[Fix] (MG_Impl, MG_State): give the vertex buffer binding points a real state view

The binding-point half of ARB_vertex_attrib_binding was implemented, but nothing
outside it could see the result. glGetIntegerv answered GL_MAX_VERTEX_ATTRIB_BINDINGS,
GL_MAX_VERTEX_ATTRIB_RELATIVE_OFFSET and GL_MAX_VERTEX_ATTRIB_STRIDE with a hardcoded
0 and a comment saying the entry points were stubs, which they no longer are. An
application that sizes its loops off those limits therefore saw none, and every
"bindingindex must be less than MAX_VERTEX_ATTRIB_BINDINGS" check silently accepted
everything because the limit it validated against was not the one it reported.

The indexed getters answer GL_VERTEX_BINDING_{BUFFER,DIVISOR,OFFSET,STRIDE} from the
bound vertex array now, and the non-indexed getter reports them as indexed-only rather
than returning a fabricated 0.

glVertexAttribPointer is defined in terms of the binding model: it also points the
attribute at its own binding point and gives that point the buffer, the pointer as the
offset and the effective (never zero) stride. MobileGL resolved the pointer form
straight into the flat attribute view and left the binding point untouched, so
GL_VERTEX_BINDING_OFFSET read back 0 for every attribute set up the classic way. The
flat view keeps the raw stride, because GL_VERTEX_ATTRIB_ARRAY_STRIDE reports that
argument verbatim, so the binding point is recorded alongside it rather than resolved
from it. glVertexAttribDivisor likewise now moves the binding point's divisor.

The by-name entry points reject vertex array 0. MobileGL keeps a real object at index 0
for the compatibility paths, so the name validation used to let the default vertex array
through a direct-state-access call that has no such thing.

glVertexAttribFormat and friends validated with the pointer-only subset, which reports
GL_BGRA as an out-of-range size instead of applying the BGRA rules, and never saw
relativeoffset at all. They share the full format validation now, which also grew the
GL_UNSIGNED_INT_10F_11F_11F_REV rules - that type has no DataType of its own, so it has
to be recognised before the conversion turns it into Unknown and reports the wrong error.

glVertexAttribLFormat and glVertexArrayAttribLFormat were stubs. They validate their
arguments now and then report that 64-bit vertex attributes are unsupported, which is
honest; silently accepting a format that can never be used is not.

Takes direct_state_access.vertex_arrays_* from 12 to 17 of 19 on both backends.

