Designing Gameswithgame Maker

Designing GameswithGame Maker

Version 7.0
Written by Mark Overmars

What is New

Version 7.0 of Game Maker has a number of important changes over version 6.1. In particular there is a new extension mechanism. Below the most important changes are described.

Incompatibilities

Version 7.0 uses an adapted file format. As a result file names now have the extension .gmk. The new version can though still read .gm6 files created with the previous version and it is fully compatible with such files.

There is a minor incompatibility in the use of room transitions. In previous version transitions could also be used between frames in the same room. This is not longer possible. Transitions can only be used between rooms. But the number of transitions is considerably extended.

Also version 7.0 does no longer work on Windows 98 or Me. You will need Windows 2000 or later.

Extension packages

The major improvement of version 7.0 of Game Maker is the mechanism of extension packages that has been introduced. Extension packages can either add new collections of actions to Game Maker or they add new functions using DLL or GML files. A new item has been added to the resource list in which the user can indicate which extension packages to use. These are then automatically integrated in the system. Actions are shown in the object form and functions are colorcoded in the script editor, show in the list of functions. Extension packages can have help files that are automatically included in the help menu. Also all required files are automatically added to the game executables.

Three extension package are default provided.

·  GM Printing. Adds a large number of functions for printing shapes, text, sprites, screenshots, etc. and contains dialogs to select the printer and set printer preferences.

·  GM Transitions. Adds over 60 room transitions to the program.

·  GM Windows Dialogs. Adds functions to create most of the standard Windows dialogs for messages, input boxes, file selection, etc.

It is rather easy to create your own extension packages. There is a special program available for this. See the page http://www.yoyogames.com/extensions for more information on how to do this. The extension mechanism sort of replaces and enhances the current DLL mechanism (which remains available).

Publishing games

A publish button has been added to the toolbar. This will take you to our site were you can easily make your finished game available to the public.

Splash screens

The splash screen mechanism has been considerably enhanced. Splash screens, like videos and images are now default shown in the main game window. There are many new options, e.g. to change the scaling. Also other image formats can be used. And rich text files can now contain images.

Game information

The game information is now default shown in the game window and can be closed with the close button.

Separate close button event

It can now be indicated whether or not the Close button must behave like the escape key or not. If not, there is a new event in the Other events that happens when the user clicks on the Close button. So you can now assign different behavior to the Close button and to the escape key.

Room transitions

The room transition mechanism is changed and extended, giving you more control over the transitions and adding many new transitions, like fade-ins, pushing the images, blending room images, rotations, etc. It is now even possible to define your own scripts to do the transitions (but this is rather advanced stuff). An extension package with additional room transitions is provided.

Data structures

A number of additional functions have been provided to deal with data structures. For example, data structures can now be copied, there are functions to write data structures to a string and read them back. This string can then used to e.g. save the datastructure to a file. Also there are more functions for grid data structures to e.g. copy and add parts of grids.

Including files

The mechanism to include files in the executables has been considerably extended. For each file it can now be indicated under what filename it must be stored and where it must be stored. There is a choice now whether or not to include the files in the editable version of the game. Also there are functions to export the files at a different moment than the start of the game.

Adding sprites and backgrounds with alpha channel

There are now functions sprite_add_alpha() and sprite_replace_alpha() to add or replace a sprite from a file that has an alpha channel (such as png files) to get nicer transparancy effects. Similar functions exist for backgrounds.

New registration mechanism

Version 7 uses a new registration mechanism. The free and registered version are now called the Lite and Pro Edition. There is an improved online purchase process that immediately upgrades the program after the payment is made. Old version 5 and 6 registration keys can be exchanged for version 7 activation codes.

Other changes

There are a number of other changes and additions. Here are some of the important ones.

·  The selected direction(s) in the Move Fixed action are now colored red.

·  When running a game the loading bar is shown considerably earlier such that it is clear the game is running.

·  Renamed all actions for more easy reference (compatible with the book).

·  When adding or replacing sprites and backgrounds or when using splash images, many different file formats can now be used, including jpg, tif, bmp, gif, png, etc.

·  In the image editor there now is a command (Ctrl-A) to select the whole image.

·  A toolbar button was added on the main form to save the game as stand-alone executable.

·  In the constants list in game settings, buttons were added to move them up or down in the list and to insert a constant above the current one.

·  Function message_position(-1,-1) now sets the message box to the screen center.

·  Print buttons were added in the script and code editor.

·  Save and print buttons were added to the debug info forms.

·  Events were added that happen when an instance lies outside a view or intersects the view boundary.

·  The form showing errors in the game is enhanced and allows for copying them to the clipboard.

·  Functions random_set_seed(seed), random_get_seed(), and randomize() were added.

·  In the image editor you can now jump to next/prev subimage of a sprite.

·  Global variables can now be declared using the keyword globalvar. After this declaration it is no longer necessary to add the word global and a dot in front of them.

·  During game play F9 now takes a screenshot unless this is switched off in the global game settings.

·  Added functions draw_line_width(x1,y1,x2,y2,w) and draw_line_width_color(x1,y1,x2,y2,w,col1,col2) to draw lines with a width.

