[core] Rework attribute binding (again)

These changes are necessary for programs whose set of active attributes is not fixed at compile time by a template parameter pack, but rather varies based on the generated shader text at runtime. In such cases, the attribute location of a given named attribute may vary between instances of the same Program.

Previously, attribute bindings were implicitly associated with a location based on template parameter order, and -1 was used to indicate an inactive attribute. This left us unable to disable the appropriate attribute when it went from active to inactive. Now, the state tracker for bindings explicitly associates locations and state, and an empty optional is used to indicate an inactive attribute.

In addition, a gl::VertexArray class is now exposed, allowing more flexibility in the relationship between Programs, Segments, and attribute bindings. In this commit, that relationship does not change, but the subsequent commit adjusts it to match gl-js, reduce rebinds, and work around buggy VAO implementations.

VertexArray uses a pimpl idiom in order to support implementations that lack the VAO extension. In that case, all VertexArrays share global binding state, reflecting the platform reality in the absence of VAOs, while still providing a uniform API.

30 files changed, 369 insertions, 310 deletions

diff --git a/cmake/core-files.cmake b/cmake/core-files.cmake
index 069b6cb4c9..8a3c42a1f4 100644
--- a/cmake/core-files.cmake
+++ b/cmake/core-files.cmake
@@ -76,8 +76,6 @@ set(MBGL_CORE_FILES
     src/mbgl/gl/program.hpp
     src/mbgl/gl/program_binary_extension.hpp
     src/mbgl/gl/renderbuffer.hpp
-    src/mbgl/gl/segment.cpp
-    src/mbgl/gl/segment.hpp
     src/mbgl/gl/state.hpp
     src/mbgl/gl/stencil_mode.cpp
     src/mbgl/gl/stencil_mode.hpp
@@ -87,6 +85,8 @@ set(MBGL_CORE_FILES
     src/mbgl/gl/uniform.hpp
     src/mbgl/gl/value.cpp
     src/mbgl/gl/value.hpp
+    src/mbgl/gl/vertex_array.cpp
+    src/mbgl/gl/vertex_array.hpp
     src/mbgl/gl/vertex_array_extension.hpp
     src/mbgl/gl/vertex_buffer.hpp
 
@@ -155,6 +155,8 @@ set(MBGL_CORE_FILES
     src/mbgl/programs/programs.hpp
     src/mbgl/programs/raster_program.cpp
     src/mbgl/programs/raster_program.hpp
+    src/mbgl/programs/segment.cpp
+    src/mbgl/programs/segment.hpp
     src/mbgl/programs/symbol_program.cpp
     src/mbgl/programs/symbol_program.hpp
     src/mbgl/programs/uniforms.hpp
diff --git a/src/mbgl/gl/attribute.cpp b/src/mbgl/gl/attribute.cpp
index 2f817cdcd8..bb5b2ddc34 100644
--- a/src/mbgl/gl/attribute.cpp
+++ b/src/mbgl/gl/attribute.cpp
@@ -1,16 +1,14 @@
 #include <mbgl/gl/attribute.hpp>
-#include <mbgl/gl/context.hpp>
 #include <mbgl/gl/gl.hpp>
 
-#include <cstring>
-
 namespace mbgl {
 namespace gl {
 
-AttributeLocation bindAttributeLocation(ProgramID id, AttributeLocation location, const char* name) {
-    assert(location < 8);
+void bindAttributeLocation(ProgramID id, AttributeLocation location, const char* name) {
+    if (location >= MAX_ATTRIBUTES) {
+        throw gl::Error("too many vertex attributes");
+    }
     MBGL_CHECK_ERROR(glBindAttribLocation(id, location, name));
-    return location;
 }
 
 std::set<std::string> getActiveAttributes(ProgramID id) {
@@ -37,56 +35,5 @@ std::set<std::string> getActiveAttributes(ProgramID id) {
     return activeAttributes;
 }
 
-void DisabledAttribute::bind(Context&, AttributeLocation location, std::size_t) const {
-    MBGL_CHECK_ERROR(glDisableVertexAttribArray(location));
-}
-
-template <class T> DataType DataTypeOf    = static_cast<DataType>(0);
-template <> DataType DataTypeOf< int8_t>  = DataType::Byte;
-template <> DataType DataTypeOf<uint8_t>  = DataType::UnsignedByte;
-template <> DataType DataTypeOf< int16_t> = DataType::Short;
-template <> DataType DataTypeOf<uint16_t> = DataType::UnsignedShort;
-template <> DataType DataTypeOf< int32_t> = DataType::Integer;
-template <> DataType DataTypeOf<uint32_t> = DataType::UnsignedInteger;
-template <> DataType DataTypeOf<float>    = DataType::Float;
-
-template <class T, std::size_t N>
-void AttributeBinding<T, N>::bind(Context& context, AttributeLocation location, std::size_t vertexOffset) const {
-    // FillProgram will attempt to bind at location -1 because it includes
-    // a fill-outline-color paint property but does not use it or have an
-    // a_outline_color shader attribute - in this case, we have nothing to bind.
-    if (location == -1) return;
-
-    context.vertexBuffer = vertexBuffer;
-    MBGL_CHECK_ERROR(glEnableVertexAttribArray(location));
-    MBGL_CHECK_ERROR(glVertexAttribPointer(
-        location,
-        static_cast<GLint>(attributeSize),
-        static_cast<GLenum>(DataTypeOf<T>),
-        static_cast<GLboolean>(false),
-        static_cast<GLsizei>(vertexSize),
-        reinterpret_cast<GLvoid*>(attributeOffset + (vertexSize * vertexOffset))));
-}
-
-template class AttributeBinding<uint8_t, 1>;
-template class AttributeBinding<uint8_t, 2>;
-template class AttributeBinding<uint8_t, 3>;
-template class AttributeBinding<uint8_t, 4>;
-
-template class AttributeBinding<uint16_t, 1>;
-template class AttributeBinding<uint16_t, 2>;
-template class AttributeBinding<uint16_t, 3>;
-template class AttributeBinding<uint16_t, 4>;
-
-template class AttributeBinding<int16_t, 1>;
-template class AttributeBinding<int16_t, 2>;
-template class AttributeBinding<int16_t, 3>;
-template class AttributeBinding<int16_t, 4>;
-
-template class AttributeBinding<float, 1>;
-template class AttributeBinding<float, 2>;
-template class AttributeBinding<float, 3>;
-template class AttributeBinding<float, 4>;
-
 } // namespace gl
 } // namespace mbgl
diff --git a/src/mbgl/gl/attribute.hpp b/src/mbgl/gl/attribute.hpp
index f018a1d261..ed4168c21f 100644
--- a/src/mbgl/gl/attribute.hpp
+++ b/src/mbgl/gl/attribute.hpp
@@ -1,59 +1,51 @@
 #pragma once
 