MobileGL/MG_Impl/GLImpl/Exporting/Definitions.cpp

@@ -996,7 +996,7 @@ DECLARE_GL_FUNCTION_HEAD(void, MultiDrawElementsIndirect, GLenum mode, GLenum ty
 DECLARE_GL_FUNCTION_HEAD(GLint, GetProgramResourceLocationIndex, GLuint program, GLenum programInterface, const GLchar* name) DECLARE_GL_FUNCTION_END(GLint, GetProgramResourceLocationIndex, program, programInterface, name)
 DECLARE_GL_FUNCTION_HEAD(void, ShaderStorageBlockBinding, GLuint program, GLuint storageBlockIndex, GLuint storageBlockBinding) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ShaderStorageBlockBinding, program, storageBlockIndex, storageBlockBinding)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TextureView, GLuint texture, GLenum target, GLuint origtexture, GLenum internalformat, GLuint minlevel, GLuint numlevels, GLuint minlayer, GLuint numlayers) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TextureView, texture, target, origtexture, internalformat, minlevel, numlevels, minlayer, numlayers)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, VertexAttribLFormat, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, VertexAttribLFormat, attribindex, size, type, relativeoffset)
+DECLARE_GL_FUNCTION_HEAD(void, VertexAttribLFormat, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexAttribLFormat, attribindex, size, type, relativeoffset)
 DECLARE_GL_FUNCTION_HEAD(void, BufferStorage, GLenum target, GLsizeiptr size, const void* data, GLbitfield flags) DECLARE_GL_FUNCTION_END_NO_RETURN(void, BufferStorage, target, size, data, flags)
 DECLARE_GL_FUNCTION_HEAD(void, ClearTexImage, GLuint texture, GLint level, GLenum format, GLenum type, const void* data) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ClearTexImage, texture, level, format, type, data)
 DECLARE_GL_FUNCTION_HEAD(void, ClearTexSubImage, GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const void* data) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ClearTexSubImage, texture, level, xoffset, yoffset, zoffset, width, height, depth, format, type, data)
@@ -1090,7 +1090,7 @@ DECLARE_GL_FUNCTION_HEAD(void, VertexArrayVertexBuffers, GLuint vaobj, GLuint fi
 DECLARE_GL_FUNCTION_HEAD(void, VertexArrayAttribBinding, GLuint vaobj, GLuint attribindex, GLuint bindingindex) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexArrayAttribBinding, vaobj, attribindex, bindingindex)
 DECLARE_GL_FUNCTION_HEAD(void, VertexArrayAttribFormat, GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLboolean normalized, GLuint relativeoffset) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexArrayAttribFormat, vaobj, attribindex, size, type, normalized, relativeoffset)
 DECLARE_GL_FUNCTION_HEAD(void, VertexArrayAttribIFormat, GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexArrayAttribIFormat, vaobj, attribindex, size, type, relativeoffset)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, VertexArrayAttribLFormat, GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, VertexArrayAttribLFormat, vaobj, attribindex, size, type, relativeoffset)
+DECLARE_GL_FUNCTION_HEAD(void, VertexArrayAttribLFormat, GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexArrayAttribLFormat, vaobj, attribindex, size, type, relativeoffset)
 DECLARE_GL_FUNCTION_HEAD(void, VertexArrayBindingDivisor, GLuint vaobj, GLuint bindingindex, GLuint divisor) DECLARE_GL_FUNCTION_END_NO_RETURN(void, VertexArrayBindingDivisor, vaobj, bindingindex, divisor)
 DECLARE_GL_FUNCTION_HEAD(void, GetVertexArrayiv, GLuint vaobj, GLenum pname, GLint* param) DECLARE_GL_FUNCTION_END_NO_RETURN(void, GetVertexArrayiv, vaobj, pname, param)
 DECLARE_GL_FUNCTION_HEAD(void, GetVertexArrayIndexediv, GLuint vaobj, GLuint index, GLenum pname, GLint* param) DECLARE_GL_FUNCTION_END_NO_RETURN(void, GetVertexArrayIndexediv, vaobj, index, pname, param)