·  d3d_start() and d3d_end() now return whether successful.

·  You can now set the variable cursor_sprite to automatically draw a sprite at the cursor location.

·  Increased the maximum number of arguments to DLL functions to 16.

·  In the options under Other you can now indicate version information for the game that will be embedded in the executable.

·  Added functions sprite_save(ind,subimg,fname) and background_save(ind,fname) to save the resources as bitmaps.

·  Added a variable program_directory that stores the location of the game executable.

·  Added a constant c_orange.

·  ...

Corrected bugs

The following bugs were corrected.

·  Solved the problem that sometimes led to corrupted files. Version 7 will read files that were previously marked as being corrupt.

·  A problem with limited real precision was solved. This hould also solve problems with functions dealing with the date and time.

·  A bug in timelines was corrected when duplicating to an earlier moment.

·  Bitwise assignments now work correctly and give no syntax errors.

·  show_message() actions and function now keep the box in the screen center.

·  Using snow effects and explosion effects together now works correctly.

·  A vulnerability to obtain information from a running game was removed.

·  Debug info forms no longer keep jumping to the top position.

·  Game Maker and the created games now work correctly under Windows Vista. As a result though the file size of the games has been considerably increased.

·  When copying something in the code editor the font is now correct and color coding is applied.

·  Backgrounds no longer loose their settings when a new image is loaded.

·  An off-by-one error in drawing filled rectangles was solved.

·  The game window is now made visible before executing create events.

·  Solved a bug in the function median().

·  Solved a crash when resizing a grid.

·  Comparing and finding values in grids now works correctly for string values.

·  Editing a non-transparent sprite will no longer sometimes turn it transparent in the preview.

·  Solved a bug in collision checking with scaled instances.

·  Solved a bug in collision checking with e.g. lines and rectangles that were not on integer coordinates.

·  Function file_bin_open now create the file if it does not yet exist.

·  Added checks in the object_set_parent function to avoid cycles.

·  Solved an error in the bounce action with diagonal bounces.

·  Corrected a bug in the rain effect when the room was higher than 1000 pixels.

·  Corrected a bug that instances without sprites would contstantly get Outside Room events.

·  Corrected a bug when dragging actions between Object and Timeline form (it is no longer possible).

·  Increase the minimal height of the background form to make it impossible to hide the OK button.

·  Corrected a bug with addressing variables in an instance after it changed object during the same step.

·  Corrected a bug that (de-)activating instances without a sprite could work wrong.

·  Corrected an error in drawing a path with 0 length.

·  Solved a bug that the Exit Event action inside a Repeat block did not exit the event.

·  Corrected the position of the loading bar for the game.

·  Corrected an error in removing instance outside a room in the room editor.

·  ...

Using Game Maker

Game Maker is an easy to use program for creating your own computer games. This section of the help file gives you all the information you need for creating your first games. Later sections will discuss more advanced topics, how to finish and distribute your game, and the built-in programming language GML.

So you want to create your own computer games

Playing computer games is fun. But it is actually more fun to design your own computer games and let other people play them. Unfortunately, creating computer games is not easy. Commercial computer games you buy nowadays typically take one to three years of development with teams of anywhere between 10 and 50 people. Budgets easily reach millions of dollars. And all these people are highly experienced: programmers, art designers, sound technicians, etc.

So does this mean that it is impossible to create your own computer games? Fortunately no. Of course you should not expect to create your own Quake or Age of Empires within a few weeks. But that is also not necessary. Simpler games, like Tetris, Pacman, Space Invaders, etc. are also fun to play and a lot easier to create. Unfortunately they still require good programming skills to handle the graphics, sounds, user interaction, etc.

But here comes Game Maker which was written to make it a lot easier to create such games. There is no need to program. An intuitive and easy to use drag-and-drop interface allows you to create your own games very quickly. You can import and create images, sprites (animated images) and sounds and use them. You can easily define the objects in your game and indicate their behavior, and you can define appealing rooms with scrolling backgrounds in which the game takes place. And if you want full control there is actually an easy-to-use programming language built into Game Maker that gives you full control over what is happening in your game.

Game Maker focuses on two-dimensional games. So it is not meant to create 3D worlds like Quake, even though there is some limited functionality for 3D graphics. But don’t let this put you down. Many great games, like Age of Empires, the Command & Conquer series, and Diablo use two-dimensional sprite technology, even though they look very 3-dimensional. And designing two-dimensional games is a lot easier and faster.

Game Maker comes in two editions, the Lite Edition and the Pro Edition. The Lite Edition can be used free of charge but it is limited in its functionality and will display popup messages. You can though freely distribute the games you create with it, you can even sell them if you like. See the enclosed license agreement for more details. You are strongly encouraged to upgrade your copy of Game Maker to the Pro Edition. It will considerably extend the functionality of Game Maker and it will remove the logo when running games. This will also support the further development of Game Maker.

This document will tell you all you need to know about Game Maker and how you can create your own games with it. Please realize that, even with a program like Game Maker, designing computer games is not completely effortless. There are too many aspects that are important: game play, graphics, sounds, user interaction, etc. Start with easy examples and you will realize that creating games is great fun. Also check the web site