From c48b54f3fb7bbe9046915eb99eca02fa84dc55c9 Mon Sep 17 00:00:00 2001
From: tcmal <me@aria.rip>
Date: Sun, 25 Aug 2024 17:44:22 +0100
Subject: feat(render): multithreaded texture loading

also a bunch of supporting changes
---
 stockton-render/src/draw/texture/repo.rs | 192 +++++++++++++++++++++++++++++++
 1 file changed, 192 insertions(+)
 create mode 100644 stockton-render/src/draw/texture/repo.rs

(limited to 'stockton-render/src/draw/texture/repo.rs')

diff --git a/stockton-render/src/draw/texture/repo.rs b/stockton-render/src/draw/texture/repo.rs
new file mode 100644
index 0000000..7bc8fb5
--- /dev/null
+++ b/stockton-render/src/draw/texture/repo.rs
@@ -0,0 +1,192 @@
+use stockton_levels::prelude::HasTextures;
+
+use super::{
+    block::TexturesBlock,
+    loader::{BlockRef, LoaderRequest, TextureLoader, TextureLoaderRemains, NUM_SIMULTANEOUS_CMDS},
+    resolver::TextureResolver,
+    LoadableImage,
+};
+use crate::types::*;
+
+use std::{
+    collections::HashMap,
+    marker::PhantomData,
+    mem::ManuallyDrop,
+    pin::Pin,
+    sync::mpsc::{channel, Receiver, Sender},
+    thread::JoinHandle,
+};
+
+use hal::{
+    prelude::*,
+    pso::{DescriptorSetLayoutBinding, DescriptorType, ShaderStageFlags},
+    Features,
+};
+use log::debug;
+
+/// The number of textures in one 'block'
+/// The textures of the loaded file are divided into blocks of this size.
+/// Whenever a texture is needed, the whole block its in is loaded.
+pub const BLOCK_SIZE: usize = 8;
+
+pub struct TextureRepo<'a> {
+    joiner: ManuallyDrop<JoinHandle<Result<TextureLoaderRemains, &'static str>>>,
+    ds_layout: Pin<Box<DescriptorSetLayout>>,
+    req_send: Sender<LoaderRequest>,
+    resp_recv: Receiver<TexturesBlock<DynamicBlock>>,
+    blocks: HashMap<BlockRef, Option<TexturesBlock<DynamicBlock>>>,
+
+    _a: PhantomData<&'a ()>,
+}
+
+impl<'a> TextureRepo<'a> {
+    pub fn new<
+        T: HasTextures + Send + Sync,
+        R: 'static + TextureResolver<I> + Send + Sync,
+        I: 'static + LoadableImage + Send,
+    >(
+        device: &'static mut Device,
+        adapter: &Adapter,
+        texs: &'static T,
+        resolver: R,
+    ) -> Result<Self, &'static str> {
+        let (req_send, req_recv) = channel();
+        let (resp_send, resp_recv) = channel();
+        let family = adapter
+            .queue_families
+            .iter()
+            .find(|family| {
+                family.queue_type().supports_transfer()
+                    && family.max_queues() >= NUM_SIMULTANEOUS_CMDS
+            })
+            .unwrap();
+        let gpu = unsafe {
+            adapter
+                .physical_device
+                .open(&[(family, &[1.0])], Features::empty())
+                .unwrap()
+        };
+
+        let mut ds_layout = Box::pin(
+            unsafe {
+                device.create_descriptor_set_layout(
+                    &[
+                        DescriptorSetLayoutBinding {
+                            binding: 0,
+                            ty: DescriptorType::SampledImage,
+                            count: BLOCK_SIZE,
+                            stage_flags: ShaderStageFlags::FRAGMENT,
+                            immutable_samplers: false,
+                        },
+                        DescriptorSetLayoutBinding {
+                            binding: 1,
+                            ty: DescriptorType::Sampler,
+                            count: BLOCK_SIZE,
+                            stage_flags: ShaderStageFlags::FRAGMENT,
+                            immutable_samplers: false,
+                        },
+                    ],
+                    &[],
+                )
+            }
+            .map_err(|_| "Couldn't create descriptor set layout")?,
+        );
+
+        let long_ds_pointer: &'static DescriptorSetLayout =
+            unsafe { &mut *(&mut *ds_layout as *mut DescriptorSetLayout) };
+
+        let joiner = {
+            let loader = TextureLoader::new(
+                device,
+                adapter,
+                family.id(),
+                gpu,
+                long_ds_pointer,
+                req_recv,
+                resp_send,
+                texs,
+                resolver,
+            )?;
+
+            std::thread::spawn(move || loader.loop_forever())
+        };
+
+        Ok(TextureRepo {
+            joiner: ManuallyDrop::new(joiner),
+            ds_layout,
+            blocks: HashMap::new(),
+            req_send,
+            resp_recv,
+            _a: PhantomData::default(),
+        })
+    }
+
+    pub fn get_ds_layout(&self) -> &DescriptorSetLayout {
+        &*self.ds_layout
+    }
+
+    pub fn queue_load(&mut self, block_id: BlockRef) -> Result<(), &'static str> {
+        if self.blocks.contains_key(&block_id) {
+            return Ok(());
+        }
+
+        self.force_queue_load(block_id)
+    }
+
+    pub fn force_queue_load(&mut self, block_id: BlockRef) -> Result<(), &'static str> {
+        self.req_send
+            .send(LoaderRequest::Load(block_id))
+            .map_err(|_| "Couldn't send load request")?;
+
+        self.blocks.insert(block_id, None);
+
+        Ok(())
+    }
+
+    pub fn attempt_get_descriptor_set(&mut self, block_id: BlockRef) -> Option<&DescriptorSet> {
+        self.blocks
+            .get(&block_id)
+            .and_then(|opt| opt.as_ref().map(|z| z.descriptor_set.raw()))
+    }
+
+    pub fn process_responses(&mut self) {
+        let resp_iter: Vec<_> = self.resp_recv.try_iter().collect();
+        for resp in resp_iter {
+            debug!("Got block {:?} back from loader", resp.id);
+            self.blocks.insert(resp.id, Some(resp));
+        }
+    }
+
+    pub fn deactivate(mut self, device: &mut Device) {
+        unsafe {
+            use std::ptr::read;
+
+            // Join the loader thread
+            self.req_send.send(LoaderRequest::End).unwrap();
+            let mut remains = read(&*self.joiner).join().unwrap().unwrap();
+
+            // Process any ones that just got done loading
+            self.process_responses();
+
+            // Return all the texture memory and descriptors.
+            for (i, v) in self.blocks.drain() {
+                debug!("Deactivating blockref {:?}", i);
+                if let Some(block) = v {
+                    block.deactivate(
+                        device,
+                        &mut *remains.tex_allocator,
+                        &mut remains.descriptor_allocator,
+                    );
+                }
+            }
+
+            debug!("Deactivated all blocks");
+
+            // Dispose of both allocators
+            read(&*remains.tex_allocator).dispose();
+            read(&*remains.descriptor_allocator).dispose(device);
+
+            debug!("Disposed of allocators");
+        }
+    }
+}
-- 
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