Crate rasen

Build a SPIR-V module from an operation graph

This library lets you define a shader module as a graph (using the petgraph library) of Node, describing the operations needed to obtain the outputs of the shader.

extern crate petgraph;
extern crate rasen;

use petgraph::Graph;
use rasen::*;

fn main() {
  let mut graph = Graph::<Node, ()>::new();

  // A vec3 input at location 0
  let normal = graph.add_node(Node::Input(0, TypeName::Vec3));

  // 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::Vec4));

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

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

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

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

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

  let bytecode = build_program(&graph);
  // bytecode is now a Vec<u8> you can pass to Vulkan to create the shader module
}

On a lower level, you can use the Module struct to build your module by adding operations directly into it.

Operations can be transformed to bytecode using the bytecode module, and specifically the to_bytecode function.

Reexports

pub use graph::*;

pub use bytecode::to_bytecode;

Modules

bytecode	Transform operations into bytecode
graph	Enumerations used in a shader graph
spirv	Definitions for various SPIR-V values

Structs

Module

Builder struct used to define a SPIR-V module

Functions

build_program

Transform a node graph to SPIR-V bytecode