imgui-rs-vulkan-renderer

A Vulkan renderer for imgui-rs using Ash.

Compatibility

How it works

The renderer records drawing command to a command buffer supplied by the application. Here is a little breakdown of the features of this crate and how they work.

• Vertex/Index buffers

The renderer creates a vertex buffer and a index buffer that will be updated every time Renderer::cmd_draw is called. If the vertex/index count is more than what the buffers can actually hold then the buffers are resized (actually destroyed then re-created).

• Frames in flight

The renderer support having multiple frames in flight. You need to specify the number of frames during initialization of the renderer. The renderer manages one vertex and index buffer per frame.

• No draw call execution

The Renderer::cmd_draw only record commands to a command buffer supplied by the application. It does not submit anything to the gpu.

• Custom textures

The renderer supports custom textures. See Renderer::textures for details.

• Custom Vulkan allocators

Custom Vulkan allocators are not supported for the moment.

Features

gpu-allocator

This feature adds support for gpu-allocator. It adds Renderer::with_gpu_allocator which takes a Arc<Mutex<gpu_allocator::vulkan::Allocator>>. All internal allocator are then done using the allocator.

vk-mem

This feature adds support for vk-mem-rs. It adds Renderer::with_vk_mem_allocator which takes a Arc<Mutex<vk_mem::Allocator>>. All internal allocator are then done using the allocator.

Since we cannot publish a crate with patched dependencies you'll need to patch it on your end by adding this to your Cargo.toml file

[patch.crates-io]
vk-mem = { git = "https://github.com/adrien-ben/vk-mem-rs", tag = "0.2.3-ash-0.34-0.37" }

I'm still not sure with the Arc<Mutex<...>> stuff. It works for me but i'm unsure it'a the best way to go. Any suggestion is welcome.

dynamic-rendering

This feature is useful if you want to integrate the library in an app making use of Vulkan's dynamic rendering. When enabled, functions that usually takes a vk::RenderPass as argument will now take a DynamicRendering which contains the format of the color attachment the UI will be drawn to and an optional depth attachment format.

Integration

You can find an example of integration in the common module of the examples.

// Example with default allocator
let renderer = Renderer::with_default_allocator(
    &instance,
    physical_device,
    device.clone(),
    graphics_queue,
    command_pool,
    render_pass,
    &mut imgui,
    Some(Options {
        in_flight_frames: 1,
        ..Default::default()
    }),
).unwrap();

Examples

You can run a set of examples by running the following command:

# If you want to enable validation layers
export VK_LAYER_PATH=$VULKAN_SDK/Bin
export VK_INSTANCE_LAYERS=VK_LAYER_KHRONOS_validation

# Or with Powershell
$env:VK_LAYER_PATH = "$env:VULKAN_SDK\Bin"
$env:VK_INSTANCE_LAYERS = "VK_LAYER_KHRONOS_validation"

# If you changed the shader code (you'll need glslangValidator on you PATH)
# There is also a PowerShell version (compile_shaders.ps1)
./compile_shaders.sh

# Run an example
cargo run --example <example>

# Example can be one of the following value:
# - collapsing_header
# - color_button
# - custom_textures
# - disablement
# - draw_list
# - hello_world
# - keyboard
# - long_list
# - multiple_fonts
# - progress_bar
# - radio_button
# - slider : TODO: crashes
# - tables_api
# - test_drawing_channels_split
# - test_window_impl
# - test_window
# - text_callbacks
# - text_input