Preserve depth buffer between 3D layers + optimize render order

include/mbgl/renderer/renderer_backend.hpp

@@ -35,6 +35,8 @@ class RendererBackend {
     // set to the current state.
     virtual void bind() = 0;
 
+    virtual Size getFramebufferSize() const = 0;
+
 protected:
     // Called with the name of an OpenGL extension that should be loaded. RendererBackend implementations
     // must call the API-specific version that obtains the function pointer for this function,

platform/android/src/native_map_view.cpp

@@ -115,6 +115,10 @@ void NativeMapView::bind() {
     setViewport(0, 0, getFramebufferSize());
 }
 
+mbgl::Size NativeMapView::getFramebufferSize() const {
+    return { static_cast<uint32_t>(fbWidth), static_cast<uint32_t>(fbHeight) };
+}
+
 /**
  * From mbgl::RendererBackend.
  */
@@ -1428,10 +1432,6 @@ void NativeMapView::_destroySurface() {
     }
 }
 
-mbgl::Size NativeMapView::getFramebufferSize() const {
-    return { static_cast<uint32_t>(fbWidth), static_cast<uint32_t>(fbHeight) };
-}
-
 void NativeMapView::updateAssumedState() {
     assumeFramebufferBinding(0);
     assumeViewport(0, 0, getFramebufferSize());

platform/android/src/native_map_view.hpp

@@ -58,6 +58,9 @@ class NativeMapView : public RendererBackend, public MapObserver {
     // mbgl::RendererBackend //
 
     void bind() override;
+
+    mbgl::Size getFramebufferSize() const override;
+
     void updateAssumedState() override;
 
     // Deprecated //
@@ -282,8 +285,6 @@ class NativeMapView : public RendererBackend, public MapObserver {
 
     EGLConfig chooseConfig(const EGLConfig configs[], EGLint numConfigs);
 
-    mbgl::Size getFramebufferSize() const;
-
     void updateFps();
 
 private:

platform/default/mbgl/gl/headless_backend.cpp

@@ -64,6 +64,10 @@ void HeadlessBackend::bind() {
     context_.viewport = { 0, 0, size };
 }
 
+Size HeadlessBackend::getFramebufferSize() const {
+    return size;
+}
+
 void HeadlessBackend::updateAssumedState() {
     // no-op
 }

platform/default/mbgl/gl/headless_backend.hpp

@@ -15,6 +15,7 @@ class HeadlessBackend : public RendererBackend {
     ~HeadlessBackend() override;
 
     void bind() override;
+    Size getFramebufferSize() const override;
     void updateAssumedState() override;
 
     void setSize(Size);

platform/glfw/glfw_view.hpp

@@ -37,7 +37,7 @@ class GLFWView : public mbgl::RendererBackend, public mbgl::MapObserver {
     void invalidate();
 
     mbgl::Size getSize() const;
-    mbgl::Size getFramebufferSize() const;
+    mbgl::Size getFramebufferSize() const override;
 
     // mbgl::RendererBackend implementation
     void bind() override;

platform/ios/src/MGLMapView.mm

@@ -5464,6 +5464,10 @@ void bind() override {
         }
     }
 
+    mbgl::Size getFramebufferSize() const override {
+        return nativeView.framebufferSize;
+    }
+
     void onCameraWillChange(mbgl::MapObserver::CameraChangeMode mode) override {
         bool animated = mode == mbgl::MapObserver::CameraChangeMode::Animated;
         [nativeView cameraWillChangeAnimated:animated];

platform/macos/src/MGLMapView.mm

@@ -2883,6 +2883,10 @@ void bind() override {
         setViewport(0, 0, nativeView.framebufferSize);
     }
 
+    mbgl::Size getFramebufferSize() const override {
+        return nativeView.framebufferSize;
+    }
+
     mbgl::PremultipliedImage readStillImage() {
         return readFramebuffer(nativeView.framebufferSize);
     }

platform/node/test/ignores.json

@@ -17,7 +17,6 @@
   "render-tests/debug/tile": "https://github.com/mapbox/mapbox-gl-native/issues/3841",
   "render-tests/extent/1024-circle": "needs investigation",
   "render-tests/extent/1024-symbol": "needs investigation",
-  "render-tests/fill-extrusion-multiple/multiple": "https://github.com/mapbox/mapbox-gl-native/issues/9894",
   "render-tests/fill-extrusion-pattern/@2x": "https://github.com/mapbox/mapbox-gl-js/issues/3327",
   "render-tests/fill-extrusion-pattern/function-2": "https://github.com/mapbox/mapbox-gl-js/issues/3327",
   "render-tests/fill-extrusion-pattern/function": "https://github.com/mapbox/mapbox-gl-js/issues/3327",

platform/qt/src/qmapboxgl.cpp

@@ -1505,7 +1505,7 @@ QMapboxGLPrivate::QMapboxGLPrivate(QMapboxGL *q, const QMapboxGLSettings &settin
                                              static_cast<mbgl::GLContextMode>(settings.contextMode())),
             *this);
     connect(frontend.get(), SIGNAL(updated()), this, SLOT(invalidate()));
-    
+
     mapObj = std::make_unique<mbgl::Map>(
             *frontend,
             *this, sanitizedSize(size),
@@ -1528,18 +1528,18 @@ QMapboxGLPrivate::~QMapboxGLPrivate()
 {
 }
 
