1 files changed, 73 insertions, 0 deletions
diff --git a/src/mbgl/geometry/vao.hpp b/src/mbgl/geometry/vao.hpp
new file mode 100644
index 0000000000..2ecba731f7
--- /dev/null
+++ b/src/mbgl/geometry/vao.hpp
@@ -0,0 +1,73 @@
+#ifndef MBGL_GEOMETRY_VAO
+#define MBGL_GEOMETRY_VAO
+
+#include <mbgl/shader/shader.hpp>
+#include <mbgl/platform/gl.hpp>
+#include <mbgl/util/noncopyable.hpp>
+
+#include <stdexcept>
+
+namespace mbgl {
+
+class VertexArrayObject : public util::noncopyable {
+public:
+    inline VertexArrayObject() {};
+
+    inline VertexArrayObject(VertexArrayObject &&rhs) noexcept
+        : vao(rhs.vao),
+          bound_shader(rhs.bound_shader),
+          bound_shader_name(rhs.bound_shader_name),
+          bound_vertex_buffer(rhs.bound_vertex_buffer),
+          bound_elements_buffer(rhs.bound_elements_buffer),
+          bound_offset(rhs.bound_offset) {};
+
+    template <typename Shader, typename VertexBuffer>
+    inline void bind(Shader& shader, VertexBuffer &vertexBuffer, char *offset) {
+        bindVertexArrayObject();
+        if (bound_shader == 0) {
+            vertexBuffer.bind();
+            shader.bind(offset);
+            if (vao) {
+                storeBinding(shader, vertexBuffer.getID(), 0, offset);
+            }
+        } else {
+            verifyBinding(shader, vertexBuffer.getID(), 0, offset);
+        }
+    }
+
+    template <typename Shader, typename VertexBuffer, typename ElementsBuffer>
+    inline void bind(Shader& shader, VertexBuffer &vertexBuffer, ElementsBuffer &elementsBuffer, char *offset) {
+        bindVertexArrayObject();
+        if (bound_shader == 0) {
+            vertexBuffer.bind();
+            elementsBuffer.bind();
+            shader.bind(offset);
+            if (vao) {
+                storeBinding(shader, vertexBuffer.getID(), elementsBuffer.getID(), offset);
+            }
+        } else {
+            verifyBinding(shader, vertexBuffer.getID(), elementsBuffer.getID(), offset);
+        }
+    }
+
+    ~VertexArrayObject();
+
+private:
+    void bindVertexArrayObject();
+    void storeBinding(Shader &shader, GLuint vertexBuffer, GLuint elementsBuffer, char *offset);
+    void verifyBinding(Shader &shader, GLuint vertexBuffer, GLuint elementsBuffer, char *offset);
+
+    GLuint vao = 0;
+
+    // For debug reasons, we're storing the bind information so that we can
+    // detect errors and report
+    GLuint bound_shader = 0;
+    const char *bound_shader_name = "";
+    GLuint bound_vertex_buffer = 0;
+    GLuint bound_elements_buffer = 0;
+    char *bound_offset = 0;
+};
+
+}
+
+#endif