adding Descriptors fundamental implementation

src/vulkan/DescriptorPool.zig

@@ -2,9 +2,12 @@ const std = @import("std");
 const vk = @import("vulkan");
 
 const VkError = @import("error_set.zig").VkError;
+const Dispatchable = @import("Dispatchable.zig").Dispatchable;
 
 const Device = @import("Device.zig");
 
+const DescriptorSet = @import("DescriptorSet.zig");
+
 const Self = @This();
 pub const ObjectType: vk.ObjectType = .descriptor_pool;
 
@@ -15,6 +18,7 @@ vtable: *const VTable,
 
 pub const VTable = struct {
     destroy: *const fn (*Self, std.mem.Allocator) void,
+    freeDescriptorSets: *const fn (*Self, []*Dispatchable(DescriptorSet)) VkError!void,
 };
 
 pub fn init(device: *Device, allocator: std.mem.Allocator, info: *const vk.DescriptorPoolCreateInfo) VkError!Self {
@@ -22,9 +26,14 @@ pub fn init(device: *Device, allocator: std.mem.Allocator, info: *const vk.Descr
     return .{
         .owner = device,
         .flags = info.flags,
+        .vtable = undefined,
     };
 }
 
 pub inline fn destroy(self: *Self, allocator: std.mem.Allocator) void {
     self.vtable.destroy(self, allocator);
 }
+
+pub inline fn freeDescriptorSets(self: *Self, sets: []*Dispatchable(DescriptorSet)) VkError!void {
+    try self.vtable.freeDescriptorSets(self, sets);
+}