From 5dddb64f6a2fd072f2a26d4400f9a2a84386dc4e Mon Sep 17 00:00:00 2001
From: Irene Knapp <ireneista@irenes.space>
Date: Mon, 13 Jul 2026 13:25:16 -0700
Subject: it spins!!!!

ahem. more formally: provide animated uniforms to the shader, and use them

the tutorial just wants us to do three matrices, and to defer all the actual math to a library it recommends. that would certainly be simpler. anyway, we use quaterion+offset for everything but the projection frustum, and do all the math ourselves

Change-Id: I399f432bebb1e7ca4d4342efa1d5aaf37b32f427
Force-Push: yes
---
 src/graphics_permanent.rs | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

(limited to 'src/graphics_permanent.rs')

diff --git a/src/graphics_permanent.rs b/src/graphics_permanent.rs
index c2225a3..b58e8a4 100644
--- a/src/graphics_permanent.rs
+++ b/src/graphics_permanent.rs
@@ -127,11 +127,13 @@ impl PermanentGraphicsState {
         = init_vulkan_device(&instance, &surface,
                              enable_validation, enable_portability)?;
 
+    let descriptor_set_layout = init_descriptor_set_layout(&device)?;
+
     Ok((PermanentGraphicsState {
       window, entry, instance, debug_messager, surface, device,
-      graphics_queue, presentation_queue,
+      graphics_queue, presentation_queue
     }, GraphicsStateForReinit {
-      physical_device, indices
+      physical_device, indices, descriptor_set_layout
     }, enable_swapchain))
   }
 
@@ -214,6 +216,17 @@ impl PermanentGraphicsState {
 pub struct GraphicsStateForReinit {
   pub physical_device: vk::PhysicalDevice,
   pub indices: QueueFamilyIndices,
+  pub descriptor_set_layout: vk::DescriptorSetLayout,
+}
+
+
+impl GraphicsStateForReinit {
+  #[allow(unsafe_code)]
+  pub fn destroy(self, device: &Device) -> () {
+    unsafe {
+      device.destroy_descriptor_set_layout(self.descriptor_set_layout, None)
+    };
+  }
 }
 
 
@@ -517,6 +530,29 @@ fn init_vulkan_device(instance: &Instance, surface: &vk::SurfaceKHR,
 }
 
 
+#[allow(unsafe_code)]
+fn init_descriptor_set_layout(device: &Device)
+    -> Result<vk::DescriptorSetLayout>
+{
+  let uniform_block_binding = vk::DescriptorSetLayoutBinding::builder()
+          .binding(0)
+          .descriptor_type(vk::DescriptorType::UNIFORM_BUFFER)
+          .descriptor_count(1)
+          .stage_flags(vk::ShaderStageFlags::VERTEX);
+
+  let bindings = [uniform_block_binding];
+  let descriptor_set_layout_info
+          = vk::DescriptorSetLayoutCreateInfo::builder()
+                .bindings(&bindings);
+  let descriptor_set_layout = unsafe {
+    device.create_descriptor_set_layout(&descriptor_set_layout_info, None)
+  }?;
+
+  Ok(descriptor_set_layout)
+}
+
+
+
 //   To Vulkan, a "physical" device is the actual GPU, and a "logical"
 // device is per-process state that represents a connection to the GPU.
 // Before we can create a logical device, we must choose which physical
-- 
cgit 1.4.1