Check if left mouse button is held down? - c++

So I am just getting myself into coding using C++ and after learning a bit I started coding an auto clicker. I have already made it so you can toggle the auto clicker using a button on your keyboard or something of that sort, but that isn't what I'm looking for.
The problem I'm having is that I can't seem to find a way to check if the left mouse button is held down. If it is held down, then keep on clicking until the left mouse button is no longer held.
Also, I have looked around a lot to see how to do this, and I have gotten a few different things I should do, but none of them work. I was told to use:
if((GetKeyState(VK_LBUTTON) & 0x100) != 0)
from this answer here, but I also found that people were told to use:
if(GetKeyState(VK_LBUTTON) & 0x8000
Sadly I can't find where I found this in my history.
I have tried getting the key state of WM_LBUTTONDOWN but it doesn't seem to pick up the mouse button is being pressed.
I can get it working by checking the key state of VK_LBUTTON, but that only checks to see if the left mouse button has been pressed, not held. So it just continuously clicks until you break the while loop or close the program.
Not really worth putting this down but my 12 am self, thought that checking if the left button had been pressed (like the one before), it would set a boolean value to true and then keep on clicking. But after that, I couldn't get it to stop like before. Now looking back at the code, I understand why it wasn't working.
while (1) {
if(GetKeyState(WM_LBUTTONDOWN)) {
Sleep(delay);
mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
std::cout << "Clicked" << endl;
}
if (GetKeyState(VK_ESCAPE)) {
break;
}
}
Like I said before, I have tried all different combinations to try and get this to work. But I can't see if the left mouse button is held down. I hope someone has the answer and can help me out and other people out. Anyways, thanks and have a nice day.

GetKeyState() takes a virtual key code as input, but WM_LBUTTONDOWN is not a virtual key code, it is a window message. Use VK_LBUTTON instead.
Also, GetKeyState() relies on a state machine that is local to the calling thread. That state machine is updated only when the thread processes keyboard/mouse window messages from its message queue. Your code has no such message processing. For what you are attempting, use GetAsyncKeyState() instead.
Also, mouse_event() is deprecated and has been for a long time. Use SendInput() instead.
Try this:
while (GetAsyncKeyState(VK_ESCAPE) >= 0)
{
if (GetAsyncKeyState(VK_LBUTTON) < 0)
{
Sleep(delay);
INPUT input[2] = {};
input[0].type = INPUT_MOUSE;
input[0].mi.dx = x;
input[0].mi.dy = y;
input[0].mi.dwFlags = MOUSEEVENTF_LEFTDOWN;
input[1] = input[0];
input[1].mi.dwFlags = MOUSEEVENTF_LEFTUP;
SendInput(2, input, sizeof(INPUT));
std::cout << "Clicked" << endl;
}
}

I'm not sure whether I understood the q correctly .. but for checking the pressed state you have always to check the lowest bit in the returned high-byte of GetKeyState(VK_LBUTTON) (see GetKeyState() in MSDN-- means:
bool leftButtonPressed = 0 != (GetKeyState(VK_LBUTTON) & 0x800);
WM_LBUTTONDOWN is the message that is send to a window reporting a Left-button-down-event in the client area -- so using that in the GetKeyState() function is wrong. Try
const int delay = 50;
while (1)
{
if (GetKeyState(VK_LBUTTON) & 0x800)
{
Sleep(delay);
mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0);
mouse_event(MOUSEEVENTF_LEFTUP, 0,0, 0, 0);
std::cout << "Clicked" << std::endl;
}
if (GetKeyState(VK_ESCAPE) & 0x800)
{
break;
}
}

Related

When I click the console, the cursor shows up again. How can I prevent that?

I'm still new to this. so I'm basically on a visual studio project. something called a console application.
#include <windows.h>
#include <iostream>
HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE);
COORD coords;
void setcursor(bool visible, DWORD size) { //if we set it to (0,0) in main. the cursor won't be there anymore. the size becomes 20, and it no longer becomes visible? that's the gist of it.
CONSOLE_CURSOR_INFO lpCursor;
if (size == 0) size = 20; //makes the cursor bigger so it won't show?
lpCursor.bVisible = visible;
lpCursor.dwSize = size;
SetConsoleCursorInfo(console, &lpCursor);
}
void gotoxy(int x, int y) { //to change the coordinates the text outputs to on the cmd
coords.X = x;
coords.Y = y;
SetConsoleCursorPosition(console, coords);
}
this thing(method?), below, called the "setcursor". after i make the cmd screen thing bigger and then even after I minimize it again afterwards. it stops working. the cursor thing appears again as though i never had that method set up. how do i make the cursor go for good.
int main()
{
gotoxy(4, 4);
setcursor(0, 0); //makes that cursor on the console that awaits your text input go invisible or something.
int x;
std::cin >> x;
std::cout << x;
}
The cursor in the command window will redisplay when you resize or minimize/restore the command window. You would need to recall this function setcursor(...) on every window shape change to make it invisible again.
The SetConsolCursorInfo function will reject a cursor size of 0. This is why you test for that and, prevent it in this line if (size == 0) size = 20;
Based on JimmyNJ's answer. I figured that I need a way to detect window size changes, cause that void thinge resets back to 0 by itself.
so i went ahead searched up questions on stack overflow on to that endeavor.
link
I tried something with the answer given in the question above.
It detects changes in the window buffer size (I have no idea what this means), perhaps the screen resolution?
Declare this above main()
HWND g_hWindow = GetConsoleWindow();
void CALLBACK EventProc(HWINEVENTHOOK hook, DWORD event, HWND wnd, LONG object, LONG child, DWORD thread, DWORD time) {
setcursor(0, 0);
}
and inside main() write this:
HWINEVENTHOOK eventHook = SetWinEventHook(EVENT_CONSOLE_LAYOUT, EVENT_CONSOLE_LAYOUT, NULL, EventProc, 0, 0, WINEVENT_OUTOFCONTEXT);
if (eventHook != 0) {
setcursor(0, 0);
}
Note that in the console game i am making, i have that 'if' in a do-while loop. Also this doesn't fix things properly. As again that void thinge likes to reset itself to zero. but when it does, this fixes it.

