|
It's a simple language that allows you to create games easily and quickly. All you have to do is decide where things go on screen, how they move and how they affect your man ... then you play. My aim was to put the fun back into programming and allow anybody to be able to create a game.
Use cursor controls or WASD to move, space to jump and C to crouch. Move the mouse over any game to view the code. The language is quite easy to learn so why not spend a few minutes to learn it. You cannot make changes to other peoples screens but you can use parts of their code. Always remember to save your game. If you have any questions or suggestions then please contact me through my home page.
Try it out
A simple example
The following game is reasonably short but gives an idea of what the language is about. Items are placed around the screen and your man has
to get to the other side of the screen to finish. The loop places elevators at various points across the screen.
"Example game" at 220 460
ladder at 40 200
platform at 10 200
platform at 10 100
loop x 150 to 600 step 120
elevator at x 100
end
|
Index
Hello World
We'll now go through the language so you can write games yourself. To enter a program just move the mouse over the screen and click edit. The follwing program will display "Hello World" in the top left of the screen. When you've entered the program just click done and then run.
Now let's try displaying the text elsewhere on screen (the screen size is 640 by 480) and maybe changing the colour and font. The font can be changed to small, medium or large. It doesn't matter whether a command is all on one line or spread over multiple lines.
"hello world" at 200, 270
"hello world" at 230, 240 font medium
"hello world" at 260, 210 color blue font small
"hello" + " world" at 200 160
"My favourite number is " + 7 at 120 120
|
We could even randomise where and how text appears on screen. The random word picks a random value that's in the right range. Try running the following a few times to see how things change:
"Hello World" at random, random
font random
colour random
|
Why limit ourselves to one message? Let's put it in a loop to place this message 50 times on screen. Remember to put the "end" at the bottom.
loop n 50
"Hello World" at random, random
font random
colour random
end
|
In fact, why limit ourselves to text that stands still? let's move the text around the screen. You'll need to look at the section on the move command to fully understand what's possible.
loop n 50
"Hello World" at random, random
font random
colour random
move random 50 then reverse
end
|
Index
Boxes
So far we've just looked at displaying text on screen. Here's how to place a box on screen. The 40 by 40
indicates the width and height. If you don't give any dimensions then it defaults to 60 by 60. You could try setting the colour of a box or placing many boxes around the screen.
It default to a size of 60 by 60 and, if there's no "at" command then it will display in the top left of the screen. Of course we can change the size of the box, change it's position on screen and alter it's colour:
box 90 by 90 at 260 300 colour blue
|
Index
Images
The program comes with a number of inbuilt images. You can also tile images horizontally and vertically to
create larger images. Colour and font commands won't work with images.
image water.png
image platform.png
image ladder.png
image water.png at 280 300
image water.png
tile 10 by 5
at 200 200
|
Index
Numbers
Numbers can be displayed on screen using colours and fonts. Simple math is catered for so wherever a number appears in your program, you can replace this with a variable or a mathematical expression. If you look at the syntax for the language you'll see that some words are shown in yellow, these words can be replaced by numbers or even just a random command. The random command will try to produce a number that's in the correct range for where it's being used.
5 at 300 250
1+5 at 250+50 200
2 * 3 + 4 at 300 150
0 at 300 100 colour random font 0
|
Index
Movement
You can make anything on screen move a set distance in any direction (up, down, left or right). You could also use the numbers 0, 1, 2, 3 or use random to pick a direction. The move command below will move the box up 100 points and then reverse back down. Other options instead of reverse include restart, end, stop and back. I suggest trying them out to see what they do. The move command can be applied to anything so you could change your "hello world" example to move the text around the screen.
