pixelpusher

Concurrent software rendering, triangle rasterization and pixel buffer manipulation.

Features and limitations

Can draw software-rendered triangles concurrently, using goroutines. The work of drawing the triangles is divided on the available CPU cores.
Provides flat-shaded triangles.
Everything is drawn to a []uint32 pixel buffer (containing "red", "green", "blue" and "alpha").
Tested together with SDL2, but can be used with any graphics library that can output pixels from a pixel buffer.
The software rendering of 3D graphics in the screenshot above is provided by fauxgl. The outputs from this can be combined with effects from pixelpusher.

Getting started

This program imports pixelpusher, sets up a callback function for drawing pixels to the gfx.Pixels slice, creates a pixelpusher.Config struct and then calls the .Run function. The window title is Red Pixel:

package main

import (
    pp "github.com/xyproto/pixelpusher"
)

func onDraw(canvas *pp.Canvas) error {
    // x=0, y=0, red=255, green=0, blue=0
    return pp.Plot(canvas, 0, 0, 255, 0, 0)
}

func main() {
    // The window title is "Red Pixel"
    canvas := pp.New("Red Pixel")
    // onDraw will be called whenever it is time to draw a frame
    canvas.Run(onDraw, nil, nil, nil)
}

This program allows the user to press the arrow keys or the WASD keys to move a red pixel around and draw something. Press ctrl-s to save the image and press Esc or q to quit.

package main

import (
    "errors"

    pp "github.com/xyproto/pixelpusher"
)

var x, y = 160, 100

func onDraw(canvas *pp.Canvas) error {
    return pp.Plot(canvas, x, y, 255, 0, 0)
}

func onPress(left, right, up, down, space, enter, esc bool) error {
    if up {
        y--
    } else if down {
        y++
    }
    if left {
        x--
    } else if right {
        x++
    }
    if esc {
        return errors.New("quit")
    }
    return nil
}

func main() {
    pp.New("Simple Draw").Run(onDraw, onPress, nil, nil)
}