 #include <mbgl/gl/types.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/util/ignore.hpp>
 #include <mbgl/util/indexed_tuple.hpp>
-#include <mbgl/util/variant.hpp>
+#include <mbgl/util/optional.hpp>
 
 #include <cstddef>
 #include <vector>
 #include <set>
 #include <functional>
+#include <string>
+#include <array>
 
 namespace mbgl {
 namespace gl {
 
-class DisabledAttribute {
-public:
-    void bind(Context&, AttributeLocation, std::size_t vertexOffset) const;
+static constexpr std::size_t MAX_ATTRIBUTES = 8;
 
-    friend bool operator==(const DisabledAttribute&,
-                           const DisabledAttribute&) {
-        return true;
-    }
-};
+template <class> struct DataTypeOf;
+template <> struct DataTypeOf< int8_t>  : std::integral_constant<DataType, DataType::Byte> {};
+template <> struct DataTypeOf<uint8_t>  : std::integral_constant<DataType, DataType::UnsignedByte> {};
+template <> struct DataTypeOf< int16_t> : std::integral_constant<DataType, DataType::Short> {};
+template <> struct DataTypeOf<uint16_t> : std::integral_constant<DataType, DataType::UnsignedShort> {};
+template <> struct DataTypeOf< int32_t> : std::integral_constant<DataType, DataType::Integer> {};
+template <> struct DataTypeOf<uint32_t> : std::integral_constant<DataType, DataType::UnsignedInteger> {};
+template <> struct DataTypeOf<float>    : std::integral_constant<DataType, DataType::Float> {};
 
-template <class T, std::size_t N>
 class AttributeBinding {
 public:
-    AttributeBinding(BufferID vertexBuffer_,
-                     std::size_t vertexSize_,
-                     std::size_t attributeOffset_,
-                     std::size_t attributeSize_ = N)
-        : vertexBuffer(vertexBuffer_),
-          vertexSize(vertexSize_),
-          attributeOffset(attributeOffset_),
-          attributeSize(attributeSize_)
-        {}
-
-    void bind(Context&, AttributeLocation, std::size_t vertexOffset) const;
+    DataType attributeType;
+    std::size_t attributeSize;
+    std::size_t attributeOffset;
+
+    BufferID vertexBuffer;
+    std::size_t vertexSize;
+    std::size_t vertexOffset;
 
     friend bool operator==(const AttributeBinding& lhs,
                            const AttributeBinding& rhs) {
-        return lhs.vertexBuffer == rhs.vertexBuffer
-            && lhs.vertexSize == rhs.vertexSize
-            && lhs.attributeOffset == rhs.attributeOffset
-            && lhs.attributeSize == rhs.attributeSize;
+        return std::tie(lhs.attributeType, lhs.attributeSize, lhs.attributeOffset, lhs.vertexBuffer, lhs.vertexSize, lhs.vertexOffset)
+            == std::tie(rhs.attributeType, rhs.attributeSize, rhs.attributeOffset, rhs.vertexBuffer, rhs.vertexSize, rhs.vertexOffset);
     }
-
-private:
-    BufferID vertexBuffer;
-    std::size_t vertexSize;
-    std::size_t attributeOffset;
-    std::size_t attributeSize;
 };
 
+using AttributeBindingArray = std::array<optional<AttributeBinding>, MAX_ATTRIBUTES>;
+
 /*
     gl::Attribute<T,N> manages the binding of a vertex buffer to a GL program attribute.
       - T is the underlying primitive type (exposed as Attribute<T,N>::ValueType)
@@ -67,10 +59,7 @@ public:
     using Value = std::array<T, N>;
 
     using Location = AttributeLocation;
-
-    using Binding = variant<
-        DisabledAttribute,
-        AttributeBinding<T, N>>;
+    using Binding = AttributeBinding;
 
     /*
         Create a binding for this attribute.  The `attributeSize` parameter may be used to
@@ -82,28 +71,24 @@ public:
                            std::size_t attributeIndex,
                            std::size_t attributeSize = N) {
         static_assert(std::is_standard_layout<Vertex>::value, "vertex type must use standard layout");
-        return AttributeBinding<T, N> {
+        return AttributeBinding {
+            DataTypeOf<T>::value,
+            attributeSize,
+            Vertex::attributeOffsets[attributeIndex],
             buffer.buffer,
             sizeof(Vertex),
-            Vertex::attributeOffsets[attributeIndex],
-            attributeSize
+            0,
         };
     }
 
-    static void bind(Context& context,
-                     const Location& location,
-                     Binding& oldBinding,
-                     const Binding& newBinding,
-                     std::size_t vertexOffset) {
-        if (oldBinding == newBinding) {
-            return;
+    static optional<Binding> offsetBinding(const optional<Binding>& binding, std::size_t vertexOffset) {
+        if (binding) {
+            AttributeBinding result = *binding;
+            result.vertexOffset = vertexOffset;
+            return result;
+        } else {
+            return binding;
         }
-
-        Binding::visit(newBinding, [&] (const auto& binding) {
-            binding.bind(context, location, vertexOffset);
-        });
-
-        oldBinding = newBinding;
     }
 };
 
@@ -223,7 +208,7 @@ const std::size_t Vertex<A1, A2, A3, A4, A5>::attributeOffsets[5] = {
 
 } // namespace detail
 
-AttributeLocation bindAttributeLocation(ProgramID, AttributeLocation, const char * name);
+void bindAttributeLocation(ProgramID, AttributeLocation, const char * name);
 std::set<std::string> getActiveAttributes(ProgramID);
 
 template <class... As>
@@ -232,10 +217,10 @@ public:
     using Types = TypeList<As...>;
     using Locations = IndexedTuple<
         TypeList<As...>,
-        TypeList<typename As::Type::Location...>>;
+        TypeList<optional<typename As::Type::Location>...>>;
     using Bindings = IndexedTuple<
         TypeList<As...>,
-        TypeList<typename As::Type::Binding...>>;
+        TypeList<optional<typename As::Type::Binding>...>>;
     using NamedLocations = std::vector<std::pair<const std::string, AttributeLocation>>;
 
     using Vertex = detail::Vertex<typename As::Type...>;
@@ -246,13 +231,17 @@ public:
     static Locations bindLocations(const ProgramID& id) {
         std::set<std::string> activeAttributes = getActiveAttributes(id);
 
-        AttributeLocation location = -1;
-        auto bindAndIncrement = [&](const char* name) {
-            location++;
-            return bindAttributeLocation(id, location, name);
+        AttributeLocation location = 0;
+        auto maybeBindLocation = [&](const char* name) -> optional<AttributeLocation> {
+            if (activeAttributes.count(name)) {
+                bindAttributeLocation(id, location, name);
+                return location++;
+            } else {
+                return {};
+            }
         };
-        return Locations{ (activeAttributes.count(As::name()) ? bindAndIncrement(As::name())
-                                                              : -1)... };
+
+        return Locations { maybeBindLocation(As::name())... };
     }
 
     template <class Program>
@@ -261,7 +250,17 @@ public:
     }
 
     static NamedLocations getNamedLocations(const Locations& locations) {
-        return NamedLocations{ { As::name(), locations.template get<As>() }... };
+        NamedLocations result;
+
+        auto maybeAddLocation = [&] (const std::string& name, const optional<AttributeLocation>& location) {
+            if (location) {
+                result.emplace_back(name, *location);
+            }
+        };
+
+        util::ignore({ (maybeAddLocation(As::name(), locations.template get<As>()), 0)... });
+
+        return result;
     }
 
     template <class DrawMode>
@@ -269,16 +268,23 @@ public:
         return Bindings { As::Type::binding(buffer, Index<As>)... };
     }
 
