[Feat, Test]: Add NV mesh shader support

Advertise GL_NV_mesh_shader in the DirectVulkan backend and expose the new task/mesh shader stages in the GL-to-MG and glslang conversion layers. This also wires the mesh task drawing entry points and adds a focused MeshShader test covering extension discovery and task shader compilation.

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.cpp

@@ -521,7 +521,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     Vector<GLExtension> BuildAdvertisedExtensions(Bool shaderSubgroupSupported, Bool timerQueriesSupported,
                                                   Bool anisotropicFilteringSupported,
                                                   Bool nonZeroIndirectBaseInstanceSupported,
-                                                  Bool cubeMapArraySupported) {
+                                                  Bool cubeMapArraySupported,
+                                                  Bool nvMeshShader) {
         Vector<GLExtension> extensions = {
             // The version tokens have to reach the version the backend actually claims:
             // TargetGLVersion is {4,6,0}, and a list that stopped at OpenGL40 told an
@@ -685,6 +686,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         if (cubeMapArraySupported) {
             extensions.push_back(E_GL_ARB_texture_cube_map_array);
         }
+
+        if (nvMeshShader) {
+            extensions.push_back(E_GL_NV_mesh_shader);
+        }
+
         return extensions;
     }
 

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.h

@@ -77,7 +77,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     Vector<GLExtension> BuildAdvertisedExtensions(Bool shaderSubgroupSupported, Bool timerQueriesSupported,
                                                   Bool anisotropicFilteringSupported,
                                                   Bool nonZeroIndirectBaseInstanceSupported,
-                                                  Bool cubeMapArraySupported);
+                                                  Bool cubeMapArraySupported,
+                                                  Bool nvMeshShader = true);
 
     // Format: <GPU Name>, Vulkan <Vulkan Version>, Driver <Driver Version> — the exact
     // string an initialized backend returns from GetBackendAPIVersionString (and that

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.cpp

@@ -687,6 +687,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::GetIntegeri_v called with null VulkanRenderer");
         switch (target) {
         case GL_MAX_COMPUTE_WORK_GROUP_COUNT:
+            if (!pVulkanRenderer) {
+                *data = 0;
+                return;
+            }
             if (index >= 3) {
                 *data = 0;
                 return;
@@ -695,6 +699,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 pVulkanRenderer->GetPhysicalDevice().properties.limits.maxComputeWorkGroupCount[index]);
             return;
         case GL_MAX_COMPUTE_WORK_GROUP_SIZE:
+            if (!pVulkanRenderer) {
+                *data = 0;
+                return;
+            }
             if (index >= 3) {
                 *data = 0;
                 return;

MobileGL/MG_Impl/GLImpl/Drawing/GL_Drawing.cpp

@@ -1196,6 +1196,15 @@ namespace MobileGL::MG_Impl::GLImpl {
         DrawElements_Backend(mode, count, type, indices);
     }
 
+    void DrawMeshTasksNV(GLuint first, GLuint count) {}
+
+    void DrawMeshTasksIndirectNV(GLintptr indirect) {}
+
+    void MultiDrawMeshTasksIndirectNV(GLintptr indirect, GLsizei drawcount, GLsizei stride) {}
+
+    void MultiDrawMeshTasksIndirectCountNV(GLintptr indirect, GLintptr drawcount, GLsizei maxdrawcount,
+                                           GLsizei stride) {}
+
     void BeginTransformFeedback(GLenum primitiveMode) {
         if (primitiveMode != GL_POINTS && primitiveMode != GL_LINES && primitiveMode != GL_TRIANGLES) {
             MG_State::pGLContext->RecordError(

MobileGL/MG_Impl/GLImpl/Drawing/GL_Drawing.h

@@ -66,4 +66,9 @@ namespace MobileGL::MG_Impl::GLImpl {
                                      GLsizei drawcount, const GLint* basevertex);
     void Clear(GLbitfield mask);
     void DrawElements(GLenum mode, GLsizei count, GLenum type, const void* indices);
+
+    void DrawMeshTasksNV(GLuint first, GLuint count);
+    void DrawMeshTasksIndirectNV(GLintptr indirect);
+    void MultiDrawMeshTasksIndirectNV(GLintptr indirect, GLsizei drawcount, GLsizei stride);
+    void MultiDrawMeshTasksIndirectCountNV(GLintptr indirect, GLintptr drawcount, GLsizei maxdrawcount, GLsizei stride);
 } // namespace MobileGL::MG_Impl::GLImpl

