1 files changed, 80 insertions, 0 deletions
diff --git a/src/mbgl/gl/vao.hpp b/src/mbgl/gl/vao.hpp
new file mode 100644
index 0000000000..c2e3470367
--- /dev/null
+++ b/src/mbgl/gl/vao.hpp
@@ -0,0 +1,80 @@
+#pragma once
+
+#include <mbgl/shader/shader.hpp>
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/vertex_buffer.hpp>
+#include <mbgl/util/noncopyable.hpp>
+#include <mbgl/util/optional.hpp>
+
+#include <stdexcept>
+
+namespace mbgl {
+
+class VertexArrayObject : public util::noncopyable {
+public:
+    VertexArrayObject();
+    ~VertexArrayObject();
+
+    template <typename Shader, typename T>
+    void bind(Shader& shader,
+              const gl::VertexBuffer<T>& vertexBuffer,
+              int8_t* offset,
+              gl::Context& context) {
+        bindVertexArrayObject(context);
+        if (bound_shader == 0) {
+            context.vertexBuffer = vertexBuffer.buffer;
+            shader.bind(vertexBuffer, offset);
+            if (vertexArray) {
+                storeBinding(shader, vertexBuffer.buffer, 0, offset);
+            }
+        } else {
+            verifyBinding(shader, vertexBuffer.buffer, 0, offset);
+        }
+    }
+
+    template <typename Shader, typename T, typename P>
+    void bind(Shader& shader,
+              const gl::VertexBuffer<T>& vertexBuffer,
+              const gl::IndexBuffer<P>& indexBuffer,
+              int8_t* offset,
+              gl::Context& context) {
+        bindVertexArrayObject(context);
+        if (bound_shader == 0) {
+            context.vertexBuffer = vertexBuffer.buffer;
+            context.elementBuffer = indexBuffer.buffer;
+            shader.bind(vertexBuffer, offset);
+            if (vertexArray) {
+                storeBinding(shader, vertexBuffer.buffer, indexBuffer.buffer, offset);
+            }
+        } else {
+            verifyBinding(shader, vertexBuffer.buffer, indexBuffer.buffer, offset);
+        }
+    }
+
+    gl::VertexArrayID getID() const {
+        return *vertexArray;
+    }
+
+private:
+    void bindVertexArrayObject(gl::Context&);
+    void storeBinding(Shader& shader,
+                      gl::BufferID vertexBuffer,
+                      gl::BufferID elementsBuffer,
+                      int8_t* offset);
+    void verifyBinding(Shader& shader,
+                       gl::BufferID vertexBuffer,
+                       gl::BufferID elementsBuffer,
+                       int8_t* offset);
+
+    mbgl::optional<gl::UniqueVertexArray> vertexArray;
+
+    // For debug reasons, we're storing the bind information so that we can
+    // detect errors and report
+    gl::ProgramID bound_shader = 0;
+    const char* bound_shader_name = "";
+    gl::BufferID bound_vertex_buffer = 0;
+    gl::BufferID bound_elements_buffer = 0;
+    int8_t *bound_offset = nullptr;
+};
+
+} // namespace mbgl