Math: add castInto() overloads for Float and Double.

doc/changelog.dox

@@ -224,7 +224,8 @@ See also:
 @subsubsection changelog-latest-changes-math Math library
 
 -   Added @ref Math::castInto() overloads for casting between @ref UnsignedByte
-    and @ref UnsignedShort or @ref Byte and @ref Short
+    and @ref UnsignedShort or @ref Byte and @ref Short, and for casting between
+    @ref Float and @ref Double
 
 @subsubsection changelog-latest-changes-meshtools MeshTools library
 

src/Magnum/Math/PackingBatch.cpp

@@ -288,6 +288,14 @@ void castInto(const Corrade::Containers::StridedArrayView2D<const Short>& src, c
     castIntoImplementation(src, dst);
 }
 
+void castInto(const Corrade::Containers::StridedArrayView2D<const Float>& src, const Corrade::Containers::StridedArrayView2D<Double>& dst) {
+    castIntoImplementation(src, dst);
+}
+
+void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src, const Corrade::Containers::StridedArrayView2D<Float>& dst) {
+    castIntoImplementation(src, dst);
+}
+
 static_assert(sizeof(HalfMantissaTable) + sizeof(HalfOffsetTable) + sizeof(HalfExponentTable) == 8576,
     "improper size of half->float conversion tables");
 

src/Magnum/Math/PackingBatch.h

@@ -348,6 +348,43 @@ MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const
  */
 MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Short>& src, const Corrade::Containers::StridedArrayView2D<Byte>& dst);
 
+/**
+@brief Cast 32-bit floating-point values into a 64-bit floating-point representation
+@param[in]  src     Source float values
+@param[out] dst     Destination double values
+@m_since_latest
+
+This function performs an equivalent of @cpp Double(a) @ce over the range, so
+e.g. @cpp 135.0f @ce becomes @cpp 135.0 @ce. Second dimension is meant to
+contain vector/matrix components, or have a size of 1 for scalars. Expects that
+@p src and @p dst have the same size and that the second dimension in both is
+contiguous.
+
+@see @ref castInto(const Corrade::Containers::StridedArrayView2D<const Double>&, const Corrade::Containers::StridedArrayView2D<Float>&),
+    @ref Corrade::Containers::StridedArrayView::isContiguous()
+*/
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Float>& src, const Corrade::Containers::StridedArrayView2D<Double>& dst);
+
+/**
+@brief Cast 64-bit floating-point values into a 32-bit floating-point representation
+@param[in]  src     Source double values
+@param[out] dst     Destination float values
+@m_since_latest
+
+This function performs an equivalent of @cpp Float(a) @ce over the range, so
+e.g. @cpp 135.0 @ce becomes @cpp 135.0f @ce. Second dimension is meant to
+contain vector/matrix components, or have a size of 1 for scalars. Expects that
+@p src and @p dst have the same size and that the second dimension in both is
+contiguous.
+
+@attention Numbers with more than 23 bits of precision will not be represented
+    accurately when cast into a @ref Magnum::Float "Float".
+
+@see @ref castInto(const Corrade::Containers::StridedArrayView2D<const Float>&, const Corrade::Containers::StridedArrayView2D<Double>&),
+    @ref Corrade::Containers::StridedArrayView::isContiguous()
+*/
+MAGNUM_EXPORT void castInto(const Corrade::Containers::StridedArrayView2D<const Double>& src, const Corrade::Containers::StridedArrayView2D<Float>& dst);
+
 /* Since 1.8.17, the original short-hand group closing doesn't work anymore.
    FFS. */
 /**

src/Magnum/Math/Test/PackingBatchTest.cpp

@@ -57,6 +57,8 @@ struct PackingBatchTest: Corrade::TestSuite::Tester {
     template<class T, class U> void castUnsignedInteger();
     template<class T, class U> void castSignedInteger();
 
+    void castFloatDouble();
+
     template<class T> void assertionsPackUnpack();
     void assertionsPackUnpackHalf();
     template<class U, class T> void assertionsCast();
@@ -89,6 +91,8 @@ PackingBatchTest::PackingBatchTest() {
               &PackingBatchTest::castSignedInteger<Short, Int>,
               &PackingBatchTest::castSignedInteger<Byte, Short>,
 
+              &PackingBatchTest::castFloatDouble,
+
               &PackingBatchTest::assertionsPackUnpack<UnsignedByte>,
               &PackingBatchTest::assertionsPackUnpack<Byte>,
               &PackingBatchTest::assertionsPackUnpack<UnsignedShort>,
@@ -105,7 +109,8 @@ PackingBatchTest::PackingBatchTest() {
               &PackingBatchTest::assertionsCast<UnsignedShort, UnsignedByte>,
               &PackingBatchTest::assertionsCast<Int, Byte>,
               &PackingBatchTest::assertionsCast<Int, Short>,
-              &PackingBatchTest::assertionsCast<Short, Byte>});
+              &PackingBatchTest::assertionsCast<Short, Byte>,
+              &PackingBatchTest::assertionsCast<Double, Float>});
 }
 
 typedef Math::Constants<Float> Constants;
@@ -573,6 +578,42 @@ template<class T, class U> void PackingBatchTest::castSignedInteger() {
         Corrade::TestSuite::Compare::Container);
 }
 
+void PackingBatchTest::castFloatDouble() {
+    struct Data {
+        Math::Vector2<Float> src;
+        Math::Vector2<Double> dst;
+    } data[]{
+        {{0.25f, -89.5f}, {}},
+        {{-119.0f, 22.75f}, {}},
+        {{13.0f, 127.5f}, {}}
+    };
+
+    constexpr Math::Vector2<Double> expectedTargetType[] {
+        {0.25, -89.5},
+        {-119.0, 22.75},
+        {13.0, 127.5}
+    };
+
+    constexpr Math::Vector2<Float> expectedOriginalType[] {
+        {0.25f, -89.5f},
+        {-119.0f, 22.75f},
+        {13.0f, 127.5f}
+    };
+
+    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_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));
+    CORRADE_COMPARE_AS(src, Corrade::Containers::stridedArrayView(expectedOriginalType),
+        Corrade::TestSuite::Compare::Container);
+}
+
 template<class T> void PackingBatchTest::assertionsPackUnpack() {
     #ifdef CORRADE_NO_ASSERT
     CORRADE_SKIP("CORRADE_NO_ASSERT defined, can't test assertions");