-    static void bind(Context& context,
-                     const Locations& locations,
-                     Bindings& oldBindings,
-                     const Bindings& newBindings,
-                     std::size_t vertexOffset) {
-        util::ignore({ (As::Type::bind(context,
-                                       locations.template get<As>(),
-                                       oldBindings.template get<As>(),
-                                       newBindings.template get<As>(),
-                                       vertexOffset), 0)... });
+    static Bindings offsetBindings(const Bindings& bindings, std::size_t vertexOffset) {
+        return Bindings { As::Type::offsetBinding(bindings.template get<As>(), vertexOffset)... };
+    }
+
+    static AttributeBindingArray toBindingArray(const Locations& locations, const Bindings& bindings) {
+        AttributeBindingArray result;
+
+        auto maybeAddBinding = [&] (const optional<AttributeLocation>& location,
+                                    const optional<AttributeBinding>& binding) {
+            if (location) {
+                result.at(*location) = binding;
+            }
+        };
+
+        util::ignore({ (maybeAddBinding(locations.template get<As>(), bindings.template get<As>()), 0)... });
+
+        return result;
     }
 };
 
diff --git a/src/mbgl/gl/context.cpp b/src/mbgl/gl/context.cpp
index 3ab1260d27..2d7354a64e 100644
--- a/src/mbgl/gl/context.cpp
+++ b/src/mbgl/gl/context.cpp
@@ -177,8 +177,8 @@ UniqueBuffer Context::createIndexBuffer(const void* data, std::size_t size) {
     BufferID id = 0;
     MBGL_CHECK_ERROR(glGenBuffers(1, &id));
     UniqueBuffer result { std::move(id), { this } };
-    vertexArrayObject = 0;
-    elementBuffer = result;
+    bindVertexArray = 0;
+    globalVertexArrayState.indexBuffer = result;
     MBGL_CHECK_ERROR(glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, data, GL_STATIC_DRAW));
     return result;
 }
@@ -229,11 +229,16 @@ optional<std::pair<BinaryProgramFormat, std::string>> Context::getBinaryProgram(
 }
 #endif
 
-UniqueVertexArray Context::createVertexArray() {
-    assert(supportsVertexArrays());
-    VertexArrayID id = 0;
-    MBGL_CHECK_ERROR(vertexArray->genVertexArrays(1, &id));
-    return UniqueVertexArray(std::move(id), { this });
+VertexArray Context::createVertexArray() {
+    if (supportsVertexArrays()) {
+        VertexArrayID id = 0;
+        MBGL_CHECK_ERROR(vertexArray->genVertexArrays(1, &id));
+        return { std::make_unique<VertexArrayState>(UniqueVertexArray(std::move(id), { this }), *this) };
+    } else {
+        // On GL implementations which do not support vertex arrays, attribute bindings are global state.
+        // So return a VertexArray which shares our global state tracking and whose deleter is a no-op.
+        return { UniqueVertexArrayState(&globalVertexArrayState, [] (VertexArrayState*) {}) };
+    }
 }
 
 UniqueFramebuffer Context::createFramebuffer() {
@@ -502,8 +507,8 @@ void Context::setDirtyState() {
        tex.setDirty();
     }
     vertexBuffer.setDirty();
-    elementBuffer.setDirty();
-    vertexArrayObject.setDirty();
+    bindVertexArray.setDirty();
+    globalVertexArrayState.setDirty();
 }
 
 void Context::clear(optional<mbgl::Color> color,
@@ -622,8 +627,8 @@ void Context::performCleanup() {
         for (const auto id : abandonedBuffers) {
             if (vertexBuffer == id) {
                 vertexBuffer.setDirty();
-            } else if (elementBuffer == id) {
-                elementBuffer.setDirty();
+            } else if (globalVertexArrayState.indexBuffer == id) {
+                globalVertexArrayState.indexBuffer.setDirty();
             }
         }
         MBGL_CHECK_ERROR(glDeleteBuffers(int(abandonedBuffers.size()), abandonedBuffers.data()));
@@ -643,8 +648,8 @@ void Context::performCleanup() {
     if (!abandonedVertexArrays.empty()) {
         assert(supportsVertexArrays());
         for (const auto id : abandonedVertexArrays) {
-            if (vertexArrayObject == id) {
-                vertexArrayObject.setDirty();
+            if (bindVertexArray == id) {
+                bindVertexArray.setDirty();
             }
         }
         MBGL_CHECK_ERROR(vertexArray->deleteVertexArrays(int(abandonedVertexArrays.size()),
diff --git a/src/mbgl/gl/context.hpp b/src/mbgl/gl/context.hpp
index 56c0618989..8929d24e54 100644
--- a/src/mbgl/gl/context.hpp
+++ b/src/mbgl/gl/context.hpp
@@ -9,6 +9,7 @@
 #include <mbgl/gl/framebuffer.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
+#include <mbgl/gl/vertex_array.hpp>
 #include <mbgl/gl/types.hpp>
 #include <mbgl/gl/draw_mode.hpp>
 #include <mbgl/gl/depth_mode.hpp>
@@ -53,9 +54,7 @@ public:
     void verifyProgramLinkage(ProgramID);
     void linkProgram(ProgramID);
     UniqueTexture createTexture();
-
-    bool supportsVertexArrays() const;
-    UniqueVertexArray createVertexArray();
+    VertexArray createVertexArray();
 
 #if MBGL_HAS_BINARY_PROGRAMS
     bool supportsProgramBinaries() const;
@@ -200,10 +199,11 @@ public:
     State<value::BindFramebuffer> bindFramebuffer;
     State<value::Viewport> viewport;
     std::array<State<value::BindTexture>, 2> texture;
-    State<value::BindVertexArray, const Context&> vertexArrayObject { *this };
     State<value::Program> program;
     State<value::BindVertexBuffer> vertexBuffer;
-    State<value::BindElementBuffer> elementBuffer;
+
+    State<value::BindVertexArray, const Context&> bindVertexArray { *this };
+    VertexArrayState globalVertexArrayState { UniqueVertexArray(0, { this }), *this };
 
 #if not MBGL_USE_GLES2
     State<value::PixelZoom> pixelZoom;
@@ -248,6 +248,8 @@ private:
     void drawPixels(Size size, const void* data, TextureFormat);
 #endif // MBGL_USE_GLES2
 
