[core] Do not expose TexturePool::Impl

Now using the same Pimpl mechanism from mbgl::Map.

src/mbgl/gl/texture_pool.cpp

@@ -7,35 +7,68 @@
 namespace mbgl {
 namespace gl {
 
-GLuint TexturePool::getTextureID(gl::ObjectStore& store) {
-    auto nextAvailableID = [](auto& pool_) {
-        auto it = pool_.availableIDs.begin();
-        GLuint id = *it;
-        pool_.availableIDs.erase(it);
-        return id;
+class TexturePool::Impl : private util::noncopyable {
+public:
+    class Group : private util::noncopyable {
+        public:
+            Group(gl::ObjectStore& store) : pool(store.createTexturePool()), availableIDs(gl::TextureMax) {
+                std::copy(pool.get().begin(), pool.get().end(), availableIDs.begin());
+            }
+
+            Group(Group&& o) : pool(std::move(o.pool)), availableIDs(std::move(o.availableIDs)) {}
+            Group& operator=(Group&& o) { pool = std::move(o.pool); availableIDs = std::move(o.availableIDs); return *this; }
+
+            gl::UniqueTexturePool pool;
+            std::vector<GLuint> availableIDs;
     };
 
-    for (auto& pool : pools) {
-        if (pool.availableIDs.empty()) continue;
-        return nextAvailableID(pool);
+    GLuint getTextureID(gl::ObjectStore& store) {
+        auto nextAvailableID = [](auto& pool_) {
+            auto it = pool_.availableIDs.begin();
+            GLuint id = *it;
+            pool_.availableIDs.erase(it);
+            return id;
+        };
+
+        for (auto& pool : pools) {
+            if (pool.availableIDs.empty()) continue;
+            return nextAvailableID(pool);
+        }
+
+        // All texture IDs are in use.
+        pools.emplace_back(Group { store });
+        return nextAvailableID(pools.back());
     }
 
-    // All texture IDs are in use.
-    pools.emplace_back(Impl { store });
-    return nextAvailableID(pools.back());
+    void releaseTextureID(GLuint& id) {
+        for (auto it = pools.begin(); it != pools.end(); ++it) {
+            if (std::find(it->pool.get().begin(), it->pool.get().end(), id) != it->pool.get().end()) {
+                it->availableIDs.push_back(id);
+                id = 0;
+                if (GLsizei(it->availableIDs.size()) == gl::TextureMax) {
+                    pools.erase(it);
+                }
+                return;
+            }
+        }
+    }
+
+private:
+    std::vector<Group> pools;
+};
+
+TexturePool::TexturePool() : impl(std::make_unique<Impl>()) {
+}
+
+TexturePool::~TexturePool() {
+}
+
+GLuint TexturePool::getTextureID(gl::ObjectStore& store) {
+    return impl->getTextureID(store);
 }
 
 void TexturePool::releaseTextureID(GLuint& id) {
-    for (auto it = pools.begin(); it != pools.end(); ++it) {
-        if (std::find(it->pool.get().begin(), it->pool.get().end(), id) != it->pool.get().end()) {
-            it->availableIDs.push_back(id);
-            id = 0;
-            if (GLsizei(it->availableIDs.size()) == gl::TextureMax) {
-                pools.erase(it);
-            }
-            return;
-        }
-    }
+    impl->releaseTextureID(id);
 }
 
 } // namespace gl

src/mbgl/gl/texture_pool.hpp

@@ -4,33 +4,22 @@
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/gl/object_store.hpp>
 
-#include <algorithm>
 #include <memory>
-#include <vector>
 
 namespace mbgl {
 namespace gl {
 
 class TexturePool : private util::noncopyable {
 public:
+    TexturePool();
+    ~TexturePool();
+
     GLuint getTextureID(gl::ObjectStore&);
     void releaseTextureID(GLuint&);
 
 private:
-    class Impl : private util::noncopyable {
-    public:
-        Impl(gl::ObjectStore& store) : pool(store.createTexturePool()), availableIDs(gl::TextureMax) {
-            std::copy(pool.get().begin(), pool.get().end(), availableIDs.begin());
-        }
-
-        Impl(Impl&& o) : pool(std::move(o.pool)), availableIDs(std::move(o.availableIDs)) {}
-        Impl& operator=(Impl&& o) { pool = std::move(o.pool); availableIDs = std::move(o.availableIDs); return *this; }
-
-        gl::UniqueTexturePool pool;
-        std::vector<GLuint> availableIDs;
-    };
-
-    std::vector<Impl> pools;
+    class Impl;
+    const std::unique_ptr<Impl> impl;
 };
 
 } // namespace gl