From 6b2715eebe848c5becec32076e57f9f78e15609a Mon Sep 17 00:00:00 2001
From: David Allemang <allemang.d@gmail.com>
Date: Tue, 2 Jul 2024 00:01:36 -0400
Subject: [PATCH] reuse command buffers

---
 src/au/flights.zig |  7 +++++++
 src/main.zig       | 27 ++++++++++++---------------
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/src/au/flights.zig b/src/au/flights.zig
index 65350a9..86825c3 100644
--- a/src/au/flights.zig
+++ b/src/au/flights.zig
@@ -11,6 +11,7 @@ pub fn Flights(T: type) type {
             complete: vk.Semaphore = .null_handle,
             fence: vk.Fence = .null_handle,
             pool: vk.CommandPool = .null_handle,
+            cmd: vk.CommandBuffer = .null_handle,
             ctx: T,
         };
 
@@ -31,6 +32,11 @@ pub fn Flights(T: type) type {
                 flight.complete = try au.D.createSemaphore(&.{}, null);
                 flight.fence = try au.D.createFence(&.{ .flags = .{ .signaled_bit = true } }, null);
                 flight.pool = try au.D.createCommandPool(&.{ .queue_family_index = au.device_config.family }, null);
+                try au.D.allocateCommandBuffers(&vk.CommandBufferAllocateInfo{
+                    .command_buffer_count = 1,
+                    .command_pool = flight.pool,
+                    .level = .primary,
+                }, @ptrCast(&flight.cmd));
                 flight.ctx = try T.init();
             }
 
@@ -42,6 +48,7 @@ pub fn Flights(T: type) type {
                 au.D.destroySemaphore(flight.acquire, null);
                 au.D.destroySemaphore(flight.complete, null);
                 au.D.destroyFence(flight.fence, null);
+                au.D.freeCommandBuffers(flight.pool, 1, &.{flight.cmd});
                 au.D.destroyCommandPool(flight.pool, null);
                 flight.ctx.deinit();
             }
diff --git a/src/main.zig b/src/main.zig
index 7582341..1f6ad39 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -270,28 +270,20 @@ pub fn main() !void {
         const image = sc.getImage(acq.image_index);
         const view = sc.getView(acq.image_index);
 
-        var render_cmd = au.CommandBufferProxy.init(.null_handle, au.D.wrapper);
-        try au.D.allocateCommandBuffers(
-            &.{
-                .command_pool = flight.pool,
-                .level = .primary,
-                .command_buffer_count = 1,
-            },
-            @ptrCast(&render_cmd.handle),
-        );
+        var cmd = au.CommandBufferProxy.init(flight.cmd, au.D.wrapper);
 
-        try render_cmd.beginCommandBuffer(&.{ .flags = .{ .one_time_submit_bit = true } });
+        try cmd.beginCommandBuffer(&.{ .flags = .{ .one_time_submit_bit = true } });
 
         try flight.ctx.record_render(
-            render_cmd,
+            cmd,
             image,
             view,
             vk.Rect2D{ .offset = .{ .x = 0, .y = 0 }, .extent = sc.cinfo.image_extent },
         );
 
-        try render_cmd.endCommandBuffer();
+        try cmd.endCommandBuffer();
 
-        try au.Q.submit(
+        au.Q.submit(
             1,
             &.{
                 vk.SubmitInfo{
@@ -299,13 +291,18 @@ pub fn main() !void {
                     .p_wait_semaphores = @ptrCast(&flight.acquire),
                     .p_wait_dst_stage_mask = @ptrCast(&vk.PipelineStageFlags{ .color_attachment_output_bit = true }),
                     .command_buffer_count = 1,
-                    .p_command_buffers = @ptrCast(&render_cmd.handle),
+                    .p_command_buffers = @ptrCast(&cmd.handle),
                     .signal_semaphore_count = 1,
                     .p_signal_semaphores = @ptrCast(&flight.complete),
                 },
             },
             flight.fence,
-        );
+        ) catch {
+            std.debug.print("Failed to submit.\nWaiting for idle...", .{});
+            au.D.deviceWaitIdle() catch
+                std.debug.print("deviceWaitIdle failed\n", .{});
+            @panic("Submission failed");
+        };
 
         _ = try au.Q.presentKHR(&vk.PresentInfoKHR{
             .wait_semaphore_count = 1,