Contribution on collision mask!
Hello everyone, I was having trouble with mask bump into buttons , like I wanted to put buttons next , but when he opened the screen in the browser to test the mouse always " picked up " long before the sprite ( do not know the reason for this ) , finally I realized that to make a smaller rectangle that sprite however monochrome example blue, pink , it automatically gains the proportional masks to its size , then you put it behind the sprite button and use the option to link two objects and other events for the purpose of your button , then the collision mask for buttons by going to work perfectly ^^
PS : do not laugh at me , hugs !!! 