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Getting input from keyboard problem

Sep 25, 2019 at 5:23pm
adam2016 (1529)
Hey guys,

first off my code is messy, none modular and hard to read but I'm not making any useful program, I'm just learning how to use the GetAsyncKeyState from the windows API to get input from a user.

anyhow I have followed many online sources but for some reason the program fails to read from the keyboard,

anyone possibly know why?

thanks

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  #include <iostream>
#include <cstdlib>
#include <windows.h>

using namespace std;

char sprite = 'X';

void printBoard(char buffer[][30])
{

    for(int i = 0; i < 20; i++)
    {

        for(int j = 0; j < 30; j++)
        {

            if(buffer[i][j] == sprite)
            {

                cout << sprite;
            }
            else
            {
                cout << buffer[i][j];
            }

        }
        cout << endl;
    }
}

void keyPress(bool& right,bool& left,bool& down,bool& up){

  if(GetAsyncKeyState(VK_LEFT & 0x8000)){

    right = false;
    down = false;
    up = false;
    left = true;
  }
  if(GetAsyncKeyState((VK_RIGHT) & 0x8000)){

    left = false;
    down = false;
    up = false;
    right = true;
  }
  if(GetAsyncKeyState(VK_UP & 0x8000)){

    down = false;
    right = false;
    left = false;
    up = true;
  }
  if(GetAsyncKeyState('f') & 0x8000){

    up = false;
    right = false;
    left = false;
    down = true;
    cout << "HI" << endl;
  }

}


int main()
{

    while(true){

        if(GetAsyncKeyState(VK_LEFT) & 0x8000){

            cout << "HEY" << endl; // not working :/
        }

    }

    char buffer[20][30];

    for(int i = 0; i < 20; i++)
    {

        for(int j = 0; j <30; j++)
        {

            if(i == 0)
            {

                //cout << "yes" << endl;
                buffer[i][j] = '#';
                continue;
            }
            if(i == 19)
            {

                buffer[i][j] = '#';
                continue;
            }
            if(j == 0)
            {

                buffer[i][j] = '#';
                continue;
            }
            if(j == 29)
            {

                buffer[i][j] = '#';
                continue;
            }

            buffer[i][j] = ' ';

        }
    }

    int xPos = 15;
    int yPos = 10;
    bool left = false;
    bool right = false;
    bool up = false;
    bool down = false;

    buffer[yPos][xPos] = sprite;

    keyPress(right,left,down,up);


    while(1)
    {

        printBoard(buffer);
        system("cls");

        if(right)
        {
            xPos++;

            if(buffer[yPos][xPos] == '#')
            {

                right = false;
                left = true;
                xPos--;
            }
            else
            {
                buffer[yPos][xPos-1] = ' ';
                buffer[yPos][xPos] = sprite;
            }
        }
        
        if(left){

            xPos--;

            if(buffer[yPos][xPos] == '#')
            {
                left = false;
                right = true;
                xPos++;
            }
            else
            {
                buffer[yPos][xPos+1] = ' ';
                buffer[yPos][xPos] = sprite;
            }
        }
    }
}
Edit & run on cpp.sh
Sep 25, 2019 at 5:38pm
adam2016 (1529)
**update

strange when I include Windows.h with a capital 'w' everything works as expected, I wonder why windows.h with a lower case doesn't work, are they both valid headers? whats the diff?

thanks
Sep 25, 2019 at 5:50pm
Ganado (6823)
There should be no difference unless you're doing something weird like cross-compiling for Windows from Linux. (Windows filesystem is case-insensitive, Linux isn't)

Can you change it back to lowercase and then re-compile and see if it starts to fail again?
Last edited on Sep 25, 2019 at 5:54pm
Sep 25, 2019 at 7:16pm
adam2016 (1529)
strange seems to be working now with lower case w, wonder what was wrong first time around.
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