[core] fix zoom function evaluation for CrossFadedDDPupstream/line-crash-fix

4 files changed, 33 insertions, 8 deletions

diff --git a/src/mbgl/layout/pattern_layout.hpp b/src/mbgl/layout/pattern_layout.hpp
index 0ffac36b75..86d34d3074 100644
--- a/src/mbgl/layout/pattern_layout.hpp
+++ b/src/mbgl/layout/pattern_layout.hpp
@@ -22,6 +22,27 @@ public:
     PatternLayerMap patterns;
 };
 
+class PatternUtil {
+public:
+    static std::string getPatternForZoom(style::PropertyValue<std::string>& value, float z)  {
+        return value.match(
+            [&] (const style::Undefined&) {
+                return std::string("");
+            },
+            [&] (const std::string& _value) {
+                return _value;
+            },
+            [&] (const style::PropertyExpression<std::string>& expression) {
+                if (expression.isFeatureConstant() && !expression.isZoomConstant()) {
+                    return expression.evaluate(z);
+                } else {
+                    return std::string("");
+                }
+            }
+        );
+    }
+};
+
 template <class B>
 class PatternLayout : public Layout {
 public:
@@ -35,10 +56,10 @@ public:
                     zoom(parameters.tileID.overscaledZ),
                     overscaling(parameters.tileID.overscaleFactor()),
                     hasPattern(false) {
-
         using PatternLayer = typename B::RenderLayerType;
         const auto renderLayer = layers.at(0)->as<PatternLayer>();
         const typename PatternLayer::StyleLayerImpl& leader = renderLayer->impl();
+
         layout = leader.layout.evaluate(PropertyEvaluationParameters(zoom));
         sourceLayerID = leader.sourceLayer;
         groupID = renderLayer->getID();
@@ -54,8 +75,12 @@ public:
                 hasPattern = true;
             } else if (!constantPattern.to.empty()){
                 hasPattern = true;
+                auto patternPropertyValue = layer->as<PatternLayer>()->unevaluated.template get<typename PatternLayer::PatternProperty>().getValue();
+                std::string lowZoom = PatternUtil::getPatternForZoom(patternPropertyValue, zoom - 1);
+                std::string highZoom = PatternUtil::getPatternForZoom(patternPropertyValue, zoom + 1);
+                patternDependencies.emplace(highZoom, ImageType::Pattern);
                 patternDependencies.emplace(constantPattern.to, ImageType::Pattern);
-                patternDependencies.emplace(constantPattern.from, ImageType::Pattern);
+                patternDependencies.emplace(lowZoom, ImageType::Pattern);
             }
         }
 
@@ -119,7 +144,6 @@ public:
     std::map<std::string, typename B::PossiblyEvaluatedPaintProperties> layerPaintProperties;
     const std::string bucketLeaderID;
 
-
 private:
     const std::unique_ptr<GeometryTileLayer> sourceLayer;
     std::vector<PatternFeature> features;
diff --git a/src/mbgl/renderer/data_driven_property_evaluator.hpp b/src/mbgl/renderer/data_driven_property_evaluator.hpp
index d65ac36713..6e2cfbbd07 100644
--- a/src/mbgl/renderer/data_driven_property_evaluator.hpp
+++ b/src/mbgl/renderer/data_driven_property_evaluator.hpp
@@ -62,8 +62,10 @@ public:
         if (!expression.isFeatureConstant()) {
             return ResultType(expression);
         } else {
-            const T evaluated = expression.evaluate(floor(parameters.z));
-            return ResultType(calculate(evaluated, evaluated, evaluated));
+            const T min = expression.evaluate(floor(parameters.z - 1));
+            const T mid = expression.evaluate(floor(parameters.z));
+            const T max = expression.evaluate(floor(parameters.z + 1));
+            return ResultType(calculate(min, mid, max));
         }
     }
 
diff --git a/src/mbgl/renderer/layers/render_line_layer.cpp b/src/mbgl/renderer/layers/render_line_layer.cpp
index e499de8c4e..9ecac3fcc8 100644
--- a/src/mbgl/renderer/layers/render_line_layer.cpp
+++ b/src/mbgl/renderer/layers/render_line_layer.cpp
@@ -54,7 +54,6 @@ void RenderLineLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     unevaluated.evaluate(parameters).concat(extra.evaluate(dashArrayParams)));
 
     crossfade = parameters.getCrossfadeParameters();
-
     passes = (evaluated.get<style::LineOpacity>().constantOr(1.0) > 0
               && evaluated.get<style::LineColor>().constantOr(Color::black()).a > 0
               && evaluated.get<style::LineWidth>().constantOr(1.0) > 0)
@@ -145,7 +144,7 @@ void RenderLineLayer::render(PaintParameters& parameters, RenderSource*) {
             optional<ImagePosition> posA = geometryTile.getPattern(linePatternValue.from);
             optional<ImagePosition> posB = geometryTile.getPattern(linePatternValue.to);
             // if pattern property is constant and patterns aren't available, don't draw
-            if (!linePatternValue.to.empty() && (!posA || !posB)) continue;
+            if (!linePatternValue.to.empty() && (!posA && !posB)) continue;
 
             const auto& binders = bucket.paintPropertyBinders.at(getID());
             binders.setPatternParameters(posA, posB, crossfade);
diff --git a/src/mbgl/renderer/paint_property_binder.hpp b/src/mbgl/renderer/paint_property_binder.hpp
index 3f801d09ff..31abec68a9 100644
--- a/src/mbgl/renderer/paint_property_binder.hpp
+++ b/src/mbgl/renderer/paint_property_binder.hpp
@@ -134,7 +134,7 @@ public:
     void upload(gl::Context&) override {}
 
     void setPatternParameters(const optional<ImagePosition>& posA, const optional<ImagePosition>& posB, CrossfadeParameters&) override {
-        if (!posA || !posB) {
+        if (!posA && !posB) {
             return;
         } else {
             constantPatternPositions = std::tuple<std::array<uint16_t, 4>, std::array<uint16_t, 4>> { posB->tlbr(), posA->tlbr() };