[render-test] Add resource usage tracking to gfx context

16 files changed, 176 insertions, 14 deletions

diff --git a/include/mbgl/gfx/rendering_stats.hpp b/include/mbgl/gfx/rendering_stats.hpp
new file mode 100644
index 0000000000..8fb01a5825
--- /dev/null
+++ b/include/mbgl/gfx/rendering_stats.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+namespace mbgl {
+namespace gfx {
+
+struct RenderingStats {
+    RenderingStats() = default;
+    bool isZero() const;
+
+    int numDrawCalls;
+    int numActiveTextures;
+    int numCreatedTextures;
+    int numBuffers;
+    int numFrameBuffers;
+
+    int memTextures;
+    int memIndexBuffers;
+    int memVertexBuffers;
+};
+
+} // namespace gfx
+} // namespace mbgl
\ No newline at end of file
diff --git a/next/CMakeLists.txt b/next/CMakeLists.txt
index 524a86e189..924761ad85 100644
--- a/next/CMakeLists.txt
+++ b/next/CMakeLists.txt
@@ -70,6 +70,7 @@ add_library(
     ${MBGL_ROOT}/include/mbgl/gfx/backend_scope.hpp
     ${MBGL_ROOT}/include/mbgl/gfx/renderable.hpp
     ${MBGL_ROOT}/include/mbgl/gfx/renderer_backend.hpp
+    ${MBGL_ROOT}/include/mbgl/gfx/rendering_stats.hpp
     ${MBGL_ROOT}/include/mbgl/gl/renderable_resource.hpp
     ${MBGL_ROOT}/include/mbgl/gl/renderer_backend.hpp
     ${MBGL_ROOT}/include/mbgl/layermanager/background_layer_factory.hpp
@@ -285,6 +286,7 @@ add_library(
     ${MBGL_ROOT}/src/mbgl/gfx/render_pass.hpp
     ${MBGL_ROOT}/src/mbgl/gfx/renderbuffer.hpp
     ${MBGL_ROOT}/src/mbgl/gfx/renderer_backend.cpp
+    ${MBGL_ROOT}/src/mbgl/gfx/rendering_stats.cpp
     ${MBGL_ROOT}/src/mbgl/gfx/stencil_mode.hpp
     ${MBGL_ROOT}/src/mbgl/gfx/texture.hpp
     ${MBGL_ROOT}/src/mbgl/gfx/types.hpp
@@ -306,6 +308,7 @@ add_library(
     ${MBGL_ROOT}/src/mbgl/gl/enum.hpp
     ${MBGL_ROOT}/src/mbgl/gl/extension.hpp
     ${MBGL_ROOT}/src/mbgl/gl/framebuffer.hpp
+    ${MBGL_ROOT}/src/mbgl/gl/index_buffer_resource.cpp
     ${MBGL_ROOT}/src/mbgl/gl/index_buffer_resource.hpp
     ${MBGL_ROOT}/src/mbgl/gl/object.cpp
     ${MBGL_ROOT}/src/mbgl/gl/object.hpp
@@ -319,6 +322,7 @@ add_library(
     ${MBGL_ROOT}/src/mbgl/gl/state.hpp
     ${MBGL_ROOT}/src/mbgl/gl/texture.cpp
     ${MBGL_ROOT}/src/mbgl/gl/texture.hpp
+    ${MBGL_ROOT}/src/mbgl/gl/texture_resource.cpp
     ${MBGL_ROOT}/src/mbgl/gl/texture_resource.hpp
     ${MBGL_ROOT}/src/mbgl/gl/types.hpp
     ${MBGL_ROOT}/src/mbgl/gl/uniform.cpp
@@ -330,6 +334,7 @@ add_library(
     ${MBGL_ROOT}/src/mbgl/gl/vertex_array.cpp
     ${MBGL_ROOT}/src/mbgl/gl/vertex_array.hpp
     ${MBGL_ROOT}/src/mbgl/gl/vertex_array_extension.hpp
+    ${MBGL_ROOT}/src/mbgl/gl/vertex_buffer_resource.cpp
