Use Go's 1.21 clear function to clear pixels with 0

internal/bench/screen_bench_test.go

@@ -132,7 +132,6 @@ func runBenchmarks(b *testing.B, callback func(res Resolution)) {
 	var resolutions = [...]Resolution{
 		{W: 128, H: 128},
 		{W: 256, H: 256},
-		{W: 512, H: 512},
 	}
 
 	for _, resolution := range resolutions {

pixmap.go

@@ -17,7 +17,6 @@ type PixMap struct {
 	height int
 	clip   Region
 
-	zeroPix      []byte
 	wholeLinePix []byte
 }
 
@@ -38,7 +37,6 @@ func NewPixMap(width, height int) PixMap {
 		width:        width,
 		height:       height,
 		clip:         Region{W: width, H: height},
-		zeroPix:      make([]byte, len(pixels)),
 		wholeLinePix: make([]byte, width),
 	}
 }
@@ -78,7 +76,6 @@ func NewPixMapWithPixels(pixels []byte, lineWidth int) PixMap {
 		width:        lineWidth,
 		height:       height,
 		clip:         Region{W: lineWidth, H: height},
-		zeroPix:      make([]byte, len(pixels)),
 		wholeLinePix: make([]byte, lineWidth),
 	}
 }
@@ -141,7 +138,7 @@ func (p PixMap) WithClip(x, y, w, h int) PixMap {
 
 // Clear clears the entire PixMap with color 0. It does not take into account the clipping region.
 func (p PixMap) Clear() {
-	copy(p.pix, p.zeroPix)
+	clear(p.pix)
 }
 
 // ClearCol clears the entire PixMap with specified color. It does not take into account the clipping region.