GL: deprecate Mesh::indexTypeSize() in favor of meshIndexTypeSize().

Because it makes no sense to only be able to query the index type size
on a live mesh.

doc/changelog-old.dox

@@ -272,7 +272,7 @@ Released 2018-05-01, tagged as
     function is deprecated, use @ref Magnum::MeshIndexType /
     @ref GL::MeshIndexType and @ref meshIndexTypeSize() instead
 -   The `GL::Mesh::indexSize()` function is deprecated, use
-    @ref GL::Mesh::indexTypeSize() instead
+    @cpp GL::Mesh::indexTypeSize() @ce instead
 -   The `Sampler` class and the `Sampler::Filter`, `Sampler::Mipmap`,
     `Sampler::Wrapping`, `Sampler::CompareMode`, `Sampler::CompareFunction` and
     `Sampler::DepthStencilMode` enums are deprecated, use @ref GL::Sampler,

doc/changelog.dox

@@ -1075,6 +1075,9 @@ See also:
     and [mosra/magnum#596](https://github.com/mosra/magnum/pull/596).
 -   @cpp GL::MeshView::setIndexRange() @ce is deprecated in favor of
     @ref GL::MeshView::setIndexOffset() that has a much less confusing name
+-   @cpp GL::Mesh::indexTypeSize() @ce is deprecated in favor of a standalone
+    @ref GL::meshIndexTypeSize() utility that you can call on the enum returned
+    from @ref GL::Mesh::indexType()
 -   The @cpp Array @ce, @cpp Array1D @ce, @cpp Array2D @ce and
     @cpp Array3D @ce types that were used exclusively for specifying
     @ref SamplerWrapping in various texture APIs are deprecated in favor of
@@ -3119,7 +3122,8 @@ Released 2019-10-24, tagged as
     (and root include path) which were deprecated in 2018.04 and everything
     related to this change:
     -   @cpp GL::Mesh::IndexType @ce and @cpp GL::Mesh::indexSize() @ce,
-        use @ref GL::MeshIndexType and @ref GL::Mesh::indexTypeSize() instead
+        use @ref GL::MeshIndexType and @cpp GL::Mesh::indexTypeSize() @ce
+        instead
 -   Removed @cpp Primitives::Capsule2D @ce, @cpp Primitives::Capsule3D @ce,
     @cpp Primitives::Circle @ce, @cpp Primitives::Crosshair2D @ce,
     @cpp Primitives::Crosshair3D @ce, @cpp Primitives::Cube @ce,

src/Magnum/GL/Mesh.cpp

@@ -107,6 +107,16 @@ MeshIndexType meshIndexType(const Magnum::MeshIndexType type) {
     return IndexTypeMapping[UnsignedInt(type) - 1];
 }
 
+UnsignedInt meshIndexTypeSize(const MeshIndexType type) {
+    switch(type) {
+        case MeshIndexType::UnsignedByte: return 1;
+        case MeshIndexType::UnsignedShort: return 2;
+        case MeshIndexType::UnsignedInt: return 4;
+    }
+
+    CORRADE_ASSERT_UNREACHABLE("GL::meshIndexTypeSize(): invalid type" << type, {});
+}
+
 #ifndef DOXYGEN_GENERATING_OUTPUT
 Debug& operator<<(Debug& debug, const MeshPrimitive value) {
     debug << "GL::MeshPrimitive" << Debug::nospace;
@@ -354,17 +364,13 @@ MeshIndexType Mesh::indexType() const {
     return _indexType;
 }
 
+#ifdef MAGNUM_BUILD_DEPRECATED
 UnsignedInt Mesh::indexTypeSize() const {
     CORRADE_ASSERT(_indexBuffer.id(), "Mesh::indexTypeSize(): mesh is not indexed", {});
 
-    switch(_indexType) {
+    return meshIndexTypeSize(_indexType);
-        case MeshIndexType::UnsignedByte: return 1;
-        case MeshIndexType::UnsignedShort: return 2;
-        case MeshIndexType::UnsignedInt: return 4;
-    }
-
-    CORRADE_INTERNAL_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
 }
+#endif
 
 Mesh& Mesh::addVertexBufferInstanced(Buffer& buffer, const UnsignedInt divisor, const GLintptr offset, const GLsizei stride, const DynamicAttribute& attribute) {
     for(UnsignedInt i = 0; i != attribute.vectors(); ++i)

src/Magnum/GL/Mesh.h

@@ -26,7 +26,7 @@
 */
 
 /** @file
- * @brief Class @ref Magnum::GL::Mesh, enum @ref Magnum::GL::MeshPrimitive, @ref Magnum::GL::MeshIndexType, function @ref Magnum::GL::meshPrimitive(), @ref Magnum::GL::meshIndexType()
+ * @brief Class @ref Magnum::GL::Mesh, enum @ref Magnum::GL::MeshPrimitive, @ref Magnum::GL::MeshIndexType, function @ref Magnum::GL::meshPrimitive(), @ref Magnum::GL::meshIndexType(), @ref Magnum::GL::meshIndexTypeSize()
  */
 
 #include <Corrade/Utility/ConfigurationValue.h>
@@ -221,6 +221,14 @@ cast to @ref MeshIndexType.
 */
 MAGNUM_GL_EXPORT MeshIndexType meshIndexType(Magnum::MeshIndexType type);
 
