To build:
This entry requires SDL to be installed. See the faq.md if you don't know how to do this for your system.
make
To use:
cat mario.level | ./prog 320 200 800 300 128 144 mario.rgba mario8.wav 10343679
Try:
cat giana.level | ./prog 320 200 1000 300 192 168 giana.rgba giana8.wav 5459393
cat mario.level | ./prog 320 200 800 300 128 144 mario.rgba mario8.wav 10343679 && telnet telehack.com 23
If you end up telnetting to the server you can try:
ls # show files including games
wumpus.bas # play Hunt the Wumpus
advent.gam # you know what this is! :-)
starwars # animated Star Wars 'film'
NOTE: the author stated that the sky colour is incorrect in some versions of
macOS, offering a workaround. Others tested this out in the most recent macOS
version and this does not seem to be a problem any more. As he played (and beat)
the entire series many times years ago he can confirm that the sky is more or
less correct though it's possible that because he's practically blind he might
have missed something :-) He guesses that the problem might have been the
version of SDL1 but he does not know this either way.
Others notes ironically that the author stated that in Super Mario Bros one cannot go through walls but there are known glitches where you can in some areas (as he recalls this also applied to the arcade version, Mario Bros, but he cannot confirm this now) :-)
Judges' remarks:
A classic for a particular generation. Like all good programs, being data driven means you can do fun things in small spaces.
NOTE: the author states to use tabsize=4 to see the magic of the formatting of
the code. In vim you can do:
:set tabstop=4
in command mode to see this effect. You don't need to modify your .vimrc file!
You can also use expand as described below if your terminal has enough rows
and you don't want to move about in the code. The vim command should immediately
take effect.
Author's remarks:
Remarks
Use tabsize=4 to see the magic.
expand -t 4 prog.c
The program returns 0 if the player wins or non-zero if the player loses so you can test it and make something useful (or not), like this:
cat mario.level | ./prog 320 200 800 300 128 144 mario.rgba mario8.wav 10343679 && telnet telehack.com 23
and type in: starwars
This is an engine for platform game. It can be used to create games like the legendary Super Mario Bros.
With this simple and clear source code you can create all the games you want, for free!
In my two tests I tried to create one level of Super Mario Bros and one of The Great Giana The Sisters.
Both games are classic platform games and both share the same fundamental rules:
-
There is a character.
-
There are power-ups that can change the look of the character and/or give the character more or different powers or abilities!
-
There are walls, floors and ceilings. The character can move and jump over these type of obstacles but cannot walk through them.
-
There are enemies and; if the character collides with an enemy, the character dies or loses its powers.
Running under macOS
[NOTE: this seems to no longer be the case as of 2023 and most likely much earlier. However one can change the look of the game doing this anyway:]
The color of the sky is wrong on macOS. You need to flip some bytes from the last parameter of the program:
-
MARIO LAST PARAMETER:
4292124159 -
GIANA LAST PARAMETER:
3243070463
Regarding how to compile
The code requires SDL1.
The build process will generate some warnings (60~ on clang) about:
incompatible pointer types: because all pointers are declared tointorchar, to save bytes.type specifier missing, defaults to 'int': because I need to save bytes.using the result of an assignment as a condition without parentheses: becausewhile(c=getchar())is not evil.
How it works
Parameters
- Window width.
- Window height.
- Level width.
- Level height.
- Sprites image width.
- Sprites image height.
- Filename of the sprites image (raw RGBA image).
- Filename of the music (WAVE 8000 Hz 8bit Mono).
- Sky color. This number depends on the system where you run the program. See note on macOS.
Sprites
The program read a single image that contains all the game sprites. The image must be a grid of 8xN sprites. The size of a single sprite must be square. The program calculates the size in this way:
sprite_size = image_width / 8
Each sprite is identified by its position inside the grid, counting line by line, from left to right (for example sprite 0 is the top left sprite in the grid, sprite 8 is the first sprite of the second row of the grid etc.).