+    bool supportsVertexArrays() const;
+
     friend detail::ProgramDeleter;
     friend detail::ShaderDeleter;
     friend detail::BufferDeleter;
diff --git a/src/mbgl/gl/object.cpp b/src/mbgl/gl/object.cpp
index e2d476e0c0..2c5f1bca1f 100644
--- a/src/mbgl/gl/object.cpp
+++ b/src/mbgl/gl/object.cpp
@@ -33,7 +33,9 @@ void TextureDeleter::operator()(TextureID id) const {
 
 void VertexArrayDeleter::operator()(VertexArrayID id) const {
     assert(context);
-    context->abandonedVertexArrays.push_back(id);
+    if (id != 0) {
+        context->abandonedVertexArrays.push_back(id);
+    }
 }
 
 void FramebufferDeleter::operator()(FramebufferID id) const {
diff --git a/src/mbgl/gl/program.hpp b/src/mbgl/gl/program.hpp
index ce2b5a335b..9d8b0a5b04 100644
--- a/src/mbgl/gl/program.hpp
+++ b/src/mbgl/gl/program.hpp
@@ -5,6 +5,7 @@
 #include <mbgl/gl/context.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
+#include <mbgl/gl/vertex_array.hpp>
 #include <mbgl/gl/attribute.hpp>
 #include <mbgl/gl/uniform.hpp>
 
@@ -116,10 +117,12 @@ public:
               DepthMode depthMode,
               StencilMode stencilMode,
               ColorMode colorMode,
-              UniformValues&& uniformValues,
-              AttributeBindings&& attributeBindings,
+              const UniformValues& uniformValues,
+              VertexArray& vertexArray,
+              const AttributeBindings& attributeBindings,
               const IndexBuffer<DrawMode>& indexBuffer,
-              const SegmentVector<Attributes>& segments) {
+              std::size_t indexOffset,
+              std::size_t indexLength) {
         static_assert(std::is_same<Primitive, typename DrawMode::Primitive>::value, "incompatible draw mode");
 
         context.setDrawMode(drawMode);
@@ -129,18 +132,15 @@ public:
 
         context.program = program;
 
-        Uniforms::bind(uniformsState, std::move(uniformValues));
+        Uniforms::bind(uniformsState, uniformValues);
 
-        for (const auto& segment : segments) {
-            segment.bind(context,
-                         indexBuffer.buffer,
-                         attributeLocations,
-                         attributeBindings);
+        vertexArray.bind(context,
+                        indexBuffer.buffer,
+                        Attributes::toBindingArray(attributeLocations, attributeBindings));
 
-            context.draw(drawMode.primitiveType,
-                         segment.indexOffset,
-                         segment.indexLength);
-        }
+        context.draw(drawMode.primitiveType,
+                     indexOffset,
+                     indexLength);
     }
 
 private:
diff --git a/src/mbgl/gl/segment.hpp b/src/mbgl/gl/segment.hpp
deleted file mode 100644
index fe0658bf8e..0000000000
--- a/src/mbgl/gl/segment.hpp
+++ /dev/null
@@ -1,73 +0,0 @@
-#pragma once
-
-#include <mbgl/gl/context.hpp>
-#include <mbgl/gl/vertex_buffer.hpp>
-#include <mbgl/util/optional.hpp>
-#include <mbgl/util/logging.hpp>
-
-#include <cstddef>
-#include <vector>
-
-namespace mbgl {
-namespace gl {
-
-template <class Attributes>
-class Segment {
-public:
-    Segment(std::size_t vertexOffset_,
-            std::size_t indexOffset_,
-            std::size_t vertexLength_ = 0,
-            std::size_t indexLength_ = 0)
-        : vertexOffset(vertexOffset_),
-          indexOffset(indexOffset_),
-          vertexLength(vertexLength_),
-          indexLength(indexLength_) {}
-
-    const std::size_t vertexOffset;
-    const std::size_t indexOffset;
-
-    std::size_t vertexLength;
-    std::size_t indexLength;
-
-    void bind(Context& context,
-              BufferID indexBuffer_,
-              const typename Attributes::Locations& attributeLocations,
-              const typename Attributes::Bindings& attributeBindings_) const {
-        if (context.supportsVertexArrays()) {
-            if (!vao) {
-                vao = context.createVertexArray();
-                context.vertexBuffer.setDirty();
-            }
-            context.vertexArrayObject = *vao;
-            if (indexBuffer != indexBuffer_) {
-                indexBuffer = indexBuffer_;
-                context.elementBuffer.setDirty();
-                context.elementBuffer = indexBuffer_;
-            }
-        } else {
-            // No VAO support. Force attributes to be rebound.
-            context.elementBuffer = indexBuffer_;
-            attributeBindings = {};
-        }
-
-        Attributes::bind(context,
-                         attributeLocations,
-                         attributeBindings,
-                         attributeBindings_,
-                         vertexOffset);
-    }
-
-private:
-    mutable optional<UniqueVertexArray> vao;
-    mutable optional<BufferID> indexBuffer;
-    mutable typename Attributes::Bindings attributeBindings;
-};
-
-template <class Attributes>
-class SegmentVector : public std::vector<Segment<Attributes>> {
-public:
-    SegmentVector() = default;
-};
-
-} // namespace gl
-} // namespace mbgl
diff --git a/src/mbgl/gl/types.hpp b/src/mbgl/gl/types.hpp
index 0595419674..c80399016e 100644
--- a/src/mbgl/gl/types.hpp
+++ b/src/mbgl/gl/types.hpp
@@ -15,7 +15,7 @@ using VertexArrayID = uint32_t;
 using FramebufferID = uint32_t;
 using RenderbufferID = uint32_t;
 
-using AttributeLocation = int32_t;
+using AttributeLocation = uint32_t;
 using UniformLocation = int32_t;
 using TextureUnit = uint8_t;
 
diff --git a/src/mbgl/gl/uniform.hpp b/src/mbgl/gl/uniform.hpp
index bb3453b2d8..3cac09c526 100644
--- a/src/mbgl/gl/uniform.hpp
+++ b/src/mbgl/gl/uniform.hpp
@@ -82,7 +82,7 @@ public:
         return NamedLocations{ { Us::name(), state.template get<Us>().location }... };
     }
 
-    static void bind(State& state, Values&& values) {
+    static void bind(State& state, const Values& values) {
         util::ignore({ (state.template get<Us>() = values.template get<Us>(), 0)... });
     }
 };
diff --git a/src/mbgl/gl/value.cpp b/src/mbgl/gl/value.cpp
index c081c941f5..10818e8499 100644
--- a/src/mbgl/gl/value.cpp
+++ b/src/mbgl/gl/value.cpp
@@ -353,6 +353,24 @@ BindVertexArray::Type BindVertexArray::Get(const Context& context) {
     return binding;
 }
 
