Revert "Merge pull request CesiumGS#798 from CesiumGS/upgrade-to-zlib…

…-ng"

This reverts commit 09c1eb7, reversing
changes made to bec474f.

.gitmodules

@@ -62,9 +62,9 @@
 [submodule "extern/libjpeg-turbo"]
 	path = extern/libjpeg-turbo
 	url = https://github.com/CesiumGS/libjpeg-turbo.git
+[submodule "extern/zlib"]
+	path = extern/zlib
+	url = https://github.com/madler/zlib.git
 [submodule "extern/meshoptimizer"]
 	path = extern/meshoptimizer
 	url = https://github.com/zeux/meshoptimizer
-[submodule "extern/zlib-ng"]
-	path = extern/zlib-ng
-	url = https://github.com/zlib-ng/zlib-ng.git

CHANGES.md

@@ -10,7 +10,6 @@
 
 - Added `contains` method to `BoundingSphere`.
 - Added `GlobeRectangle::MAXIMUM` static field.
-- Switched from `zlib` to `zlib-ng` in order to improve the performance of decompressing gzipped data.
 
 ##### Fixes :wrench:
 

CesiumUtility/src/Gunzip.cpp

@@ -1,6 +1,6 @@
 #include "CesiumUtility/Gunzip.h"
 #define ZLIB_CONST
-#include "zlib-ng.h"
+#include "zlib.h"
 
 #define CHUNK 65536
 
@@ -16,13 +16,13 @@ bool CesiumUtility::gunzip(
     std::vector<std::byte>& out) {
   int ret;
   unsigned int index = 0;
-  zng_stream strm;
+  z_stream strm;
   strm.zalloc = Z_NULL;
   strm.zfree = Z_NULL;
   strm.opaque = Z_NULL;
   strm.avail_in = 0;
   strm.next_in = Z_NULL;
-  ret = zng_inflateInit2(&strm, 16 + MAX_WBITS);
+  ret = inflateInit2(&strm, 16 + MAX_WBITS);
   if (ret != Z_OK) {
     return false;
   }
@@ -34,18 +34,18 @@ bool CesiumUtility::gunzip(
     out.resize(index + CHUNK);
     strm.next_out = reinterpret_cast<Bytef*>(&out[index]);
     strm.avail_out = CHUNK;
-    ret = zng_inflate(&strm, Z_NO_FLUSH);
+    ret = inflate(&strm, Z_NO_FLUSH);
     switch (ret) {
     case Z_NEED_DICT:
     case Z_DATA_ERROR:
     case Z_MEM_ERROR:
-      zng_inflateEnd(&strm);
+      inflateEnd(&strm);
       return false;
     }
     index += CHUNK - strm.avail_out;
   } while (ret != Z_STREAM_END);
 
-  zng_inflateEnd(&strm);
+  inflateEnd(&strm);
   out.resize(index);
   return true;
 }

extern/CMakeLists.txt

@@ -168,9 +168,8 @@ add_subdirectory(libmorton)
 
 # The zlib cmake build makes its working directory dirty.
 # So we make a copy of it to avoid that annoyance.
-set(WITH_GTEST OFF CACHE INTERNAL "Disable zlib-ng testing")
-file(COPY "${CMAKE_CURRENT_LIST_DIR}/zlib-ng/" DESTINATION "${CMAKE_CURRENT_BINARY_DIR}/zlib-ng-src")
-add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/zlib-ng-src ${CMAKE_CURRENT_BINARY_DIR}/zlib-ng)
+file(COPY "${CMAKE_CURRENT_LIST_DIR}/zlib/" DESTINATION "${CMAKE_CURRENT_BINARY_DIR}/zlib-src")
+add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/zlib-src ${CMAKE_CURRENT_BINARY_DIR}/zlib)
 
 if(DEFINED CMAKE_TOOLCHAIN_FILE)
     if(NOT IS_ABSOLUTE ${CMAKE_TOOLCHAIN_FILE})