better random_blocks

Fonderie/crapulator.c

@@ -206,7 +206,7 @@ switch (idFx) {
 		break;
 
 	case 26:
-		retval = random_blocks(image, 80);
+		retval = random_blocks(image, 70);
 		break;
 
 	default :

Fonderie/glitches.c

@@ -100,13 +100,19 @@ int random_blocks(FloatImg *picture, int percent)
 {
 int		x, y;
 
-for (y=0; y<picture->height; y+=8) {
-	for (x=0; x<picture->width; x+=8) {
+if ( (picture->width%16) || (picture->height%8) )
+	{
+	fprintf(stderr, "%s: %d%d bad dims\n", __func__,
+				picture->width, picture->height);
+	}
 
+for (y=0; y<picture->height; y+=16) {
+	for (x=0; x<picture->width; x+=16) {
 		if (percent < (rand()%100) ) {
-
-			un_petit_flou_8x8(picture,x, y);
-
+			un_petit_flou_8x8(picture, x,   y);
+			un_petit_flou_8x8(picture, x+8, y);
+			un_petit_flou_8x8(picture, x,   y+8);
+			un_petit_flou_8x8(picture, x+8, y+8);
 			}
 
 		}