drag a selection around clones/copies it

1 files changed, 11 insertions, 1 deletions

diff --git a/js/blit.js b/js/blit.js
index 09f39b2..8683f22 100644
--- a/js/blit.js
+++ b/js/blit.js
@@ -18,7 +18,17 @@ var blit = (function(){
 			}
 		})
 	}
-	blit.set = blit.replace = function(A, B, x, y){
+	// copy the region of A beginning at x,y into B
+	blit.copy_from = function(A, B, x, y){
+		x = x || 0 ; y = y || 0
+		B.forEach(function(lex, u, v){
+			var cell = A.getCell(u+x, v+y)
+			if (cell) {
+				lex.clone(cell)
+			}
+		})
+	}
+	blit.copy_to = function(A, B, x, y){
 		x = x || 0 ; y = y || 0
 		B.forEach(function(lex, u, v){
 			var cell = A.getCell(u+x, v+y)