From dff1a1ce60607381946e04cdfcaadfe47a7109f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Mon, 6 Mar 2023 17:50:46 +0100
Subject: [PATCH] Math: add also castInto(T[], T[]) overloads.

For generic code, which would otherwise have to invent some SFINAE
"use castInto() if the types are different and Utility::copy()
otherwise" nastiness in every such case, and that's just annoying.
---
 src/Magnum/Math/PackingBatch.cpp          | 60 ++++++++++++++++++++
 src/Magnum/Math/PackingBatch.h            | 67 ++++++++++++++++++++++
 src/Magnum/Math/Test/PackingBatchTest.cpp | 68 ++++++++++++++---------
 3 files changed, 170 insertions(+), 25 deletions(-)

diff --git a/src/Magnum/Math/PackingBatch.cpp b/src/Magnum/Math/PackingBatch.cpp
index b75246a68..54ed1eff1 100644
--- a/src/Magnum/Math/PackingBatch.cpp
+++ b/src/Magnum/Math/PackingBatch.cpp
@@ -26,6 +26,7 @@
 #include "PackingBatch.h"
 
 #include <Corrade/Containers/StridedArrayView.h>
+#include <Corrade/Utility/Algorithms.h>
 #include <Corrade/Utility/Assert.h>
 
 #include "Magnum/Math/Packing.h"
@@ -400,6 +401,65 @@ void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src,
     castIntoImplementation(src, dst);
 }
 
+namespace {
+
+template<class T> inline void copyImplementation(const Corrade::Containers::StridedArrayView2D<const T>& src, const Corrade::Containers::StridedArrayView2D<T>& dst) {
+    /* Utility::copy() has its own assertions, but those are debug-only for
+       perf reasons and don't require the second dimension to be contiguous.
+       Here the use case is different and the behavior should be consistent
+       with other castInto() overloads to avoid surprises. */
+    CORRADE_ASSERT(src.size() == dst.size(),
+        "Math::castInto(): wrong destination size, got" << dst.size() << "but expected" << src.size(), );
+    CORRADE_ASSERT(src.template isContiguous<1>(),
+        "Math::castInto(): second source view dimension is not contiguous", );
+    CORRADE_ASSERT(dst.template isContiguous<1>(),
+        "Math::castInto(): second destination view dimension is not contiguous", );
+
+    Corrade::Utility::copy(src, dst);
+}
+
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedByte>& src, const Corrade::Containers::StridedArrayView2D<UnsignedByte>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Byte>& src, const Corrade::Containers::StridedArrayView2D<Byte>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedShort>& src, const Corrade::Containers::StridedArrayView2D<UnsignedShort>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Short>& src, const Corrade::Containers::StridedArrayView2D<Short>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedInt>& src, const Corrade::Containers::StridedArrayView2D<UnsignedInt>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Int>& src, const Corrade::Containers::StridedArrayView2D<Int>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedLong>& src, const Corrade::Containers::StridedArrayView2D<UnsignedLong>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Long>& src, const Corrade::Containers::StridedArrayView2D<Long>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Float>& src, const Corrade::Containers::StridedArrayView2D<Float>& dst) {
+    copyImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src, const Corrade::Containers::StridedArrayView2D<Double>& dst) {
+    copyImplementation(src, dst);
+}
+
 static_assert(sizeof(HalfMantissaTable) + sizeof(HalfOffsetTable) + sizeof(HalfExponentTable) == 8576,
     "improper size of half->float conversion tables");
 
diff --git a/src/Magnum/Math/PackingBatch.h b/src/Magnum/Math/PackingBatch.h
index 403c817b4..ea96e1f28 100644
--- a/src/Magnum/Math/PackingBatch.h
+++ b/src/Magnum/Math/PackingBatch.h
@@ -557,6 +557,73 @@ contiguous.
 */
 MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src, const Corrade::Containers::StridedArrayView2D<Float>& dst);
 
