From f89c417b8947c3350b020cdc1340e647cf206db4 Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvarkus@gmail.com>
Date: Tue, 5 Jun 2018 13:42:34 -0400
Subject: [PATCH] Compute PSO creation refactor

---
 libportability-gfx/src/impls.rs | 120 +++++++++++++++++---------------
 1 file changed, 62 insertions(+), 58 deletions(-)

diff --git a/libportability-gfx/src/impls.rs b/libportability-gfx/src/impls.rs
index 754f87b..8d454ba 100644
--- a/libportability-gfx/src/impls.rs
+++ b/libportability-gfx/src/impls.rs
@@ -594,16 +594,15 @@ pub extern "C" fn gfxCreateDevice(
 #[inline]
 pub extern "C" fn gfxDestroyDevice(gpu: VkDevice, _pAllocator: *const VkAllocationCallbacks) {
     // release all the owned command queues
-    if let Some(d) = gpu.unbox() {
+    if let Some(mut d) = gpu.unbox() {
         #[cfg(feature = "renderdoc")]
         {
             use renderdoc::api::RenderDocV100;
             let device = gpu.capturing as *mut c_void;
-            let mut d = d;
             d.renderdoc.end_frame_capture(device as *mut _, ptr::null());
         }
 
-        for (_, family) in d.queues {
+        for (_, family) in d.queues.drain() {
             for queue in family {
                 let _ = queue.unbox();
             }
@@ -1487,7 +1486,7 @@ pub extern "C" fn gfxCreateGraphicsPipelines(
                 .pSpecializationInfo
                 .as_ref()
                 .map(conv::map_specialization_info)
-                .unwrap_or(vec![])
+                .unwrap_or_default()
             };
 
             shader_stages.push((
@@ -1866,69 +1865,74 @@ pub extern "C" fn gfxCreateComputePipelines(
         slice::from_raw_parts(pCreateInfos, createInfoCount as _)
     };
 
-    let mut shader_stages = Vec::with_capacity(infos.len());
-
     // Collect all information which we will borrow later. Need to work around
     // the borrow checker here.
     // TODO: try to refactor it once we have a more generic API
-    for info in infos {
-        let name = unsafe { CStr::from_ptr(info.stage.pName).to_owned() };
-        let specialization = unsafe { info.stage
-            .pSpecializationInfo
-            .as_ref()
-            .map(conv::map_specialization_info)
-            .unwrap_or(vec![])
-        };
+    let shader_stages = infos
+        .iter()
+        .map(|info| {
+            let name = unsafe { CStr::from_ptr(info.stage.pName).to_owned() };
+            let specialization = unsafe { info.stage
+                .pSpecializationInfo
+                .as_ref()
+                .map(conv::map_specialization_info)
+                .unwrap_or_default()
+            };
 
-        shader_stages.push((
-            name.into_string().unwrap(),
-            specialization,
-        ));
-    }
+            (
+                name.into_string().unwrap(),
+                specialization,
+            )
+        })
+        .collect::<Vec<_>>();
 
-    let descs = infos.into_iter().zip(&shader_stages).map(|(info, &(ref entry, ref specialization))| {
-        let shader = pso::EntryPoint {
-            entry,
-            module: &*info.stage.module,
-            specialization,
-        };
-        let layout = &*info.layout;
+    let descs = infos
+        .into_iter()
+        .zip(&shader_stages)
+        .map(|(info, &(ref entry, ref specialization))| {
+            let shader = pso::EntryPoint {
+                entry,
+                module: &*info.stage.module,
+                specialization,
+            };
+            let layout = &*info.layout;
 
-        let flags = {
-            let mut flags = pso::PipelineCreationFlags::empty();
+            let flags = {
+                let mut flags = pso::PipelineCreationFlags::empty();
 
-            if info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_DISABLE_OPTIMIZATION_BIT as u32 != 0 {
-                flags |= pso::PipelineCreationFlags::DISABLE_OPTIMIZATION;
-            }
-            if info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT as u32 != 0 {
-                flags |= pso::PipelineCreationFlags::ALLOW_DERIVATIVES;
-            }
-
-            flags
-        };
-
-        let parent = {
-            let is_derivative = info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_DERIVATIVE_BIT as u32 != 0;
-
-            if let Some(base_pso) = info.basePipelineHandle.as_ref() {
-                match *base_pso {
-                    Pipeline::Graphics(_) => panic!("Base pipeline handle must be a compute pipeline"),
-                    Pipeline::Compute(ref pso) => pso::BasePipeline::Pipeline(pso),
+                if info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_DISABLE_OPTIMIZATION_BIT as u32 != 0 {
+                    flags |= pso::PipelineCreationFlags::DISABLE_OPTIMIZATION;
+                }
+                if info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT as u32 != 0 {
+                    flags |= pso::PipelineCreationFlags::ALLOW_DERIVATIVES;
                 }
-            } else if is_derivative && info.basePipelineIndex > 0 {
-                pso::BasePipeline::Index(info.basePipelineIndex as _)
-            } else {
-                pso::BasePipeline::None // TODO
-            }
-        };
 
-        pso::ComputePipelineDesc {
-            shader,
-            layout,
-            flags,
-            parent,
-        }
-    }).collect::<Vec<_>>();
+                flags
+            };
+
+            let parent = {
+                let is_derivative = info.flags & VkPipelineCreateFlagBits::VK_PIPELINE_CREATE_DERIVATIVE_BIT as u32 != 0;
+
+                if let Some(base_pso) = info.basePipelineHandle.as_ref() {
+                    match *base_pso {
+                        Pipeline::Graphics(_) => panic!("Base pipeline handle must be a compute pipeline"),
+                        Pipeline::Compute(ref pso) => pso::BasePipeline::Pipeline(pso),
+                    }
+                } else if is_derivative && info.basePipelineIndex > 0 {
+                    pso::BasePipeline::Index(info.basePipelineIndex as _)
+                } else {
+                    pso::BasePipeline::None // TODO
+                }
+            };
+
+            pso::ComputePipelineDesc {
+                shader,
+                layout,
+                flags,
+                parent,
+            }
+        })
+        .collect::<Vec<_>>();
 
     let pipelines = gpu.device.create_compute_pipelines(&descs);