+/**
+@brief Size of given mesh index type
+@m_since_latest
+
+@see @ref Magnum::meshIndexTypeSize()
+*/
+MAGNUM_GL_EXPORT UnsignedInt meshIndexTypeSize(MeshIndexType type);
+
 namespace Implementation {
 
 struct MeshState;
@@ -653,13 +661,16 @@ class MAGNUM_GL_EXPORT Mesh: public AbstractObject {
          */
         MeshIndexType indexType() const;
 
+        #ifdef MAGNUM_BUILD_DEPRECATED
         /**
          * @brief Index type size
          *
          * Expects that the mesh is indexed.
-         * @see @ref isIndexed(), @ref meshIndexTypeSize(Magnum::MeshIndexType)
+         * @m_deprecated_since_latest Use @ref meshIndexTypeSize() on the value
+         *      returned from @ref indexType() instead.
          */
-        UnsignedInt indexTypeSize() const;
+        CORRADE_DEPRECATED("use meshIndexTypeSize() on indexType() instead") UnsignedInt indexTypeSize() const;
+        #endif
 
         /** @brief Primitive type */
         MeshPrimitive primitive() const { return _primitive; }

src/Magnum/GL/MeshView.cpp

@@ -59,7 +59,7 @@ void MeshView::draw(AbstractShaderProgram&& shader, std::initializer_list<Contai
 MeshView& MeshView::setIndexOffset(Int offset) {
     CORRADE_ASSERT(_original.get()._indexBuffer.id(),
         "GL::MeshView::setIndexOffset(): mesh is not indexed", *this);
-    _indexOffset = _original.get()._indexOffset + offset*_original.get().indexTypeSize();
+    _indexOffset = _original.get()._indexOffset + offset*meshIndexTypeSize(_original.get().indexType());
     return *this;
 }
 

src/Magnum/GL/Test/MeshGLTest.cpp

@@ -2524,7 +2524,6 @@ template<class T> void MeshGLTest::setIndexBuffer() {
 
     MAGNUM_VERIFY_NO_GL_ERROR();
     CORRADE_COMPARE(mesh.indexType(), MeshIndexType::UnsignedByte);
-    CORRADE_COMPARE(mesh.indexTypeSize(), 1);
 
     const auto value = Checker(MultipleShader{},
         #ifndef MAGNUM_TARGET_GLES2
@@ -2556,7 +2555,6 @@ template<class T> void MeshGLTest::setIndexBufferRange() {
 
     MAGNUM_VERIFY_NO_GL_ERROR();
     CORRADE_COMPARE(mesh.indexType(), GL::MeshIndexType::UnsignedShort);
-    CORRADE_COMPARE(mesh.indexTypeSize(), 2);
 
     const auto value = Checker(MultipleShader{},
         #ifndef MAGNUM_TARGET_GLES2
@@ -2590,7 +2588,6 @@ void MeshGLTest::setIndexBufferUnsignedInt() {
 
     MAGNUM_VERIFY_NO_GL_ERROR();
     CORRADE_COMPARE(mesh.indexType(), GL::MeshIndexType::UnsignedInt);
-    CORRADE_COMPARE(mesh.indexTypeSize(), 4);
 
     const auto value = Checker(MultipleShader{},
         #ifndef MAGNUM_TARGET_GLES2

src/Magnum/GL/Test/MeshTest.cpp

@@ -58,6 +58,9 @@ struct MeshTest: TestSuite::Tester {
     void mapIndexTypeImplementationSpecific();
     void mapIndexTypeInvalid();
 
+    void indexTypeSize();
+    void indexTypeSizeInvalid();
+
     void debugPrimitive();
     void debugIndexType();
 };
@@ -81,6 +84,9 @@ MeshTest::MeshTest() {
               &MeshTest::mapIndexTypeImplementationSpecific,
               &MeshTest::mapIndexTypeInvalid,
 
+              &MeshTest::indexTypeSize,
+              &MeshTest::indexTypeSizeInvalid,
+
               &MeshTest::debugPrimitive,
               &MeshTest::debugIndexType});
 }
@@ -264,6 +270,24 @@ void MeshTest::mapIndexTypeInvalid() {
         "GL::meshIndexType(): invalid type MeshIndexType(0x12)\n");
 }
 
+void MeshTest::indexTypeSize() {
+    CORRADE_COMPARE(meshIndexTypeSize(MeshIndexType::UnsignedByte), 1);
+    CORRADE_COMPARE(meshIndexTypeSize(MeshIndexType::UnsignedShort), 2);
+    CORRADE_COMPARE(meshIndexTypeSize(MeshIndexType::UnsignedInt), 4);
+}
+
+void MeshTest::indexTypeSizeInvalid() {
+    CORRADE_SKIP_IF_NO_ASSERT();
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    meshIndexTypeSize(MeshIndexType{});
+    meshIndexTypeSize(MeshIndexType(0xbadcafe));
+    CORRADE_COMPARE(out.str(),
+        "GL::meshIndexTypeSize(): invalid type GL::MeshIndexType(0x0)\n"
+        "GL::meshIndexTypeSize(): invalid type GL::MeshIndexType(0xbadcafe)\n");
+}
+
 void MeshTest::debugPrimitive() {
     std::ostringstream o;
     Debug(&o) << MeshPrimitive::TriangleFan << MeshPrimitive(0xdead);