+/**
+@brief Copy values
+@param[in]  src     Source values
+@param[out] dst     Destination values
+@m_since_latest
+
+Provided for convenience when writing generic code, delegates to @relativeref{Corrade,Utility::copy()}. Expects that @p src and @p dst have the
+same size, for consistency with other @ref castInto() expects also that the
+second dimension in both is contiguous even though it's not required by
+@relativeref{Corrade,Utility::copy()}.
+*/
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedByte>& src, const Corrade::Containers::StridedArrayView2D<UnsignedByte>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Byte>& src, const Corrade::Containers::StridedArrayView2D<Byte>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedShort>& src, const Corrade::Containers::StridedArrayView2D<UnsignedShort>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Short>& src, const Corrade::Containers::StridedArrayView2D<Short>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedInt>& src, const Corrade::Containers::StridedArrayView2D<UnsignedInt>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Int>& src, const Corrade::Containers::StridedArrayView2D<Int>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const UnsignedLong>& src, const Corrade::Containers::StridedArrayView2D<UnsignedLong>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Long>& src, const Corrade::Containers::StridedArrayView2D<Long>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Float>& src, const Corrade::Containers::StridedArrayView2D<Float>& dst);
+
+/**
+ * @overload
+ * @m_since_latest
+ */
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src, const Corrade::Containers::StridedArrayView2D<Double>& dst);
+
 /* Since 1.8.17, the original short-hand group closing doesn't work anymore.
    FFS. */
 /**
diff --git a/src/Magnum/Math/Test/PackingBatchTest.cpp b/src/Magnum/Math/Test/PackingBatchTest.cpp
index 2efed391a..eed84d288 100644
--- a/src/Magnum/Math/Test/PackingBatchTest.cpp
+++ b/src/Magnum/Math/Test/PackingBatchTest.cpp
@@ -56,8 +56,7 @@ struct PackingBatchTest: Corrade::TestSuite::Tester {
 
     template<class T, class U> void castUnsignedInteger();
     template<class T, class U> void castSignedInteger();
-
-    void castFloatDouble();
+    template<class T, class U> void castFloatDouble();
 
     template<class T> void assertionsPackUnpack();
     void assertionsPackUnpackHalf();
@@ -90,20 +89,29 @@ PackingBatchTest::PackingBatchTest() {
               &PackingBatchTest::castSignedFloatingPoint<Double, Short>,
               &PackingBatchTest::castSignedFloatingPoint<Double, Int>,
 
+              &PackingBatchTest::castUnsignedInteger<UnsignedByte, UnsignedByte>,
               &PackingBatchTest::castUnsignedInteger<UnsignedByte, UnsignedShort>,
               &PackingBatchTest::castUnsignedInteger<UnsignedByte, UnsignedInt>,
+              &PackingBatchTest::castUnsignedInteger<UnsignedShort, UnsignedShort>,
               &PackingBatchTest::castUnsignedInteger<UnsignedShort, UnsignedInt>,
+              &PackingBatchTest::castUnsignedInteger<UnsignedInt, UnsignedInt>,
               &PackingBatchTest::castUnsignedInteger<UnsignedByte, UnsignedLong>,
               &PackingBatchTest::castUnsignedInteger<UnsignedShort, UnsignedLong>,
               &PackingBatchTest::castUnsignedInteger<UnsignedInt, UnsignedLong>,
+              &PackingBatchTest::castUnsignedInteger<UnsignedLong, UnsignedLong>,
+              &PackingBatchTest::castSignedInteger<Byte, Byte>,
               &PackingBatchTest::castSignedInteger<Byte, Short>,
               &PackingBatchTest::castSignedInteger<Byte, Int>,
+              &PackingBatchTest::castSignedInteger<Short, Short>,
               &PackingBatchTest::castSignedInteger<Short, Int>,
+              &PackingBatchTest::castSignedInteger<Int, Int>,
               &PackingBatchTest::castSignedInteger<Byte, Long>,
               &PackingBatchTest::castSignedInteger<Short, Long>,
               &PackingBatchTest::castSignedInteger<Int, Long>,
-
-              &PackingBatchTest::castFloatDouble,
+              &PackingBatchTest::castSignedInteger<Long, Long>,
+              &PackingBatchTest::castFloatDouble<Float, Double>,
+              &PackingBatchTest::castFloatDouble<Float, Float>,
+              &PackingBatchTest::castFloatDouble<Double, Double>,
 
