The primitive can’t be used this way, failed with following code.
impl PdfPrimitive
{
pub fn new() -> Self
{
let render_params = vello::RenderParams {
base_color: vello::peniko::Color::BLACK,
width,
height,
antialiasing_method: vello::AaConfig::Area,
};
Self {
render_params
}
}
}
impl iced_wgpu::Primitive for PdfPrimitive
{
fn prepare(
&self,
device: &wgpu::Device,
queue: &wgpu::Queue,
format: wgpu::TextureFormat,
storage: &mut iced_wgpu::primitive::Storage,
bounds: &Rectangle,
viewport: &iced::graphics::Viewport,
)
{
// 1. Unable to save renderer variable to self for it is not mutable
// 2. also the vello Renderer doesn't fulfill the
// this constraint: pub trait Primitive: Debug + Send + Sync + 'static,
let renderer = vello::Renderer::new(
device,
RendererOptions {
surface_format: None,
use_cpu: false,
num_init_threads: NonZeroUsize::new(1),
antialiasing_support: vello::AaSupport::area_only(),
},
).ok();
}
fn render(
&self,
encoder: &mut wgpu::CommandEncoder,
storage: &Storage,
target: &wgpu::TextureView,
clip_bounds: &Rectangle<u32>,
) {
// the VelloBackend needs to mutate its argument, but self is not mutable
// maybe I can use Refcell
let mut backend: VelloBackend<'_> = VelloBackend::new(&mut self.cache);
let resolver = self.file.resolver();
render_page(&mut backend, &resolver, &page, Transform2F::default()).ok()?;
let scene = backend.finish();
let mut render_pass = encoder.begin_render_pass(
&wgpu::RenderPassDescriptor {
label: Some("iced_wgpu render pass"),
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: frame,
resolve_target: None,
ops: wgpu::Operations {
load: match clear_color {
Some(background_color) => wgpu::LoadOp::Clear({
let [r, g, b, a] =
graphics::color::pack(background_color)
.components();
wgpu::Color {
r: f64::from(r),
g: f64::from(g),
b: f64::from(b),
a: f64::from(a),
}
}),
None => wgpu::LoadOp::Load,
},
store: wgpu::StoreOp::Store,
},
})],
depth_stencil_attachment: None,
timestamp_writes: None,
occlusion_query_set: None,
},
);
render_pass.set_scissor_rect(clip_bounds.x, clip_bounds.y, clip_bounds.width, clip_bounds.height);
// Unable to get queue and device, because the prepare method is not mutable
if let Some(renderer) = self.renderer.as_mut() {
renderer
.render_to_texture(device, queue, &scene, &target, &self.render_params)
.or_else(|_| bail!("Got non-Send/Sync error from rendering"))?;
}
}
}
