extract graph compilation logic

This commit is contained in:
janis 2026-10-25 00:18:52 +02:00
parent 5f7bbba49d
commit 195cf3e08a
Signed by: janis
SSH key fingerprint: SHA256:bB1qbbqmDXZNT0KKD5c2Dfjg53JGhj7B3CFcLIzSqq8

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@ -111,52 +111,12 @@ impl RenderGraph {
pub fn compile(self) -> Result<CompiledGraph, GraphError> {
let command_count = self.commands.len();
let mut edges = vec![BTreeSet::new(); command_count];
let mut indegree = vec![0usize; command_count];
let accesses = self.commands.side_effects.command_accesses();
for current in 0..command_count {
for prior in 0..current {
let dependency = accesses[prior].iter().any(|earlier| {
accesses[current].iter().any(|later| {
earlier.resource == later.resource && earlier.scope.conflicts(&later.scope)
})
});
if dependency && edges[prior].insert(current) {
indegree[current] += 1;
}
}
}
let mut ready: BTreeSet<_> = indegree
.iter()
.enumerate()
.filter_map(|(index, &degree)| (degree == 0).then_some(index))
.collect();
let mut order = Vec::with_capacity(command_count);
while let Some(index) = ready.pop_first() {
order.push(index.into());
for &dependent in &edges[index] {
indegree[dependent] -= 1;
if indegree[dependent] == 0 {
ready.insert(dependent);
}
}
}
if order.len() != command_count {
return Err(GraphError::DependencyCycle);
}
for command_accesses in accesses {
for access in command_accesses {
if !self.resources.contains_key(&access.resource) {
return Err(GraphError::UnknownResource(access.resource));
}
}
}
let barriers = build_barriers(&order, accesses, &self.resources);
let lifetimes = bind_resources(&self.resources, accesses);
let compiler = GraphCompiler::new(&self.resources, accesses, command_count);
let order = compiler.topo_sort()?;
compiler.validate_resources()?;
let barriers = compiler.build_barriers(&order);
let lifetimes = compiler.bind_lifetimes();
Ok(CompiledGraph {
resources: self.resources,
@ -169,6 +129,211 @@ impl RenderGraph {
}
}
struct GraphCompiler<'a> {
resources: &'a BTreeMap<ResourceId, ResourceDesc>,
accesses: &'a [Vec<crate::recorder::ResourceAccess>],
command_count: usize,
}
impl<'a> GraphCompiler<'a> {
fn new(
resources: &'a BTreeMap<ResourceId, ResourceDesc>,
accesses: &'a [Vec<crate::recorder::ResourceAccess>],
command_count: usize,
) -> Self {
Self {
resources,
accesses,
command_count,
}
}
fn dependencies(&self) -> (Vec<BTreeSet<usize>>, Vec<usize>) {
let mut edges = vec![BTreeSet::new(); self.command_count];
let mut indegree = vec![0usize; self.command_count];
for current in 0..self.command_count {
for prior in 0..current {
let dependency = self.accesses[prior].iter().any(|earlier| {
self.accesses[current].iter().any(|later| {
earlier.resource == later.resource && earlier.scope.conflicts(&later.scope)
})
});
if dependency && edges[prior].insert(current) {
indegree[current] += 1;
}
}
}
(edges, indegree)
}
fn topo_sort(&self) -> Result<Vec<CommandIndex>, GraphError> {
let (edges, mut indegree) = self.dependencies();
let mut ready: BTreeSet<_> = indegree
.iter()
.enumerate()
.filter_map(|(index, &degree)| (degree == 0).then_some(index))
.collect();
let mut order = Vec::with_capacity(self.command_count);
while let Some(index) = ready.pop_first() {
order.push(index.into());
for &dependent in &edges[index] {
indegree[dependent] -= 1;
if indegree[dependent] == 0 {
ready.insert(dependent);
}
}
}
if order.len() != self.command_count {
return Err(GraphError::DependencyCycle);
}
Ok(order)
}
fn validate_resources(&self) -> Result<(), GraphError> {
for command_accesses in self.accesses {
for access in command_accesses {
if !self.resources.contains_key(&access.resource) {
return Err(GraphError::UnknownResource(access.resource));
}
}
}
Ok(())
}
fn build_barriers(&self, order: &[CommandIndex]) -> Vec<PipelineBarrier> {
let mut result = Vec::new();
for (ordered_index, &command_index) in order.iter().enumerate() {
let mut barrier_resources = Vec::new();
for current in &self.accesses[command_index.index()] {
let previous = order[..ordered_index]
.iter()
.rev()
.flat_map(|&prior_index| self.accesses[prior_index.index()].iter().rev())
