tsoding/nothing

A simple platformer about nothing

Nothing

Dependencies

• gcc or clang or MSVC 2015+
• cmake
• libsdl2-dev

Ubuntu

$ sudo apt-get install gcc cmake libsdl2-dev

MacOS

$ brew install gcc cmake sdl2

NixOS

For NixOS we have a development environment defined in default.nix with all of the required dependencies. You can enter the environment with nix-shell command:

$ nix-shell

Arch Linux

$ sudo pacman -S gcc cmake sdl2

Windows

Visual Studio

• Visual Studio 2015+
• SDL2 VC Development Libraries

MinGW

• mingw-w64
• SDL2 MinGW Development Libraries

Quick Start

Linux

CMake

$ mkdir build
$ cd build/
$ cmake ..
$ make
$ ./nothing

SCU

$ ./build-posix.sh
$ ./nothing

Windows

Visual Studio

• Enter the Visual Studio Command Line Development Environment https://docs.microsoft.com/en-us/cpp/build/building-on-the-command-line
  • Basically just find vcvarsall.bat and run vcvarsall.bat x64 inside of cmd
• Download SDL2 VC Development Libraries and copy it to path\to\nothing

> cd path\to\nothing
> 7z x SDL2-devel-2.0.9-VC.zip
> move SDL2-2.0.9 SDL2
> mkdir build
> cd build
> cmake ..
> cmake --build .
> .\nothing

MinGW (with MSYS)

$ cd path/to/nothing
$ wget https://www.libsdl.org/release/SDL2-devel-2.0.10-mingw.tar.gz
$ tar xzf SDL2-devel-2.0.10-mingw.tar.gz
$ mv SDL2-2.0.10 SDL2
$ rm SDL2-devel-2.0.10-mingw.tar.gz
$ mkdir build && cd build
$ cmake .. -G "MSYS Makefiles"
$ cmake --build .
$ ./nothing

MinGW (without MSYS)

• Download SDL2 MinGW Development Libraries and copy it to path\to\nothing

> cd path\to\nothing
> 7z x SDL2-devel-2.0.10-mingw.tar.gz -so | 7z x -si -ttar
> move SDL2-2.0.10 SDL2
> del SDL2-devel-2.0.10-mingw.tar.gz
> mkdir build
> cd build
> cmake .. -G "MinGW Makefiles"
> cmake --build .
> .\nothing

Controls

Game

Keyboard

Key	Action
d	Move to the right
a	Move to the left
w/SPACE	Jump
c	Open debug console
r	Reload the current level including the Player's position
q	Reload the current level preserving the Player's position
p	Toggle game pause
l	Toggle transparency on objects. Useful for debugging levels
TAB	Switch to Level Editor
CTRL+q	Quit the game

Gamepad

Button	Action
Left Stick	Movement of the Player
1	Jump

Consolé

Key	Action
ESC	Exit console
Enter	Evaluate the expression
Up/Down	Traverse console history
CTRL+L	Clear
Ctrl+X, CTRL+W	Cut
Ctrl+C, ALT+W	Copy
Ctrl+V, CTRL+Y	Paste

Level Editor

To access the Level Editor open a level and press TAB.

Key	Action
s	Save level
Mouse Wheel	Zoom and pan
CTRL+z	Undo
q	Toggle snapping mode
SHIFT+Up/Down	Change overlaping order of selected object
CTRL+c/v	Copy/paste selected object
F2	Rename selected object
DELETE	Delete selected object

Support

You can support my work via

• Twitch channel: https://www.twitch.tv/subs/tsoding
• Patreon: https://www.patreon.com/tsoding

nothing's Issues

Add some glow to the goal to make it stand out

• Introduced in #63

Implement camera

I really want to implement it as a wrapper around SDL_Renderer.

Implement camera_center_at

Camera should encapsulate size of the screen and use it to center itself at a certain position

Add inotifyTools to default.nix

• Introduced by #52

throw_error() is difficult to use

throw_error() sets up the type of the currently propagating error. If you check the result of one of the error source functions (like SDL2 or libc functions) on the low level of abstraction then you have to explicitly invoke throw_error(). If you check the result of the application functions on the higher level of abstractions you don't have to invoke throw_error(). That always confuses me. I propose to make a wrapper layer over SDL2 and libc that invokes throw_error() and just forget about this function.

