You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: fancy_console_backing.rs
    path of file: ./repos/bracket-lib/bracket-terminal/src/hal/webgpu/backing
    
    the code of the file until where you have to start completion: //! Provides a map between fancy/flexible consoles and webgpu back-end.

use super::index_array_helper::IndexBuffer;
use super::vertex_array_helper::FloatBuffer;
use crate::hal::{
    scaler::{FontScaler, ScreenScaler},
    Font, Shader, WgpuLink,
};
use crate::prelude::FlexiTile;
use crate::BResult;
use bracket_color::prelude::RGBA;
use bracket_geometry::prelude::PointF;
use wgpu::{BufferUsages, RenderPipeline};

/// Provides a mapping between fancy/flexible terminals and webgpu.
/// Maintains a vertex buffer of font positions, an index buffer,
/// and its own pipeline.
pub struct FancyConsoleBackend {
    /// 
    
    pub fn wgpu_draw(&mut self, font: &Font) -> BResult<()> {
        use crate::hal::BACKEND;
        let mut be = BACKEND.lock();
        if let Some(wgpu) = be.wgpu.as_mut() {
            let mut encoder = wgpu
                .device
                .create_command_encoder(&wgpu::CommandEncoderDescriptor {
                    label: Some("Render Encoder"),
                });
            {
                let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                    label: Some("Render Pass"),
                    color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                        view: wgpu.backing_buffer.view(),
                        resolve_target: None,
                        ops: wgpu::Operations {
                            load: wgpu::LoadOp::Load,
                            store: true,
                        },
                    })],
                    depth_stencil_attachment: None,
                });
                render_pass.set_pipeline(&self.render_pipeline);
                render_pass.set_bind_group(0, font.bind_group.as_ref().unwrap(), &[]);
                render_pass.set_vertex_buffer(0, self.vao.slice());
                render_pass.set_index_buffer(self.index.slice(), wgpu::IndexFormat::Uint16);
                render_pass.draw_indexed(0..self.index.len(), 0, 0..1);
            }

            // submit will accept anything that implements IntoIter
            wgpu.queue.submit(std::iter::once(encoder.finish()));
            //output.present();
        }
        Ok(())
    }