2 files changed, 138 insertions, 0 deletions
diff --git a/src/mbgl/renderer/buckets/heatmap_bucket.cpp b/src/mbgl/renderer/buckets/heatmap_bucket.cpp
new file mode 100644
index 0000000000..a185e04ad2
--- /dev/null
+++ b/src/mbgl/renderer/buckets/heatmap_bucket.cpp
@@ -0,0 +1,98 @@
+#include <mbgl/renderer/buckets/heatmap_bucket.hpp>
+#include <mbgl/renderer/bucket_parameters.hpp>
+#include <mbgl/programs/heatmap_program.hpp>
+#include <mbgl/style/layers/heatmap_layer_impl.hpp>
+#include <mbgl/renderer/layers/render_heatmap_layer.hpp>
+#include <mbgl/util/constants.hpp>
+#include <mbgl/util/math.hpp>
+
+namespace mbgl {
+
+using namespace style;
+
+HeatmapBucket::HeatmapBucket(const BucketParameters& parameters, const std::vector<const RenderLayer*>& layers)
+    : mode(parameters.mode) {
+    for (const auto& layer : layers) {
+        paintPropertyBinders.emplace(
+            std::piecewise_construct,
+            std::forward_as_tuple(layer->getID()),
+            std::forward_as_tuple(
+                layer->as<RenderHeatmapLayer>()->evaluated,
+                parameters.tileID.overscaledZ));
+    }
+}
+
+void HeatmapBucket::upload(gl::Context& context) {
+    vertexBuffer = context.createVertexBuffer(std::move(vertices));
+    indexBuffer = context.createIndexBuffer(std::move(triangles));
+
+    for (auto& pair : paintPropertyBinders) {
+        pair.second.upload(context);
+    }
+
+    uploaded = true;
+}
+
+bool HeatmapBucket::hasData() const {
+    return !segments.empty();
+}
+
+void HeatmapBucket::addFeature(const GeometryTileFeature& feature,
+                              const GeometryCollection& geometry) {
+    constexpr const uint16_t vertexLength = 4;
+
+    for (auto& points : geometry) {
+        for(auto& point : points) {
+            auto x = point.x;
+            auto y = point.y;
+
+            // Do not include points that are outside the tile boundaries.
+            // Include all points in Still mode. You need to include points from
+            // neighbouring tiles so that they are not clipped at tile boundaries.
+            if ((mode == MapMode::Continuous) &&
+                (x < 0 || x >= util::EXTENT || y < 0 || y >= util::EXTENT)) continue;
+
+            if (segments.empty() || segments.back().vertexLength + vertexLength > std::numeric_limits<uint16_t>::max()) {
+                // Move to a new segments because the old one can't hold the geometry.
+                segments.emplace_back(vertices.vertexSize(), triangles.indexSize());
+            }
+
+            // this geometry will be of the Point type, and we'll derive
+            // two triangles from it.
+            //
+            // ┌─────────┐
+            // │ 4     3 │
+            // │         │
+            // │ 1     2 │
+            // └─────────┘
+            //
+            vertices.emplace_back(HeatmapProgram::vertex(point, -1, -1)); // 1
+            vertices.emplace_back(HeatmapProgram::vertex(point,  1, -1)); // 2
+            vertices.emplace_back(HeatmapProgram::vertex(point,  1,  1)); // 3
+            vertices.emplace_back(HeatmapProgram::vertex(point, -1,  1)); // 4
+
+            auto& segment = segments.back();
+            assert(segment.vertexLength <= std::numeric_limits<uint16_t>::max());
+            uint16_t index = segment.vertexLength;
+
+            // 1, 2, 3
+            // 1, 4, 3
+            triangles.emplace_back(index, index + 1, index + 2);
+            triangles.emplace_back(index, index + 3, index + 2);
+
+            segment.vertexLength += vertexLength;
+            segment.indexLength += 6;
+        }
+    }
+
+    for (auto& pair : paintPropertyBinders) {
+        pair.second.populateVertexVectors(feature, vertices.vertexSize());
+    }
+}
+
+float HeatmapBucket::getQueryRadius(const RenderLayer& layer) const {
+    (void)layer;
+    return 0;
+}
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/buckets/heatmap_bucket.hpp b/src/mbgl/renderer/buckets/heatmap_bucket.hpp
new file mode 100644
index 0000000000..3b9f1edb81
--- /dev/null
+++ b/src/mbgl/renderer/buckets/heatmap_bucket.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <mbgl/renderer/bucket.hpp>
+#include <mbgl/map/mode.hpp>
+#include <mbgl/tile/geometry_tile_data.hpp>
+#include <mbgl/gl/vertex_buffer.hpp>
+#include <mbgl/gl/index_buffer.hpp>
+#include <mbgl/programs/segment.hpp>
+#include <mbgl/programs/heatmap_program.hpp>
+#include <mbgl/style/layers/heatmap_layer_properties.hpp>
+
+namespace mbgl {
+
+class BucketParameters;
+
+class HeatmapBucket : public Bucket {
+public:
+    HeatmapBucket(const BucketParameters&, const std::vector<const RenderLayer*>&);
+
+    void addFeature(const GeometryTileFeature&,
+                    const GeometryCollection&) override;
+    bool hasData() const override;
+
+    void upload(gl::Context&) override;
+
+    float getQueryRadius(const RenderLayer&) const override;
+
+    gl::VertexVector<HeatmapLayoutVertex> vertices;
+    gl::IndexVector<gl::Triangles> triangles;
+    SegmentVector<HeatmapAttributes> segments;
+
+    optional<gl::VertexBuffer<HeatmapLayoutVertex>> vertexBuffer;
+    optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
+
+    std::map<std::string, HeatmapProgram::PaintPropertyBinders> paintPropertyBinders;
+
+    const MapMode mode;
+};
+
+} // namespace mbgl