+const optional<AttributeBinding> VertexAttribute::Default {};
+
+void VertexAttribute::Set(const optional<AttributeBinding>& binding, Context& context, AttributeLocation location) {
+    if (binding) {
+        context.vertexBuffer = binding->vertexBuffer;
+        MBGL_CHECK_ERROR(glEnableVertexAttribArray(location));
+        MBGL_CHECK_ERROR(glVertexAttribPointer(
+            location,
+            static_cast<GLint>(binding->attributeSize),
+            static_cast<GLenum>(binding->attributeType),
+            static_cast<GLboolean>(false),
+            static_cast<GLsizei>(binding->vertexSize),
+            reinterpret_cast<GLvoid*>(binding->attributeOffset + (binding->vertexSize * binding->vertexOffset))));
+    } else {
+        MBGL_CHECK_ERROR(glDisableVertexAttribArray(location));
+    }
+}
+
 #if not MBGL_USE_GLES2
 
 const constexpr PointSize::Type PointSize::Default;
diff --git a/src/mbgl/gl/value.hpp b/src/mbgl/gl/value.hpp
index aa5cca6fec..62fe88a2f4 100644
--- a/src/mbgl/gl/value.hpp
+++ b/src/mbgl/gl/value.hpp
@@ -4,6 +4,7 @@
 #include <mbgl/gl/depth_mode.hpp>
 #include <mbgl/gl/stencil_mode.hpp>
 #include <mbgl/gl/color_mode.hpp>
+#include <mbgl/gl/attribute.hpp>
 #include <mbgl/util/color.hpp>
 #include <mbgl/util/size.hpp>
 #include <mbgl/util/range.hpp>
@@ -232,6 +233,12 @@ struct BindVertexArray {
     static Type Get(const Context&);
 };
 
+struct VertexAttribute {
+    using Type = optional<gl::AttributeBinding>;
+    static const Type Default;
+    static void Set(const Type&, Context&, AttributeLocation);
+};
+
 #if not MBGL_USE_GLES2
 
 struct PointSize {
diff --git a/src/mbgl/gl/vertex_array.cpp b/src/mbgl/gl/vertex_array.cpp
new file mode 100644
index 0000000000..68a500ac45
--- /dev/null
+++ b/src/mbgl/gl/vertex_array.cpp
@@ -0,0 +1,18 @@
+#include <mbgl/gl/vertex_array.hpp>
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/gl.hpp>
+
+namespace mbgl {
+namespace gl {
+
+void VertexArray::bind(Context& context, BufferID indexBuffer, const AttributeBindingArray& bindings) {
+    context.bindVertexArray = state->vertexArray;
+    state->indexBuffer = indexBuffer;
+
+    for (AttributeLocation location = 0; location < MAX_ATTRIBUTES; ++location) {
+        state->bindings[location] = bindings[location];
+    }
+}
+
+} // namespace gl
+} // namespace mbgl
diff --git a/src/mbgl/gl/vertex_array.hpp b/src/mbgl/gl/vertex_array.hpp
new file mode 100644
index 0000000000..9ccf48d9bd
--- /dev/null
+++ b/src/mbgl/gl/vertex_array.hpp
@@ -0,0 +1,58 @@
+#pragma once
+
+#include <mbgl/gl/object.hpp>
+#include <mbgl/gl/attribute.hpp>
+#include <mbgl/gl/state.hpp>
+#include <mbgl/gl/value.hpp>
+
+#include <array>
+#include <memory>
+
+namespace mbgl {
+namespace gl {
+
+class Context;
+
+class VertexArrayState {
+public:
+    VertexArrayState(UniqueVertexArray vertexArray_, Context& context)
+        : vertexArray(std::move(vertexArray_)),
+          bindings(makeBindings(context, std::make_index_sequence<MAX_ATTRIBUTES>())) {
+    }
+
+    void setDirty() {
+        indexBuffer.setDirty();
+        for (auto& binding : bindings) {
+            binding.setDirty();
+        }
+    }
+
+    UniqueVertexArray vertexArray;
+    State<value::BindElementBuffer> indexBuffer;
+
+    using AttributeState = State<value::VertexAttribute, Context&, AttributeLocation>;
+    std::array<AttributeState, MAX_ATTRIBUTES> bindings;
+
+private:
+    template <std::size_t... I>
+    std::array<AttributeState, MAX_ATTRIBUTES> makeBindings(Context& context, std::index_sequence<I...>) {
+        return {{ AttributeState { context, I }... }};
+    }
+};
+
+using UniqueVertexArrayState = std::unique_ptr<VertexArrayState, std::function<void (VertexArrayState*)>>;
+
+class VertexArray {
+public:
+    VertexArray(UniqueVertexArrayState state_)
+        : state(std::move(state_)) {
+    }
+
+    void bind(Context&, BufferID indexBuffer, const AttributeBindingArray&);
+
+private:
+    UniqueVertexArrayState state;
+};
+
+} // namespace gl
+} // namespace mbgl
diff --git a/src/mbgl/programs/binary_program.cpp b/src/mbgl/programs/binary_program.cpp
index 3b37cfa442..1cad0a2693 100644
--- a/src/mbgl/programs/binary_program.cpp
+++ b/src/mbgl/programs/binary_program.cpp
@@ -96,7 +96,7 @@ std::string BinaryProgram::serialize() const {
     return data;
 }
 
-gl::AttributeLocation BinaryProgram::attributeLocation(const std::string& name) const {
+optional<gl::AttributeLocation> BinaryProgram::attributeLocation(const std::string& name) const {
     for (const auto& pair : attributes) {
         if (pair.first == name) {
             return pair.second;
@@ -111,7 +111,7 @@ gl::UniformLocation BinaryProgram::uniformLocation(const std::string& name) cons
             return pair.second;
         }
     }
-    return {};
+    return -1;
 }
 
 } // namespace mbgl
diff --git a/src/mbgl/programs/binary_program.hpp b/src/mbgl/programs/binary_program.hpp
index 8ff3863dc1..2806f4fb3e 100644
--- a/src/mbgl/programs/binary_program.hpp
+++ b/src/mbgl/programs/binary_program.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/gl/types.hpp>
+#include <mbgl/util/optional.hpp>
 
