github.com/nevalang/neva@v0.23.1-0.20240507185603-7696a9bb8dda/internal/runtime/funcs/image_new.go

package funcs

import (
	"context"
	"image"

	"github.com/nevalang/neva/internal/runtime"
)

type imageNew struct{}

func (imageNew) Create(io runtime.FuncIO, _ runtime.Msg) (func(ctx context.Context), error) {
	pixelsIn, err := io.In.Port("pixels")
	if err != nil {
		return nil, err
	}

	imgOut, err := io.Out.Port("img")
	if err != nil {
		return nil, err
	}

	errOut, err := io.Out.Port("err")
	if err != nil {
		return nil, err
	}

	return func(ctx context.Context) {
		for {
			im := make(map[pixelMsg]struct{})
			var (
				width  int64
				height int64
			)
		stream:
			for {
				select {
				case m := <-pixelsIn:
					var pix pixelStreamMsg
					pix.decode(m)
					if pix.x < 0 || pix.y < 0 {
						select {
						case errOut <- runtime.NewMapMsg(map[string]runtime.Msg{
							"text": runtime.NewStrMsg("image.New: Pixel out of bounds"),
						}):
						case <-ctx.Done():
							return
						}
					}
					if pix.x >= width {
						width = pix.x + 1
					}
					if pix.y >= height {
						height = pix.y + 1
					}
					im[pix.pixelMsg] = struct{}{}
					if pix.last {
						break stream
					}
				case <-ctx.Done():
					return
				}
			}
			img := image.NewRGBA(image.Rect(0, 0, int(width), int(height)))
			for pix := range im {
				img.Set(int(pix.x), int(pix.y), pix.color.color())
			}
			var i imageMsg
			i.decodeImage(img)
			select {
			case imgOut <- i.encode():
			case <-ctx.Done():
				return
			}
		}
	}, nil
}