-mbgl::Size QMapboxGLPrivate::framebufferSize() const {
+mbgl::Size QMapboxGLPrivate::getFramebufferSize() const {
     return sanitizedSize(fbSize);
 }
 
 void QMapboxGLPrivate::updateAssumedState() {
     assumeFramebufferBinding(fbObject);
-    assumeViewport(0, 0, framebufferSize());
+    assumeViewport(0, 0, getFramebufferSize());
 }
 
 void QMapboxGLPrivate::bind() {
     setFramebufferBinding(fbObject);
-    setViewport(0, 0, framebufferSize());
+    setViewport(0, 0, getFramebufferSize());
 }
 
 void QMapboxGLPrivate::invalidate()

platform/qt/src/qmapboxgl_p.hpp

@@ -20,10 +20,10 @@ class QMapboxGLPrivate : public QObject, public mbgl::RendererBackend, public mb
     explicit QMapboxGLPrivate(QMapboxGL *, const QMapboxGLSettings &, const QSize &size, qreal pixelRatio);
     virtual ~QMapboxGLPrivate();
 
-    mbgl::Size framebufferSize() const;
 
     // mbgl::RendererBackend implementation.
     void bind() final;
+    mbgl::Size getFramebufferSize() const final;
     void updateAssumedState() final;
     void activate() final {}
     void deactivate() final {}

src/mbgl/gl/context.cpp

@@ -457,6 +457,9 @@ Framebuffer Context::createFramebuffer(const Texture& color) {
 Framebuffer
 Context::createFramebuffer(const Texture& color,
                            const Renderbuffer<RenderbufferType::DepthComponent>& depthTarget) {
+    if (color.size != depthTarget.size) {
+        throw std::runtime_error("Renderbuffer size mismatch");
+    }
     auto fbo = createFramebuffer();
     bindFramebuffer = fbo;
     MBGL_CHECK_ERROR(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color.texture, 0));

src/mbgl/gl/renderbuffer.hpp

@@ -9,9 +9,23 @@ namespace gl {
 template <RenderbufferType renderbufferType>
 class Renderbuffer {
 public:
+    Renderbuffer(Size size_, UniqueRenderbuffer renderbuffer_, bool dirty_ = false)
+        : size(std::move(size_)), renderbuffer(std::move(renderbuffer_)), dirty(dirty_) {
+    }
+
     using type = std::integral_constant<RenderbufferType, renderbufferType>;
     Size size;
-    gl::UniqueRenderbuffer renderbuffer;
+    UniqueRenderbuffer renderbuffer;
+
+    void shouldClear(bool clear) {
+        dirty = clear;
+    }
+    bool needsClearing() {
+        return dirty;
+    }
+
+private:
+    bool dirty;
 };
 
 } // namespace gl

src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp

@@ -37,8 +37,9 @@ void RenderFillExtrusionLayer::transition(const TransitionParameters& parameters
 void RenderFillExtrusionLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
-    passes = (evaluated.get<style::FillExtrusionOpacity>() > 0) ? RenderPass::Translucent
-                                                         : RenderPass::None;
+    passes = (evaluated.get<style::FillExtrusionOpacity>() > 0)
+                 ? (RenderPass::Translucent | RenderPass::Pass3D)
+                 : RenderPass::None;
 }
 
 bool RenderFillExtrusionLayer::hasTransition() const {
@@ -50,113 +51,100 @@ void RenderFillExtrusionLayer::render(PaintParameters& parameters, RenderSource*
         return;
     }
 
-    const auto size = parameters.context.viewport.getCurrentValue().size;
+    if (parameters.pass == RenderPass::Pass3D) {
+        const auto& size = parameters.staticData.backendSize;
 
