1 files changed, 36 insertions, 7 deletions

diff --git a/include/llmr/geometry/vao.hpp b/include/llmr/geometry/vao.hpp
index 49401e01d2..a2a5a8a0d0 100644
--- a/include/llmr/geometry/vao.hpp
+++ b/include/llmr/geometry/vao.hpp
@@ -10,19 +10,47 @@ namespace llmr {
 template <typename Shader>
 class VertexArrayObject {
 public:
-    template <typename Buffer>
-    void bind(Shader& shader, Buffer& buffer, char *offset) {
+    template <typename VertexBuffer>
+    void bind(Shader& shader, VertexBuffer& vertex_buffer, char *offset) {
         if (!vao) {
             glGenVertexArrays(1, &vao);
             glBindVertexArray(vao);
 
-            buffer.bind();
+            vertex_buffer.bind();
             shader.bind(offset);
 
-            buffer_ptr = &buffer;
+            vertex_buffer_ptr = &vertex_buffer;
+            elements_buffer_ptr = nullptr;
             offset_ptr = offset;
-        } else if (buffer_ptr != &buffer) {
-            throw std::runtime_error("trying to bind VAO to another buffer");
+        } else if (vertex_buffer_ptr != &vertex_buffer) {
+            throw std::runtime_error("trying to bind VAO to another vertex buffer");
+        } else if (elements_buffer_ptr != nullptr) {
+            throw std::runtime_error("trying to bind VAO to another elements buffer");
+        } else if (offset_ptr != offset) {
+            throw std::runtime_error("trying to bind VAO to another offset");
+        } else {
+            // We have been given the correct information.
+            glBindVertexArray(vao);
+        }
+    }
+
+    template <typename VertexBuffer, typename ElementsBuffer>
+    void bind(Shader& shader, VertexBuffer& vertex_buffer, ElementsBuffer& elements_buffer, char *offset) {
+        if (!vao) {
+            glGenVertexArrays(1, &vao);
+            glBindVertexArray(vao);
+
+            vertex_buffer.bind();
+            elements_buffer.bind();
+            shader.bind(offset);
+
+            vertex_buffer_ptr = &vertex_buffer;
+            elements_buffer_ptr = &elements_buffer;
+            offset_ptr = offset;
+        } else if (vertex_buffer_ptr != &vertex_buffer) {
+            throw std::runtime_error("trying to bind VAO to another vertex buffer");
+        } else if (elements_buffer_ptr != &elements_buffer) {
+            throw std::runtime_error("trying to bind VAO to another elements buffer");
         } else if (offset_ptr != offset) {
             throw std::runtime_error("trying to bind VAO to another offset");
         } else {
@@ -42,7 +70,8 @@ private:
 
     // For debug reasons, we're storing the bind information so that we can
     // detect errors and report
-    void *buffer_ptr = nullptr;
+    void *vertex_buffer_ptr = nullptr;
+    void *elements_buffer_ptr = nullptr;
     char *offset_ptr = 0;
 };