 #include <string>
 #include <vector>
@@ -29,7 +30,8 @@ public:
     const std::string& identifier() const {
         return binaryIdentifier;
     }
-    gl::AttributeLocation attributeLocation(const std::string& name) const;
+
+    optional<gl::AttributeLocation> attributeLocation(const std::string& name) const;
     gl::UniformLocation uniformLocation(const std::string& name) const;
 
 private:
diff --git a/src/mbgl/programs/program.hpp b/src/mbgl/programs/program.hpp
index 65f17e5bdc..3ff6e59c6b 100644
--- a/src/mbgl/programs/program.hpp
+++ b/src/mbgl/programs/program.hpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/gl/program.hpp>
 #include <mbgl/gl/features.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/binary_program.hpp>
 #include <mbgl/programs/attributes.hpp>
 #include <mbgl/programs/program_parameters.hpp>
@@ -51,26 +52,37 @@ public:
               gl::DepthMode depthMode,
               gl::StencilMode stencilMode,
               gl::ColorMode colorMode,
-              UniformValues&& uniformValues,
+              const UniformValues& uniformValues,
               const gl::VertexBuffer<LayoutVertex>& layoutVertexBuffer,
               const gl::IndexBuffer<DrawMode>& indexBuffer,
-              const gl::SegmentVector<Attributes>& segments,
+              const SegmentVector<Attributes>& segments,
               const PaintPropertyBinders& paintPropertyBinders,
               const typename PaintProperties::Evaluated& currentProperties,
               float currentZoom) {
-        program.draw(
-            context,
-            std::move(drawMode),
-            std::move(depthMode),
-            std::move(stencilMode),
-            std::move(colorMode),
-            uniformValues
-                .concat(paintPropertyBinders.uniformValues(currentZoom, currentProperties)),
-            LayoutAttributes::bindings(layoutVertexBuffer)
-                .concat(paintPropertyBinders.attributeBindings(currentProperties)),
-            indexBuffer,
-            segments
-        );
+        typename AllUniforms::Values allUniformValues = uniformValues
+            .concat(paintPropertyBinders.uniformValues(currentZoom, currentProperties));
+
+        typename Attributes::Bindings allAttributeBindings = LayoutAttributes::bindings(layoutVertexBuffer)
+            .concat(paintPropertyBinders.attributeBindings(currentProperties));
+
+        for (auto& segment : segments) {
+            if (!segment.vertexArray) {
+                segment.vertexArray = context.createVertexArray();
+            }
+
+            program.draw(
+                context,
+                std::move(drawMode),
+                std::move(depthMode),
+                std::move(stencilMode),
+                std::move(colorMode),
+                allUniformValues,
+                *segment.vertexArray,
+                Attributes::offsetBindings(allAttributeBindings, segment.vertexOffset),
+                indexBuffer,
+                segment.indexOffset,
+                segment.indexLength);
+        }
     }
 };
 
diff --git a/src/mbgl/gl/segment.cpp b/src/mbgl/programs/segment.cpp
index aabdc83cd4..bb09843e21 100644
--- a/src/mbgl/gl/segment.cpp
+++ b/src/mbgl/programs/segment.cpp
@@ -1,4 +1,4 @@
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 
 namespace mbgl {
 namespace gl {
diff --git a/src/mbgl/programs/segment.hpp b/src/mbgl/programs/segment.hpp
new file mode 100644
index 0000000000..d8cc9679d7
--- /dev/null
+++ b/src/mbgl/programs/segment.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/vertex_array.hpp>
+#include <mbgl/util/optional.hpp>
+
+#include <cstddef>
+#include <vector>
+#include <map>
+
+namespace mbgl {
+
+template <class Attributes>
+class Segment {
+public:
+    Segment(std::size_t vertexOffset_,
+            std::size_t indexOffset_,
+            std::size_t vertexLength_ = 0,
+            std::size_t indexLength_ = 0)
+        : vertexOffset(vertexOffset_),
+          indexOffset(indexOffset_),
+          vertexLength(vertexLength_),
+          indexLength(indexLength_) {}
+
+    const std::size_t vertexOffset;
+    const std::size_t indexOffset;
+
+    std::size_t vertexLength;
+    std::size_t indexLength;
+
+    mutable optional<gl::VertexArray> vertexArray;
+};
+
+template <class Attributes>
+class SegmentVector : public std::vector<Segment<Attributes>> {
+public:
+    SegmentVector() = default;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/programs/symbol_program.hpp b/src/mbgl/programs/symbol_program.hpp
index 47d92f912c..2fddebde09 100644
--- a/src/mbgl/programs/symbol_program.hpp
+++ b/src/mbgl/programs/symbol_program.hpp
@@ -7,6 +7,7 @@
 
 #include <mbgl/programs/attributes.hpp>
 #include <mbgl/programs/uniforms.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/shaders/symbol_icon.hpp>
 #include <mbgl/shaders/symbol_sdf.hpp>
 #include <mbgl/util/geometry.hpp>
@@ -156,7 +157,7 @@ public:
     }
     
     SymbolSizeAttributes::Bindings attributeBindings() const override {
-        return SymbolSizeAttributes::Bindings { gl::DisabledAttribute() };
+        return SymbolSizeAttributes::Bindings { {} };
     }
 
     void upload(gl::Context&) override {}
@@ -352,29 +353,40 @@ public:
               gl::DepthMode depthMode,
               gl::StencilMode stencilMode,
               gl::ColorMode colorMode,
-              UniformValues&& uniformValues,
+              const UniformValues& uniformValues,
               const gl::VertexBuffer<LayoutVertex>& layoutVertexBuffer,
               const SymbolSizeBinder& symbolSizeBinder,
               const gl::IndexBuffer<DrawMode>& indexBuffer,
-              const gl::SegmentVector<Attributes>& segments,
+              const SegmentVector<Attributes>& segments,
               const PaintPropertyBinders& paintPropertyBinders,
               const typename PaintProperties::Evaluated& currentProperties,
               float currentZoom) {
-        program.draw(
-            context,
-            std::move(drawMode),
-            std::move(depthMode),
-            std::move(stencilMode),
-            std::move(colorMode),
-            uniformValues
-                .concat(symbolSizeBinder.uniformValues(currentZoom))
-                .concat(paintPropertyBinders.uniformValues(currentZoom, currentProperties)),
-            LayoutAttributes::bindings(layoutVertexBuffer)
-                .concat(symbolSizeBinder.attributeBindings())
-                .concat(paintPropertyBinders.attributeBindings(currentProperties)),
-            indexBuffer,
-            segments
-        );
+        typename AllUniforms::Values allUniformValues = uniformValues
+            .concat(symbolSizeBinder.uniformValues(currentZoom))
+            .concat(paintPropertyBinders.uniformValues(currentZoom, currentProperties));
+
+        typename Attributes::Bindings allAttributeBindings = LayoutAttributes::bindings(layoutVertexBuffer)
+            .concat(symbolSizeBinder.attributeBindings())
+            .concat(paintPropertyBinders.attributeBindings(currentProperties));
+
+        for (auto& segment : segments) {
+            if (!segment.vertexArray) {
+                segment.vertexArray = context.createVertexArray();
+            }
+
+            program.draw(
+                context,
+                std::move(drawMode),
+                std::move(depthMode),
+                std::move(stencilMode),
+                std::move(colorMode),
+                allUniformValues,
+                *segment.vertexArray,
+                Attributes::offsetBindings(allAttributeBindings, segment.vertexOffset),
+                indexBuffer,
+                segment.indexOffset,
+                segment.indexLength);
+        }
     }
 };
 
diff --git a/src/mbgl/renderer/circle_bucket.hpp b/src/mbgl/renderer/circle_bucket.hpp
index b048fd7675..0f27e2a7e3 100644
--- a/src/mbgl/renderer/circle_bucket.hpp
+++ b/src/mbgl/renderer/circle_bucket.hpp
@@ -5,7 +5,7 @@
 #include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/circle_program.hpp>
 #include <mbgl/style/layers/circle_layer_properties.hpp>
 
