[core] change approach to stencil clipping to (almost) match JS

4 files changed, 0 insertions, 242 deletions

diff --git a/src/mbgl/algorithm/covered_by_children.hpp b/src/mbgl/algorithm/covered_by_children.hpp
deleted file mode 100644
index fe5af3f3db..0000000000
--- a/src/mbgl/algorithm/covered_by_children.hpp
+++ /dev/null
@@ -1,39 +0,0 @@
-#pragma once
-
-#include <mbgl/tile/tile_id.hpp>
-
-namespace mbgl {
-namespace algorithm {
-
-template <typename Iterator>
-bool coveredByChildren(const UnwrappedTileID& id, Iterator it, const Iterator& end) {
-    for (const auto& child : id.children()) {
-        it = std::lower_bound(it, end, child, [](const auto& a, const auto& b) { return std::get<0>(a) < b; });
-
-        // Child is not present, neither its grandchildren.
-        if (it == end) {
-            return false;
-        }
-
-        // Child is not present, but its grandchildren are.
-        if (std::get<0>(*it) != child) {
-            // This child is not covered by its grandchildren.
-            if (!coveredByChildren(child, it, end)) {
-                return false;
-            }
-        }
-    }
-
-    // We looked at all four children (recursively) and verified that they're covered.
-    return true;
-}
-
-template <typename Container>
-bool coveredByChildren(const UnwrappedTileID& id, const Container& container) {
-    return coveredByChildren(
-        id, container.upper_bound(id),
-        container.lower_bound(UnwrappedTileID{ static_cast<int16_t>(id.wrap + 1), { 0, 0, 0 } }));
-}
-
-} // namespace algorithm
-} // namespace mbgl
diff --git a/src/mbgl/algorithm/generate_clip_ids.cpp b/src/mbgl/algorithm/generate_clip_ids.cpp
deleted file mode 100644
index aefa55b929..0000000000
--- a/src/mbgl/algorithm/generate_clip_ids.cpp
+++ /dev/null
@@ -1,76 +0,0 @@
-#include <mbgl/algorithm/generate_clip_ids_impl.hpp>
-#include <mbgl/algorithm/covered_by_children.hpp>
-
-#include <mbgl/util/std.hpp>
-
-#include <list>
-#include <vector>
-#include <bitset>
-#include <cassert>
-#include <algorithm>
-#include <iterator>
-
-namespace mbgl {
-namespace algorithm {
-
-ClipIDGenerator::Leaf::Leaf(ClipID& clip_) : clip(clip_) {
-}
-
-void ClipIDGenerator::Leaf::add(const CanonicalTileID& p) {
-    // Ensure that no already present child is a parent of the new p.
-    for (const auto& child : children) {
-        if (p.isChildOf(child)) {
-            return;
-        }
-    }
-    children.emplace(p);
-}
-
-bool ClipIDGenerator::Leaf::operator==(const Leaf& other) const {
-    return children == other.children;
-}
-
-std::map<UnwrappedTileID, ClipID> ClipIDGenerator::getClipIDs() const {
-    std::map<UnwrappedTileID, ClipID> clipIDs;
-
-    // Merge everything.
-    for (auto& pair : pool) {
-        auto& id = pair.first;
-        auto& leaf = pair.second;
-        auto res = clipIDs.emplace(id, leaf.clip);
-        if (!res.second) {
-            // Merge with the existing ClipID when there was already an element with the
-            // same tile ID.
-            res.first->second |= leaf.clip;
-        }
-    }
-
-    for (auto it = clipIDs.begin(); it != clipIDs.end(); ++it) {
-        auto& childId = it->first;
-        auto& childClip = it->second;
-
-        // Loop through all preceding stencils, and find all parents.
-
-        for (auto parentIt = std::reverse_iterator<decltype(it)>(it);
-             parentIt != clipIDs.rend(); ++parentIt) {
-            auto& parentId = parentIt->first;
-            if (childId.isChildOf(parentId)) {
-                // Once we have a parent, we add the bits  that this ID hasn't set yet.
-                const auto& parentClip = parentIt->second;
-                const auto mask = ~(childClip.mask & parentClip.mask);
-                childClip.reference |= mask & parentClip.reference;
-                childClip.mask |= parentClip.mask;
-            }
-        }
-    }
-
-    // Remove tiles that are entirely covered by children.