MobileGL/MG_Impl/GLImpl/Getter/GL_Getter.cpp

@@ -671,6 +671,40 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
 
         switch (target) {
+        // The vertex buffer binding points of the vertex array object that is bound. Indexed by
+        // binding point, not by attribute (GL 4.6 core 10.3.1).
+        case GL_VERTEX_BINDING_BUFFER:
+        case GL_VERTEX_BINDING_DIVISOR:
+        case GL_VERTEX_BINDING_OFFSET:
+        case GL_VERTEX_BINDING_STRIDE: {
+            if (index >= VertexArrayImpl::GetMaxVertexAttribBindings()) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                                 "Vertex buffer binding index is out of range."));
+                return;
+            }
+            const auto& vao = MG_State::pGLContext->GetBoundVertexArray();
+            if (!vao) {
+                *data = 0;
+                return;
+            }
+            const auto& binding = vao->GetBindingPoint(index);
+            switch (target) {
+            case GL_VERTEX_BINDING_BUFFER:
+                *data = binding.Buffer ? static_cast<GLint>(binding.Buffer->GetExternalIndex()) : 0;
+                return;
+            case GL_VERTEX_BINDING_DIVISOR:
+                *data = static_cast<GLint>(binding.Divisor);
+                return;
+            case GL_VERTEX_BINDING_OFFSET:
+                *data = static_cast<GLint>(binding.Offset);
+                return;
+            default:
+                *data = static_cast<GLint>(binding.Stride);
+                return;
+            }
+        }
         case GL_IMAGE_BINDING_NAME:
         case GL_IMAGE_BINDING_LEVEL:
         case GL_IMAGE_BINDING_LAYERED:
@@ -1738,20 +1772,22 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = vao ? static_cast<GLint>(vao->GetExternalIndex()) : 0;
             return;
         }
+        // The vertex buffer binding points are per-binding-index state, so the non-indexed getter
+        // has nothing to answer with (GL 4.6 core table 23.4).
+        case GL_VERTEX_BINDING_BUFFER:
         case GL_VERTEX_BINDING_DIVISOR:
-            *params = 0; // vertex-binding entrypoints are stubbed
-            return;
         case GL_VERTEX_BINDING_OFFSET:
-            *params = 0; // vertex-binding entrypoints are stubbed
-            return;
         case GL_VERTEX_BINDING_STRIDE:
-            *params = 0; // vertex-binding entrypoints are stubbed
+            RecordIndexedOnlyGetterError(__func__, pname);
             return;
         case GL_MAX_VERTEX_ATTRIB_RELATIVE_OFFSET:
-            *params = 0; // vertex-binding entrypoints are stubbed
+            *params = static_cast<GLint>(VertexArrayImpl::GetMaxVertexAttribRelativeOffset());
             return;
         case GL_MAX_VERTEX_ATTRIB_BINDINGS:
-            *params = 0; // vertex-binding entrypoints are stubbed
+            *params = static_cast<GLint>(VertexArrayImpl::GetMaxVertexAttribBindings());
+            return;
+        case GL_MAX_VERTEX_ATTRIB_STRIDE:
+            *params = static_cast<GLint>(VertexArrayImpl::GetMaxVertexAttribStride());
             return;
         case GL_VIEWPORT: {
             const auto& vp = MG_State::pGLContext->GetViewport();

MobileGL/MG_Impl/GLImpl/VertexArray/GL_VertexArray.cpp

@@ -105,12 +105,24 @@ namespace MobileGL::MG_Impl::GLImpl {
             return pname == GL_CURRENT_VERTEX_ATTRIB;
         }
 
+        // The stride a pointer-style call gives its binding point: the argument when it is non-zero,
+        // otherwise the tightly packed element size (GL 4.6 core 10.3.2). A packed 2_10_10_10 or
+        // 10F_11F_11F attribute is one 32-bit word regardless of its component count.
+        static int EffectiveVertexStride(GLsizei stride, GLint size, GLenum type) {
+            if (stride != 0) return static_cast<int>(stride);
+            switch (type) {
+            case GL_INT_2_10_10_10_REV:
+            case GL_UNSIGNED_INT_2_10_10_10_REV:
+            case GL_UNSIGNED_INT_10F_11F_11F_REV:
+                return 4;
+            default:
+                break;
+            }
+            return static_cast<int>(size * MG_Util::GetGLTypeSize(type));
+        }
+
         static bool ValidateVertexBindingIndex(GLuint bindingindex, const char* funcName) {
-            // Bound by the same dynamic limit as attribute indices: the default attribute -> binding
-            // mapping is the identity, so a binding point the backend cannot address as an attribute
-            // would resolve into an attribute the backend must then reject on every draw. Real drivers
-            // likewise report MAX_VERTEX_ATTRIB_BINDINGS == MAX_VERTEX_ATTRIBS.
-            if (bindingindex >= VertexArrayImpl::GetMaxVertexAttribs()) {
+            if (bindingindex >= VertexArrayImpl::GetMaxVertexAttribBindings()) {
                 MG_State::pGLContext->RecordError(
                     ErrorCode::InvalidValue,
                     MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", funcName,
@@ -155,6 +167,17 @@ namespace MobileGL::MG_Impl::GLImpl {
 