@@ -29,7 +29,7 @@ public:
 
     gl::VertexVector<CircleLayoutVertex> vertices;
     gl::IndexVector<gl::Triangles> triangles;
-    gl::SegmentVector<CircleAttributes> segments;
+    SegmentVector<CircleAttributes> segments;
 
     optional<gl::VertexBuffer<CircleLayoutVertex>> vertexBuffer;
     optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
diff --git a/src/mbgl/renderer/debug_bucket.hpp b/src/mbgl/renderer/debug_bucket.hpp
index 756e58a6de..fc3128e944 100644
--- a/src/mbgl/renderer/debug_bucket.hpp
+++ b/src/mbgl/renderer/debug_bucket.hpp
@@ -33,7 +33,7 @@ public:
     const optional<Timestamp> expires;
     const MapDebugOptions debugMode;
 
-    gl::SegmentVector<DebugAttributes> segments;
+    SegmentVector<DebugAttributes> segments;
     optional<gl::VertexBuffer<DebugLayoutVertex>> vertexBuffer;
     optional<gl::IndexBuffer<gl::Lines>> indexBuffer;
 };
diff --git a/src/mbgl/renderer/fill_bucket.hpp b/src/mbgl/renderer/fill_bucket.hpp
index 421d8b332b..d3cd92d451 100644
--- a/src/mbgl/renderer/fill_bucket.hpp
+++ b/src/mbgl/renderer/fill_bucket.hpp
@@ -4,7 +4,7 @@
 #include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/fill_program.hpp>
 #include <mbgl/style/layers/fill_layer_properties.hpp>
 
@@ -30,8 +30,8 @@ public:
     gl::VertexVector<FillLayoutVertex> vertices;
     gl::IndexVector<gl::Lines> lines;
     gl::IndexVector<gl::Triangles> triangles;
-    gl::SegmentVector<FillAttributes> lineSegments;
-    gl::SegmentVector<FillAttributes> triangleSegments;
+    SegmentVector<FillAttributes> lineSegments;
+    SegmentVector<FillAttributes> triangleSegments;
 
     optional<gl::VertexBuffer<FillLayoutVertex>> vertexBuffer;
     optional<gl::IndexBuffer<gl::Lines>> lineIndexBuffer;
diff --git a/src/mbgl/renderer/fill_extrusion_bucket.hpp b/src/mbgl/renderer/fill_extrusion_bucket.hpp
index c54805d743..d1e695c5a3 100644
--- a/src/mbgl/renderer/fill_extrusion_bucket.hpp
+++ b/src/mbgl/renderer/fill_extrusion_bucket.hpp
@@ -4,7 +4,7 @@
 #include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/fill_extrusion_program.hpp>
 #include <mbgl/style/layers/fill_extrusion_layer_properties.hpp>
 
@@ -27,7 +27,7 @@ public:
 
     gl::VertexVector<FillExtrusionLayoutVertex> vertices;
     gl::IndexVector<gl::Triangles> triangles;
-    gl::SegmentVector<FillExtrusionAttributes> triangleSegments;
+    SegmentVector<FillExtrusionAttributes> triangleSegments;
 
     optional<gl::VertexBuffer<FillExtrusionLayoutVertex>> vertexBuffer;
     optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
diff --git a/src/mbgl/renderer/line_bucket.hpp b/src/mbgl/renderer/line_bucket.hpp
index c319548714..95ef2f9a6f 100644
--- a/src/mbgl/renderer/line_bucket.hpp
+++ b/src/mbgl/renderer/line_bucket.hpp
@@ -4,7 +4,7 @@
 #include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/line_program.hpp>
 #include <mbgl/style/layers/line_layer_properties.hpp>
 
@@ -34,7 +34,7 @@ public:
 
     gl::VertexVector<LineLayoutVertex> vertices;
     gl::IndexVector<gl::Triangles> triangles;
-    gl::SegmentVector<LineAttributes> segments;
+    SegmentVector<LineAttributes> segments;
 
     optional<gl::VertexBuffer<LineLayoutVertex>> vertexBuffer;
     optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
diff --git a/src/mbgl/renderer/paint_property_binder.hpp b/src/mbgl/renderer/paint_property_binder.hpp
index 906a2ea07b..36d2e98082 100644
--- a/src/mbgl/renderer/paint_property_binder.hpp
+++ b/src/mbgl/renderer/paint_property_binder.hpp
@@ -3,6 +3,7 @@
 #include <mbgl/programs/attributes.hpp>
 #include <mbgl/gl/attribute.hpp>
 #include <mbgl/gl/uniform.hpp>
+#include <mbgl/gl/context.hpp>
 #include <mbgl/util/type_list.hpp>
 #include <mbgl/renderer/paint_property_statistics.hpp>
 
@@ -80,7 +81,7 @@ public:
 
     virtual void populateVertexVector(const GeometryTileFeature& feature, std::size_t length) = 0;
     virtual void upload(gl::Context& context) = 0;
-    virtual AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const = 0;
+    virtual optional<AttributeBinding> attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const = 0;
     virtual float interpolationFactor(float currentZoom) const = 0;
     virtual T uniformValue(const PossiblyEvaluatedPropertyValue<T>& currentValue) const = 0;
 
@@ -102,8 +103,8 @@ public:
     void populateVertexVector(const GeometryTileFeature&, std::size_t) override {}
     void upload(gl::Context&) override {}
 
-    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>&) const override {
-        return gl::DisabledAttribute();
+    optional<AttributeBinding> attributeBinding(const PossiblyEvaluatedPropertyValue<T>&) const override {
+        return {};
     }
 
     float interpolationFactor(float) const override {
@@ -146,9 +147,9 @@ public:
         vertexBuffer = context.createVertexBuffer(std::move(vertexVector));
     }
 
-    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
+    optional<AttributeBinding> attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
         if (currentValue.isConstant()) {
-            return gl::DisabledAttribute();
+            return {};
         } else {
             return Attribute::binding(*vertexBuffer, 0, BaseAttribute::Dimensions);
         }
@@ -207,9 +208,9 @@ public:
         vertexBuffer = context.createVertexBuffer(std::move(vertexVector));
     }
 
-    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
+    optional<AttributeBinding> attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
         if (currentValue.isConstant()) {
-            return gl::DisabledAttribute();
+            return {};
         } else {
             return Attribute::binding(*vertexBuffer, 0);
         }
diff --git a/src/mbgl/renderer/painter.cpp b/src/mbgl/renderer/painter.cpp
index da4903864b..da3268ed76 100644
--- a/src/mbgl/renderer/painter.cpp
+++ b/src/mbgl/renderer/painter.cpp
@@ -278,7 +278,7 @@ void Painter::render(const Style& style, const FrameData& frame_, View& view, Sp
         context.activeTexture = 0;
         context.texture[0] = 0;
 