-    if (!parameters.staticData.extrusionTexture || parameters.staticData.extrusionTexture->getSize() != size) {
-        parameters.staticData.extrusionTexture = OffscreenTexture(parameters.context, size, OffscreenTextureAttachment::Depth);
-    }
-
-    parameters.staticData.extrusionTexture->bind();
-
-    parameters.context.setStencilMode(gl::StencilMode::disabled());
-    parameters.context.setDepthMode(parameters.depthModeForSublayer(0, gl::DepthMode::ReadWrite));
-    parameters.context.clear(Color{ 0.0f, 0.0f, 0.0f, 0.0f }, 1.0f, {});
-
-    if (evaluated.get<FillExtrusionPattern>().from.empty()) {
-        for (const RenderTile& tile : renderTiles) {
-            assert(dynamic_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl)));
-            FillExtrusionBucket& bucket = *reinterpret_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl));
-
-            parameters.programs.fillExtrusion.get(evaluated).draw(
-                parameters.context,
-                gl::Triangles(),
-                parameters.depthModeForSublayer(0, gl::DepthMode::ReadWrite),
-                gl::StencilMode::disabled(),
-                parameters.colorModeForRenderPass(),
-                FillExtrusionUniforms::values(
-                    tile.translatedClipMatrix(evaluated.get<FillExtrusionTranslate>(),
-                                              evaluated.get<FillExtrusionTranslateAnchor>(),
-                                              parameters.state),
-                    parameters.state,
-                    parameters.evaluatedLight
-                ),
-                *bucket.vertexBuffer,
-                *bucket.indexBuffer,
-                bucket.triangleSegments,
-                bucket.paintPropertyBinders.at(getID()),
-                evaluated,
-                parameters.state.getZoom(),
-                getID());
+        if (!renderTexture || renderTexture->getSize() != size) {
+            renderTexture = OffscreenTexture(parameters.context, size, *parameters.staticData.depthRenderbuffer);
         }
-    } else {
-        optional<ImagePosition> imagePosA = parameters.imageManager.getPattern(evaluated.get<FillExtrusionPattern>().from);
-        optional<ImagePosition> imagePosB = parameters.imageManager.getPattern(evaluated.get<FillExtrusionPattern>().to);
 
-        if (!imagePosA || !imagePosB) {
-            return;
+        renderTexture->bind();
+
+        optional<float> depthClearValue = {};
+        if (parameters.staticData.depthRenderbuffer->needsClearing()) depthClearValue = 1.0;
+        // Flag the depth buffer as no longer needing to be cleared for the remainder of this pass.
+        parameters.staticData.depthRenderbuffer->shouldClear(false);
+
+        parameters.context.setStencilMode(gl::StencilMode::disabled());
+        parameters.context.clear(Color{ 0.0f, 0.0f, 0.0f, 0.0f }, depthClearValue, {});
+
+        if (evaluated.get<FillExtrusionPattern>().from.empty()) {
+            for (const RenderTile& tile : renderTiles) {
+                assert(dynamic_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl)));
+                FillExtrusionBucket& bucket =
+                    *reinterpret_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl));
+
+                parameters.programs.fillExtrusion.get(evaluated).draw(
+                    parameters.context, gl::Triangles(),
+                    parameters.depthModeFor3D(gl::DepthMode::ReadWrite),
+                    gl::StencilMode::disabled(), parameters.colorModeForRenderPass(),
+                    FillExtrusionUniforms::values(
+                        tile.translatedClipMatrix(evaluated.get<FillExtrusionTranslate>(),
+                                                  evaluated.get<FillExtrusionTranslateAnchor>(),
+                                                  parameters.state),
+                        parameters.state, parameters.evaluatedLight),
+                    *bucket.vertexBuffer, *bucket.indexBuffer, bucket.triangleSegments,
+                    bucket.paintPropertyBinders.at(getID()), evaluated, parameters.state.getZoom(),
+                    getID());
+            }
+        } else {
+            optional<ImagePosition> imagePosA =
+                parameters.imageManager.getPattern(evaluated.get<FillExtrusionPattern>().from);
+            optional<ImagePosition> imagePosB =
+                parameters.imageManager.getPattern(evaluated.get<FillExtrusionPattern>().to);
+
+            if (!imagePosA || !imagePosB) {
+                return;
+            }
+
+            parameters.imageManager.bind(parameters.context, 0);
+
+            for (const RenderTile& tile : renderTiles) {
+                assert(dynamic_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl)));
+                FillExtrusionBucket& bucket =
+                    *reinterpret_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl));
+
+                parameters.programs.fillExtrusionPattern.get(evaluated).draw(
+                    parameters.context, gl::Triangles(),
+                    parameters.depthModeFor3D(gl::DepthMode::ReadWrite),
+                    gl::StencilMode::disabled(), parameters.colorModeForRenderPass(),
+                    FillExtrusionPatternUniforms::values(
+                        tile.translatedClipMatrix(evaluated.get<FillExtrusionTranslate>(),
+                                                  evaluated.get<FillExtrusionTranslateAnchor>(),
+                                                  parameters.state),
+                        parameters.imageManager.getPixelSize(), *imagePosA, *imagePosB,
+                        evaluated.get<FillExtrusionPattern>(), tile.id, parameters.state,
+                        -std::pow(2, tile.id.canonical.z) / util::tileSize / 8.0f,
+                        parameters.evaluatedLight),
+                    *bucket.vertexBuffer, *bucket.indexBuffer, bucket.triangleSegments,
+                    bucket.paintPropertyBinders.at(getID()), evaluated, parameters.state.getZoom(),
+                    getID());
+            }
         }
 