Some positions of the grid have a predefined purpose:
Position | Description
:-----------------|:--------------
0 | Player standing right
1 | Player walking right frame 0
2 | Player walking right frame 1
3 | Player jumping right
4 | Player standing left
5 | Player walking left frame 0
6 | Player walking left frame 1
7 | Player jumping left
8 *(second row)* | Super player standing right
9 | Super player walking right frame 0
10 | Super player walking right frame 1
11 | Super player jumping right
12 | Super player standing left
13 | Super player walking left frame 0
14 | Super player walking left frame 1
15 | Super player jumping left
24 | Player dead
32 | Player won
40 | Super player won
All the others sprites can be used as you want, depending on the game you want to create.
Levels
The program reads the level description from stdin.
The level description is a sequence of rows where each row describe an object. You can input as many objects as you want but the maximum number of objects handled by the program is 333. You can modify this value by editing the source here:
C[333*7],d=333;
Each row has six columns:
Screen X:xposition of the object in the level.Screen Y:yposition of the object in the level.Sprite:idof the sprite to be used for the object.CLASSFLAGS: a bitmask that describe how the object behaves.CLASSPARAM0: a parameter that depends onCLASSFLAGS.CLASSPARAM1: a parameter that depends onCLASSFLAGS.
CLASSFLAGS must be a combination (bitwise OR) of some of these constants:
-
ENEMY(1)An enemy. CLASSPARAM0 can be 0 if the enemies don't move, 1 if the initial move direction is right, -1 if that direction is left. All enemies that walk will change their direction after 20 steps. The sprite of an enemy must have 2 other adjacent sprites: SPRITE-1, used when the enemy dies, and SPRITE+1, used when it moves. -
BLOCK(2)A wall. Player can walk over the object but can not pass through it. -
OBJECT BLOCK(4)When the player hits the object from below, a new object is created. CLASSFLAGS of the new object is defined in CLASSPARAM0. The sprite used for the new object is defined in CLASSPARAM1. The sprite of the new object must have an adjacent sprite: SPRITE+1, used when the block is hit. -
POWERUP(8)This is a power-up like the classic Mario mushroom. When the character hits the power-up object, the character becomes the Super character. If CLASSFLAGS has the bit ZOOM, the character height will be doubled. The Super character can hit the enemies without dying, but when this happens, the Super character goes back to being normal. -
END(16)When the player hits this object the level ends; the player wins. -
ZOOM(32)This flag can be used with POWERUP to indicate a power-up that will double the size of the player (like the Mario mushroom). -
DESTROY(64)When the player hits the object (e.g. the classic Mario coin) the object disappears but the engine does not counts the points, so, from the player point of view, this object is useless. -
DESTROYUP(128)This object is like a BLOCK but when the player hits the object from below, the object disappears.
If CLASSFLAGS is 0 the object only has an aesthetic function.
The last row of the level descriptor must have all its columns set equal to
-1.
Limitations
Some classical features are missing: throwing objects, shooting, multiple lives, score tracking. You can add those features if you want!
The program allows only one level. It's easy to add a menu and multiple levels but the size of the engine would too big for the contest.
When the Super character becomes bigger (ZOOM flag), the character can
collide with blocks and get stuck inside them. This is a KNOWN BUG. When your
player become bigger, stay away from blocks!
There's only one audio track (game effects are missing).
Credits
Some of the sprites used in the examples are identical to those of the original games; the others were designed by me.
The music used in the examples have been resampled, starting from the original versions for the Commodore Amiga and Nintendo NES.
Super Mario Bros is a game created by Nintendo Co., Ltd. My use of the sprites does not intend to infringe the intellectual property of Nintendo but only demonstrates the operation of the program. From my point of view this is a tribute to the legendary game Super Mario Bros!
The Great Giana The Sisters is the game created by Time Warp Productions and my justification for the sprites for Mario are the same for this game. Long live The Great Giana The Sisters !! :)
Copyright and CC BY-SA 4.0 License:
This file is Copyright (c) 2023 by Landon Curt Noll. All Rights Reserved. You are free to share and adapt this file under the terms of this license:
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
For more information, see: https://creativecommons.org/licenses/by-sa/4.0/