[node, tests] Consolidate headless rendering logic in HeadlessFrontend

8 files changed, 183 insertions, 173 deletions

diff --git a/platform/default/mbgl/gl/headless_backend.cpp b/platform/default/mbgl/gl/headless_backend.cpp
index 82660331fa..a854fe9731 100644
--- a/platform/default/mbgl/gl/headless_backend.cpp
+++ b/platform/default/mbgl/gl/headless_backend.cpp
@@ -9,10 +9,26 @@
 
 namespace mbgl {
 
-HeadlessBackend::HeadlessBackend() = default;
+class HeadlessBackend::View {
+public:
+    View(gl::Context& context, Size size)
+        : color(context.createRenderbuffer<gl::RenderbufferType::RGBA>(size)),
+          depthStencil(context.createRenderbuffer<gl::RenderbufferType::DepthStencil>(size)),
+          framebuffer(context.createFramebuffer(color, depthStencil)) {
+    }
+
+    gl::Renderbuffer<gl::RenderbufferType::RGBA> color;
+    gl::Renderbuffer<gl::RenderbufferType::DepthStencil> depthStencil;
+    gl::Framebuffer framebuffer;
+};
+
+HeadlessBackend::HeadlessBackend(Size size_)
+    : size(size_) {
+}
 
 HeadlessBackend::~HeadlessBackend() {
     BackendScope guard { *this };
+    view.reset();
     context.reset();
 }
 
@@ -36,8 +52,29 @@ void HeadlessBackend::deactivate() {
     active = false;
 }
 
+void HeadlessBackend::bind() {
+    gl::Context& context_ = getContext();
+
+    if (!view) {
+        view = std::make_unique<View>(context_, size);
+    }
+
+    context_.bindFramebuffer = view->framebuffer.framebuffer;
+    context_.scissorTest = false;
+    context_.viewport = { 0, 0, size };
+}
+
 void HeadlessBackend::updateAssumedState() {
     // no-op
 }
 
+void HeadlessBackend::setSize(Size size_) {
+    size = size_;
+    view.reset();
+}
+
+PremultipliedImage HeadlessBackend::readStillImage() {
+    return getContext().readFramebuffer<PremultipliedImage>(size);
+}
+
 } // namespace mbgl
diff --git a/platform/default/mbgl/gl/headless_backend.hpp b/platform/default/mbgl/gl/headless_backend.hpp
index 5f39eb9f00..d845e9930c 100644
--- a/platform/default/mbgl/gl/headless_backend.hpp
+++ b/platform/default/mbgl/gl/headless_backend.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/map/view.hpp>
 #include <mbgl/renderer/renderer_backend.hpp>
 
 #include <memory>
@@ -9,13 +10,17 @@ namespace mbgl {
 
 class HeadlessDisplay;
 
-class HeadlessBackend : public RendererBackend {
+class HeadlessBackend : public View, public RendererBackend {
 public:
-    HeadlessBackend();
+    HeadlessBackend(Size = { 256, 256 });
     ~HeadlessBackend() override;
 
+    void bind() override;
     void updateAssumedState() override;
 
+    void setSize(Size);
+    PremultipliedImage readStillImage();
+
     struct Impl {
         virtual ~Impl() = default;
         virtual void activateContext() = 0;
@@ -37,7 +42,12 @@ private:
     std::shared_ptr<HeadlessDisplay> display;
     std::unique_ptr<Impl> impl;
 
+    Size size;
+    float pixelRatio;
     bool active = false;
+
+    class View;
+    std::unique_ptr<View> view;
 };
 