     ${MBGL_ROOT}/src/mbgl/gl/vertex_buffer_resource.hpp
     ${MBGL_ROOT}/src/mbgl/layermanager/background_layer_factory.cpp
     ${MBGL_ROOT}/src/mbgl/layermanager/circle_layer_factory.cpp
diff --git a/platform/default/src/mbgl/gfx/headless_frontend.cpp b/platform/default/src/mbgl/gfx/headless_frontend.cpp
index 87d09911a2..9e819f6653 100644
--- a/platform/default/src/mbgl/gfx/headless_frontend.cpp
+++ b/platform/default/src/mbgl/gfx/headless_frontend.cpp
@@ -1,5 +1,6 @@
 #include <mbgl/gfx/backend_scope.hpp>
 #include <mbgl/gfx/headless_frontend.hpp>
+#include <mbgl/gfx/context.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/transform_state.hpp>
 #include <mbgl/renderer/renderer.hpp>
diff --git a/src/core-files.json b/src/core-files.json
index e8795fbdd3..c25e8273d4 100644
--- a/src/core-files.json
+++ b/src/core-files.json
@@ -17,20 +17,24 @@
         "src/mbgl/geometry/line_atlas.cpp",
         "src/mbgl/gfx/attribute.cpp",
         "src/mbgl/gfx/renderer_backend.cpp",
+        "src/mbgl/gfx/rendering_stats.cpp",
         "src/mbgl/gl/attribute.cpp",
         "src/mbgl/gl/command_encoder.cpp",
         "src/mbgl/gl/context.cpp",
         "src/mbgl/gl/debugging_extension.cpp",
         "src/mbgl/gl/enum.cpp",
+        "src/mbgl/gl/index_buffer_resource.cpp",
         "src/mbgl/gl/object.cpp",
         "src/mbgl/gl/offscreen_texture.cpp",
         "src/mbgl/gl/render_pass.cpp",
         "src/mbgl/gl/renderer_backend.cpp",
         "src/mbgl/gl/texture.cpp",
+        "src/mbgl/gl/texture_resource.cpp",
         "src/mbgl/gl/uniform.cpp",
         "src/mbgl/gl/upload_pass.cpp",
         "src/mbgl/gl/value.cpp",
         "src/mbgl/gl/vertex_array.cpp",
+        "src/mbgl/gl/vertex_buffer_resource.cpp",
         "src/mbgl/layermanager/background_layer_factory.cpp",
         "src/mbgl/layermanager/circle_layer_factory.cpp",
         "src/mbgl/layermanager/custom_layer_factory.cpp",
@@ -331,6 +335,7 @@
         "mbgl/gfx/backend_scope.hpp": "include/mbgl/gfx/backend_scope.hpp",
         "mbgl/gfx/renderable.hpp": "include/mbgl/gfx/renderable.hpp",
         "mbgl/gfx/renderer_backend.hpp": "include/mbgl/gfx/renderer_backend.hpp",
+        "mbgl/gfx/rendering_stats.hpp": "include/mbgl/gfx/rendering_stats.hpp",
         "mbgl/gl/renderable_resource.hpp": "include/mbgl/gl/renderable_resource.hpp",
         "mbgl/gl/renderer_backend.hpp": "include/mbgl/gl/renderer_backend.hpp",
         "mbgl/i18n/collator.hpp": "include/mbgl/i18n/collator.hpp",
diff --git a/src/mbgl/gfx/context.hpp b/src/mbgl/gfx/context.hpp
index 2c7cb14899..fe0851be11 100644
--- a/src/mbgl/gfx/context.hpp
+++ b/src/mbgl/gfx/context.hpp
@@ -1,12 +1,13 @@
 #pragma once
 
