Awesome
shadergraph
Functional GLSL linker
ShaderGraph is a library for linking together GLSL snippets into stand-alone shaders. It is mainly meant to build complicated shaders 100% programmatically. But it can also act as the back-end to a live graph-based shader editor, as its graph model is persistent.
Snippets can be simple one-liners, or multi-function source files. Snippets can also declare callbacks, as functions without bodies, linked in from elsewhere. This allows complicated execution flows to be built very easily.
vec3 getColor();
void main() {
gl_FragColor = vec4(getColor(), 1.0);
}
ShaderGraph is designed to play well with Three.js, but does not depend on it. It merely follows the same code/object conventions.
There is no editing UI included, only a way to display a graph as an HTML/CSS/SVG diagram.
Live Examples
ShaderGraph
- Require
- Combined Vertex/Fragment Material
- Instanced Uniform
- De-duped Attributes
- Split Outputs
- Fanned Outputs
- Passed Outputs
- Isolate Subgraphs
- Deep Nesting
- Deep Callback
- Isolated require
ShaderGraph 2 drives all shaders in MathBox² (in development). For more info, see the articles on acko.net:
Here's a real-world vertex shader for a line primitive, sampling color and position from two textures:
<a href="http://acko.net/files/shadergraph2/vertex-color-shader-tidy.png"><img src="http://acko.net/files/shadergraph2/vertex-color-shader-tidy.png"></a>
<a href="http://acko.net/files/mathbox2/iframe-readyornot.html"><img src="http://acko.net/files/mathbox2/cover2.jpg" alt="MathBox 2 - Audio Visualizer example"></a>
You can also use ShaderGraph's graph visualizer directly for other purposes:
Basic Use
Install via npm:
npm install shadergraph
Include build/shadergraph.js
.
To use ShaderGraph, you initialize it once with a given snippet library. A snippet library is either a dictionary of named snippets, or a fetch function.
// Dynamic fetch
var fetch = function (name) {
return "...";
};
// Static fetch
var fetch = {
getColor: "...",
setColor: "...",
getRampColor: "...",
};
var shadergraph = ShaderGraph.load(fetch);
You can use the chainable Factory API to build graphs. It's a smart wrapper around a partially built graph. It allows you to make splits and joins, hook up callbacks via requires, import other factories, etc.
Instead of including snippets by name, you can also pass in GLSL code directly
to .pipe(…)
and .require(…)
regardless of whether you are using a fetch
function/library or not.
Snippets are instanced by default, letting you bind unique uniforms to specific snippets in the chain:
// Prepare new shader
var shader = shadergraph.shader();
// Prepare uniform (three.js style)
var uniforms = {
diffuseColor: { type: "v3", value: { x: 0.5, y: 0.75, z: 1.0 } },
};
// Build shader graph
shader
// Require a callback
.require("getRampColor")
// Build two-step chain that uses the callback and the uniform
.pipe("getColor", uniforms)
.pipe("setColor");
var program = shader.link();
Instancing behavior can be configured globally or per shader (see below).
Materials
ShaderGraph also includes a material helper, to build a vertex/fragment shader simultaneously:
// Prepare new material (vertex + fragment shader)
var material = shadergraph.material();
// Build vertex shader graph
material.vertex.pipe("vertex");
// Build fragment shader graph
material.fragment.pipe("getColor").pipe("setColor");
// Link both shaders and combine into a three.js style material
var program = material.link();
The returned program
object is compatible with Three.js' ShaderMaterial
objects.
Caveats
- Call
shadergraph.inspect(…)
anywhere to insert an inspector for a graph, and find missing/wrong connections. - Preprocessing directives like
#ifdef
and#define
are ignored, but do pass through. Be careful when using them. Consider using snippets and/or callbacks instead. - Structs are not supported,
glsl-parser
seems to choke on them. Array types are probably a bit buggy still.
