Math: more Frustum data access functions, test for constexprness.

src/Magnum/Math/Frustum.h

@@ -101,6 +101,24 @@ template<class T> class Frustum {
         /** @brief Plane at given index */
         constexpr Vector4<T> operator[](std::size_t i) const { return _data[i]; }
 
+        /** @brief Left plane */
+        constexpr Vector4<T> left() const { return _data[0]; }
+
+        /** @brief Right plane */
+        constexpr Vector4<T> right() const { return _data[1]; }
+
+        /** @brief Bottom plane */
+        constexpr Vector4<T> bottom() const { return _data[2]; }
+
+        /** @brief Top plane */
+        constexpr Vector4<T> top() const { return _data[3]; }
+
+        /** @brief Near plane */
+        constexpr Vector4<T> near() const { return _data[4]; }
+
+        /** @brief Far plane */
+        constexpr Vector4<T> far() const { return _data[5]; }
+
     private:
         Vector4<T> _data[6];
 };

src/Magnum/Math/Test/FrustumTest.cpp

@@ -41,6 +41,8 @@ struct FrustumTest: Corrade::TestSuite::Tester {
     void constructCopy();
     void constructFromMatrix();
 
+    void data();
+
     void compare();
 
     void debug();
@@ -57,21 +59,23 @@ FrustumTest::FrustumTest() {
               &FrustumTest::constructCopy,
               &FrustumTest::constructFromMatrix,
 
+              &FrustumTest::data,
+
               &FrustumTest::compare,
 
               &FrustumTest::debug});
 }
 
 void FrustumTest::construct() {
-    Vector4 planes[6]{
-        {-1.0f,  0.0f,  0.0f, 1.0f},
-        { 1.0f,  0.0f,  0.0f, 1.0f},
-        { 0.0f, -1.0f,  0.0f, 1.0f},
-        { 0.0f,  1.0f,  0.0f, 1.0f},
-        { 0.0f,  0.0f, -1.0f, 1.0f},
-        { 0.0f,  0.0f,  1.0f, 1.0f}};
+    constexpr Vector4 planes[6]{
+        {-1.0f,  2.0f, -3.0f, 0.1f},
+        { 1.0f, -2.0f,  3.0f, 0.2f},
+        {-4.0f,  5.0f, -6.0f, 0.3f},
+        { 4.0f, -5.0f,  6.0f, 0.4f},
+        {-7.0f,  8.0f, -9.0f, 0.5f},
+        { 7.0f,  8.0f,  9.0f, 0.6f}};
 
-    Frustum frustum{
+    constexpr Frustum frustum{
         planes[0], planes[1],
         planes[2], planes[3],
         planes[4], planes[5]};
@@ -164,6 +168,23 @@ void FrustumTest::constructFromMatrix() {
     CORRADE_COMPARE(Frustum::fromMatrix({}), Frustum{});
 }
 
+void FrustumTest::data() {
+    /* Using default-constructed to verify that the planes are in correct order */
+    constexpr Frustum a;
+
+    constexpr Vector4 right = a.planes()[1];
+    CORRADE_COMPARE(right, (Vector4{-1.0f, 0.0f, 0.0f, 1.0f}));
+
+    constexpr Vector4 bottom = a[2];
+    CORRADE_COMPARE(bottom, (Vector4{0.0f, 1.0f, 0.0f, 1.0f}));
+
+    constexpr Vector4 near = a.near();
+    CORRADE_COMPARE(near, (Vector4{0.0f, 0.0f, 1.0f, 1.0f}));
+
+    constexpr Float b = *a.data();
+    CORRADE_COMPARE(b, 1.0f);
+}
+
 void FrustumTest::compare() {
     Frustum a{
         {-1.0f,  2.0f, -3.0f, 0.1f},