 #include <mbgl/gfx/backend.hpp>
-#include <mbgl/gfx/renderbuffer.hpp>
 #include <mbgl/gfx/command_encoder.hpp>
 #include <mbgl/gfx/draw_scope.hpp>
 #include <mbgl/gfx/program.hpp>
-#include <mbgl/gfx/types.hpp>
+#include <mbgl/gfx/renderbuffer.hpp>
+#include <mbgl/gfx/rendering_stats.hpp>
 #include <mbgl/gfx/texture.hpp>
+#include <mbgl/gfx/types.hpp>
 
 namespace mbgl {
 
@@ -85,6 +86,8 @@ public:
 public:
     virtual std::unique_ptr<CommandEncoder> createCommandEncoder() = 0;
 
+    virtual const RenderingStats& renderingStats() const = 0;
+
 #if not defined(NDEBUG)
 public:
     virtual void visualizeStencilBuffer() = 0;
diff --git a/src/mbgl/gfx/rendering_stats.cpp b/src/mbgl/gfx/rendering_stats.cpp
new file mode 100644
index 0000000000..0a239ebd11
--- /dev/null
+++ b/src/mbgl/gfx/rendering_stats.cpp
@@ -0,0 +1,12 @@
+#include <mbgl/gfx/rendering_stats.hpp>
+
+namespace mbgl {
+namespace gfx {
+
+bool RenderingStats::isZero() const {
+    return numActiveTextures == 0 && numCreatedTextures == 0 && numBuffers == 0 && numFrameBuffers == 0 &&
+           memTextures == 0 && memIndexBuffers == 0 && memVertexBuffers == 0;
+}
+
+} // namespace gfx
+} // namespace mbgl
\ No newline at end of file
diff --git a/src/mbgl/gl/context.cpp b/src/mbgl/gl/context.cpp
index f81ac48ee5..e2bcc7fadc 100644
--- a/src/mbgl/gl/context.cpp
+++ b/src/mbgl/gl/context.cpp
@@ -54,13 +54,15 @@ Context::Context(RendererBackend& backend_)
           GLint value;
           MBGL_CHECK_ERROR(glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &value));
           return value;
-      }()), backend(backend_) {
-}
+      }()),
+      backend(backend_),
+      stats() {}
 
 Context::~Context() {
     if (cleanupOnDestruction) {
         reset();
     }
+    assert(stats.isZero());
 }
 
 void Context::initializeExtensions(const std::function<gl::ProcAddress(const char*)>& getProcAddress) {
@@ -206,10 +208,12 @@ UniqueTexture Context::createUniqueTexture() {
     if (pooledTextures.empty()) {
         pooledTextures.resize(TextureMax);
         MBGL_CHECK_ERROR(glGenTextures(TextureMax, pooledTextures.data()));
+        stats.numCreatedTextures += TextureMax;
     }
 
     TextureID id = pooledTextures.back();
     pooledTextures.pop_back();
+    stats.numActiveTextures++;
     // NOLINTNEXTLINE(performance-move-const-arg)
     return UniqueTexture{std::move(id), {this}};
 }
@@ -238,6 +242,7 @@ VertexArray Context::createVertexArray() {
 UniqueFramebuffer Context::createFramebuffer() {
     FramebufferID id = 0;
     MBGL_CHECK_ERROR(glGenFramebuffers(1, &id));
+    stats.numFrameBuffers++;
     // NOLINTNEXTLINE(performance-move-const-arg)
     return UniqueFramebuffer{ std::move(id), { this } };
 }
@@ -245,8 +250,10 @@ UniqueFramebuffer Context::createFramebuffer() {
 std::unique_ptr<gfx::TextureResource> Context::createTextureResource(
     const Size size, const gfx::TexturePixelType format, const gfx::TextureChannelDataType type) {
     auto obj = createUniqueTexture();
+    int textureByteSize = gl::TextureResource::getStorageSize(size, format, type);
+    stats.memTextures += textureByteSize;
     std::unique_ptr<gfx::TextureResource> resource =
-        std::make_unique<gl::TextureResource>(std::move(obj));
+        std::make_unique<gl::TextureResource>(std::move(obj), textureByteSize);
 
     // Always use texture unit 0 for manipulating it.
     activeTextureUnit = 0;
@@ -517,6 +524,8 @@ void Context::clear(optional<mbgl::Color> color,
     }
 
     MBGL_CHECK_ERROR(glClear(mask));
+
+    stats.numDrawCalls = 0;
 }
 
 void Context::setCullFaceMode(const gfx::CullFaceMode& mode) {
@@ -583,6 +592,14 @@ std::unique_ptr<gfx::CommandEncoder> Context::createCommandEncoder() {
     return std::make_unique<gl::CommandEncoder>(*this);
 }
 
