adding command descriptors and buffer base

src/vulkan/commands.zig

@@ -0,0 +1,61 @@
+const std = @import("std");
+const vk = @import("vulkan");
+
+const Buffer = @import("Buffer.zig");
+
+pub const CommandType = enum {
+    BindVertexBuffer,
+    Draw,
+    DrawIndexed,
+    DrawIndirect,
+    DrawIndexedIndirect,
+    BindPipeline,
+};
+
+pub const CommandBindVertexBuffer = struct {
+    buffers: std.ArrayList(Buffer),
+    offsets: std.ArrayList(vk.DeviceSize),
+    first_binding: u32,
+};
+
+pub const CommandDraw = struct {
+    vertex_count: u32,
+    instance_count: u32,
+    first_vertex: u32,
+    first_instance: u32,
+};
+
+pub const CommandDrawIndexed = struct {
+    index_count: u32,
+    instance_count: u32,
+    first_index: u32,
+    vertex_offset: i32,
+    first_instance: u32,
+};
+
+pub const CommandDrawIndirect = struct {
+    buffer: *Buffer,
+    offset: vk.DeviceSize,
+    count: u32,
+    stride: u32,
+};
+
+pub const CommandDrawIndexedIndirect = struct {
+    buffer: *Buffer,
+    offset: vk.DeviceSize,
+    count: u32,
+    stride: u32,
+};
+
+pub const CommandBindPipeline = struct {
+    bind_point: vk.PipelineBindPoint,
+};
+
+pub const Command = union(CommandType) {
+    BindVertexBuffer: CommandBindVertexBuffer,
+    Draw: CommandDraw,
+    DrawIndexed: CommandDrawIndexed,
+    DrawIndirect: CommandDrawIndirect,
+    DrawIndexedIndirect: CommandDrawIndexedIndirect,
+    BindPipeline: CommandBindPipeline,
+};