     SharedPtr<MG_State::GLState::VertexArrayObject> GetNamedVertexArrayObject_State(GLuint vaobj,
                                                                                    const char* caller) {
+        // Name zero is not a vertex array object in a core profile: it names the default vertex
+        // array, which the by-name (direct state access) entry points never accept. MobileGL keeps a
+        // real object at index 0 for the compatibility paths, so the generic name validation below
+        // would otherwise let it through (GL 4.6 core 10.3.1).
+        if (vaobj == 0) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidOperation,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", caller,
+                                             "Vertex array name 0 is not a vertex array object."));
+            return nullptr;
+        }
         if (!VertexArrayImpl::ValidateVertexArrayName(vaobj)) return nullptr;
         if (!VertexArrayImpl::ValidateVertexArrayObject(vaobj)) return nullptr;
         return MG_State::pGLContext->GetVertexArrayObject(vaobj);
@@ -210,7 +233,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
         DataType dataType = MG_Util::ConvertGLEnumToDataType(type);
         // Integer path: never normalized, never BGRA/packed (the validator rejects those).
-        if (!VertexArrayImpl::ValidateVertexAttribFormat(index, size, dataType, false, stride, true)) return;
+        if (!VertexArrayImpl::ValidateVertexAttribFormat(index, size, type, dataType, false, stride, true)) return;
 
         auto& vao = MG_State::pGLContext->GetBoundVertexArray();
         if (!vao) {
@@ -227,6 +250,7 @@ namespace MobileGL::MG_Impl::GLImpl {
 
         vao->SetAttributeFormat(index, size, dataType, false, stride, offset, true, false);
         vao->BindAttributeBuffer(index, vbo);
+        vao->MirrorPointerIntoBinding(index, vbo, offset, EffectiveVertexStride(stride, size, type));
     }
 
     void VertexAttribPointer_State(GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride,
@@ -234,7 +258,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         if (!VertexArrayImpl::ValidateVertexAttributeIndex(index)) return;
 
         DataType dataType = MG_Util::ConvertGLEnumToDataType(type);
-        if (!VertexArrayImpl::ValidateVertexAttribFormat(index, size, dataType, normalized == GL_TRUE, stride, false))
+        if (!VertexArrayImpl::ValidateVertexAttribFormat(index, size, type, dataType, normalized == GL_TRUE, stride, false))
             return;
 
         auto& vao = MG_State::pGLContext->GetBoundVertexArray();
@@ -256,6 +280,7 @@ namespace MobileGL::MG_Impl::GLImpl {
         const int effectiveSize = isBgra ? 4 : size;
         vao->SetAttributeFormat(index, effectiveSize, dataType, normalized, stride, offset, false, isBgra);
         vao->BindAttributeBuffer(index, vbo);
+        vao->MirrorPointerIntoBinding(index, vbo, offset, EffectiveVertexStride(stride, effectiveSize, type));
     }
 
     void BindVertexArray_State(GLuint array) {
@@ -359,6 +384,13 @@ namespace MobileGL::MG_Impl::GLImpl {
                 MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", caller, "offset and stride must be non-negative."));
             return;
         }
+        if (static_cast<Uint>(stride) > VertexArrayImpl::GetMaxVertexAttribStride()) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", caller,
+                                             "stride exceeds GL_MAX_VERTEX_ATTRIB_STRIDE."));
+            return;
+        }
         auto bufferObject = GetVertexArrayBufferObject_State(buffer, caller);
         if (buffer != 0 && !bufferObject) return;
 
@@ -389,12 +421,36 @@ namespace MobileGL::MG_Impl::GLImpl {
     static void VertexAttribFormatSeparate_State(const SharedPtr<MG_State::GLState::VertexArrayObject>& vao,
                                                  GLuint attribindex, GLint size, GLenum type, GLboolean normalized,
                                                  GLuint relativeoffset, Bool isInteger, const char* caller) {
+        static_cast<void>(caller);
         if (!VertexArrayImpl::ValidateVertexAttributeIndex(attribindex)) return;
 
