[Fix] (Getter): answer the GL 4.6 limit surface honestly - tess/cull/subroutine pnames, TBuiltInResource drift, 84 UBO binding points, 64-bit GL_MAX_ELEMENT_INDEX, per-category sample truth

MobileGL/MG_State/GLState/BufferState/BufferState.h

@@ -19,7 +19,14 @@ namespace MobileGL::MG_State::GLState {
                 BufferTarget::DrawIndirect, BufferTarget::Parameter, BufferTarget::ShaderStorage);
     constexpr const auto BufferBindPointTargets = ToArray(BufferTarget::Uniform, BufferTarget::TransformFeedback,
                                                           BufferTarget::AtomicCounter, BufferTarget::ShaderStorage);
-    constexpr SizeT BufferBindingPointCount = 36;
+    // How many indexed binding points each of BufferBindPointTargets gets. 84 is the GL 4.5 core
+    // minimum for GL_MAX_UNIFORM_BUFFER_BINDINGS (table 23.64) and this array is the capacity
+    // that limit is clamped against - at 36 the clamp in GL_Getter was degenerate (lo == hi) and
+    // no application could ever be told about, or bind to, a binding point past the 36th. The
+    // other three targets advertise their own, smaller ceilings out of
+    // GetIndexedBufferQueryPointCount, so widening this does not widen what they promise; it only
+    // costs the unused tail of three arrays.
+    constexpr SizeT BufferBindingPointCount = 84;
 
     class BufferState {
     public:

MobileGL/MG_State/GLState/ProgramState/ProgramLinkTask.cpp

@@ -29,13 +29,11 @@ namespace {
     // capacity, which is also the width of the Uint32 masks backends build from it.
     static MobileGL::Int GetReflectionVertexAttribLimit(
         const MobileGL::MG_Util::ShaderTranspiler::CompileEnv& env) {
-        constexpr MobileGL::Int capacity =
-            static_cast<MobileGL::Int>(MobileGL::MG_State::GLState::VertexArrayObject::MAX_VERTEX_ATTRIBS);
-        if (!env.HasBackend()) return capacity;
-
-        const MobileGL::Int backendLimit = env.params.MaxVertexAttribs;
-        if (backendLimit <= 0) return capacity;
-        return std::min(backendLimit, capacity);
+        // One shared definition with glGetIntegerv(GL_MAX_VERTEX_ATTRIBS) and with
+        // BuildTBuiltInResource's gl_MaxVertexAttribs - the three used to carry three copies of
+        // this formula and glslang's copy was a hardcoded 64.
+        return MobileGL::MG_Util::ShaderTranspiler::ResolveMaxVertexAttribs(env.HasBackend(),
+                                                                            env.params.MaxVertexAttribs);
     }
 
     // Everything the post-link query surface ever asks a glslang::TType, flattened into a