debugging the swapchain recreate bugs

src/inspect.zig

@@ -93,6 +93,8 @@ pub fn main() !void {
         std.debug.print("type: {any}\n", .{props.device_type});
         // props.device_type
 
+        std.debug.print("max_push_constants_size: {d}\n", .{props.limits.max_push_constants_size});
+
         var family_count: u32 = undefined;
         vki.getPhysicalDeviceQueueFamilyProperties(pdev, &family_count, null);
         const families = try ally.alloc(vk.QueueFamilyProperties, family_count);

src/main.zig

@@ -164,7 +164,7 @@ fn create_device(
 
     pdev_search: for (pdevs) |pdev| {
         const props = vki.getPhysicalDeviceProperties(pdev);
-        // if (props.device_type != .discrete_gpu) continue :pdev_search;
+        if (props.device_type != .discrete_gpu) continue :pdev_search;
 
         var format_count: u32 = undefined;
         _ = try vki.getPhysicalDeviceSurfaceFormatsKHR(pdev, surface, &format_count, null);
@@ -348,6 +348,7 @@ pub fn main() !void {
     defer destroyCommandBuffers(&gc, pool, ally, cmdbufs);
 
     while (c.glfwWindowShouldClose(window) == c.GLFW_FALSE) {
+        std.log.debug("new frame", .{ });
         var w: c_int = undefined;
         var h: c_int = undefined;
         c.glfwGetFramebufferSize(window, &w, &h);
@@ -364,13 +365,19 @@ pub fn main() !void {
             error.OutOfDateKHR => Swapchain.PresentState.suboptimal,
             else => |narrow| return narrow,
         };
+        
+        std.log.debug("state: {}", .{state});
 
         if (state == .suboptimal or extent.width != @as(u32, @intCast(w)) or extent.height != @as(u32, @intCast(h))) {
             extent.width = @intCast(w);
             extent.height = @intCast(h);
+            std.log.debug("about to recreate", .{ });
             try swapchain.recreate(extent);
 
+            std.log.debug("about to destroy command buffers", .{ });
             destroyCommandBuffers(&gc, pool, ally, cmdbufs);
+            
+            std.log.debug("about to create command buffers", .{ });
             cmdbufs = try createCommandBuffers(
                 &gc,
                 pool,
@@ -499,8 +506,17 @@ fn createCommandBuffers(
     for (cmdbufs, swapchain.swap_images) |cmdbuf, image| {
         try gc.vkd.beginCommandBuffer(cmdbuf, &.{});
 
-        const pre_render_barriers: []const vk.ImageMemoryBarrier = &.{
+        gc.vkd.cmdPipelineBarrier(
-            vk.ImageMemoryBarrier{
+            cmdbuf,
+            .{ .top_of_pipe_bit = true },
+            .{ .color_attachment_output_bit = true },
+            .{},
+            0,
+            null,
+            0,
+            null,
+            1,
+            @ptrCast(&vk.ImageMemoryBarrier{
                 .src_access_mask = .{},
                 .dst_access_mask = .{ .color_attachment_write_bit = true },
                 .old_layout = .undefined,
@@ -515,19 +531,7 @@ fn createCommandBuffers(
                     .base_array_layer = 0,
                     .layer_count = 1,
                 },
-            },
+            }),
-        };
-        gc.vkd.cmdPipelineBarrier(
-            cmdbuf,
-            .{ .top_of_pipe_bit = true },
-            .{ .color_attachment_output_bit = true },
-            .{},
-            0,
-            null,
-            0,
-            null,
-            @intCast(pre_render_barriers.len),
-            pre_render_barriers.ptr,
         );
 
         gc.vkd.cmdSetViewport(cmdbuf, 0, 1, @ptrCast(&viewport));
@@ -564,8 +568,17 @@ fn createCommandBuffers(
 
         gc.vkd.cmdEndRenderingKHR(cmdbuf);
 
-        const post_render_barriers: []const vk.ImageMemoryBarrier = &.{
+        gc.vkd.cmdPipelineBarrier(
-            vk.ImageMemoryBarrier{
+            cmdbuf,
+            .{ .color_attachment_output_bit = true },
+            .{ .bottom_of_pipe_bit = true },
+            .{},
+            0,
+            null,
+            0,
+            null,
+            1,
+            @ptrCast(&vk.ImageMemoryBarrier{
                 .src_access_mask = .{ .color_attachment_write_bit = true },
                 .dst_access_mask = .{},
                 .old_layout = .color_attachment_optimal,
@@ -580,19 +593,7 @@ fn createCommandBuffers(
                     .base_array_layer = 0,
                     .layer_count = 1,
                 },
-            },
+            }),
-        };
-        gc.vkd.cmdPipelineBarrier(
-            cmdbuf,
-            .{ .color_attachment_output_bit = true },
-            .{ .bottom_of_pipe_bit = true },
-            .{},
-            0,
-            null,
-            0,
-            null,
-            @intCast(post_render_barriers.len),
-            post_render_barriers.ptr,
         );
 
         try gc.vkd.endCommandBuffer(cmdbuf);

src/swapchain.zig

@@ -111,9 +111,18 @@ pub const Swapchain = struct {
         var next_image_acquired = try gc.vkd.createSemaphore(gc.dev, &.{}, null);
         errdefer gc.vkd.destroySemaphore(gc.dev, next_image_acquired, null);
 
-        const result = try gc.vkd.acquireNextImageKHR(gc.dev, handle, std.math.maxInt(u64), next_image_acquired, .null_handle);
+        const result = try gc.vkd.acquireNextImageKHR(
-        if (result.result != .success) {
+            gc.dev,
-            return error.ImageAcquireFailed;
+            handle,
+            std.math.maxInt(u64),
+            next_image_acquired,
+            .null_handle,
+        );
+        switch (result.result) {
+            vk.Result.success, vk.Result.suboptimal_khr => {},
+            vk.Result.timeout => return error.Timeout,
+            vk.Result.not_ready => return error.NotReady,
+            else => unreachable,
         }
 
         std.mem.swap(vk.Semaphore, &swap_images[result.image_index].image_acquired, &next_image_acquired);
@@ -267,6 +276,15 @@ const SwapImage = struct {
     }
 
     fn deinit(self: SwapImage, gc: *const Context) void {
+        // todo critical: this waitForFence deadlocks when recreating swapchain on nvidia.
+        // Something about the main "present" loop is fucked. Can't just ignore the fence; validation layers show errors
+        // that you can't destroy a fence while a queue depends on it (details may be wrong... I don't fully understand)
+        // I suspect this is more an issue with the vulkan-zig example, so I probably need to revisit vulkan-tutorial or
+        // try to rebuild the swapchain infrastructure myself.
+        //
+        // I do think it's clunky how the swapchain is created and recreated; duplicate logic in creation and recreation
+        // that could maybe be avoided with .null_handle? Maybe there's some more straightforward way to handle it.
+
         self.waitForFence(gc) catch return;
         gc.vkd.destroyImageView(gc.dev, self.view, null);
         gc.vkd.destroySemaphore(gc.dev, self.image_acquired, null);