Raster
The canvas.Raster is like an image but draws exactly one spot
for each pixel on the screen. This means that as a user interface
scales or the image resizes more pixels will be requested to fill
the space. To do this we use a Generator function as illustrated in
this example - it will be used to return the colour of each pixel.
The generator functions can be pixel based (as in this example where we
generate a new random colour for each pixel) or based on full images.
Generating complete images (with canvas.NewRaster()) is more efficient
but sometimes controlling pixels directly is more convenient.
package main
import (
"image/color"
"math/rand"
"fyne.io/fyne/v2"
"fyne.io/fyne/v2/app"
"fyne.io/fyne/v2/canvas"
)
func main() {
myApp := app.New()
w := myApp.NewWindow("Raster")
raster := canvas.NewRasterWithPixels(
func(_, _, w, h int) color.Color {
return color.RGBA{R: uint8(rand.Intn(255)),
G: uint8(rand.Intn(255)),
B: uint8(rand.Intn(255)), A: 0xff}
})
// raster := canvas.NewRasterFromImage()
w.SetContent(raster)
w.Resize(fyne.NewSize(120, 100))
w.ShowAndRun()
}
If your pixel data is stored in an image you can load it through the
NewRasterFromImage() function which will load the image to display
pixel perfect on screen.