MobileGL/MG_Impl/GLImpl/Exporting/Definitions.cpp

@@ -2412,10 +2412,10 @@ DECLARE_GL_FUNCTION_STUB_HEAD(void, BufferPageCommitmentMemNV, GLenum target, GL
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TexPageCommitmentMemNV, GLenum target, GLint layer, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLuint memory, GLuint64 offset, GLboolean commit) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TexPageCommitmentMemNV, target, layer, level, xoffset, yoffset, zoffset, width, height, depth, memory, offset, commit)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, NamedBufferPageCommitmentMemNV, GLuint buffer, GLintptr offset, GLsizeiptr size, GLuint memory, GLuint64 memOffset, GLboolean commit) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, NamedBufferPageCommitmentMemNV, buffer, offset, size, memory, memOffset, commit)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, TexturePageCommitmentMemNV, GLuint texture, GLint layer, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLuint memory, GLuint64 offset, GLboolean commit) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, TexturePageCommitmentMemNV, texture, layer, level, xoffset, yoffset, zoffset, width, height, depth, memory, offset, commit)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, DrawMeshTasksNV, GLuint first, GLuint count) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, DrawMeshTasksNV, first, count)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, DrawMeshTasksIndirectNV, GLintptr indirect) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, DrawMeshTasksIndirectNV, indirect)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, MultiDrawMeshTasksIndirectNV, GLintptr indirect, GLsizei drawcount, GLsizei stride) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, MultiDrawMeshTasksIndirectNV, indirect, drawcount, stride)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, MultiDrawMeshTasksIndirectCountNV, GLintptr indirect, GLintptr drawcount, GLsizei maxdrawcount, GLsizei stride) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, MultiDrawMeshTasksIndirectCountNV, indirect, drawcount, maxdrawcount, stride)
+DECLARE_GL_FUNCTION_HEAD(void, DrawMeshTasksNV, GLuint first, GLuint count) DECLARE_GL_FUNCTION_END_NO_RETURN(void, DrawMeshTasksNV, first, count)
+DECLARE_GL_FUNCTION_HEAD(void, DrawMeshTasksIndirectNV, GLintptr indirect) DECLARE_GL_FUNCTION_END_NO_RETURN(void, DrawMeshTasksIndirectNV, indirect)
+DECLARE_GL_FUNCTION_HEAD(void, MultiDrawMeshTasksIndirectNV, GLintptr indirect, GLsizei drawcount, GLsizei stride) DECLARE_GL_FUNCTION_END_NO_RETURN(void, MultiDrawMeshTasksIndirectNV, indirect, drawcount, stride)
+DECLARE_GL_FUNCTION_HEAD(void, MultiDrawMeshTasksIndirectCountNV, GLintptr indirect, GLintptr drawcount, GLsizei maxdrawcount, GLsizei stride) DECLARE_GL_FUNCTION_END_NO_RETURN(void, MultiDrawMeshTasksIndirectCountNV, indirect, drawcount, maxdrawcount, stride)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, GenOcclusionQueriesNV, GLsizei n, GLuint* ids) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, GenOcclusionQueriesNV, n, ids)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, DeleteOcclusionQueriesNV, GLsizei n, const GLuint* ids) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, DeleteOcclusionQueriesNV, n, ids)
 DECLARE_GL_FUNCTION_STUB_HEAD(GLboolean, IsOcclusionQueryNV, GLuint id) DECLARE_GL_FUNCTION_STUB_END(GLboolean, IsOcclusionQueryNV, id)

MobileGL/MG_State/GLState/ProgramState/ShaderStage.h

@@ -18,6 +18,8 @@ namespace MobileGL {
         TessEval,
         Geometry,
         Fragment,
+        Task,
+        Mesh,
         Compute,
         ShaderStageCount,
         Unknown = -1

MobileGL/MG_Test/CMakeLists.txt

@@ -89,6 +89,7 @@ add_subdirectory(Swapchain)
 add_subdirectory(ShaderTranspiler)
 add_subdirectory(Util)
 add_subdirectory(SelfTest)
+add_subdirectory(MeshShader)
 # The DirectGLES post-transpile ESSL passes are pure String -> String, so unlike the
 # DirectVulkan suite below this one needs no device and always builds.
 add_subdirectory(Backend/DirectGLES)

MobileGL/MG_Test/MeshShader/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.14)
+
+add_executable(
+        MeshShaderTest
+        MeshShaderTest.cpp
+)
+
+target_include_directories(MeshShaderTest PRIVATE
+        ${MGL_ROOT}/include
+        ${MGL_ROOT}/MobileGL
+)
+
+target_link_libraries(
+        MeshShaderTest PRIVATE
+        GTest::gtest_main
+        ${LINK_LIBRARIES}
+)
+
+include(GoogleTest)
+gtest_discover_tests(MeshShaderTest DISCOVERY_TIMEOUT 30 PROPERTIES LABELS unit)

