Crate densa_render 

wgpu renderer for densa.

GpuRenderer draws a frame’s densa_draw::Instances, as built by a Canvas from any painter (grids, paragraphs, your own), with one instanced draw call: each quad is a solid rectangle or a glyph sampled from the atlas. It keeps the atlas texture in step with the glyph cache’s updates, growing it on the GPU as the cache grows.

Applications built on densa-window never call it. A frame loop of your own does:

use densa_draw::{Canvas, InstanceBuffer, Rect};
use densa_render::{AtlasError, Color, GpuRenderer};
use densa_text::{AtlasConfig, GlyphCache};

/// Once per device: the renderer, and a glyph cache kept within the device's texture limit.
fn setup(device: &wgpu::Device, format: wgpu::TextureFormat) -> (GpuRenderer, GlyphCache) {
    let renderer = GpuRenderer::new(device, format, 65_536);
    let mut cache = GlyphCache::new(AtlasConfig::default());
    let _ = cache.limit_side(GpuRenderer::max_atlas_side(device));
    (renderer, cache)
}

/// Each frame: paint through a canvas, follow the glyph atlas, draw in one call.
fn frame(
    device: &wgpu::Device,
    queue: &wgpu::Queue,
    (renderer, cache): (&mut GpuRenderer, &mut GlyphCache),
    instances: &mut InstanceBuffer,
    target: &wgpu::TextureView,
    size: (u32, u32),
) -> Result<(), AtlasError> {
    let mut canvas = Canvas::begin(cache, instances);
    canvas.fill_rect(Rect::new(10.0, 10.0, 100.0, 20.0), Color::WHITE);
    // Grids, paragraphs and charts paint onto the same canvas here.
    renderer.apply_atlas_updates(device, queue, cache.drain_updates())?;
    let count = renderer.prepare(queue, size, instances.as_slice());
    let mut encoder = device.create_command_encoder(&Default::default());
    renderer.render(&mut encoder, target, Color::BLACK, count);
    queue.submit([encoder.finish()]);
    Ok(())
}

Structs

Color

A color in linear RGB with straight (not premultiplied) alpha: the space densa blends in.

GpuRenderer

GPU resources for drawing a frame of Instances in one draw call.

Enums

AtlasError

Why the GPU atlas could not follow the glyph cache.