Game Maker Tutorials 1

1. Game Maker Tutorials 1 Variables and Simple Controls

2. Content • GML (game maker language) • Variables • Relative and Not Relative • IF statements • IF ELSE statements

3. Variable • What is it? • Location in memory with a variable _______ • Programs use it to _______ information • Why do we need it? • To keep track of things • ________________ • _____________

4. How to create variable in GM? • In the _________ tab • The square symbol ______ • Click and the screen appears

5. Creating a variable • Lets create a variable to hold the amount of keys we have • We need to give it a name, But lets make it global E.g. global.keys We set the value to say… 6 • Now we have create a location in memory named “keys” and stored 6 in it. • _______________________ • _____ just means it is accessible by all objects in the game.

6. How do we increment instead? • We tick the Relative box With “Relative” meansadd 6 to the original This is an ______ This is an _________ _______________ ______________________

7. If Statement • Used to make decisions • e.g. Lets look at some code global.keys = 6 //increment or set? If global.keys > 0 //variable check { global.keys = global.keys – 1 //decrement } To do a if statement you use _________ symbols Since we want to check a variable we use

8. How to do in GM? If global.keys > 0 { global.keys = global.keys – 1 }

9. Setting up your IF statement If global.keys > 0 = equals > < >= <= less than and equal

10. IF statement global.keys = 0 ; //_______________ If global.keys > 0 //______________ { global.keys = global.keys – 1 ; //____________ } • What will happen now?

11. IF Else Statement global.keys= 0 //set to zero if global.keys > 0 //variable check { global.keys = global.keys – 1; //decrement } else { draw_text(x,y, “you got no keys); } • ___________________________________

12. Having MORE Else Test element: global.keys if global.keys < 0 // below but not equal to { draw_text(x,y, 'no keys'); } else if global.keys =1 //checks a single number { draw_text(x,y, 'happy'); } else if global.keys >= 3 and global.keys < 6 //handles a range { draw_text(x,y, 'coolness'); } else if global.keys >= 7 //greater and equal to { draw_text(x,y, 'awesomeness'); } else { draw_text(x,y, 'joy'); }