sand.diff

diff --git a/renderer/replacepixels.go b/renderer/replacepixels.go
index 2de8786..72c9dd6 100644
--- a/renderer/replacepixels.go
+++ b/renderer/replacepixels.go
@@ -8,11 +8,17 @@ import (
        "github.com/hajimehoshi/ebiten/v2"
 )
 
-var screenBuffer *image.RGBA
+var (
+       screenBuffer    *image.RGBA
+       screenBufferImg *ebiten.Image
+)
 
 func ReplacePixels(screen *ebiten.Image, data []particles.Particle) {
        if screenBuffer == nil {
-               screenBuffer = image.NewRGBA(image.Rect(0, 0, settings.ResolutionWidth, settings.ResolutionHeight))
+               screenBuffer = image.NewRGBA(image.Rect(0, 0, settings.ScreenWidth, settings.ScreenHeight))
+       }
+       if screenBufferImg == nil {
+               screenBufferImg = ebiten.NewImage(settings.ScreenWidth, settings.ScreenHeight)
        }
 
        const l = settings.ScreenWidth * settings.ScreenHeight
@@ -20,16 +26,11 @@ func ReplacePixels(screen *ebiten.Image, data []particles.Particle) {
        for x := 0; x < settings.ScreenWidth; x++ {
                for y := 0; y < settings.ScreenHeight; y++ {
                        particleData := particles.GetDataXY(x, y)
-                       for px := x * settings.Scale; px < (x+1)*settings.Scale; px++ {
-                               for py := y * settings.Scale; py < (y+1)*settings.Scale; py++ {
-                                       pxIdx := (px + py*settings.ResolutionWidth) * 4
-                                       screenBuffer.Pix[pxIdx] = particleData.Color.R
-                                       screenBuffer.Pix[pxIdx+1] = particleData.Color.G
-                                       screenBuffer.Pix[pxIdx+2] = particleData.Color.B
-                                       screenBuffer.Pix[pxIdx+3] = particleData.Color.A
-                               }
-                       }
-
+                       pxIdx := (x + y*settings.ScreenWidth) * 4
+                       screenBuffer.Pix[pxIdx] = particleData.Color.R
+                       screenBuffer.Pix[pxIdx+1] = particleData.Color.G
+                       screenBuffer.Pix[pxIdx+2] = particleData.Color.B
+                       screenBuffer.Pix[pxIdx+3] = particleData.Color.A
                }
        }
 
@@ -58,5 +59,8 @@ func ReplacePixels(screen *ebiten.Image, data []particles.Particle) {
                }
        */
 
-       screen.ReplacePixels(screenBuffer.Pix)
+       screenBufferImg.ReplacePixels(screenBuffer.Pix)
+       op := &ebiten.DrawImageOptions{}
+       op.GeoM.Scale(settings.Factor, settings.Factor)
+       screen.DrawImage(screenBufferImg, op)
 }