glm: Add patch to fix on big-endian, mark broken on non-Linux big-endian

From 06ce42e72324b32b1f4c37c646e99950c2bd5f6b Mon Sep 17 00:00:00 2001

From: Max Rees <maxcrees@me.com>

Date: Sun, 15 Mar 2020 15:13:27 -0400

Subject: [PATCH] Fix test suite on big endian platforms

---

 glm/gtc/packing.inl      | 55 ++++++++++++++++++++++++++++++++++++++++

 test/gtc/gtc_packing.cpp |  3 ++-

 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/glm/gtc/packing.inl b/glm/gtc/packing.inl

index 8c906e16c1..b1c99a5076 100644

--- a/glm/gtc/packing.inl

+++ b/glm/gtc/packing.inl

@@ -9,6 +9,9 @@

 #include "../detail/type_half.hpp"

 #include <cstring>

 #include <limits>

+extern "C" {

+#include <endian.h>

+}

 namespace glm{

 namespace detail

@@ -183,9 +186,15 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 3;

 			uint y : 3;

 			uint z : 2;

+#else

+			uint z : 2;

+			uint y : 3;

+			uint x : 3;

+#endif

 		} data;

 		uint8 pack;

 	};

@@ -194,8 +203,13 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 4;

 			uint y : 4;

+#else

+			uint y : 4;

+			uint x : 4;

+#endif

 		} data;

 		uint8 pack;

 	};

@@ -204,10 +218,17 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 4;

 			uint y : 4;

 			uint z : 4;

 			uint w : 4;

+#else

+			uint w : 4;

+			uint z : 4;

+			uint y : 4;

+			uint x : 4;

+#endif

 		} data;

 		uint16 pack;

 	};

@@ -216,9 +237,15 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 5;

 			uint y : 6;

 			uint z : 5;

+#else

+			uint z : 5;

+			uint y : 6;

+			uint x : 5;

+#endif

 		} data;

 		uint16 pack;

 	};

@@ -227,10 +254,17 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 5;

 			uint y : 5;

 			uint z : 5;

 			uint w : 1;

+#else

+			uint w : 1;

+			uint z : 5;

+			uint y : 5;

+			uint x : 5;

+#endif

 		} data;

 		uint16 pack;

 	};

@@ -239,10 +273,17 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 10;

 			uint y : 10;

 			uint z : 10;

 			uint w : 2;

+#else

+			uint w : 2;

+			uint z : 10;

+			uint y : 10;

+			uint x : 10;

+#endif

 		} data;

 		uint32 pack;

 	};

@@ -251,10 +292,17 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			int x : 10;

 			int y : 10;

 			int z : 10;

 			int w : 2;

+#else

+			int w : 2;

+			int z : 10;

+			int y : 10;

+			int x : 10;

+#endif

 		} data;

 		uint32 pack;

 	};

@@ -263,10 +311,17 @@ namespace detail

 	{

 		struct

 		{

+#if BYTE_ORDER == LITTLE_ENDIAN

 			uint x : 9;

 			uint y : 9;

 			uint z : 9;

 			uint w : 5;

+#else

+			uint w : 5;

+			uint z : 9;

+			uint y : 9;

+			uint x : 9;

+#endif

 		} data;

 		uint32 pack;

 	};

diff --git a/test/gtc/gtc_packing.cpp b/test/gtc/gtc_packing.cpp

index df5b3bb1a9..fbaaa5bccd 100644

--- a/test/gtc/gtc_packing.cpp

+++ b/test/gtc/gtc_packing.cpp

@@ -4,6 +4,7 @@

 #include <glm/ext/vector_relational.hpp>

 #include <cstdio>

 #include <vector>

+#include <arpa/inet.h>

 void print_bits(float const& s)

 {

@@ -156,7 +157,7 @@ int test_U3x10_1x2()

 	glm::u8vec4 const v0(0xff, 0x77, 0x0, 0x33);

 	glm::uint32 const p0 = *reinterpret_cast<glm::uint32 const*>(&v0[0]);

-	glm::uint32 const r0 = 0x330077ff;

+	glm::uint32 const r0 = htonl(0xff770033);

 	Error += p0 == r0 ? 0 : 1;

    "doc"

  ];

  patches = lib.optionals stdenv.hostPlatform.isLinux [

    # Remove when https://github.com/g-truc/glm/pull/1001 merged & in release.

    # Relies on <endian.h>, Linux-specific

    ./1001-glm-Fix-packing-on-BE.patch

  ];

  nativeBuildInputs = [ cmake ];

  env.NIX_CFLAGS_COMPILE =

    homepage = "https://github.com/g-truc/glm";

    license = licenses.mit;

    platforms = platforms.unix;

    # https://github.com/g-truc/glm/issues/897 indicates that packing isn't implemented properly on non-LE.

    # Patch from https://github.com/g-truc/glm/pull/1001 currently relies on Linux-only header.

    broken = !stdenv.hostPlatform.isLittleEndian && !stdenv.hostPlatform.isLinux;

    maintainers = with maintainers; [ smancill ];

  };

}