spritesheet

Spritesheet

Spritesheet is an Encoder and Decoder to build spritesheets from a list of images or seperate a spritesheet into multiple images.

Encoder

The encoder takes in a slice of images and some options. If no options are provided, defaults will be used.

// EncodeOpts provides the encoder the parameters it needs to create a spritesheet
type EncodeOpts struct {
	New        func(r image.Rectangle) draw.Image // what format you want the new image to be, defaults to RGBA
	ImgsPerRow int // Default to 5
}

// Encode takes a slice of images and based on the encode options will turn
// the images into a single sprite sheet.
// If the images are not all the same size, encode will take the max height
// and max width of any image and use that as its dimensions. For best look,
// all images should be the same size.
func Encode(images []image.Image, opts *EncodeOpts) (image.Image, error) {

Decoder

The decoder takes a spritesheet and based on width and height chops the spritesheet up into a slice of seperate images.

// DecodeOpts provides the decoder with the necessary opts to split the spritesheet into seperate images
type DecodeOpts struct {
	New           func(r image.Rectangle) draw.Image // what format you want the new image to be, defaults to RGBA
	Width, Height int
}

// Decode takes in a image, assumed to be a spritesheet, and based on the options passed will
// chop up the spritesheet into seperate images.
// a width and height are needed to know the bounds of each image
func Decode(in image.Image, opts *DecodeOpts) ([]image.Image, error) {

Scripts

In the scripts you can find a bash script for help creating spritesheets out of video. It uses ffmpeg and the cli found in cmd folder to do this.

options:

• -i - input video file
• -ss - where to seek in the video HH:MM:SS.MMM format
• -vf - fps to extract images (see https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video)
• -sl - sheet size: how many images do you want per sheet

Example to create a thumbnail every two seconds.

./scripts/video-thumbnails.sh -i oceans.mp4 -ss 00:00:00.000 -vf 1/2

Sheet_0

Sheet_1

TODO

• Finish the cli