-    util::erase_if(clipIDs, [&](const auto& stencil) {
-        return algorithm::coveredByChildren(stencil.first, clipIDs);
-    });
-
-    return clipIDs;
-}
-
-} // namespace algorithm
-} // namespace mbgl
diff --git a/src/mbgl/algorithm/generate_clip_ids.hpp b/src/mbgl/algorithm/generate_clip_ids.hpp
deleted file mode 100644
index 6950433578..0000000000
--- a/src/mbgl/algorithm/generate_clip_ids.hpp
+++ /dev/null
@@ -1,36 +0,0 @@
-#pragma once
-
-#include <mbgl/tile/tile_id.hpp>
-#include <mbgl/util/clip_id.hpp>
-
-#include <set>
-#include <vector>
-#include <map>
-
-namespace mbgl {
-namespace algorithm {
-
-class ClipIDGenerator {
-private:
-    struct Leaf {
-        Leaf(ClipID&);
-        void add(const CanonicalTileID &p);
-        bool operator==(const Leaf &other) const;
-
-        std::set<CanonicalTileID> children;
-        ClipID& clip;
-    };
-
-    uint8_t bit_offset = 0;
-    std::multimap<UnwrappedTileID, Leaf> pool;
-
-public:
-    // The given vector must be sorted by id.
-    template <typename Renderable>
-    void update(std::vector<std::reference_wrapper<Renderable>> sortedRenderables);
-
-    std::map<UnwrappedTileID, ClipID> getClipIDs() const;
-};
-
-} // namespace algorithm
-} // namespace mbgl
diff --git a/src/mbgl/algorithm/generate_clip_ids_impl.hpp b/src/mbgl/algorithm/generate_clip_ids_impl.hpp
deleted file mode 100644
index a4af9c8cbb..0000000000
--- a/src/mbgl/algorithm/generate_clip_ids_impl.hpp
+++ /dev/null
@@ -1,91 +0,0 @@
-#pragma once
-
-#include <mbgl/algorithm/generate_clip_ids.hpp>
-#include <mbgl/math/log2.hpp>
-#include <mbgl/util/logging.hpp>
-
-namespace mbgl {
-namespace algorithm {
-
-template <typename Renderable>
-void ClipIDGenerator::update(std::vector<std::reference_wrapper<Renderable>> renderables) {
-    std::size_t size = 0;
-    assert(std::is_sorted(renderables.begin(), renderables.end(),
-        [](const Renderable& a, const Renderable& b) { return a.id < b.id; }));
-
-    const auto end = renderables.end();
-    for (auto it = renderables.begin(); it != end; ++it) {
-        auto& renderable = it->get();
-        if (!renderable.used || !renderable.needsClipping) {
-            continue;
-        }
-
-        renderable.clip = {};
-        Leaf leaf{ renderable.clip };
-
-        // Try to add all remaining ids as children. We sorted the tile list
-        // by z earlier, so all preceding items cannot be children of the current
-        // tile. We also compute the lower bound of the next wrap, because items of the next wrap
-        // can never be children of the current wrap.
-        auto child_it = std::next(it);
-        const auto children_end = std::lower_bound(
-            child_it, end, UnwrappedTileID{ static_cast<int16_t>(renderable.id.wrap + 1), { 0, 0, 0 } },
-            [](auto& a, auto& b) { return a.get().id < b; });
-        for (; child_it != children_end; ++child_it) {
-            auto& childTileID = child_it->get().id;
-            if (childTileID.isChildOf(it->get().id)) {
-                leaf.add(childTileID.canonical);
-            }
-        }
-
-        // Find a leaf with matching children.
-        for (auto its = pool.equal_range(renderable.id); its.first != its.second; ++its.first) {
-            auto& existing = its.first->second;
-            if (existing == leaf) {
-                leaf.clip = existing.clip;
-                break;
-            }
-        }
-        if (leaf.clip.reference.none()) {
-            // We haven't found an existing clip ID
-            size++;
-        }
-
-        pool.emplace(renderable.id, std::move(leaf));
-    }
-
-    if (size > 0) {
-        const uint32_t bit_count = util::ceil_log2(size + 1);
-        const std::bitset<8> mask = uint64_t(((1ul << bit_count) - 1) << bit_offset);
-
-        // We are starting our count with 1 since we need at least 1 bit set to distinguish between
-        // areas without any tiles whatsoever and the current area.
-        uint8_t count = 1;
-        for (auto& it : renderables) {
-            auto& renderable = it.get();
-            if (!renderable.used || !renderable.needsClipping) {
-                continue;
-            }
-            renderable.clip.mask |= mask;
-
-            // Assign only to clip IDs that have no value yet.
-            if (renderable.clip.reference.none()) {
-                renderable.clip.reference = uint32_t(count++) << bit_offset;
-            }
-        }
-
-        bit_offset += bit_count;
-    }
-
-    // Prevent this warning from firing on every frame,
-    // which can be expensive in some platforms.
-    static bool warned = false;
-
-    if (!warned && bit_offset > 8) {
-        Log::Error(Event::OpenGL, "stencil mask overflow");
-        warned = true;
-    }
-}
-
-} // namespace algorithm
-} // namespace mbgl