-        parameters.imageManager.bind(parameters.context, 0);
-
-        for (const RenderTile& tile : renderTiles) {
-            assert(dynamic_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl)));
-            FillExtrusionBucket& bucket = *reinterpret_cast<FillExtrusionBucket*>(tile.tile.getBucket(*baseImpl));
-
-            parameters.programs.fillExtrusionPattern.get(evaluated).draw(
-                parameters.context,
-                gl::Triangles(),
-                parameters.depthModeForSublayer(0, gl::DepthMode::ReadWrite),
-                gl::StencilMode::disabled(),
-                parameters.colorModeForRenderPass(),
-                FillExtrusionPatternUniforms::values(
-                    tile.translatedClipMatrix(evaluated.get<FillExtrusionTranslate>(),
-                                              evaluated.get<FillExtrusionTranslateAnchor>(),
-                                              parameters.state),
-                    parameters.imageManager.getPixelSize(),
-                    *imagePosA,
-                    *imagePosB,
-                    evaluated.get<FillExtrusionPattern>(),
-                    tile.id,
-                    parameters.state,
-                    -std::pow(2, tile.id.canonical.z) / util::tileSize / 8.0f,
-                    parameters.evaluatedLight
-                ),
-                *bucket.vertexBuffer,
-                *bucket.indexBuffer,
-                bucket.triangleSegments,
-                bucket.paintPropertyBinders.at(getID()),
-                evaluated,
-                parameters.state.getZoom(),
-                getID());
-        }
-    }
+    } else if (parameters.pass == RenderPass::Translucent) {
+        parameters.context.bindTexture(renderTexture->getTexture());
 
-    parameters.backend.bind();
-    parameters.context.bindTexture(parameters.staticData.extrusionTexture->getTexture());
-
-    mat4 viewportMat;
-    matrix::ortho(viewportMat, 0, size.width, size.height, 0, 0, 1);
-
-    const Properties<>::PossiblyEvaluated properties;
-
-    parameters.programs.extrusionTexture.draw(
-        parameters.context,
-        gl::Triangles(),
-        gl::DepthMode::disabled(),
-        gl::StencilMode::disabled(),
-        parameters.colorModeForRenderPass(),
-        ExtrusionTextureProgram::UniformValues{
-            uniforms::u_matrix::Value{ viewportMat }, uniforms::u_world::Value{ size },
-            uniforms::u_image::Value{ 0 },
-            uniforms::u_opacity::Value{ evaluated.get<FillExtrusionOpacity>() }
-        },
-        parameters.staticData.extrusionTextureVertexBuffer,
-        parameters.staticData.quadTriangleIndexBuffer,
-        parameters.staticData.extrusionTextureSegments,
-        ExtrusionTextureProgram::PaintPropertyBinders{ properties, 0 },
-        properties,
-        parameters.state.getZoom(),
-        getID());
+        const auto& size = parameters.staticData.backendSize;
+
+        mat4 viewportMat;
+        matrix::ortho(viewportMat, 0, size.width, size.height, 0, 0, 1);
+
+        const Properties<>::PossiblyEvaluated properties;
+
+        parameters.programs.extrusionTexture.draw(
+            parameters.context, gl::Triangles(), gl::DepthMode::disabled(),
+            gl::StencilMode::disabled(), parameters.colorModeForRenderPass(),
+            ExtrusionTextureProgram::UniformValues{
+                uniforms::u_matrix::Value{ viewportMat }, uniforms::u_world::Value{ size },
+                uniforms::u_image::Value{ 0 },
+                uniforms::u_opacity::Value{ evaluated.get<FillExtrusionOpacity>() } },
+            parameters.staticData.extrusionTextureVertexBuffer,
+            parameters.staticData.quadTriangleIndexBuffer,
+            parameters.staticData.extrusionTextureSegments,
+            ExtrusionTextureProgram::PaintPropertyBinders{ properties, 0 }, properties,
+            parameters.state.getZoom(), getID());
+    }
 }
 
 bool RenderFillExtrusionLayer::queryIntersectsFeature(