Simple Input Binder

A library for binding SDL input events to user defined actions.

Copyright (c) 2024 Bryan Rykowski

Building

Place sib.hpp and sib_maps.hpp somewhere that your project can find them or add their location to the include path.

(The files #include sib.hpp and sib_maps.hpp without any preceding path)

example g++ command (assuming source files in ./sib and header files in ./include/sib):

g++ -o my_program main.cpp sib/sib.cpp sib/sib_readfile.cpp \
-I./include/sib -I{SDL header directory} \
-lSDL2 -lSDL2main

Basic Use

1. (optional) Define actions using constexpr or #define

constexpr Sib::Action_t Action_Jump = 4;
constexpr Sib::Action_t Action_Activate = 10;

This is not required, but Action_Jump is probably easier to remember than 4.

2. Create a Sib::Binder instance

Sib::Binder binder;

3. Map inputs to actions using MapXXXX() functions

binder.MapScancode(SDL_SCANCODE_SPACE, Action_Jump);
binder.MapMouseButton(SDL_BUTTON_LEFT, Action_Activate);

4. Call HandleInput(const SDL_Event& event) in your SDL event handling loop

SDL_Event e;

while (SDL_PollEvent(&e))
{
    binder.HandleInput(e);

    // Other event handling...
}

5. Check the state of actions using Pressed(Sib::Action_t action) and Released(Sib::Action_t action)

if (binder.Pressed(Action_Jump))
{
    // Do jump logic...
}

6. Once you're done processing inputs, reset the pressed/released state of actions

binder.ResetInputs();

This will reset all the pressed and released flags, so make sure to wait until you're done reading them.

It needs to be done before you call HandleInput() again.

Advanced Use

Configuration File

The ReadFile() function can be used to configure input binds at runtime. Syntax is described in Config Syntax

Number of Actions

By default SIB_MAX_ACTIONS is defined as 32. If Sib::Action_t remains typedefed as an unsigned char, this can be increased up to 256 by editing this file or by macro definition:

g++ -DSIB_MAX_ACTION=128 -o my_program {other compile options...}

If even more actions are needed, Action_t could be typedefed as an unsigned short.

Multiple Actions per Input

Only one action can be mapped to an input. This could be limiting for applications that have more complex requirements. A simple solution is to use more than one Sib::Binder and just send input events to some or all of them as necessary.