box 50 by 50 at 280 50
colour yellow
move up 400 then restart
|
You can follow the move command above with an optional speed, wait or start command:
- speed
- says how fast the item should move and can be either slow, medium or fast. Alternatively use 0,1,2 or random
- wait
- says how long to wait (in 1/10's of a second) before moving each time
- start
- just makes pretend that the item is already in the middle of it's travels so start 25 would have the item appear half way through it's travel
loop n 50
"Hello World" at random, random
font random
colour random
move random 50 then reverse
wait 10
end
|
Index
Loops
We've already met simple loops like "loop n 50" where a set of statements between the loop and the end will repeat 50 times with the value of n changing from 1,2,3..50. The loop statement can come in a few different forms:
- loop n 10
- loop n 10 to 50
- loop n 10 to 50 step 5
Here's an example with boxes:
loop x 0 to 600 step 60
box 50 by 50
at x 200
colour random
move up 100 then reverse speed slow
end
|
Now here's another example but trying to show moving waves on water:
screen "Sea" at 250 460 colour blue
image water.png
tile 33 by 5
at 0 60
loop x 0 to 640 step 10
image water.png at x 60
move up 10 then reverse
end
|
Index
Action
The above almost looked like a game but the man doesn't know what items he can stand on. The action command can be placed after anything and tells the program whether the man can stand, stand, climb, die, push or finish. The finish stands for finish the screen. Let's change the program so the man has to jump across the screen.
loop x 0 to 600 step 60
box 50 by 50
at x 200
colour random
move up 100 then reverse speed slow
action stand
end
|
We could make the game a bit better by having a title and adding somethings that try to harm you:
"Block world" at 210 450
loop x 10 to 600 step 100
box 50 by 50
at x 200
colour random
move up 100 then reverse speed slow
action stand
end
loop n 7
box 5 by 5
at 600, random
colour yellow
move left 900 then restart
action die
end
|
Index
Define
If you remember in the first example it mentioned platforms, ladders and elevators but these don't appear in the language. Instead youcan something things using the commands above. These particular ones are defined in the initialisation script but you could define any you want.
define platform
image platform.png
action stand
tile 5 by 1
define ladder
image ladder.png
action climb
tile 1 by 5
define elevator
image elevator.png
action stand
move up 300 then reverse
speed slow
define fireball
image fireball_right.png
move left 1200 then restart
action die
define background
image stars.png
at 0, 480
tile 40 by 40
|
Index
Changing the background
The last item above showed how the background is made up, it's just an image of stars that is tiled together across the whole screen. You can change the background or get rid of it as you please.
# change the background to grass
set background image grass.png
# or you could even forget the background all together
forget background
# or create a blue background
forget background
define background box 640 by 480 at 0 480 colour blue
# a moving background
set background move left 160 then restart
|
Index
Draw order
Things are drawn in the order they are declared. The background is declared before everything else because we want it to be behind all the other images. The man is usually added after all your images so he always appears on top of the other images. In the following example he appears before the bars so it looks like he's behind bars.
box 120 by 60 at 10 210 action stand
man at 40 270
# bars
loop x 10 to 70 step 10
box 5 by 60 at x 270
end
|
Index
Colour
There are a few words that define certain colours (red, yellow, lightyellow, orange, lightgreen, green, lightblue, blue, indigo, violet, cyan, magneta, white, lightgray, gray, darkgray, black). If you want to use other colours then you can use an RGB Hex value. Just go to a page like this and pick a colour then look for the Hex value for it. You could use the following to give a box a nice light blue shade. I'm afraid it's outside this tutorial to explain RGB (Red Green Blue) or Hex (numbers based on base 16!) but you can look it up on the web if you're interested. If you live in America and want to use the color instead of colour then that's fine to.
box at 240 300 color 0x004C99
|
The default colour is normally gray but you can change this by making your first command a colour command.
colour red
"some text"
box
"more text" colour green
|
Index
Random numbers
The key word random will produce a random number in the range 0 to 640 (the width of the screen). If random is being used instead of a yellow keyword (see the syntax) then a value is chosen that's in the range required. Here's a few examples:
"my favourite number is "+random
colour random
font random
loop n 12
"my favourite dice number is " + (random % 6 +1)
end
|
If you use random to help arrange your game and want to get the same sequence of random numbers again then move the mouse over the screen, click data and look for system variable called "seed". If you then set seed to this value in your code then the same sequence of random numbers will be generated each time ie
seed 241
loop n 6
box at random random colour random
end
|
Index
Activating movement
Normally when you make something move it will start moving when the game begins. If you want the item to only move when something is touched by the man then you need to specify the following. The item that activates a movement will sparkle.
platform at 10 200
box at 100 200 action stand
move right 400 then stop when "begin"
start "begin"
|
The start "string" activates the movement.