Reference
Constructor
var fetch = function (name) { return … };
var fetch = { name: "...", name: "..." };
var config = {
globalUniforms: false, // Make uniforms global
globalVaryings: true, // Make varyings global
globalAttributes: true, // Make attributes global
globals: [], // Make specific symbols global
autoInspect: false, // Pop-up a graph inspector if compilation fails
}
shadergraph = ShaderGraph.load(fetch, config);
ShaderGraph
-
.shader(config = {})
Returns an empty
shader
graph wrapped in a factory. Override globalconfig
options. -
.material(config = {})
Returns an empty
material
wrapping two factories:material.vertex
andmaterial.fragment
. Override globalconfig
options. -
.visualize(graph/factory/material)
Draw the given graph(s), returns an HTML
element
. Callelement.update()
after inserting. -
.inspect(graph/factory/material)
Draw the graph and insert it into the body as a floating inspector.
Factory
-
.pipe(name/code, uniforms = {}, namespace = null, defines = {})
.pipe(name/code, namespace = null, uniforms = {}, defines = {})
.pipe(name/code, uniforms = {}, defines = {})
.pipe(factory)
Add the given code/snippet/factory to the graph and connect it to what came before. Binds dictionary of
uniforms
. Set thenamespace
.Connections are made first between connectors of the same type and name, and then between connectors of the same type (in the order specified in the shader). Any callbacks previously added to the graph are also connected, if possible.
-
.require(name/code, uniforms = {}, namespace = null, defines = {})
.require(name/code, namespace = null, uniforms = {}, defines = {})
.require(name/code, uniforms = {}, defines = {})
.require(factory)
Add the given code/snippet/factory to the graph as a callback for what comes next. Binds dictionary of
uniforms
. Set thenamespace
. -
.isolate().….end()
Create a finished, isolated subgraph and add it to the graph.
This is useful, for example, to force the attaching of callbacks to a subgraph:
var shader = shadergraph.shader(); shader.require("getColor"); // Require two instances of callback shader.require("getColor"); shader.isolate(); shader.require("getColorSum"); // Define callback with two open callback inputs shader.end(); // Hook up both callbacks shader.pipe("setColor"); // Connect to main snippet
-
.callback().….end()
Create an isolated subgraph and add it to the graph as a callback.
-
.split().….next().….end()
Create two or more branches and split connections across them 1-to-1. Connectors which are connected to a branch will not be available for any subsequent branch.
-
.fan().….next().….end()
Create two or more branches and fan connections across them 1-to-N. All connectors are available in each branch.
-
.pass()
Use this instead of
.end()
to make additional passthrough connections that skip the entire block. In other words, all connectors at the beginning of the branch will be available again for subsequent nodes. -
.graph()
Finalize the graph and return it. The factory is reset to an empty state.
-
.compile(name)
Finalize the graph and compile it immediately (no callbacks). Returns a GLSL shader string. The factory is reset to an empty state.
-
.link(name)
Finalize the graph and link it with its subgraphs immediately (with callbacks). Returns a complete GLSL shader string with a main function. The factory is reset to an empty state.
Graph
-
.compile(name)
Compile the graph (no callbacks). The graph is retained.
-
.link(name)
Compile and link the graph and its subgraphs (with callbacks). The graph is retained.
Material
-
.link(options = {})
Link the material's vertex and fragment shader. Returns Three.js style ShaderMaterial options, merged with any existing options passed in.
Manual Use
If you want to build graphs by hand instead of with factories, this is possible, but not as nice. You will need to construct objects and inject a few dependencies. Use the Factory API as a guide.
The underlying namespaces are exposed as ShaderGraph.Graph
,
ShaderGraph.Block
, … Block
and its subclasses are the logical pieces of the
shader. Each block has a Node
associated with it that lives in the Graph
and
contains a set of Outlets
. Connections can be made node-to-node with
node.connect(node)
(auto-matching by name and type), or outlet-to-outlet with
outlet.connect(outlet)
.
To compile Graphs created without a factory, you will need to call .compile()
or .link()
on the graph's tail block directly.
Steven Wittens - http://acko.net/