xgb-render: go back to RGBA because of alignment

Size 9 just happened to have the buffer 16 bytes wide.

prototypes/xgb-xrender.go

@@ -226,7 +226,7 @@ func main() {
 
 	// LCD subpixel rendering isn't supported. :(
 	opts := &truetype.Options{
-		Size:    9,
+		Size:    10,
 		DPI:     96, // TODO: Take this from the screen or monitor.
 		Hinting: font.HintingFull,
 	}
@@ -234,10 +234,12 @@ func main() {
 	bounds := f.Bounds(fixed.Int26_6(opts.Size * float64(opts.DPI) *
 		(64.0 / 72.0)))
 
-	var alphaFormat render.Pictformat
+	var rgbFormat render.Pictformat
 	for _, pf := range pformats.Formats {
-		if pf.Depth == 8 && pf.Direct.AlphaMask == 0xff {
-			alphaFormat = pf.Id
+		// Hopefully. Might want to check byte order.
+		if pf.Depth == 32 && pf.Direct.AlphaMask != 0 {
+			rgbFormat = pf.Id
+			break
 		}
 	}
 
@@ -248,11 +250,12 @@ func main() {
 
 	// NOTE: A depth of 24 will not work, the server always rejects it.
 	// Composite alpha doesn't make sense since golang/freetype can't use it.
-	_ = render.CreateGlyphSet(X, gsid, alphaFormat)
+	// We use RGBA here just so that lines are padded to 32 bits.
+	_ = render.CreateGlyphSet(X, gsid, rgbFormat)
 
 	// NOTE: We could do gamma post-correction in higher precision if we
 	// implemented our own clone of the image.Image implementation.
-	nrgb := image.NewGray(image.Rect(
+	nrgb := image.NewRGBA(image.Rect(
 		+bounds.Min.X.Floor(),
 		-bounds.Min.Y.Floor(),
 		+bounds.Max.X.Ceil(),