use crate::{
pipeline::{
PipelineCompiler, PipelineDescriptor, PipelineLayout, PipelineSpecialization,
VERTEX_FALLBACK_LAYOUT_NAME,
},
renderer::{
BindGroup, BindGroupId, BufferId, BufferUsage, RenderResource, RenderResourceBinding,
RenderResourceBindings, RenderResourceContext, SharedBuffers,
},
shader::Shader,
};
use bevy_asset::{Assets, Handle};
use bevy_ecs::{
FetchResource, Query, Res, ResMut, ResourceIndex, ResourceQuery, Resources, SystemId,
TypeAccess, UnsafeClone,
};
use bevy_property::Properties;
use std::{any::TypeId, ops::Range, sync::Arc};
use thiserror::Error;
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum RenderCommand {
SetPipeline {
pipeline: Handle<PipelineDescriptor>,
},
SetVertexBuffer {
slot: u32,
buffer: BufferId,
offset: u64,
},
SetIndexBuffer {
buffer: BufferId,
offset: u64,
},
SetBindGroup {
index: u32,
bind_group: BindGroupId,
dynamic_uniform_indices: Option<Arc<[u32]>>,
},
DrawIndexed {
indices: Range<u32>,
base_vertex: i32,
instances: Range<u32>,
},
Draw {
vertices: Range<u32>,
instances: Range<u32>,
},
}
#[derive(Debug, Properties, Clone)]
pub struct Draw {
pub is_visible: bool,
pub is_transparent: bool,
#[property(ignore)]
pub render_commands: Vec<RenderCommand>,
}
impl Default for Draw {
fn default() -> Self {
Self {
is_visible: true,
is_transparent: false,
render_commands: Default::default(),
}
}
}
impl Draw {
pub fn clear_render_commands(&mut self) {
self.render_commands.clear();
}
pub fn set_pipeline(&mut self, pipeline: &Handle<PipelineDescriptor>) {
self.render_command(RenderCommand::SetPipeline {
pipeline: pipeline.clone_weak(),
});
}
pub fn set_vertex_buffer(&mut self, slot: u32, buffer: BufferId, offset: u64) {
self.render_command(RenderCommand::SetVertexBuffer {
slot,
buffer,
offset,
});
}
pub fn set_index_buffer(&mut self, buffer: BufferId, offset: u64) {
self.render_command(RenderCommand::SetIndexBuffer { buffer, offset });
}
pub fn set_bind_group(&mut self, index: u32, bind_group: &BindGroup) {
self.render_command(RenderCommand::SetBindGroup {
index,
bind_group: bind_group.id,
dynamic_uniform_indices: bind_group.dynamic_uniform_indices.clone(),
});
}
pub fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>) {
self.render_command(RenderCommand::DrawIndexed {
base_vertex,
indices,
instances,
});
}
#[inline]
pub fn render_command(&mut self, render_command: RenderCommand) {
self.render_commands.push(render_command);
}
}
#[derive(Debug, Error)]
pub enum DrawError {
#[error("Pipeline does not exist.")]
NonExistentPipeline,
#[error("No pipeline set")]
NoPipelineSet,
#[error("Pipeline has no layout")]
PipelineHasNoLayout,
#[error("Failed to get a buffer for the given RenderResource.")]