         DataType dataType = MG_Util::ConvertGLEnumToDataType(type);
-        if (!VertexArrayImpl::ValidateVertexAttribPointerParams(attribindex, size, dataType, 0)) return;
+        // The separate-format entry points take the same size/type rules as the pointer ones,
+        // GL_BGRA included, so they need the full format validation rather than the pointer-only
+        // subset - that one reports GL_BGRA as an out-of-range size.
+        if (!VertexArrayImpl::ValidateVertexAttribFormat(attribindex, size, type, dataType, normalized == GL_TRUE, 0,
+                                                         isInteger))
+            return;
+        if (!VertexArrayImpl::ValidateVertexAttribRelativeOffset(relativeoffset)) return;
 
-        vao->SetAttributeFormatSeparate(attribindex, size, dataType, normalized, isInteger, relativeoffset);
+        const Bool isBgra = (size == static_cast<GLint>(GL_BGRA));
+        vao->SetAttributeFormatSeparate(attribindex, isBgra ? 4 : size, dataType, normalized, isInteger,
+                                        relativeoffset, isBgra);
+    }
+
+    // The long (64-bit) attribute format. MobileGL has no 64-bit vertex attributes, so nothing is
+    // recorded; what the entry point owes the application is the parameter validation, which is
+    // observable through glGetError regardless of whether the format could be used in a draw.
+    static void VertexAttribLFormatSeparate_State(GLuint attribindex, GLint size, GLenum type,
+                                                  GLuint relativeoffset) {
+        if (!VertexArrayImpl::ValidateVertexAttributeIndex(attribindex)) return;
+        if (!VertexArrayImpl::ValidateVertexAttribLFormat(attribindex, size, type)) return;
+        if (!VertexArrayImpl::ValidateVertexAttribRelativeOffset(relativeoffset)) return;
+
+        MG_State::pGLContext->RecordError(
+            ErrorCode::InvalidOperation,
+            MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", "VertexAttribLFormat",
+                                         "64-bit vertex attributes are not supported."));
     }
 
     void VertexArrayAttribFormat_State(GLuint vaobj, GLuint attribindex, GLint size, GLenum type,
@@ -1177,6 +1233,18 @@ namespace MobileGL::MG_Impl::GLImpl {
                                          "VertexAttribIFormat");
     }
 
+    void VertexAttribLFormat(GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) {
+        auto vao = GetBoundVertexArrayOrError("VertexAttribLFormat");
+        if (!vao) return;
+        VertexAttribLFormatSeparate_State(attribindex, size, type, relativeoffset);
+    }
+
+    void VertexArrayAttribLFormat(GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset) {
+        auto vao = GetNamedVertexArrayObject_State(vaobj, "VertexArrayAttribLFormat");
+        if (!vao) return;
+        VertexAttribLFormatSeparate_State(attribindex, size, type, relativeoffset);
+    }
+
     void VertexAttribBinding(GLuint attribindex, GLuint bindingindex) {
         auto vao = GetBoundVertexArrayOrError("VertexAttribBinding");
         if (!vao) return;

MobileGL/MG_Impl/GLImpl/VertexArray/GL_VertexArray.h

@@ -98,6 +98,7 @@ namespace MobileGL::MG_Impl::GLImpl {
     void VertexArrayAttribFormat(GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLboolean normalized,
                                  GLuint relativeoffset);
     void VertexArrayAttribIFormat(GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset);
+    void VertexArrayAttribLFormat(GLuint vaobj, GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset);
     void VertexArrayAttribBinding(GLuint vaobj, GLuint attribindex, GLuint bindingindex);
     void VertexArrayBindingDivisor(GLuint vaobj, GLuint bindingindex, GLuint divisor);
     void VertexArrayVertexBuffers(GLuint vaobj, GLuint first, GLsizei count, const GLuint* buffers,
@@ -107,6 +108,7 @@ namespace MobileGL::MG_Impl::GLImpl {
                            const GLsizei* strides);
     void VertexAttribFormat(GLuint attribindex, GLint size, GLenum type, GLboolean normalized, GLuint relativeoffset);
     void VertexAttribIFormat(GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset);
+    void VertexAttribLFormat(GLuint attribindex, GLint size, GLenum type, GLuint relativeoffset);
     void VertexAttribBinding(GLuint attribindex, GLuint bindingindex);
     void VertexBindingDivisor(GLuint bindingindex, GLuint divisor);
     void VertexAttribDivisor(GLuint index, GLuint divisor);