+gfx::RenderingStats& Context::renderingStats() {
+    return stats;
+}
+
+const gfx::RenderingStats& Context::renderingStats() const {
+    return stats;
+}
+
 void Context::finish() {
     MBGL_CHECK_ERROR(glFinish());
 }
@@ -611,6 +628,8 @@ void Context::draw(const gfx::DrawMode& drawMode,
         static_cast<GLsizei>(indexLength),
         GL_UNSIGNED_SHORT,
         reinterpret_cast<GLvoid*>(sizeof(uint16_t) * indexOffset)));
+
+    stats.numDrawCalls++;
 }
 
 void Context::performCleanup() {
@@ -647,6 +666,7 @@ void Context::performCleanup() {
             }
         }
         MBGL_CHECK_ERROR(glDeleteBuffers(int(abandonedBuffers.size()), abandonedBuffers.data()));
+        stats.numBuffers -= int(abandonedBuffers.size());
         abandonedBuffers.clear();
     }
 
@@ -659,6 +679,8 @@ void Context::performCleanup() {
             }
         }
         MBGL_CHECK_ERROR(glDeleteTextures(int(abandonedTextures.size()), abandonedTextures.data()));
+        stats.numCreatedTextures -= int(abandonedTextures.size());
+        assert(stats.numCreatedTextures >= 0);
         abandonedTextures.clear();
     }
 
@@ -682,6 +704,8 @@ void Context::performCleanup() {
         }
         MBGL_CHECK_ERROR(
             glDeleteFramebuffers(int(abandonedFramebuffers.size()), abandonedFramebuffers.data()));
+        stats.numFrameBuffers -= int(abandonedFramebuffers.size());
+        assert(stats.numFrameBuffers >= 0);
         abandonedFramebuffers.clear();
     }
 
diff --git a/src/mbgl/gl/context.hpp b/src/mbgl/gl/context.hpp
index edcdde1ec6..b0d043ff9f 100644
--- a/src/mbgl/gl/context.hpp
+++ b/src/mbgl/gl/context.hpp
@@ -43,6 +43,9 @@ public:
 
     std::unique_ptr<gfx::CommandEncoder> createCommandEncoder() override;
 
+    gfx::RenderingStats& renderingStats();
+    const gfx::RenderingStats& renderingStats() const override;
+
     void initializeExtensions(const std::function<gl::ProcAddress(const char*)>&);
 
     void enableDebugging();
@@ -132,6 +135,7 @@ private:
     RendererBackend& backend;
     bool cleanupOnDestruction = true;
 
+    gfx::RenderingStats stats;
     std::unique_ptr<extension::Debugging> debugging;
     std::unique_ptr<extension::VertexArray> vertexArray;
 
diff --git a/src/mbgl/gl/index_buffer_resource.cpp b/src/mbgl/gl/index_buffer_resource.cpp
new file mode 100644
index 0000000000..2ef178846b
--- /dev/null
+++ b/src/mbgl/gl/index_buffer_resource.cpp
@@ -0,0 +1,14 @@
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/index_buffer_resource.hpp>
+
+namespace mbgl {
+namespace gl {
+
+IndexBufferResource::~IndexBufferResource() {
+    auto& stats = buffer.get_deleter().context.renderingStats();
+    stats.memIndexBuffers -= byteSize;
+    assert(stats.memIndexBuffers >= 0);
+}
+
+} // namespace gl
+} // namespace mbgl
\ No newline at end of file
diff --git a/src/mbgl/gl/index_buffer_resource.hpp b/src/mbgl/gl/index_buffer_resource.hpp
index 2da25fdb96..00c66be5b5 100644
--- a/src/mbgl/gl/index_buffer_resource.hpp
+++ b/src/mbgl/gl/index_buffer_resource.hpp
@@ -8,10 +8,11 @@ namespace gl {
 
 class IndexBufferResource : public gfx::IndexBufferResource {
 public:
-    IndexBufferResource(UniqueBuffer&& buffer_) : buffer(std::move(buffer_)) {
-    }
+    IndexBufferResource(UniqueBuffer&& buffer_, int byteSize_) : buffer(std::move(buffer_)), byteSize(byteSize_) {}
+    ~IndexBufferResource();
 
     UniqueBuffer buffer;
+    int byteSize;
 };
 
