Cinder-Pipeline

Cinder-Pipeline is an imaging pipeline to construct and evaluate chained shader-based effectors.

A Context is the container around which nodes are created, connections are made and nodes are evaluated. Context evaluates a Node by walking up the tree through the node's input connections and constructs an ordered collection of dependencies. A Node may have multiple input NodePort which are both keyed and typed. Several data types are supported:

enum class NodePortType {
  FBOImage, // native input/output type for imaging node
  Texture,  // ci::gl::TextureRef
  Bool,     // bool
  Float,    // float
  Int,      // int
  Vec2,     // ci::Vec2
  Color,    // ci::ColorA
  Index,    // int used to index into port's value vector
  FilePath  // ci::fs::path
};

Although multiple data types are supported, being an imaging pipeline, dependencies are only calculated on NodePortType::FBOImage ports. Supporting that, all Node instances have a fixed single output port NodeOutputPortKeyImage of type NodePortType::FBOImage.

Currently there are two abstract derived node classes, SourceNode and EffectorNode. SourceNode has two derived classes TextureSourceNode and FileSourceNode that will both bring textures into the pipeline. EffectorNode is intended to act as a base for shader-based operators and the input ports can vary based on the specific need.

USAGE

// setup context internals (FBO) at source texture size
auto context = Context::create();
context->setup(texture->getSize(), 2);

// create source
auto sourceNode = context->makeNode(new TextureSourceNode);
auto texture = gl::Texture::create(loadImage(loadAsset(RES_LENNA_IMAGE)));
sourceNode->setValueForInputPortKey(texture, TextureSourceNodeInputPortKeyTexture);

// create red color tint
auto tintNode = context->makeNode(new TintNode);
ColorAf color = ColorAf(1.0f, 0.0f, 0.0f, 1.0f);
tintNode->setValueForInputPortKey(tintColor, TintNodeInputPortKeyColor);
context->connectNodes(sourceNode, tintNode);

// create horizontal blur
auto blurNode = context->makeNode(new GaussianBlurNode);
int direction = static_cast<int>(GaussianBlurNode::BlurDirection::Horizontal);
blurNode->setValueForInputPortKey(direction, GaussianBlurNodeInputPortKeyDirection);
context->connectNodes(tintNode, blurNode);

// evaluate (source -> tint -> blur)
auto resultTexture = context->evaluate(blurNode);

CUSTOM EFFECTOR NODE

// TODO

LIMITATIONS

At present, there is little if any error checking, the dependency solver is very naïve and many features are missing - see the TODO for more detail.

GREETZ

• Heavily inspired by Rich Eakin's Cinder-Audio2
• Shake and Quartz Composer
• Neil Mendoza for ofxPostProcessing
• Patricio Gonzalezvivo for ofxFX