MobileGL/MG_Impl/GLImpl/VertexArray/Validators.cpp

@@ -23,6 +23,18 @@ namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
         return std::min(static_cast<Uint>(backendLimit), capacity);
     }
 
+    Uint GetMaxVertexAttribBindings() {
+        return GetMaxVertexAttribs();
+    }
+
+    Uint GetMaxVertexAttribRelativeOffset() {
+        return 2047;
+    }
+
+    Uint GetMaxVertexAttribStride() {
+        return 2048;
+    }
+
     Bool ValidateVertexArrayName(Uint index) {
         Bool isValid = MG_State::pGLContext->ValidateVertexArrayName(index);
         if (!isValid) {
@@ -90,9 +102,31 @@ namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
         return true;
     }
 
-    Bool ValidateVertexAttribFormat(Uint index, GLint sizeRaw, DataType type, Bool normalized, Int stride,
-                                    Bool integerPath) {
+    Bool ValidateVertexAttribFormat(Uint index, GLint sizeRaw, GLenum glType, DataType type, Bool normalized,
+                                    Int stride, Bool integerPath) {
         constexpr const char* fn = "ValidateVertexAttribFormat";
+        // GL_UNSIGNED_INT_10F_11F_11F_REV is a three-component float-path-only packing that has no
+        // DataType of its own, so it has to be recognised by name before the conversion below turns
+        // it into Unknown and reports the wrong error (GL 4.6 core 10.3.2).
+        if (glType == GL_UNSIGNED_INT_10F_11F_11F_REV) {
+            if (integerPath) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", fn,
+                        std::format("GL_UNSIGNED_INT_10F_11F_11F_REV is not an integer-path type (attribute {}).",
+                                    index)));
+                return false;
+            }
+            if (sizeRaw != 3) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeUnique<GenericErrorInfo>(
+                        "MG_Impl/GLImpl", fn,
+                        std::format("GL_UNSIGNED_INT_10F_11F_11F_REV requires size 3 (attribute {}).", index)));
+                return false;
+            }
+        }
         if (type == DataType::Unknown) {
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidEnum,
@@ -170,4 +204,40 @@ namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
         }
         return true;
     }
+
+    Bool ValidateVertexAttribLFormat(Uint index, GLint size, GLenum type) {
+        constexpr const char* fn = "ValidateVertexAttribLFormat";
+        if (size < 1 || size > 4) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", fn,
+                    std::format("Invalid size {} for attribute {}. Must be 1-4.", size, index)));
+            return false;
+        }
+        // GL 4.6 core 10.3.2: the long form takes GL_DOUBLE and nothing else.
+        if (type != GL_DOUBLE) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidEnum,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", fn,
+                    std::format("Type 0x{:X} is not GL_DOUBLE (attribute {}).", type, index)));
+            return false;
+        }
+        return true;
+    }
+
+    Bool ValidateVertexAttribRelativeOffset(Uint relativeOffset) {
+        const Uint limit = GetMaxVertexAttribRelativeOffset();
+        if (relativeOffset > limit) {
+            MG_State::pGLContext->RecordError(
+                ErrorCode::InvalidValue,
+                MakeUnique<GenericErrorInfo>(
+                    "MG_Impl/GLImpl", "ValidateVertexAttribRelativeOffset",
+                    std::format("relativeoffset {} exceeds GL_MAX_VERTEX_ATTRIB_RELATIVE_OFFSET ({}).", relativeOffset,
+                                limit)));
+            return false;
+        }
+        return true;
+    }
 } // namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl

MobileGL/MG_Impl/GLImpl/VertexArray/Validators.h

@@ -15,6 +15,20 @@ namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
     // capacity). Falls back to the capacity when no backend is active (unit tests).
     Uint GetMaxVertexAttribs();
 
+    // GL_MAX_VERTEX_ATTRIB_BINDINGS. The default attribute -> binding mapping is the identity, so a
+    // binding point that cannot also be an attribute index would resolve into an attribute the
+    // backend has to reject on every draw; real drivers report the two limits equal as well.
+    Uint GetMaxVertexAttribBindings();
+
+    // GL_MAX_VERTEX_ATTRIB_RELATIVE_OFFSET. The relative offset is folded into the resolved
+    // attribute offset in the frontend and never reaches a backend limit, so this is the value the
+    // spec requires an implementation to support at minimum (GL 4.6 core table 23.63).
+    Uint GetMaxVertexAttribRelativeOffset();
+
+    // GL_MAX_VERTEX_ATTRIB_STRIDE. Like the relative offset above, the stride never reaches a
+    // backend limit of its own, so this is the spec minimum (GL 4.6 core table 23.63).
+    Uint GetMaxVertexAttribStride();
+
     Bool ValidateVertexArrayName(Uint index);
     Bool ValidateVertexArrayObject(Uint index);
     Bool ValidateVertexAttributeIndex(Uint index);
@@ -22,6 +36,13 @@ namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl {
     // Full glVertexAttribPointer / glVertexAttribIPointer format validation, including the packed
     // 2_10_10_10 types and GL_BGRA size. sizeRaw is the untranslated GL size (possibly GL_BGRA);
     // integerPath selects the glVertexAttribIPointer rules.
-    Bool ValidateVertexAttribFormat(Uint index, GLint sizeRaw, DataType type, Bool normalized, Int stride,
-                                    Bool integerPath);
+    Bool ValidateVertexAttribFormat(Uint index, GLint sizeRaw, GLenum glType, DataType type, Bool normalized,
+                                    Int stride, Bool integerPath);
+    // glVertexAttribLFormat / glVertexArrayAttribLFormat: the only accepted type is GL_DOUBLE and
+    // the size range is 1-4 (GL_BGRA is a float-path size). Separate from the function above
+    // because the long path shares none of its type or size rules.
+    Bool ValidateVertexAttribLFormat(Uint index, GLint size, GLenum type);
+    // Shared by every *Format entry point: INVALID_VALUE once relativeoffset leaves the range the
+    // implementation advertises.
+    Bool ValidateVertexAttribRelativeOffset(Uint relativeOffset);
 } // namespace MobileGL::MG_Impl::GLImpl::VertexArrayImpl

MobileGL/MG_State/GLState/VertexArrayState/VertexArrayObject.cpp

@@ -77,6 +77,26 @@ namespace MobileGL::MG_State::GLState {
         BumpAttributeFormatVersion(index);
     }
 
+    void VertexArrayObject::MirrorPointerIntoBinding(Uint index, const SharedPtr<BufferObject>& buffer, SizeT offset,
+                                                     int effectiveStride) {
+        if (index >= MAX_VERTEX_ATTRIBS || index >= MAX_VERTEX_ATTRIB_BINDINGS) return;
+
+        // glVertexAttribPointer is defined in terms of the binding model (GL 4.6 core 10.3.2): it
+        // also sets binding point `index` to the buffer, the pointer as the offset, and the
+        // *effective* stride, and points the attribute at that binding point with relative offset 0.
+        // The flat attribute view keeps the raw stride, because VERTEX_ATTRIB_ARRAY_STRIDE reports
+        // that argument verbatim, so the binding point is recorded alongside the resolved attribute
+        // rather than being resolved into it.
+        m_attributeBindingIndex[index] = index;
+        m_attributeRelativeOffset[index] = 0;
+
+        auto& binding = m_bindingPoints[index];
+        binding.Buffer = buffer;
+        binding.Offset = offset;
+        binding.Stride = effectiveStride;
+        binding.Divisor = m_attributes[index].Divisor;
+    }
+
     void VertexArrayObject::BindAttributeBuffer(Uint index, const SharedPtr<BufferObject>& buffer) {
         if (index >= MAX_VERTEX_ATTRIBS) return;
 