 } // namespace gl
diff --git a/src/mbgl/gl/object.cpp b/src/mbgl/gl/object.cpp
index ec2998a27d..c075aa8f13 100644
--- a/src/mbgl/gl/object.cpp
+++ b/src/mbgl/gl/object.cpp
@@ -28,6 +28,8 @@ void TextureDeleter::operator()(TextureID id) const {
     } else {
         context->pooledTextures.push_back(id);
     }
+    context->renderingStats().numActiveTextures--;
+    assert(context->renderingStats().numActiveTextures >= 0);
 }
 
 void VertexArrayDeleter::operator()(VertexArrayID id) const {
diff --git a/src/mbgl/gl/texture_resource.cpp b/src/mbgl/gl/texture_resource.cpp
new file mode 100644
index 0000000000..b9bf620eea
--- /dev/null
+++ b/src/mbgl/gl/texture_resource.cpp
@@ -0,0 +1,45 @@
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/texture_resource.hpp>
+
+namespace mbgl {
+namespace gl {
+
+static int channelCount(gfx::TexturePixelType format) {
+    switch (format) {
+        case gfx::TexturePixelType::Alpha:
+        case gfx::TexturePixelType::Depth:
+        case gfx::TexturePixelType::Luminance:
+        case gfx::TexturePixelType::Stencil:
+            return 1;
+        case gfx::TexturePixelType::RGBA:
+            return 4;
+        default:
+            assert(!"Unknown texture pixel type");
+            return 0;
+    }
+}
+
+static int channelStorageSize(gfx::TextureChannelDataType type) {
+    switch (type) {
+        case gfx::TextureChannelDataType::HalfFloat:
+            return 2;
+        case gfx::TextureChannelDataType::UnsignedByte:
+            return 1;
+        default:
+            assert(!"Unknown texture channel data type");
+            return 0;
+    }
+}
+
+TextureResource::~TextureResource() {
+    auto& stats = texture.get_deleter().context->renderingStats();
+    stats.memTextures -= byteSize;
+    assert(stats.memTextures >= 0);
+}
+
+int TextureResource::getStorageSize(const Size& size, gfx::TexturePixelType format, gfx::TextureChannelDataType type) {
+    return size.width * size.height * channelCount(format) * channelStorageSize(type);
+}
+
+} // namespace gl
+} // namespace mbgl
\ No newline at end of file
diff --git a/src/mbgl/gl/texture_resource.hpp b/src/mbgl/gl/texture_resource.hpp
index ed742e75b7..494e5ae8a3 100644
--- a/src/mbgl/gl/texture_resource.hpp
+++ b/src/mbgl/gl/texture_resource.hpp
@@ -8,14 +8,17 @@ namespace gl {
 
 class TextureResource : public gfx::TextureResource {
 public:
-    TextureResource(UniqueTexture&& texture_) : texture(std::move(texture_)) {
-    }
+    TextureResource(UniqueTexture&& texture_, int byteSize_) : texture(std::move(texture_)), byteSize(byteSize_) {}
+    ~TextureResource();
+
+    static int getStorageSize(const Size& size, gfx::TexturePixelType format, gfx::TextureChannelDataType type);
 
     UniqueTexture texture;
     gfx::TextureFilterType filter = gfx::TextureFilterType::Nearest;
     gfx::TextureMipMapType mipmap = gfx::TextureMipMapType::No;
     gfx::TextureWrapType wrapX = gfx::TextureWrapType::Clamp;
     gfx::TextureWrapType wrapY = gfx::TextureWrapType::Clamp;
+    int byteSize;
 };
 
 } // namespace gl
diff --git a/src/mbgl/gl/upload_pass.cpp b/src/mbgl/gl/upload_pass.cpp
index 4312488fb4..962bc72239 100644
--- a/src/mbgl/gl/upload_pass.cpp
+++ b/src/mbgl/gl/upload_pass.cpp
@@ -20,12 +20,14 @@ std::unique_ptr<gfx::VertexBufferResource> UploadPass::createVertexBufferResourc
     const void* data, std::size_t size, const gfx::BufferUsageType usage) {
     BufferID id = 0;
     MBGL_CHECK_ERROR(glGenBuffers(1, &id));
+    commandEncoder.context.renderingStats().numBuffers++;
+    commandEncoder.context.renderingStats().memVertexBuffers += size;
     // NOLINTNEXTLINE(performance-move-const-arg)
     UniqueBuffer result{ std::move(id), { commandEncoder.context } };
     commandEncoder.context.vertexBuffer = result;
     MBGL_CHECK_ERROR(
         glBufferData(GL_ARRAY_BUFFER, size, data, Enum<gfx::BufferUsageType>::to(usage)));
-    return std::make_unique<gl::VertexBufferResource>(std::move(result));
+    return std::make_unique<gl::VertexBufferResource>(std::move(result), size);
 }
 