BufferAllocationFailure,
}
pub struct DrawContext<'a> {
pub pipelines: ResMut<'a, Assets<PipelineDescriptor>>,
pub shaders: ResMut<'a, Assets<Shader>>,
pub pipeline_compiler: ResMut<'a, PipelineCompiler>,
pub render_resource_context: Res<'a, Box<dyn RenderResourceContext>>,
pub shared_buffers: Res<'a, SharedBuffers>,
pub current_pipeline: Option<Handle<PipelineDescriptor>>,
}
impl<'a> UnsafeClone for DrawContext<'a> {
unsafe fn unsafe_clone(&self) -> Self {
Self {
pipelines: self.pipelines.unsafe_clone(),
shaders: self.shaders.unsafe_clone(),
pipeline_compiler: self.pipeline_compiler.unsafe_clone(),
render_resource_context: self.render_resource_context.unsafe_clone(),
shared_buffers: self.shared_buffers.unsafe_clone(),
current_pipeline: self.current_pipeline.clone(),
}
}
}
impl<'a> ResourceQuery for DrawContext<'a> {
type Fetch = FetchDrawContext;
}
#[derive(Debug)]
pub struct FetchDrawContext;
impl<'a> FetchResource<'a> for FetchDrawContext {
type Item = DrawContext<'a>;
fn borrow(resources: &Resources) {
resources.borrow_mut::<Assets<PipelineDescriptor>>();
resources.borrow_mut::<Assets<Shader>>();
resources.borrow_mut::<PipelineCompiler>();
resources.borrow::<Box<dyn RenderResourceContext>>();
resources.borrow::<SharedBuffers>();
}
fn release(resources: &Resources) {
resources.release_mut::<Assets<PipelineDescriptor>>();
resources.release_mut::<Assets<Shader>>();
resources.release_mut::<PipelineCompiler>();
resources.release::<Box<dyn RenderResourceContext>>();
resources.release::<SharedBuffers>();
}
unsafe fn get(resources: &'a Resources, _system_id: Option<SystemId>) -> Self::Item {
let pipelines = {
let (value, type_state) = resources
.get_unsafe_ref_with_type_state::<Assets<PipelineDescriptor>>(
ResourceIndex::Global,
);
ResMut::new(value, type_state.mutated())
};
let shaders = {
let (value, type_state) =
resources.get_unsafe_ref_with_type_state::<Assets<Shader>>(ResourceIndex::Global);
ResMut::new(value, type_state.mutated())
};
let pipeline_compiler = {
let (value, type_state) =
resources.get_unsafe_ref_with_type_state::<PipelineCompiler>(ResourceIndex::Global);
ResMut::new(value, type_state.mutated())
};
DrawContext {
pipelines,
shaders,
pipeline_compiler,
render_resource_context: Res::new(
resources.get_unsafe_ref::<Box<dyn RenderResourceContext>>(ResourceIndex::Global),
),
shared_buffers: Res::new(
resources.get_unsafe_ref::<SharedBuffers>(ResourceIndex::Global),
),
current_pipeline: None,
}
}
fn access() -> TypeAccess<TypeId> {
let mut access = TypeAccess::default();
access.add_write(TypeId::of::<Assets<PipelineDescriptor>>());
access.add_write(TypeId::of::<Assets<Shader>>());
access.add_write(TypeId::of::<PipelineCompiler>());
access.add_read(TypeId::of::<Box<dyn RenderResourceContext>>());
access.add_read(TypeId::of::<SharedBuffers>());
access
}
}
impl<'a> DrawContext<'a> {
pub fn get_uniform_buffer<T: RenderResource>(
&self,
render_resource: &T,
) -> Result<RenderResourceBinding, DrawError> {
self.get_buffer(render_resource, BufferUsage::UNIFORM)
}
pub fn get_buffer<T: RenderResource>(
&self,
render_resource: &T,
buffer_usage: BufferUsage,
) -> Result<RenderResourceBinding, DrawError> {
self.shared_buffers
.get_buffer(render_resource, buffer_usage)
.ok_or(DrawError::BufferAllocationFailure)
}
pub fn set_pipeline(
&mut self,
draw: &mut Draw,
pipeline_handle: &Handle<PipelineDescriptor>,
specialization: &PipelineSpecialization,
) -> Result<(), DrawError> {
