Added Mesh::maxElementIndex() limit query.

doc/opengl-mapping.dox

@@ -320,9 +320,9 @@ OpenGL function                        | Matching API
 @def_gl{MAX_COLOR_TEXTURE_SAMPLES}, \n @def_gl{MAX_DEPTH_TEXTURE_SAMPLES}, \n @def_gl{MAX_INTEGER_SAMPLES} | @ref AbstractTexture::maxColorSamples(), \n @ref AbstractTexture::maxDepthSamples(), \n @ref AbstractTexture::maxIntegerSamples()
 @def_gl{MAX_DRAW_BUFFERS}              | @ref AbstractFramebuffer::maxDrawBuffers()
 @def_gl{MAX_DUAL_SOURCE_DRAW_BUFFERS}  | @ref AbstractFramebuffer::maxDualSourceDrawBuffers()
+@def_gl{MAX_ELEMENT_INDEX}             | @ref Mesh::maxElementIndex()
 @def_gl{MAX_ELEMENTS_INDICES}          | @ref Mesh::maxElementsIndices()
 @def_gl{MAX_ELEMENTS_VERTICES}         | @ref Mesh::maxElementsVertices()
-@def_gl{MAX_ELEMENT_INDEX}             | |
 @def_gl{MAX_FRAMEBUFFER_HEIGHT}        | |
 @def_gl{MAX_FRAMEBUFFER_LAYERS}        | |
 @def_gl{MAX_FRAMEBUFFER_SAMPLES}       | |

src/Magnum/Implementation/MeshState.cpp

@@ -35,7 +35,7 @@ namespace Magnum { namespace Implementation {
 
 MeshState::MeshState(Context& context, std::vector<std::string>& extensions): currentVAO(0)
     #ifndef MAGNUM_TARGET_GLES2
-    , maxElementsIndices(0), maxElementsVertices(0)
+    , maxElementIndex{0}, maxElementsIndices{0}, maxElementsVertices{0}
     #endif
 {
     #ifndef MAGNUM_TARGET_GLES

src/Magnum/Implementation/MeshState.h

@@ -64,6 +64,7 @@ struct MeshState {
 
     GLuint currentVAO;
     #ifndef MAGNUM_TARGET_GLES2
+    GLint64 maxElementIndex;
     GLint maxElementsIndices, maxElementsVertices;
     #endif
 };

src/Magnum/Mesh.cpp

@@ -41,6 +41,21 @@ namespace Magnum {
 Int Mesh::maxVertexAttributes() { return AbstractShaderProgram::maxVertexAttributes(); }
 
 #ifndef MAGNUM_TARGET_GLES2
+Long Mesh::maxElementIndex() {
+    #ifndef MAGNUM_TARGET_GLES
+    if(!Context::current()->isExtensionSupported<Extensions::GL::ARB::ES3_compatibility>())
+        return 0xFFFFFFFFl;
+    #endif
+
+    GLint64& value = Context::current()->state().mesh->maxElementIndex;
+
+    /* Get the value, if not already cached */
+    if(value == 0)
+        glGetInteger64v(GL_MAX_ELEMENT_INDEX, &value);
+
+    return value;
+}
+
 Int Mesh::maxElementsIndices() {
     GLint& value = Context::current()->state().mesh->maxElementsIndices;
 

src/Magnum/Mesh.h

@@ -375,6 +375,19 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
         static Int maxVertexAttributes();
 
         #ifndef MAGNUM_TARGET_GLES2
+        /**
+         * @brief Max supported index value
+         *
+         * The result is cached, repeated queries don't result in repeated
+         * OpenGL calls. If extension @extension{ARB,ES3_compatibility} (part
+         * of OpenGL 4.3) is not available, returns max representable 32-bit
+         * value (@f$ 2^32 - 1 @f$).
+         * @see @ref setIndexBuffer(), @fn_gl{Get} with @def_gl{MAX_ELEMENT_INDEX}
+         * @requires_gles30 No upper limit is specified for index values in
+         *      OpenGL ES 2.0
+         */
+        static Long maxElementIndex();
+
         /**
          * @brief Max recommended index count
          *
@@ -744,9 +757,9 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
          * ES 3.0 or @es_extension{OES,vertex_array_object} in OpenGL ES 2.0 is
          * available, the vertex array object is used to hold the parameters.
          *
-         * @see @ref maxElementsIndices(), @ref maxElementsVertices(),
-         *      @ref setCount(), @ref isIndexed(), @fn_gl{BindVertexArray},
-         *      @fn_gl{BindBuffer}
+         * @see @ref maxElementIndex(), @ref maxElementsIndices(),
+         *      @ref maxElementsVertices(), @ref setCount(), @ref isIndexed(),
+         *      @fn_gl{BindVertexArray}, @fn_gl{BindBuffer}
          */
         Mesh& setIndexBuffer(Buffer& buffer, GLintptr offset, IndexType type, UnsignedInt start, UnsignedInt end);
 

src/Magnum/Platform/magnum-info.cpp

@@ -291,6 +291,7 @@ MagnumInfo::MagnumInfo(const Arguments& arguments): Platform::WindowlessApplicat
     _l(AbstractFramebuffer::maxDrawBuffers())
     _l(Framebuffer::maxColorAttachments())
     #ifndef MAGNUM_TARGET_GLES2
+    _l(Mesh::maxElementIndex())
     _l(Mesh::maxElementsIndices())
     _l(Mesh::maxElementsVertices())
     #endif