-        context.vertexArrayObject = 0;
+        context.bindVertexArray = 0;
     }
 }
 
@@ -312,7 +312,7 @@ void Painter::renderPass(PaintParameters& parameters,
             MBGL_DEBUG_GROUP(context, layer.baseImpl.id + " - custom");
 
             // Reset GL state to a known state so the CustomLayer always has a clean slate.
-            context.vertexArrayObject = 0;
+            context.bindVertexArray = 0;
             context.setDepthMode(depthModeForSublayer(0, gl::DepthMode::ReadOnly));
             context.setStencilMode(gl::StencilMode::disabled());
             context.setColorMode(colorModeForRenderPass());
diff --git a/src/mbgl/renderer/painter.hpp b/src/mbgl/renderer/painter.hpp
index 4658f0c206..1919ad924e 100644
--- a/src/mbgl/renderer/painter.hpp
+++ b/src/mbgl/renderer/painter.hpp
@@ -177,10 +177,10 @@ private:
     gl::IndexBuffer<gl::Triangles> quadTriangleIndexBuffer;
     gl::IndexBuffer<gl::LineStrip> tileBorderIndexBuffer;
 
-    gl::SegmentVector<FillAttributes> tileTriangleSegments;
-    gl::SegmentVector<DebugAttributes> tileBorderSegments;
-    gl::SegmentVector<RasterAttributes> rasterSegments;
-    gl::SegmentVector<ExtrusionTextureAttributes> extrusionTextureSegments;
+    SegmentVector<FillAttributes> tileTriangleSegments;
+    SegmentVector<DebugAttributes> tileBorderSegments;
+    SegmentVector<RasterAttributes> rasterSegments;
+    SegmentVector<ExtrusionTextureAttributes> extrusionTextureSegments;
 };
 
 } // namespace mbgl
diff --git a/src/mbgl/renderer/symbol_bucket.hpp b/src/mbgl/renderer/symbol_bucket.hpp
index f7e4bcfa20..a9bc868db0 100644
--- a/src/mbgl/renderer/symbol_bucket.hpp
+++ b/src/mbgl/renderer/symbol_bucket.hpp
@@ -4,7 +4,7 @@
 #include <mbgl/map/mode.hpp>
 #include <mbgl/gl/vertex_buffer.hpp>
 #include <mbgl/gl/index_buffer.hpp>
-#include <mbgl/gl/segment.hpp>
+#include <mbgl/programs/segment.hpp>
 #include <mbgl/programs/symbol_program.hpp>
 #include <mbgl/programs/collision_box_program.hpp>
 #include <mbgl/text/glyph_range.hpp>
@@ -45,7 +45,7 @@ public:
     struct TextBuffer {
         gl::VertexVector<SymbolLayoutVertex> vertices;
         gl::IndexVector<gl::Triangles> triangles;
-        gl::SegmentVector<SymbolTextAttributes> segments;
+        SegmentVector<SymbolTextAttributes> segments;
 
         optional<gl::VertexBuffer<SymbolLayoutVertex>> vertexBuffer;
         optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
@@ -56,7 +56,7 @@ public:
     struct IconBuffer {
         gl::VertexVector<SymbolLayoutVertex> vertices;
         gl::IndexVector<gl::Triangles> triangles;
-        gl::SegmentVector<SymbolIconAttributes> segments;
+        SegmentVector<SymbolIconAttributes> segments;
 
         optional<gl::VertexBuffer<SymbolLayoutVertex>> vertexBuffer;
         optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
@@ -65,7 +65,7 @@ public:
     struct CollisionBoxBuffer {
         gl::VertexVector<CollisionBoxVertex> vertices;
         gl::IndexVector<gl::Lines> lines;
-        gl::SegmentVector<CollisionBoxAttributes> segments;
+        SegmentVector<CollisionBoxAttributes> segments;
 
         optional<gl::VertexBuffer<CollisionBoxVertex>> vertexBuffer;
         optional<gl::IndexBuffer<gl::Lines>> indexBuffer;
diff --git a/test/programs/binary_program.test.cpp b/test/programs/binary_program.test.cpp
index ce544e7652..a5cf7b6e39 100644
--- a/test/programs/binary_program.test.cpp
+++ b/test/programs/binary_program.test.cpp
@@ -14,12 +14,12 @@ TEST(BinaryProgram, ObtainValues) {
     EXPECT_EQ(42u, binaryProgram.format());
     EXPECT_EQ("binary code", binaryProgram.code());
     EXPECT_EQ("identifier", binaryProgram.identifier());
-    EXPECT_EQ(1, binaryProgram.attributeLocation("a_pos"));
-    EXPECT_EQ(0, binaryProgram.attributeLocation("u_world"));
-    EXPECT_EQ(4, binaryProgram.attributeLocation("a_data"));
+    EXPECT_EQ(1u, binaryProgram.attributeLocation("a_pos"));
+    EXPECT_FALSE(binaryProgram.attributeLocation("u_world"));
+    EXPECT_EQ(4u, binaryProgram.attributeLocation("a_data"));
     EXPECT_EQ(1, binaryProgram.uniformLocation("u_world"));
     EXPECT_EQ(3, binaryProgram.uniformLocation("u_ratio"));
-    EXPECT_EQ(0, binaryProgram.uniformLocation("a_data"));
+    EXPECT_EQ(-1, binaryProgram.uniformLocation("a_data"));
 
     auto serialized = binaryProgram.serialize();
 
@@ -28,12 +28,12 @@ TEST(BinaryProgram, ObtainValues) {
     EXPECT_EQ(42u, binaryProgram2.format());
     EXPECT_EQ("binary code", binaryProgram2.code());
     EXPECT_EQ("identifier", binaryProgram2.identifier());
-    EXPECT_EQ(1, binaryProgram2.attributeLocation("a_pos"));
-    EXPECT_EQ(0, binaryProgram2.attributeLocation("u_world"));
-    EXPECT_EQ(4, binaryProgram2.attributeLocation("a_data"));
+    EXPECT_EQ(1u, binaryProgram2.attributeLocation("a_pos"));
+    EXPECT_FALSE(binaryProgram2.attributeLocation("u_world"));
+    EXPECT_EQ(4u, binaryProgram2.attributeLocation("a_data"));
     EXPECT_EQ(1, binaryProgram2.uniformLocation("u_world"));
     EXPECT_EQ(3, binaryProgram2.uniformLocation("u_ratio"));
-    EXPECT_EQ(0, binaryProgram2.uniformLocation("a_data"));
+    EXPECT_EQ(-1, binaryProgram2.uniformLocation("a_data"));
 
     EXPECT_THROW(BinaryProgram(""), std::runtime_error);
 }