Clean up the names of entity methods

Go through all of the entities (game, level, player, etc) and make sure they follow the convention:

• One translation unit per entity
• Constructors are create_<entity-name> or create_<entity-name>_from_<resource-name> (for example create_level_from_file)
• Destructors are destroy_<entity-name>
• Regular methods are <entity-name>_<method-suffix> (for example player_render)
• Document these conventions somewhere

Unified error handling system

An extensible system that abstracts out SDL and libc (and maybe more in the future) error handling mechanisms.

Doesn't work without The Stick of the Joy

Reproduction Steps

• Just play without The Sick of The Joy

Observed

• Game crashes with "Could not find any The Sticks of the Joy"

Expected

• Being able to play both with and without The Stick of The Joy

README

Should we check malloc for NULL?

That was brought up during the stream. Some people say it's not necessary because by the time malloc returns NULL your app is already dying and there is no point in handling that anyway. Plus it makes the code uglier.

Some stuff I googled up on the topic:

• https://stackoverflow.com/questions/10157778/why-some-people-dont-check-for-null-after-calling-malloc

Forward declare typedefs for all of the entities

Limit amount of sequential jumps

Right now it looks like flappy bird lol

Triangle rendering artifacts

Horizontal blinking lines at the flat top

implement fill_triangle

• Introduced in #77

Integrate with Joystick

Implement goal hiding mechanism

• Introduced in #63

Remove the goal wave

I think floating and rotation are enough to indicate the importance of the goal

Add gif of the game play to README

Make the goal equilateral

Camera is too low

We need to keep it so the player is always somewhere at the bottom of the screen.

Random platform generator

Indicate pause state somehow visually

See if we can utilize the nonnull gcc extension

See how to disable it on non-gcc compilers

https://gcc.gnu.org/onlinedocs/gcc-6.4.0/gcc/Common-Function-Attributes.html#Common-Function-Attributes

Read platforms from file

Game freezes when the player gets stuck between two platforms

It hangs up so hard that only kill -9 can stop it.

Get rid of the FindSDL2 and FindSDL2_mixer modules in the repo

Different strength of opposing forces depending on how much the side is intersecting

<fill this in on the stream with explanation>

Player clips through small bumps

Level to reproduce: platforms.txt

Movable blocks

Pause the game

Implement collision for the left/right sides

• Introduced in #5

Implement The Floating Entity

CI

Compile to WebAssembly

Example: https://github.com/zdychacek/pacman-webassembly

Debug mode that shows goal hide regions

Parallaxy background

make all of the triangle rendering functions accept triangle_t

• Introduced in #86

---

The list of functions:

• camera_draw_triangle
• camera_fill_triangle
• draw_triangle
• fill_triangle

Switch NixOS devenv to Clang

Static platforms with different colors

Player doesn't fully touch walls

• Introduced in #20

Reproduction Steps

• Move towards a wall until you hit it

Observed

• Player stops earlier and cannot touch the wall

Expected

• Player touches the wall

make the scale depend on the view port

• Introduced in #54

So the game looks the same regardless of the size of the window

Player climbs over huge steps if they consist of stack of smaller steps

platforms.txt

Sound effect when a goal gets into the view port

Differect sound effects for visible and invisible goals.

Try to make the goal triangular

I look at the goal and I'm still not convinced, that it is something I want to collect. Let's try to change it's shape. Let's try a triangular shape. SDL2 doesn't support filling triangles out-of-the-box, so we have to implement it ourselves. Some useful info on the topic: http://www.sunshine2k.de/coding/java/TriangleRasterization/TriangleRasterization.html

P.S. we don't use SDL_gfx for educational purposes.

Conan.io support for Linux

We already have it for Windows, thanks to @ForNeVeR. We need to try to do the same for Linux maybe.

Bright background, dark platforms

Basic platform physics

Tiled level format support

http://www.mapeditor.org/

Let's see if it's feasible.

abstract out the camera point transformations

• Introduced in #77

Update gif in the README

The game has changed since the time the gif was made.