MobileGL/MG_Test/MeshShader/MeshShaderTest.cpp

@@ -0,0 +1,69 @@
+// MobileGL - MobileGL/MG_Test/MeshShader/MeshShader.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#include <gtest/gtest.h>
+
+#include <limits>
+
+#include "Includes.h"
+#include "Init.h"
+#include "MG_Impl/GLImpl/Program/GL_Program.h"
+
+#include <MG_Impl/GLImpl/Buffer/GL_Buffer.h>
+#include <MG_Impl/GLImpl/Getter/GL_Getter.h>
+#include <MG_Impl/GLImpl/VertexArray/GL_VertexArray.h>
+#include <MG_Impl/GLImpl/VertexArray/Validators.h>
+#include <MG_State/GLState/Core.h>
+
+using namespace MobileGL;
+
+class MeshShaderTest : public ::testing::Test {
+protected:
+    void SetUp() override { MobileGL::Initialize(); }
+
+    void TearDown() override {
+        EXPECT_EQ(MG_Impl::GLImpl::GetError(), GL_NO_ERROR) << "test left an unconsumed GL error behind";
+    }
+};
+
+TEST_F(MeshShaderTest, IsHaveExt) {
+    const auto* extensionsString = reinterpret_cast<const char*>(MG_Impl::GLImpl::GetString(GL_EXTENSIONS));
+    ASSERT_NE(extensionsString, nullptr);
+    // std::cout << extensionsString << std::endl;
+    const Bool isHaveExt = String(extensionsString).find("GL_NV_mesh_shader") != String::npos;
+    ASSERT_EQ(isHaveExt, true);
+}
+
+TEST_F(MeshShaderTest, TaskShaderCompile) {
+    const GLuint shader = MG_Impl::GLImpl::CreateShader(GL_TASK_SHADER_NV);
+    const char* src = R"GLSL(
+        #version 460
+        #extension GL_NV_mesh_shader : require
+
+        layout(local_size_x = 32) in;
+
+        layout(location = 0) uniform vec4 uParams;   // x = grid, y = aspect, z = time
+
+        void main()
+        {
+            if (gl_LocalInvocationID.x != 0u)
+                return;
+
+            uint grid = uint(uParams.x);
+
+            gl_TaskCountNV = grid * grid;
+        }
+    )GLSL";
+    MG_Impl::GLImpl::ShaderSource(shader, 1, &src, nullptr);
+    MG_Impl::GLImpl::CompileShader(shader);
+
+    GLint ok = GL_FALSE;
+    MG_Impl::GLImpl::GetShaderiv(shader, GL_COMPILE_STATUS, &ok);
+
+    ASSERT_EQ(ok, GL_TRUE);
+}

MobileGL/MG_Util/Converters/GLToGlslang/ProgramEnumConverter.cpp

@@ -18,6 +18,10 @@ namespace MobileGL {
                 return EShLanguage::EShLangFragment;
             case GL_COMPUTE_SHADER:
                 return EShLanguage::EShLangCompute;
+            case GL_TASK_SHADER_NV:
+                return EShLanguage::EShLangTaskNV;
+            case GL_MESH_SHADER_NV:
+                return EShLanguage::EShLangMeshNV;
             case GL_TESS_CONTROL_SHADER:
                 return EShLanguage::EShLangTessControl;
             case GL_TESS_EVALUATION_SHADER:

MobileGL/MG_Util/Converters/GLToMG/ProgramEnumConverter.cpp

@@ -22,6 +22,10 @@ namespace MobileGL {
                 return ShaderStage::Geometry;
             case GL_FRAGMENT_SHADER:
                 return ShaderStage::Fragment;
+            case GL_TASK_SHADER_NV:
+                return ShaderStage::Task;
+            case GL_MESH_SHADER_NV:
+                return ShaderStage::Mesh;
             case GL_COMPUTE_SHADER:
                 return ShaderStage::Compute;
             default:

MobileGL/MG_Util/Converters/GLToStr/GLEnumConverter.cpp

@@ -409,6 +409,8 @@ namespace MobileGL {
                 CASE(GL_MAX_TEXTURE_IMAGE_UNITS)
                 CASE(GL_FRAGMENT_SHADER)
                 CASE(GL_VERTEX_SHADER)
+                CASE(GL_TASK_SHADER_NV)
+                CASE(GL_MESH_SHADER_NV)
                 CASE(GL_MAX_FRAGMENT_UNIFORM_COMPONENTS)
                 CASE(GL_MAX_VERTEX_UNIFORM_COMPONENTS)
                 CASE(GL_MAX_VARYING_FLOATS)