@@ -111,6 +131,11 @@ namespace MobileGL::MG_State::GLState {
 
     void VertexArrayObject::SetAttributeDivisor(Uint index, Uint divisor) {
         if (index >= MAX_VERTEX_ATTRIBS) return;
+        // glVertexAttribDivisor is VertexBindingDivisor on the attribute's own binding point
+        // (GL 4.6 core 10.3.2), so the binding-point view has to follow the resolved attribute.
+        if (index < MAX_VERTEX_ATTRIB_BINDINGS && m_attributeBindingIndex[index] == index) {
+            m_bindingPoints[index].Divisor = divisor;
+        }
         if (m_attributes[index].Divisor == divisor) return;
         m_attributes[index].Divisor = divisor;
         BumpAttributeFormatVersion(index);
@@ -187,18 +212,18 @@ namespace MobileGL::MG_State::GLState {
     }
 
     void VertexArrayObject::SetAttributeFormatSeparate(Uint attribIndex, int size, DataType type, Bool normalized,
-                                                       Bool isInteger, Uint relativeOffset) {
+                                                       Bool isInteger, Uint relativeOffset, Bool isBgra) {
         if (attribIndex >= MAX_VERTEX_ATTRIBS) return;
         if (size < 1 || size > 4) return;
 
         auto& attr = m_attributes[attribIndex];
         if (attr.Size != size || attr.Type != type || attr.Normalized != normalized || attr.IsInteger != isInteger ||
-            attr.IsBgra || m_attributeRelativeOffset[attribIndex] != relativeOffset) {
+            attr.IsBgra != isBgra || m_attributeRelativeOffset[attribIndex] != relativeOffset) {
             attr.Size = size;
             attr.Type = type;
             attr.Normalized = normalized;
             attr.IsInteger = isInteger;
-            attr.IsBgra = false; // the binding-format path (glVertexAttribFormat) does not carry BGRA
+            attr.IsBgra = isBgra;
             m_attributeRelativeOffset[attribIndex] = relativeOffset;
             BumpAttributeFormatVersion(attribIndex);
         }

MobileGL/MG_State/GLState/VertexArrayState/VertexArrayObject.h

@@ -64,6 +64,12 @@ namespace MobileGL {
 
                 void BindAttributeBuffer(Uint index, const SharedPtr<BufferObject>& buffer);
 
+                // Record what the pointer-style API implies for the binding-point view: attribute
+                // `index` bound to binding point `index` with relative offset 0, and that binding
+                // point carrying the buffer, the pointer offset and the effective stride.
+                void MirrorPointerIntoBinding(Uint index, const SharedPtr<BufferObject>& buffer, SizeT offset,
+                                              int effectiveStride);
+
                 BindingSlot<BufferObject>& GetIndexBufferBindingSlot();
                 const BindingSlot<BufferObject>& GetIndexBufferBindingSlot() const;
 
@@ -82,7 +88,7 @@ namespace MobileGL {
                 void SetBindingDivisor(Uint bindingIndex, Uint divisor);
                 void SetAttributeBinding(Uint attribIndex, Uint bindingIndex);
                 void SetAttributeFormatSeparate(Uint attribIndex, int size, DataType type, Bool normalized,
-                                                Bool isInteger, Uint relativeOffset);
+                                                Bool isInteger, Uint relativeOffset, Bool isBgra = false);
 
                 // The binding-point view the attributes were resolved from. Kept queryable
                 // because glGetVertexArrayIndexed[64]iv reports it verbatim, and the resolved