 4e0ab04..ea8c5fd 100644
--- a/src/o3d/vertex_data.cpp
+++ b/src/o3d/vertex_data.cpp
@@ -2,14 +2,14 @@
 
 using namespace engine::o3d;
 
-VertexData VertexData::lerp(VertexData& vd1, VertexData& vd2, float s) {
+VertexData VertexData::lerp(const VertexData& vd1, const VertexData& vd2, float s) {
     (void) vd1;
     (void) vd2;
     (void) s;
     return {};
 }
 
-VertexData VertexData::bilerp(VertexData& vd1, VertexData& vd2, VertexData& vd3, float s, float t) {
+VertexData VertexData::bilerp(const VertexData& vd1, const VertexData& vd2, const VertexData& vd3, float s, float t) {
     (void) vd1;
     (void) vd2;
     (void) vd3;