PixelFunctions

Apply functions to each pixel in an image, concurrently.

This module contains functions that fit well together with the pixelpusher module.

The PixelFunction type has this signature:

func(v uint32) uint32

If you have a pixel buffer of type []uint32, with colors on the form ARGB, then this modules allows you to apply functions of the type PixelFunction to that slice, concurrently.

The goal is to avoid looping over all pixels more than once, while applying many different effects, concurrently.

Combine and Map

• Several PixelFunction functions can be combined to a single PixelFunction by using the Combine function.
• A PixelFuncion can be applied to a pixel buffer by using the Map function.

Example:

package main

import (
    "fmt"
    "github.com/xyproto/pf"
    "runtime"
)

func main() {
    // Resolution
    const w, h = 320, 200

    pixels := make([]uint32, w*h)

    // Find the number of available CPUs
    n := runtime.NumCPU()

    // Combine two pixel functions
    pfs := pf.Combine(pf.InvertEverything, pf.OnlyBlue)

    // Run the combined pixel functions over all pixels using all available CPUs
    pf.Map(n, pfs, pixels)

    // Retrieve the red, green and blue components of the first pixel
    red := (pixels[0] | 0x00ff0000) >> 0xffff
    green := (pixels[0] | 0x0000ff00) >> 0xff
    blue := (pixels[0] | 0x000000ff)

    // Should output only blue: rgb(0, 0, 255)
    fmt.Printf("rgb(%d, %d, %d)\n", red, green, blue)
}

General info

• License: BSD
• Version: 0.1.0
• Author: Alexander F. Rødseth <xyproto@archlinux.org>