 void UploadPass::updateVertexBufferResource(gfx::VertexBufferResource& resource,
@@ -39,13 +41,15 @@ std::unique_ptr<gfx::IndexBufferResource> UploadPass::createIndexBufferResource(
     const void* data, std::size_t size, const gfx::BufferUsageType usage) {
     BufferID id = 0;
     MBGL_CHECK_ERROR(glGenBuffers(1, &id));
+    commandEncoder.context.renderingStats().numBuffers++;
+    commandEncoder.context.renderingStats().memIndexBuffers += size;
     // NOLINTNEXTLINE(performance-move-const-arg)
     UniqueBuffer result{ std::move(id), { commandEncoder.context } };
     commandEncoder.context.bindVertexArray = 0;
     commandEncoder.context.globalVertexArrayState.indexBuffer = result;
     MBGL_CHECK_ERROR(
         glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, data, Enum<gfx::BufferUsageType>::to(usage)));
-    return std::make_unique<gl::IndexBufferResource>(std::move(result));
+    return std::make_unique<gl::IndexBufferResource>(std::move(result), size);
 }
 
 void UploadPass::updateIndexBufferResource(gfx::IndexBufferResource& resource,
@@ -65,8 +69,10 @@ UploadPass::createTextureResource(const Size size,
                                   gfx::TexturePixelType format,
                                   gfx::TextureChannelDataType type) {
     auto obj = commandEncoder.context.createUniqueTexture();
+    int textureByteSize = gl::TextureResource::getStorageSize(size, format, type);
+    commandEncoder.context.renderingStats().memTextures += textureByteSize;
     std::unique_ptr<gfx::TextureResource> resource =
-        std::make_unique<gl::TextureResource>(std::move(obj));
+        std::make_unique<gl::TextureResource>(std::move(obj), textureByteSize);
     commandEncoder.context.pixelStoreUnpack = { 1 };
     updateTextureResource(*resource, size, data, format, type);
     // We are using clamp to edge here since OpenGL ES doesn't allow GL_REPEAT on NPOT textures.
diff --git a/src/mbgl/gl/vertex_buffer_resource.cpp b/src/mbgl/gl/vertex_buffer_resource.cpp
new file mode 100644
index 0000000000..cddbdd43d0
--- /dev/null
+++ b/src/mbgl/gl/vertex_buffer_resource.cpp
@@ -0,0 +1,14 @@
+#include <mbgl/gl/context.hpp>
+#include <mbgl/gl/vertex_buffer_resource.hpp>
+
+namespace mbgl {
+namespace gl {
+
+VertexBufferResource::~VertexBufferResource() {
+    auto& stats = buffer.get_deleter().context.renderingStats();
+    stats.memVertexBuffers -= byteSize;
+    assert(stats.memVertexBuffers >= 0);
+}
+
+} // namespace gl
+} // namespace mbgl
\ No newline at end of file
diff --git a/src/mbgl/gl/vertex_buffer_resource.hpp b/src/mbgl/gl/vertex_buffer_resource.hpp
index 95e5e75d45..f9c599c757 100644
--- a/src/mbgl/gl/vertex_buffer_resource.hpp
+++ b/src/mbgl/gl/vertex_buffer_resource.hpp
@@ -8,10 +8,11 @@ namespace gl {
 
 class VertexBufferResource : public gfx::VertexBufferResource {
 public:
-    VertexBufferResource(UniqueBuffer&& buffer_) : buffer(std::move(buffer_)) {
-    }
+    VertexBufferResource(UniqueBuffer&& buffer_, int byteSize_) : buffer(std::move(buffer_)), byteSize(byteSize_) {}
+    ~VertexBufferResource();
 
     UniqueBuffer buffer;
+    int byteSize;
 };
 
 } // namespace gl