1 files changed, 86 insertions, 0 deletions
diff --git a/platform/default/mbgl/gl/headless_frontend.cpp b/platform/default/mbgl/gl/headless_frontend.cpp
new file mode 100644
index 0000000000..3f34d8eeba
--- /dev/null
+++ b/platform/default/mbgl/gl/headless_frontend.cpp
@@ -0,0 +1,86 @@
+#include <mbgl/gl/headless_frontend.hpp>
+#include <mbgl/renderer/renderer.hpp>
+#include <mbgl/map/map.hpp>
+#include <mbgl/util/run_loop.hpp>
+
+namespace mbgl {
+
+HeadlessFrontend::HeadlessFrontend(float pixelRatio_, FileSource& fileSource, Scheduler& scheduler)
+    : HeadlessFrontend({ 256, 256 }, pixelRatio_, fileSource, scheduler) {
+}
+
+HeadlessFrontend::HeadlessFrontend(Size size_, float pixelRatio_, FileSource& fileSource, Scheduler& scheduler)
+    : size(size_),
+    pixelRatio(pixelRatio_),
+    backend({ static_cast<uint32_t>(size.width * pixelRatio),
+              static_cast<uint32_t>(size.height * pixelRatio) }),
+    asyncInvalidate([this] {
+        if (renderer && updateParameters) {
+            mbgl::BackendScope guard { backend };
+            renderer->render(backend, *updateParameters);
+        }
+    }),
+    renderer(std::make_unique<Renderer>(backend, pixelRatio, fileSource, scheduler)) {
+}
+
+HeadlessFrontend::~HeadlessFrontend() = default;
+
+void HeadlessFrontend::reset() {
+    assert(renderer);
+    renderer.reset();
+}
+
+void HeadlessFrontend::update(std::shared_ptr<UpdateParameters> updateParameters_) {
+    updateParameters = updateParameters_;
+    asyncInvalidate.send();
+}
+
+void HeadlessFrontend::setObserver(RendererObserver& observer_) {
+    assert(renderer);
+    renderer->setObserver(&observer_);
+}
+
+Size HeadlessFrontend::getSize() const {
+    return size;
+}
+
+Renderer* HeadlessFrontend::getRenderer() {
+    assert(renderer);
+    return renderer.get();
+}
+
+RendererBackend* HeadlessFrontend::getBackend() {
+    return &backend;
+}
+
+void HeadlessFrontend::setSize(Size size_) {
+    if (size != size_) {
+        size = size_;
+        backend.setSize({ static_cast<uint32_t>(size_.width * pixelRatio),
+                          static_cast<uint32_t>(size_.height * pixelRatio) });
+    }
+}
+
+PremultipliedImage HeadlessFrontend::readStillImage() {
+    return backend.readStillImage();
+}
+
+PremultipliedImage HeadlessFrontend::render(Map& map) {
+    PremultipliedImage result;
+
+    map.renderStill([&](std::exception_ptr error) {
+        if (error) {
+            std::rethrow_exception(error);
+        } else {
+            result = backend.readStillImage();
+        }
+    });
+
+    while (!result.valid()) {
+        util::RunLoop::Get()->runOnce();
+    }
+
+    return result;
+}
+
+} // namespace mbgl