The when "string" should follow a move and will only begin moving when the start has activated. There can be any number of items waiting on the same start "string". There can be any number of items that start the action. If there is a start "string" then there has to be a matching when "string". You can have any number of different activations in your code.
You can have any number of
Index
What's next
I'm planning on adding the following if people find it interesting:
- larger screen
- better animations
- sound
- multi screens
- push thing
- zombies
- schools
- better animations for man
- backups of code
- define using, inheriting
- voting on screens
- use on tablets (with motion control) or facebook
- Add the following to this tutorial:
- How to vote
- random seed
- Quick example with platforms and ladders elevator
- default colour and fonts
- maths random
- activate + on
- change man start and finish positions
Index
Syntax
This is a simple language for creating platform games. You just define what goes where, how
it moves and what happens if the player touches it. Your man can move left and right, jump and climb.
You can define things as
images, as strings or as numbers. If they have an 'at x,y' position then they appear
on screen. The language itself is quite small :
statements :== # any comments you have
[ [ ( define|set|forget ) ] name ] type* terms*
loop name number [ to number [ step number ] ] statements+ end
type :== image string [ tile number by number ]
box [ number by number ]
string
number
as name
terms :== at number , number
move ( up | down | left | right ) number
then ( reverse | restart | end | stop ) move_terms*
action ( ignore | stand | climb | die | push | finish )
font ( small | medium | large )
colour number
start string
unique
move_terms :== speed ( slow | medium | fast )
wait number
start number
when string
number :== [0-9]+
random
- number
( number )
number ( * | / | + | - | % ) number # precendence problem
name # if the type is a number
0x[0-9A-F]+ # hex for RGB colours
name :== [A-Za-z][A-Z-a-z0-9_]*
string :== ".*"
string + ( string | number )
name
Colour notes
============
These are keywords
These terms are defined elsewhere
These values can be replaced by random or by numbers 0,1,2...
Index
Definitions
There is a program that is run before your program is run which defines the colours and background etc:
# main var
define background image stars.png at 0, 480 tile 40 by 40
# colours
define red 0xFF0000
define yellow 0xFFFF00
define lightyellow 0xFFFFE0
define orange 0xFF7F00
define lightgreen 0x90EE90
define green 0xFF00
define lightblue 0xADD8E6
define blue 0xFF
define indigo 0x4B0082
define violet 0x8B00FF
define cyan 0x00FFFF
define magneta 0xFF00FF
define white 0xFFFFFF
define lightgray 0xD3D3D3
define gray 0x808080
define darkgray 0xA9A9A9
define black 0x000000
# some basic items
define platform
image platform.png
action stand
tile 5 by 1
define ladder
image ladder.png
action climb
tile 1 by 5
define elevator
image elevator.png
action stand
move up 300 then reverse
speed slow
define fireball
image fireball_right.png
move left 1200 then restart
action die
# other images
define water image water.png
define lava image lava.png
define grass image grass.png
define clouds image clouds.png
define concrete image concrete.png
define brick_grey image brick_grey.png
# special var
define exit image exit_right.png action finish at 595, 260
define screen "" at 200, 600
define man image man_r1.png at 10 370
|
Index
Questions
I'm currently developing the language so things are in a state of flux. My current issues are:
- I need a better name for the language
- should I have if then else?
- should I allow grouping of multiple statements into a define?
- should I allow multiple screens in one script?
- should the language be case sensitive?
- do I need a statement separator ie ";"?
- should I have an "=" in assignments?
- is the loop statement easy to understand?
- what colours should I allow ie red, marine, aqua-blue etc?
- do I need permissions?
- should system var (width, height, seed, screen) have some sort of prefix?
- how can users add new images?
- should I handle arrays or lists?
- features for schools?
Index
|