# Nexg(Next GPU)
## **Low-level fast GPU Api**
)
[](https://deps.rs/repo/github/Ichinose0/Nexg)
[](https://crates.io/crates/nexg)
Nexg is a pure-rust library that makes coding Vulkan functionality easier and more Rust-like
Nexg aims to support gaming applications as well as operation on GPUs
# Examples
### Triangle
```rust
use std::ffi::c_void;
use std::mem::offset_of;
use std::{env, fs::File, io::BufWriter};
use nexg::{
Buffer, BufferDescriptor, CommandPoolDescriptor, CommandRecorderDescriptor, DataFormat,
Extent3d, FrameBuffer, FrameBufferDescriptor, Image, ImageDescriptor, ImageFormat,
ImageViewDescriptor, InstanceBuilder, InstanceFeature, LoadOp, Pipeline, PipelineDescriptor,
PipelineLayout, PipelineLayoutDescriptor, PipelineVertexInputDescriptor, QueueSubmitDescriptor,
RenderPass, RenderPassBeginDescriptor, RenderPassDescriptor, Shader, ShaderStage,
ShaderStageDescriptor, Spirv, StoreOp, SubPass, SubPassDescriptor,
VertexInputAttributeDescriptor, VertexInputBindingDescriptor,
};
use png::text_metadata::ZTXtChunk;
#[repr(C)]
#[derive(Clone, Copy, Debug)]
pub struct Vec4(f32, f32, f32, f32);
#[repr(C)]
#[derive(Clone, Copy, Debug)]
pub struct Vertex {
pos: Vec4,
color: Vec4,
}
const VERTEX: [Vertex; 3] = [
Vertex {
pos: Vec4(0.0, -0.5, 0.0, 0.0),
color: Vec4(1.0, 0.0, 0.0, 1.0),
},
Vertex {
pos: Vec4(0.5, 0.5, 0.0, 0.0),
color: Vec4(0.0, 1.0, 0.0, 1.0),
},
Vertex {
pos: Vec4(-0.5, 0.5, 0.0, 0.0),
color: Vec4(0.0, 0.0, 1.0, 1.0),
},
];
const WIDTH: u32 = 640;
const HEIGHT: u32 = 480;
fn main() {
let feature = InstanceFeature::empty();
let instance = InstanceBuilder::new().feature(feature).build().unwrap();
// Request suitable connecter.
let desc = RequestConnecterDescriptor::new()
.graphic_support(true)
.compute_support(true)
.transfer_support(true);
let connecters = instance.request_connecters(&[desc]).unwrap();
let connecter = connecters[0];
let index = connecter.get_queue_family_index();
let device = connecter.create_device(&instance, index).unwrap();
let queue = device.get_queue(index);
let desc = CommandPoolDescriptor::empty().queue_family_index(index);
let pool = device.create_command_pool(&desc).unwrap();
let desc = CommandRecorderDescriptor::empty();
let recorders = device.allocate_command_recorder(pool, &desc).unwrap();
let desc = ImageDescriptor::new().extent(Extent3d::new(WIDTH, HEIGHT, 1));
let image = Image::create(&instance, &device, connecter, &desc).unwrap();
let desc = ImageViewDescriptor::empty().format(ImageFormat::R8G8B8A8Unorm);
let image_view = image.create_image_view(&device, &desc);
let vertex = Shader::new(
&device,
&Spirv::new(concat!(
env!("CARGO_MANIFEST_DIR"),
"/examples/shader/shader.vert.spv"
))
.unwrap(),
);
let fragment = Shader::new(
&device,
&Spirv::new(concat!(
env!("CARGO_MANIFEST_DIR"),
"/examples/shader/shader.frag.spv"
))
.unwrap(),
);
let desc = BufferDescriptor::empty().size(std::mem::size_of::() * VERTEX.len());
let vertex_buffer = Buffer::new(&instance, connecter, &device, &desc).unwrap();
vertex_buffer.write(&device, VERTEX.as_ptr() as *const c_void);
vertex_buffer.lock(&device);
let desc = SubPassDescriptor::empty();
let subpass = SubPass::new(connecter, &desc);
let subpasses = &[subpass];
let desc = RenderPassDescriptor::empty()
.subpasses(subpasses)
.load_op(LoadOp::Clear)
.store_op(StoreOp::Store);
let render_pass = RenderPass::new(&device, &desc).unwrap();
let desc = PipelineLayoutDescriptor::empty().render_pass(&render_pass);
let pipeline_layout = PipelineLayout::new(&device, &desc).unwrap();
let shader_stages = vec![
ShaderStageDescriptor::empty()
.entry_point("main")
.stage(ShaderStage::Vertex)
.shaders(&vertex),
ShaderStageDescriptor::empty()
.entry_point("main")
.stage(ShaderStage::Fragment)
.shaders(&fragment),
];
let binding_desc = vec![VertexInputBindingDescriptor::empty()
.binding(0)
.stride(std::mem::size_of::())];
let attribute_desc = vec![
VertexInputAttributeDescriptor::empty()
.binding(0)
.location(0)
.format(DataFormat::R32G32SFloat)
.offset(offset_of!(Vertex, pos)),
VertexInputAttributeDescriptor::empty()
.binding(0)
.location(1)
.format(DataFormat::R32G32B32SFloat)
.offset(offset_of!(Vertex, color)),
];
let vertex_input_desc = PipelineVertexInputDescriptor::empty()
.attribute_desc(&attribute_desc)
.binding_desc(&binding_desc);
let desc = PipelineDescriptor::empty()
.shader_stages(&shader_stages)
.input_descriptor(&vertex_input_desc)
.width(WIDTH)
.height(HEIGHT);
let pipeline = Pipeline::new(&device, pipeline_layout, &render_pass, &desc).unwrap();
let desc = FrameBufferDescriptor::empty()
.render_pass(&render_pass)
.image_view(&image_view)
.width(WIDTH)
.height(HEIGHT);
let framebuffer = FrameBuffer::new(&device, &desc).unwrap();
let begin_desc = RenderPassBeginDescriptor::empty()
.width(WIDTH)
.height(HEIGHT)
.clear(1.0, 1.0, 1.0, 1.0)
.render_pass(&render_pass)
.frame_buffer(&framebuffer);
recorders[0].begin(&device, begin_desc);
recorders[0].bind_pipeline(&device, &pipeline[0]);
recorders[0].bind_vertex_buffer(&device, &vertex_buffer);
recorders[0].draw(&device, 3, 1, 0, 0);
recorders[0].end(&device);
let desc = QueueSubmitDescriptor::empty();
queue.submit(&device, &desc, &recorders);
let file = File::create("triangle.png").unwrap();
let w = &mut BufWriter::new(file);
let mut encoder = png::Encoder::new(w, WIDTH, HEIGHT);
encoder.set_color(png::ColorType::Rgba);
encoder.set_depth(png::BitDepth::Eight);
let mut writer = encoder.write_header().unwrap();
let slice = image.as_raw_data(&device, WIDTH, HEIGHT).unwrap();
writer.write_image_data(&slice).unwrap(); // Save
let tail_ztxt_chunk = ZTXtChunk::new(
"Comment".to_string(),
"A zTXt chunk after the image data.".to_string(),
);
writer.write_text_chunk(&tail_ztxt_chunk).unwrap();
}
```
# Notice
This API is not **an abstraction** to other graphics APIs (DirectX, Metal).
It is an API that makes it easier to use and **optimize Vulkan's functionality**.
# Goals
- Fast API with low overhead
# License
Nexg is licensed under MIT LICENSE