Attemp to reduce dependencies on half.h

Signed-off-by: Kevin Wheatley <kevin.wheatley@framestore.com>

Author: KevinJW

src/OpenColorIO/AVX.h

@@ -10,6 +10,10 @@
 
 #include <immintrin.h>
 
+#if OCIO_USE_F16C
+#include <Imath/half.h>
+#endif
+
 #include <OpenColorIO/OpenColorIO.h>
 #include "BitDepthUtils.h"
 

src/OpenColorIO/AVX2.h

@@ -10,6 +10,10 @@
 
 #include <immintrin.h>
 
+#if OCIO_USE_F16C
+#include <Imath/half.h>
+#endif
+
 #include <OpenColorIO/OpenColorIO.h>
 #include "BitDepthUtils.h"
 

src/OpenColorIO/AVX512.h

@@ -10,6 +10,8 @@
 
 #include <immintrin.h>
 
+#include <Imath/half.h>
+
 #include <OpenColorIO/OpenColorIO.h>
 #include "BitDepthUtils.h"
 

src/OpenColorIO/MathHalfUtils.h

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright Contributors to the OpenColorIO Project.
+
+#ifndef INCLUDED_OCIO_MATHHALFUTILS_H
+#define INCLUDED_OCIO_MATHHALFUTILS_H
+
+#include <OpenColorABI.h>
+
+#include <Imath/half.h>
+
+namespace OCIO_NAMESPACE
+{
+// Compares half-floats as raw integers with a tolerance (essentially in ULPs).
+// Returns true if the integer difference is strictly greater than the tolerance.
+// If aimHalf is a NaN, valHalf must also be one of the NaNs.
+// Inf is treated like any other value (diff from HALFMAX is 1).
+bool HalfsDiffer(const half expected, const half actual, const int tolerance);
+
+} // namespace OCIO_NAMESPACE
+
+#endif

src/OpenColorIO/MathUtils.cpp

@@ -7,9 +7,12 @@
 #include <type_traits>
 #include <limits>
 
+#include <Imath/half.h>
+
 #include <OpenColorIO/OpenColorIO.h>
 
 #include "MathUtils.h"
+#include "MathHalfUtils.h"
 
 namespace OCIO_NAMESPACE
 {

src/OpenColorIO/MathUtils.h

@@ -7,9 +7,7 @@
 #include <algorithm>
 #include <cmath>
 
-#include <OpenColorIO/OpenColorIO.h>
-
-#include <Imath/half.h>
+#include <OpenColorABI.h>
 
 namespace OCIO_NAMESPACE
 {
@@ -213,12 +211,6 @@ inline float AddULP(const float f, const int ulp)
 bool FloatsDiffer(const float expected, const float actual, 
                   const int tolerance, const bool compressDenorms);
 
-// Compares half-floats as raw integers with a tolerance (essentially in ULPs).
-// Returns true if the integer difference is strictly greater than the tolerance.
-// If aimHalf is a NaN, valHalf must also be one of the NaNs.
-// Inf is treated like any other value (diff from HALFMAX is 1).
-bool HalfsDiffer(const half expected, const half actual, const int tolerance);
-
 } // namespace OCIO_NAMESPACE
 
 #endif

src/OpenColorIO/SSE2.h

@@ -8,6 +8,8 @@
 #include "CPUInfo.h"
 #if OCIO_USE_SSE2
 
+#include <Imath/half.h>
+
 // Include the appropriate SIMD intrinsics header based on the architecture (Intel vs. ARM).
 #if !defined(__aarch64__) && !defined(_M_ARM64)
     #include <emmintrin.h>

src/OpenColorIO/fileformats/FileFormatDiscreet1DL.cpp

@@ -11,6 +11,8 @@
 
 #include <pystring.h>
 
+#include <Imath/half.h>
+
 #include <OpenColorIO/OpenColorIO.h>
 
 #include "BitDepthUtils.h"

src/OpenColorIO/fileformats/ctf/CTFTransform.cpp

@@ -10,6 +10,8 @@
 #include <vector>
 #include <memory>
 
+#include <Imath/half.h>
+
 #include "BitDepthUtils.h"
 #include "fileformats/ctf/CTFReaderUtils.h"
 #include "fileformats/ctf/CTFTransform.h"

src/OpenColorIO/ops/lut1d/Lut1DOpCPU.cpp

@@ -6,6 +6,8 @@
 #include <memory>
 #include <cstdint>
 
+#include <Imath/half.h>
+
 #include <OpenColorIO/OpenColorIO.h>
 
 #include "BitDepthUtils.h"