               &PackingBatchTest::assertionsPackUnpack<UnsignedByte>,
               &PackingBatchTest::assertionsPackUnpack<Byte>,
@@ -122,19 +130,29 @@ PackingBatchTest::PackingBatchTest() {
               &PackingBatchTest::assertionsCast<Double, Short>,
               &PackingBatchTest::assertionsCast<Double, UnsignedInt>,
               &PackingBatchTest::assertionsCast<Double, Int>,
+              &PackingBatchTest::assertionsCast<UnsignedByte, UnsignedByte>,
               &PackingBatchTest::assertionsCast<UnsignedShort, UnsignedByte>,
+              &PackingBatchTest::assertionsCast<UnsignedShort, UnsignedShort>,
               &PackingBatchTest::assertionsCast<UnsignedInt, UnsignedByte>,
               &PackingBatchTest::assertionsCast<UnsignedInt, UnsignedShort>,
+              &PackingBatchTest::assertionsCast<UnsignedInt, UnsignedInt>,
               &PackingBatchTest::assertionsCast<UnsignedLong, UnsignedByte>,
               &PackingBatchTest::assertionsCast<UnsignedLong, UnsignedShort>,
               &PackingBatchTest::assertionsCast<UnsignedLong, UnsignedInt>,
+              &PackingBatchTest::assertionsCast<UnsignedLong, UnsignedLong>,
+              &PackingBatchTest::assertionsCast<Byte, Byte>,
               &PackingBatchTest::assertionsCast<Short, Byte>,
+              &PackingBatchTest::assertionsCast<Short, Short>,
               &PackingBatchTest::assertionsCast<Int, Byte>,
               &PackingBatchTest::assertionsCast<Int, Short>,
+              &PackingBatchTest::assertionsCast<Int, Int>,
               &PackingBatchTest::assertionsCast<Long, Byte>,
               &PackingBatchTest::assertionsCast<Long, Short>,
               &PackingBatchTest::assertionsCast<Long, Int>,
-              &PackingBatchTest::assertionsCast<Double, Float>});
+              &PackingBatchTest::assertionsCast<Long, Long>,
+              &PackingBatchTest::assertionsCast<Float, Float>,
+              &PackingBatchTest::assertionsCast<Double, Float>,
+              &PackingBatchTest::assertionsCast<Double, Double>});
 }
 
 typedef Math::Constants<Float> Constants;
@@ -603,38 +621,38 @@ template<class T, class U> void PackingBatchTest::castSignedInteger() {
         Corrade::TestSuite::Compare::Container);
 }
 
-void PackingBatchTest::castFloatDouble() {
+template<class T, class U> void PackingBatchTest::castFloatDouble() {
     struct Data {
-        Math::Vector2<Float> src;
-        Math::Vector2<Double> dst;
+        Math::Vector2<T> src;
+        Math::Vector2<U> dst;
     } data[]{
-        {{0.25f, -89.5f}, {}},
-        {{-119.0f, 22.75f}, {}},
-        {{13.0f, 127.5f}, {}}
+        {{T(0.25), T(-89.5)}, {}},
+        {{T(-119.0), T(22.75)}, {}},
+        {{T(13.0), T(127.5)}, {}}
     };
 
-    constexpr Math::Vector2<Double> expectedTargetType[] {
-        {0.25, -89.5},
-        {-119.0, 22.75},
-        {13.0, 127.5}
+    constexpr Math::Vector2<U> expectedTargetType[] {
+        {U(0.25), U(-89.5)},
+        {U(-119.0), U(22.75)},
+        {U(13.0), U(127.5)}
     };
 
-    constexpr Math::Vector2<Float> expectedOriginalType[] {
-        {0.25f, -89.5f},
-        {-119.0f, 22.75f},
-        {13.0f, 127.5f}
+    constexpr Math::Vector2<T> expectedOriginalType[] {
+        {T(0.25), T(-89.5)},
+        {T(-119.0), T(22.75)},
+        {T(13.0), T(127.5)}
     };
 
-    Corrade::Containers::StridedArrayView1D<Math::Vector2<Float>> src{data, &data[0].src, 3, sizeof(Data)};
-    Corrade::Containers::StridedArrayView1D<Math::Vector2<Double>> dst{data, &data[0].dst, 3, sizeof(Data)};
-    castInto(Corrade::Containers::arrayCast<2, Float>(src),
-             Corrade::Containers::arrayCast<2, Double>(dst));
+    Corrade::Containers::StridedArrayView1D<Math::Vector2<T>> src{data, &data[0].src, 3, sizeof(Data)};
+    Corrade::Containers::StridedArrayView1D<Math::Vector2<U>> dst{data, &data[0].dst, 3, sizeof(Data)};
+    castInto(Corrade::Containers::arrayCast<2, T>(src),
+             Corrade::Containers::arrayCast<2, U>(dst));
     CORRADE_COMPARE_AS(dst, Corrade::Containers::stridedArrayView(expectedTargetType),
         Corrade::TestSuite::Compare::Container);
 
     /* Test the other way around as well */
-    castInto(Corrade::Containers::arrayCast<2, Double>(dst),
-             Corrade::Containers::arrayCast<2, Float>(src));
+    castInto(Corrade::Containers::arrayCast<2, U>(dst),
+             Corrade::Containers::arrayCast<2, T>(src));
     CORRADE_COMPARE_AS(src, Corrade::Containers::stridedArrayView(expectedOriginalType),
         Corrade::TestSuite::Compare::Container);
 }