.find(|previous| {
previous.resource == current.resource
&& previous.scope.conflicts(&current.scope)
});
if let Some(previous) = previous {
let (old_layout, new_layout) = Self::layouts(previous.scope, current.scope);
barrier_resources.push(BarrierResource {
id: current.resource,
range: scope_range(current.scope),
src_stage: previous.scope.stage,
src_access: previous.scope.access,
dst_stage: current.scope.stage,
dst_access: current.scope.access,
old_layout,
new_layout,
});
continue;
}
let desc = &self.resources[&current.resource];
let initial = desc.initial_state();
let (old_layout, new_layout) = Self::layouts_from_state(initial, current.scope);
let layout_transition = old_layout != new_layout && new_layout.is_some();
let initial_hazard = matches!(
desc,
ResourceDesc::ImportedBuffer { .. } | ResourceDesc::ImportedTexture { .. }
) && !initial.access.is_empty()
&& (access_flag_is_write(initial.access)
|| access_flag_is_write(current.scope.access));
if layout_transition || initial_hazard {
barrier_resources.push(BarrierResource {
id: current.resource,
range: scope_range(current.scope),
src_stage: initial.stage,
src_access: initial.access,
dst_stage: current.scope.stage,
dst_access: current.scope.access,
old_layout,
new_layout,
});
}
}
if !barrier_resources.is_empty() {
result.push(PipelineBarrier {
before_command: ordered_index.into(),
resources: barrier_resources,
});
}
}
result
}
fn layouts(
previous: SubresourceScope,
current: SubresourceScope,
) -> (Option<vk::ImageLayout>, Option<vk::ImageLayout>) {
let layout = |scope: SubresourceScope| match scope.subresource {
SubresourceScopeInner::Texture { layout, .. } => Some(layout),
SubresourceScopeInner::Buffer(_) => None,
};
(layout(previous), layout(current))
}
fn layouts_from_state(
initial: crate::resources::ResourceState,
current: SubresourceScope,
) -> (Option<vk::ImageLayout>, Option<vk::ImageLayout>) {
let current_layout = match current.subresource {
SubresourceScopeInner::Texture { layout, .. } => Some(layout),
SubresourceScopeInner::Buffer(_) => None,
};
(initial.layout, current_layout)
}
fn bind_lifetimes(&self) -> HashMap<ResourceId, ResourceLifetime> {
let mut lifetimes = HashMap::new();
for (command, command_accesses) in self.accesses.iter().enumerate() {
for access in command_accesses {
lifetimes
.entry(access.resource)
.and_modify(|lifetime: &mut ResourceLifetime| {
lifetime.last_command = command.into()
})
.or_insert(ResourceLifetime {
first_command: command.into(),
last_command: command.into(),
memory_offset: 0,
});
}
}
// Skeleton aliasing policy: resources with non-overlapping lifetimes may
// share a heap offset. Actual size/alignment-aware Vulkan allocation is TODO.
let mut slots: Vec<(u64, CommandIndex, u64)> = Vec::new(); // (offset, last use, capacity)
let mut next_offset = 0;
let mut ids: Vec<_> = lifetimes.keys().copied().collect();
ids.sort_by_key(|id| lifetimes[id].first_command);
for id in ids {
let lifetime = lifetimes.get_mut(&id).expect("lifetime key exists");
let size = match &self.resources[&id] {
ResourceDesc::CreatedBuffer(desc) => desc.size,
ResourceDesc::CreatedTexture(desc) => texture_size_estimate(desc),
ResourceDesc::ImportedBuffer { .. } | ResourceDesc::ImportedTexture { .. } => 0,
};
if self.resources[&id].is_created()
&& let Some((offset, last_use, capacity)) = slots
.iter_mut()
.find(|(_, last, cap)| *last < lifetime.first_command && *cap >= size)
{
lifetime.memory_offset = *offset;
*last_use = lifetime.last_command;
let _ = capacity;
} else {
lifetime.memory_offset = next_offset;
if self.resources[&id].is_created() {
slots.push((next_offset, lifetime.last_command, size));
next_offset = next_offset.saturating_add(size);
}
}
}
lifetimes
}
}
impl Default for RenderGraph {
fn default() -> Self {
Self::new()
@ -531,145 +696,6 @@ fn texture_size_estimate(desc: &GraphTextureDesc) -> u64 {
.saturating_mul(u64::from(desc.samples.as_raw().max(1)))
}
fn build_barriers(
order: &[CommandIndex],
accesses: &[Vec<crate::recorder::ResourceAccess>],
resource_descs: &BTreeMap<ResourceId, ResourceDesc>,
) -> Vec<PipelineBarrier> {
