video_core: draw Switch 2 task/mesh pipelines with VK_EXT_mesh_shader

While SET_MESH_CONTROL is on, a native draw binds a task program in the
vertex slot, its mesh program in the tessellation slot and a header-only
pass-through geometry program naming the per-primitive outputs. Translate
the first two as task and mesh programs with the mesh registers
(SET_MESH_SHADER_A/B, SET_MESH_INIT_SHADER) and that header, key their
pipelines by them, and build pipelines with task/mesh stages and no
vertex input, input assembly or tessellation state. The draw's vertex
count is the number of task workgroups: record vkCmdDrawMeshTasksEXT.
Enable VK_EXT_mesh_shader (task and mesh only) when the host has it; draws
are skipped without it, as they were before.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/video_core/vulkan_common/vulkan_device.cpp b/src/video_core/vulkan_common/vulkan_device.cpp
index 623ab7c30d..29b0c816fb 100644
--- a/src/video_core/vulkan_common/vulkan_device.cpp
+++ b/src/video_core/vulkan_common/vulkan_device.cpp
@@ -1511,6 +1511,15 @@ void Device::RemoveUnsuitableExtensions() {
                                VK_KHR_PIPELINE_EXECUTABLE_PROPERTIES_EXTENSION_NAME);
     }
 
+    // VK_EXT_mesh_shader: Switch 2 titles draw some geometry with task and mesh programs. Only
+    // the two stages are used; the multiview, shading rate and query features need more.
+    features.mesh_shader.multiviewMeshShader = VK_FALSE;
+    features.mesh_shader.primitiveFragmentShadingRateMeshShader = VK_FALSE;
+    features.mesh_shader.meshShaderQueries = VK_FALSE;
+    extensions.mesh_shader = features.mesh_shader.taskShader && features.mesh_shader.meshShader;
+    RemoveExtensionFeatureIfUnsuitable(extensions.mesh_shader, features.mesh_shader,
+                                       VK_EXT_MESH_SHADER_EXTENSION_NAME);
+
     // VK_KHR_shader_quad_control
     extensions.shader_quad_control = features.shader_quad_control.shaderQuadControl;
     RemoveExtensionFeatureIfUnsuitable(extensions.shader_quad_control, features.shader_quad_control,