Check libpng directly into third_party/

cmake/CMakeLists.txt

Index: cmake/CMakeLists.txt
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index ef0856a3ea338b9942af1edf460d5885ca2a1c58..8b00c51391927c73cc86e4eec7a3fb3591f4aaba 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -35,6 +35,12 @@ list (APPEND public_includes ${userconfig_directory})
 list (APPEND srcs             ../third_party/etc1/etc1.cpp ../third_party/ktx/ktx.cpp)
 list (APPEND private_includes ../third_party/etc1          ../third_party/ktx)
 
+list (APPEND private_includes ../third_party/libpng)

[scroggo, 2016/06/02 16:15:10]

I know very little of CMake, and I'm still working on setting it up. Does this
look right? It is based on the code around it. I also skipped the intel
optimizations for now; do I need to set PNG_ARM_NEON_OPT?

[msarett, 2016/06/02 16:35:33]

Looks right, I think, though I haven't done too much with CMake either.

Looks like you're skipping arm and intel opts (arm opts are in a arm/
directory).  I think that's right thing to do right now.

You might actually want to set PNG_ARM_NEON_OPT to 0, so it doesn't try to
automatically detect arm support (and then fail when we fail to compile the
files).

If you have any issues setting up CMake, the trybots may be useful for testing.

[scroggo, 2016/06/02 17:03:27]

Done.
Which trybot? I don't see one for CMake.

[msarett, 2016/06/02 17:10:36]

The CMake trybots actually run automatically in the commit queue when you modify
this file.  They are:
Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot
Build-Mac-Clang-x86_64-Release-Trybot

+file (GLOB libpng_srcs ../third_party/libpng/*.c)
+foreach (src ${libpng_srcs})
+    list (APPEND srcs ${src})
+endforeach()
+
 function (remove_srcs)
     file (GLOB_RECURSE to_remove ${ARGN})
     list (REMOVE_ITEM srcs ${to_remove})
@@ -148,7 +154,6 @@ if (UNIX AND NOT APPLE)
     find_library (FONTCONFIG_LIBRARIES fontconfig)
     find_package (GIF)
     find_package (JPEG)
-    find_package (PNG)
 endif()
 
 # Do not compile SkRawCodec.
@@ -188,17 +193,10 @@ else()
     remove_srcs(../src/utils/*Lua*)
 endif()
 
-if (PNG_FOUND)
-    list (APPEND private_includes ${PNG_INCLUDE_DIRS})
-    list (APPEND libs             ${PNG_LIBRARIES})
+# PNG
     add_definitions(-DPNG_SKIP_SETJMP_CHECK)

[scroggo, 2016/06/02 16:15:10]

I did not see this or PNG_SKIP_SKIA_OPTS anywhere in libpng or Skia. (Actually,
this one is mentioned in a change-log, so I'm guessing it got removed.) Safe to
delete?

[msarett, 2016/06/02 16:35:33]

I believe that they are both safe to delete.

nit: outdent this text

[scroggo, 2016/06/02 17:03:27]

Removed.
Done.

     add_definitions(-DPNG_SKIP_SKIA_OPTS)
     add_definitions(-DSK_HAS_PNG_LIBRARY)
-else()
-    remove_srcs(../src/images/*PNG*)
-    remove_srcs(../src/codec/*Png*)
-    remove_srcs(../src/codec/*Ico*)
-endif()
 
 if (ZLIB_FOUND)
     list (APPEND private_includes ${ZLIB_INCLUDE_DIRS})