rasen

The rasen crate contains the core graph compiler itself. It provides graph building utilities (the Graph struct), various types (rasen::types::*) and operations (rasen::node::*) definitions, and SPIR-V compilation utilities (the Builder struct).

It's perfectly possible to use this crate as-is by creating a Graph struct and buidling the module node-by-node, though this method tends to be quite verbose: ```rust extern crate rasen;

use rasen::prelude::*;

fn main() { let mut graph = Graph::new();

// A vec3 input at location 0
let normal = graph.add_node(Node::Input(0, TypeName::Vec(3)));

// Some ambient light constants
let min_light = graph.add_node(Node::Constant(TypedValue::Float(0.1)));
let max_light = graph.add_node(Node::Constant(TypedValue::Float(1.0)));
let light_dir = graph.add_node(Node::Constant(TypedValue::Vec3(0.3, -0.5, 0.2)));

// The Material color (also a constant)
let mat_color = graph.add_node(Node::Constant(TypedValue::Vec4(0.25, 0.625, 1.0, 1.0)));

// Some usual function calls
let normalize = graph.add_node(Node::Normalize);
let dot = graph.add_node(Node::Dot);
let clamp = graph.add_node(Node::Clamp);
let multiply = graph.add_node(Node::Multiply);

// And a vec4 output at location 0
let color = graph.add_node(Node::Output(0, TypeName::Vec(4)));

// Normalize the normal
graph.add_edge(normal, normalize, 0);

// Compute the dot product of the surface normal and the light direction
graph.add_edge(normalize, dot, 0);
graph.add_edge(light_dir, dot, 1);

// Restrict the result into the ambient light range
graph.add_edge(dot, clamp, 0);
graph.add_edge(min_light, clamp, 1);
graph.add_edge(max_light, clamp, 2);

// Multiply the light intensity by the surface color
graph.add_edge(clamp, multiply, 0);
graph.add_edge(mat_color, multiply, 1);

// Write the result to the output
graph.add_edge(multiply, color, 0);

let bytecode = build_program(&graph, ShaderType::Fragment).unwrap();
// bytecode is now a Vec<u8> you can pass to Vulkan to create the shader module

} ```