let specialized_pipeline = if let Some(specialized_pipeline) = self
.pipeline_compiler
.get_specialized_pipeline(pipeline_handle, specialization)
{
specialized_pipeline
} else {
self.pipeline_compiler.compile_pipeline(
&**self.render_resource_context,
&mut self.pipelines,
&mut self.shaders,
pipeline_handle,
specialization,
)
};
draw.set_pipeline(&specialized_pipeline);
self.current_pipeline = Some(specialized_pipeline.clone_weak());
Ok(())
}
pub fn get_pipeline_descriptor(&self) -> Result<&PipelineDescriptor, DrawError> {
self.current_pipeline
.as_ref()
.and_then(|handle| self.pipelines.get(handle))
.ok_or(DrawError::NoPipelineSet)
}
pub fn get_pipeline_layout(&self) -> Result<&PipelineLayout, DrawError> {
self.get_pipeline_descriptor().and_then(|descriptor| {
descriptor
.get_layout()
.ok_or(DrawError::PipelineHasNoLayout)
})
}
pub fn set_bind_groups_from_bindings(
&self,
draw: &mut Draw,
render_resource_bindings: &mut [&mut RenderResourceBindings],
) -> Result<(), DrawError> {
let pipeline = self
.current_pipeline
.as_ref()
.ok_or(DrawError::NoPipelineSet)?;
let pipeline_descriptor = self
.pipelines
.get(pipeline)
.ok_or(DrawError::NonExistentPipeline)?;
let layout = pipeline_descriptor
.get_layout()
.ok_or(DrawError::PipelineHasNoLayout)?;
for bindings in render_resource_bindings.iter_mut() {
bindings.update_bind_groups(pipeline_descriptor, &**self.render_resource_context);
}
for bind_group_descriptor in layout.bind_groups.iter() {
for bindings in render_resource_bindings.iter_mut() {
if let Some(bind_group) =
bindings.get_descriptor_bind_group(bind_group_descriptor.id)
{
draw.set_bind_group(bind_group_descriptor.index, bind_group);
break;
}
}
}
Ok(())
}
pub fn create_bind_group_resource(
&self,
index: u32,
bind_group: &BindGroup,
) -> Result<(), DrawError> {
let pipeline = self
.current_pipeline
.as_ref()
.ok_or(DrawError::NoPipelineSet)?;
let pipeline_descriptor = self
.pipelines
.get(pipeline)
.ok_or(DrawError::NonExistentPipeline)?;
let layout = pipeline_descriptor
.get_layout()
.ok_or(DrawError::PipelineHasNoLayout)?;
let bind_group_descriptor = &layout.bind_groups[index as usize];
self.render_resource_context
.create_bind_group(bind_group_descriptor.id, bind_group);
Ok(())
}
pub fn set_vertex_buffers_from_bindings(
&self,
draw: &mut Draw,
render_resource_bindings: &[&RenderResourceBindings],
) -> Result<(), DrawError> {
let pipeline = self
.current_pipeline
.as_ref()
.ok_or(DrawError::NoPipelineSet)?;
let pipeline_descriptor = self
.pipelines
.get(pipeline)
.ok_or(DrawError::NonExistentPipeline)?;
let layout = pipeline_descriptor
.get_layout()
.ok_or(DrawError::PipelineHasNoLayout)?;
let need_fallback_buffer = layout
.vertex_buffer_descriptors
.iter()
.any(|x| x.name == VERTEX_FALLBACK_LAYOUT_NAME);
for bindings in render_resource_bindings.iter() {
if let Some(index_buffer) = bindings.index_buffer {
draw.set_index_buffer(index_buffer, 0);
}
if let Some(main_vertex_buffer) = bindings.vertex_attribute_buffer {
draw.set_vertex_buffer(0, main_vertex_buffer, 0);
}
if need_fallback_buffer {
if let Some(fallback_vertex_buffer) = bindings.vertex_fallback_buffer {
draw.set_vertex_buffer(1, fallback_vertex_buffer, 0);
}
}
}
Ok(())
}
}
pub trait Drawable {
fn draw(&mut self, draw: &mut Draw, context: &mut DrawContext) -> Result<(), DrawError>;
}
pub fn clear_draw_system(mut query: Query<&mut Draw>) {
for mut draw in query.iter_mut() {
draw.clear_render_commands();
}
}