 } // namespace mbgl
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
diff --git a/platform/default/mbgl/gl/headless_frontend.hpp b/platform/default/mbgl/gl/headless_frontend.hpp
new file mode 100644
index 0000000000..18d0d2527b
--- /dev/null
+++ b/platform/default/mbgl/gl/headless_frontend.hpp
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <mbgl/renderer/renderer_frontend.hpp>
+#include <mbgl/gl/headless_backend.hpp>
+#include <mbgl/util/async_task.hpp>
+
+#include <memory>
+
+namespace mbgl {
+
+class FileSource;
+class Scheduler;
+class Renderer;
+class RendererBackend;
+class Map;
+
+class HeadlessFrontend : public RendererFrontend {
+public:
+    HeadlessFrontend(float pixelRatio_, FileSource&, Scheduler&);
+    HeadlessFrontend(Size, float pixelRatio_, FileSource&, Scheduler&);
+    ~HeadlessFrontend() override;
+
+    void reset() override;
+    void update(std::shared_ptr<UpdateParameters>) override;
+    void setObserver(RendererObserver&) override;
+
+    Size getSize() const;
+    void setSize(Size);
+
+    Renderer* getRenderer();
+    RendererBackend* getBackend();
+
+    PremultipliedImage readStillImage();
+    PremultipliedImage render(Map&);
+
+private:
+    Size size;
+    float pixelRatio;
+
+    HeadlessBackend backend;
+    util::AsyncTask asyncInvalidate;
+
+    std::unique_ptr<Renderer> renderer;
+    std::shared_ptr<UpdateParameters> updateParameters;
+};
+
+} // namespace mbgl
diff --git a/platform/default/mbgl/gl/offscreen_view.cpp b/platform/default/mbgl/gl/offscreen_view.cpp
deleted file mode 100644
index e7cf7cffe5..0000000000
--- a/platform/default/mbgl/gl/offscreen_view.cpp
+++ /dev/null
@@ -1,65 +0,0 @@
-#include <mbgl/gl/offscreen_view.hpp>
-#include <mbgl/gl/context.hpp>
-#include <mbgl/gl/framebuffer.hpp>
-#include <mbgl/gl/renderbuffer.hpp>
-#include <mbgl/util/optional.hpp>
-
-#include <cstring>
-#include <cassert>
-
-namespace mbgl {
-
-class OffscreenView::Impl {
-public:
-    Impl(gl::Context& context_, const Size size_) : context(context_), size(std::move(size_)) {
-        assert(!size.isEmpty());
-    }
-
-    void bind() {
-        if (!framebuffer) {
-            color = context.createRenderbuffer<gl::RenderbufferType::RGBA>(size);
-            depthStencil = context.createRenderbuffer<gl::RenderbufferType::DepthStencil>(size);
-            framebuffer = context.createFramebuffer(*color, *depthStencil);
-        } else {
-            context.bindFramebuffer = framebuffer->framebuffer;
-        }
-
-        context.scissorTest = false;
-        context.viewport = { 0, 0, size };
-    }
-
-    PremultipliedImage readStillImage() {
-        return context.readFramebuffer<PremultipliedImage>(size);
-    }
-
-    const Size& getSize() const {
-        return size;
-    }
-
-private:
-    gl::Context& context;
-    const Size size;
-    optional<gl::Framebuffer> framebuffer;
-    optional<gl::Renderbuffer<gl::RenderbufferType::RGBA>> color;
-    optional<gl::Renderbuffer<gl::RenderbufferType::DepthStencil>> depthStencil;
-};
-
-OffscreenView::OffscreenView(gl::Context& context, const Size size)
-    : impl(std::make_unique<Impl>(context, std::move(size))) {
-}
-
-OffscreenView::~OffscreenView() = default;
-
-void OffscreenView::bind() {
-    impl->bind();
-}
-
-PremultipliedImage OffscreenView::readStillImage() {
-    return impl->readStillImage();
-}
-
-const Size& OffscreenView::getSize() const {
-    return impl->getSize();
-}
-
-} // namespace mbgl
diff --git a/platform/default/mbgl/gl/offscreen_view.hpp b/platform/default/mbgl/gl/offscreen_view.hpp
deleted file mode 100644
index eb888272e5..0000000000
--- a/platform/default/mbgl/gl/offscreen_view.hpp
+++ /dev/null
@@ -1,28 +0,0 @@
-#pragma once
-
-#include <mbgl/map/view.hpp>
-#include <mbgl/util/image.hpp>
-
-namespace mbgl {
-
-namespace gl {
-class Context;
-} // namespace gl
-
-class OffscreenView : public View {
-public:
-    OffscreenView(gl::Context&, Size size = { 256, 256 });
-    ~OffscreenView() override;
-
-    void bind() override;
-
-    PremultipliedImage readStillImage();
-
-    const Size& getSize() const;
-
-private:
-    class Impl;
-    const std::unique_ptr<Impl> impl;
-};
-
-} // namespace mbgl
diff --git a/platform/default/mbgl/renderer/async_renderer_frontend.cpp b/platform/default/mbgl/renderer/async_renderer_frontend.cpp
deleted file mode 100644
index 230d0bb820..0000000000
--- a/platform/default/mbgl/renderer/async_renderer_frontend.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-#include "async_renderer_frontend.hpp"
-
-#include <mbgl/renderer/backend_scope.hpp>
-#include <mbgl/renderer/renderer.hpp>
-
-namespace mbgl {
-
-AsyncRendererFrontend::AsyncRendererFrontend(std::unique_ptr<Renderer> renderer_, RendererBackend& backend, View& view_)
-    : renderer(std::move(renderer_))
-    , view(view_)
-    , asyncInvalidate([&] {
-        if (renderer && updateParameters) {
-            BackendScope guard { backend };
-            renderer->render(view, *updateParameters);
-        }
-    }) {
-}
-
-AsyncRendererFrontend::~AsyncRendererFrontend() = default;
-
-void AsyncRendererFrontend::reset() {
-    assert(renderer);
-    renderer.reset();
-}
-
-void AsyncRendererFrontend::update(std::shared_ptr<UpdateParameters> updateParameters_) {
-    updateParameters = updateParameters_;
-    asyncInvalidate.send();
-}
-
-void AsyncRendererFrontend::setObserver(RendererObserver& observer_) {
-    assert(renderer);
-    renderer->setObserver(&observer_);
-}
-    
-Renderer* AsyncRendererFrontend::getRenderer() {
-    assert(renderer);
-    return renderer.get();
-}
-
-} // namespace mbgl
diff --git a/platform/default/mbgl/renderer/async_renderer_frontend.hpp b/platform/default/mbgl/renderer/async_renderer_frontend.hpp
deleted file mode 100644
index e1b2f780cd..0000000000
--- a/platform/default/mbgl/renderer/async_renderer_frontend.hpp
+++ /dev/null
@@ -1,36 +0,0 @@
-#pragma once
-
-#include <mbgl/map/view.hpp>
-#include <mbgl/renderer/renderer_frontend.hpp>
-#include <mbgl/util/async_task.hpp>
-
-#include <memory>
-#include <vector>
-
-namespace mbgl {
-    
-class Renderer;
-class RendererBackend;
-
-// Default implementation for RendererFrontend
-class AsyncRendererFrontend : public mbgl::RendererFrontend {
-public:
-    AsyncRendererFrontend(std::unique_ptr<Renderer>, RendererBackend&, View&);
-    ~AsyncRendererFrontend() override;
-
-    void reset() override;
-
-    void update(std::shared_ptr<UpdateParameters> updateParameters_) override;
-    
-    void setObserver(RendererObserver& observer_) override;
-    
-    Renderer* getRenderer();
-    
-private:
-    std::unique_ptr<Renderer> renderer;
-    View& view;
-    std::shared_ptr<UpdateParameters> updateParameters;
-    util::AsyncTask asyncInvalidate;
-};
-    
-} // namespace mbgl