let mut result = Vec::new();
for (ordered_index, &command_index) in order.iter().enumerate() {
let mut barrier_resources = Vec::new();
for current in &accesses[command_index.index()] {
let previous = order[..ordered_index]
.iter()
.rev()
.flat_map(|&prior_index| accesses[prior_index.index()].iter().rev())
.find(|previous| {
previous.resource == current.resource
&& previous.scope.conflicts(&current.scope)
});
if let Some(previous) = previous {
let (old_layout, new_layout) = layouts(previous.scope, current.scope);
barrier_resources.push(BarrierResource {
id: current.resource,
range: scope_range(current.scope),
src_stage: previous.scope.stage,
src_access: previous.scope.access,
dst_stage: current.scope.stage,
dst_access: current.scope.access,
old_layout,
new_layout,
});
continue;
}
let desc = &resource_descs[&current.resource];
let initial = desc.initial_state();
let (old_layout, new_layout) = layouts_from_state(initial, current.scope);
let layout_transition = old_layout != new_layout && new_layout.is_some();
let initial_hazard = matches!(
desc,
ResourceDesc::ImportedBuffer { .. } | ResourceDesc::ImportedTexture { .. }
) && !initial.access.is_empty()
&& (access_flag_is_write(initial.access)
|| access_flag_is_write(current.scope.access));
if layout_transition || initial_hazard {
barrier_resources.push(BarrierResource {
id: current.resource,
range: scope_range(current.scope),
src_stage: initial.stage,
src_access: initial.access,
dst_stage: current.scope.stage,
dst_access: current.scope.access,
old_layout,
new_layout,
});
}
}
if !barrier_resources.is_empty() {
result.push(PipelineBarrier {
before_command: ordered_index.into(),
resources: barrier_resources,
});
}
}
result
}
fn layouts(
previous: SubresourceScope,
current: SubresourceScope,
) -> (Option<vk::ImageLayout>, Option<vk::ImageLayout>) {
let layout = |scope: SubresourceScope| match scope.subresource {
SubresourceScopeInner::Texture { layout, .. } => Some(layout),
SubresourceScopeInner::Buffer(_) => None,
};
(layout(previous), layout(current))
}
fn layouts_from_state(
initial: crate::resources::ResourceState,
current: SubresourceScope,
) -> (Option<vk::ImageLayout>, Option<vk::ImageLayout>) {
let current_layout = match current.subresource {
SubresourceScopeInner::Texture { layout, .. } => Some(layout),
SubresourceScopeInner::Buffer(_) => None,
};
(initial.layout, current_layout)
}
fn bind_resources(
resources: &BTreeMap<ResourceId, ResourceDesc>,
accesses: &[Vec<crate::recorder::ResourceAccess>],
) -> HashMap<ResourceId, ResourceLifetime> {
let mut lifetimes = HashMap::new();
for (command, command_accesses) in accesses.iter().enumerate() {
for access in command_accesses {
lifetimes
.entry(access.resource)
.and_modify(|lifetime: &mut ResourceLifetime| {
lifetime.last_command = command.into()
})
.or_insert(ResourceLifetime {
first_command: command.into(),
last_command: command.into(),
memory_offset: 0,
});
}
}
// Skeleton aliasing policy: resources with non-overlapping lifetimes may
// share a heap offset. Actual size/alignment-aware Vulkan allocation is TODO.
let mut slots: Vec<(u64, CommandIndex, u64)> = Vec::new(); // (offset, last use, capacity)
let mut next_offset = 0;
let mut ids: Vec<_> = lifetimes.keys().copied().collect();
ids.sort_by_key(|id| lifetimes[id].first_command);
for id in ids {
let lifetime = lifetimes.get_mut(&id).expect("lifetime key exists");
let size = match &resources[&id] {
ResourceDesc::CreatedBuffer(desc) => desc.size,
ResourceDesc::CreatedTexture(desc) => texture_size_estimate(desc),
ResourceDesc::ImportedBuffer { .. } | ResourceDesc::ImportedTexture { .. } => 0,
};
if resources[&id].is_created()
&& let Some((offset, last_use, capacity)) = slots
.iter_mut()
.find(|(_, last, cap)| *last < lifetime.first_command && *cap >= size)
{
lifetime.memory_offset = *offset;
*last_use = lifetime.last_command;
let _ = capacity;
} else {
lifetime.memory_offset = next_offset;
if resources[&id].is_created() {
slots.push((next_offset, lifetime.last_command, size));
next_offset = next_offset.saturating_add(size);
}
}
}
lifetimes
}
#[cfg(test)]
mod tests {
use super::*;