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SDL Text Input
December 10, 2004 09:22 AM
I was wondering if anyone has made a SDL keyboard input library? If not, I will code one myself. However I can see a problem. I was going to track key releases and record it into a char*. However, if a user holds the key, instead of returning `aaaaaaaaaaaaa`, I believe it will return `a`. `aaaaaaaaaa` is the desired result for holding a key for an extended period of time (such as any onther input). The other side of this, how do I stop users from typing `hhhhheeeeellllllllllllooo`
385
December 10, 2004 09:44 AM
Why would you want to write a keyboard input library when SDL already has one built in?
989
December 10, 2004 11:24 AM
Maybe he meant wrapper for easy using SDL keyboard functions? In such case it could be useful.
That's what SDL event queue is doing for you if you call SDL_EnableKeyRepeat(...), just find out good values (default ones are good) and that's it.
(btw, if you want I can share code from my (working and tested) Input manager)
Quote:
However, if a user holds the key, instead of returning `aaaaaaaaaaaaa`, I believe it will return `a`. `aaaaaaaaaa` is the desired result for holding a key for an extended period of time (such as any onther input). The other side of this, how do I stop users from typing `hhhhheeeeellllllllllllooo`
That's what SDL event queue is doing for you if you call SDL_EnableKeyRepeat(...), just find out good values (default ones are good) and that's it.
(btw, if you want I can share code from my (working and tested) Input manager)
1,865
December 10, 2004 12:21 PM
Quote:
Original post by Zeophlite
I was wondering if anyone has made a SDL keyboard input library?
If not, I will code one myself. However I can see a problem.
I was going to track key releases and record it into a char*.
However, if a user holds the key, instead of returning `aaaaaaaaaaaaa`, I believe it will return `a`. `aaaaaaaaaa` is the desired result for holding a key for an extended period of time (such as any onther input). The other side of this, how do I stop users from typing `hhhhheeeeellllllllllllooo`
I actually have in my engine. It is based on this tutorial: http://cone3d.gamedev.net/cgi-bin/index.pl?page=tutorials/gfxsdl/tut6 I just wrapped up the concepts used, and made a few modifications myself.
This is my modified code, just using keyboard ( I took out the mouse ),credits given to Marius Andra for the concepts [wink]:
// SDL_Input.cppCSDL_Input::CSDL_Input(){ current_key = -1; keys = 0;}CSDL_Input::~CSDL_Input(){}bool CSDL_Input::KeyDown(int key){ current_key = key; return (keys[key] == 1);}void CSDL_Input::ClearKey(){ if( current_key > 0) { keys[current_key] = 0; current_key = -1; }}void CSDL_Input::ClearKey(int key){ keys[key] = 0; current_key = -1;}void CSDL_Input::Update(){ keys = SDL_GetKeyState(NULL);}// SDL_Input.hclass CSDL_Input{private: Uint8* keys; int current_key;public: CSDL_Input(); ~CSDL_Input(); bool KeyDown(int key); void ClearKey(int key); void ClearKey();};Here is a simpe example of how to use it:
CSDL_Input Input;...void Update(){ Input.Update(); if( Input.KeyDown(SDLK_a) ) { // process stuff here Input.ClearKey(); // Clears the last key you checked in KeyDown() // you could also have called Input.ClearKey(SDLK_a); }}Of course you would have to customized the processing for any key pressed, but that should give you a great start. Good luck!
PS. Here is an example of getting input to a string (since I feel like helping [WINK]):
CSDL_Input Input;char buffer[256];int cur = 0;void Update(){ Input.Update(); for(int x=SDLK_a;x<SDLK_z;x++) { if( Input.KeyDown(x) ) { buffer[cur] = x; cur++; break; } } if( Input.KeyDown(SDLK_BACKSPACE) ) { if(cur > 0) { buffer[cur] = ' '; cur--; } } // Handle tab,space,etc as well}Kind of inefficient, but you won't continously be running it throughout your program, hopefully just at one spot.
1,504
December 10, 2004 12:32 PM
1,951
December 10, 2004 05:51 PM
http://www.etek.chalmers.se/~e8cal1/sge/ <-- Check it out..
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