Is there a way to detect when a key is pressed only once? (not held down)

I have been looking for ways to detect when a key has been pressed but only once, but the only things I can find are GetAsyncKeyState and GetKeyState. I am making a rhythm game for fun and I use a while(true) statement to get everything done. Is there anyway to detect when a key is pressed once? (I'm also using GLFW if that helps)
You could store the state of the previous key presses, if it was not pressed in the last frame and is now, that would mean that the key is held down.
Here's an example with the LMB:
bool previousMouseState = false;
if (GetKeyState(VK_LBUTTON) < 0) {
if (!prevMouseState) {
previousMouseState = true;
//Mouse clicked.
}
} else previousMouseState = false;

SDL2 going too fast -- why does it read multiple inputs when I press just one button?

I've started writing an SDL2 program. I want integer count to go up one when the user presses the right arrow key, down one when user presses left.
#include <iostream>
#include <SDL2/SDL.h>
int main(){
SDL_Window *window= SDL_CreateWindow("test", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN);
int count= 0;
bool isRunning= true;
SDL_Event ev;
while(isRunning){
if(SDL_PollEvent(&ev)){
if(ev.type == SDL_QUIT || ev.key.keysym.scancode == SDL_SCANCODE_ESCAPE)
return 0;
}
const Uint8 *keystate= SDL_GetKeyboardState(NULL);
if(keystate[SDL_SCANCODE_LEFT])
--count;
else if(keystate[SDL_SCANCODE_RIGHT])
++count;
std::cout << count << std::endl;
}
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
Here's a sample of what's printed when I start the program and briefly tap right -- all within a second or two:
0
0
0
0
0
0
0
0
0
0
0
1
2
3
4
4
4
4
4
When I do a quick tap on the right arrow key, I want count to go up by just one, but instead it went from 0 to 4.
Why?
How do I fix this problem?
Your problem is that you ask SDL for a keystate array, which, in your scenario, is not the best method. So, what does SDL do in this case? It simply gives you an array containing information, wheter the current key is being held or not. You try to press the button as short as you can, but your loop is really quick in time. So, to resolve this, you can use the event system's keydown feature, which gives you true, when you pressed down a button (its pair is the SDL_KEYUP for key released event).
The main difference is in the question: is the key being held, or I just pressed down and changed its state?
So, here is an example (use within the SDL_PumpEvent or SDL_PollEvent):
//...
if (event.type == SDL_KEYDOWN)
{
if (event.key.keysym.sym == SDLK_LEFT)
//do left key things...;
else if (event.key.keysym.sym == SDLK_RIGHT)
//do right key stuff...;
}
//...
Note that this method doesn't use scancodes, but keycodes. (They can produce different result than scancodes, due to different types of keyboards). SDLK_ constants are all keycodes. Moreover (if you think about games), scancodes are good for player movement, keydown events are good for GUI elements
Reference for more information: https://www.libsdl.org/release/SDL-1.2.15/docs/html/guideinputkeyboard.html
I hope you understand!
Lasoloz
Similar to this Question (it actually asks about mouse buttons, but its the same for keyboards):
Instead of using keyboardState use the SDL events. SDL will trigger exactly one event per pressed button, while a fast while-loop can trigger multiple times during a single key-press.
Even though the example is far from being a minimal, complete one and it doesn't compile, I guess that the problem could be due to the lack of a call to SDL_PumpEvents.
As from the documentation:
Note: Use SDL_PumpEvents() to update the state array.
Otherwise, the state array won't be updated, with the results you are experiencing.
NOTE
That said, try to rely on events instead of the internal state array used to represent the keyboard.
EDIT
Updated after the question has been updated.
You should replace the if on SDL_PollEvent with a while, like the following one:
while (SDL_PollEvent(&event)) {
// here you have an event, you can use it
}
Otherwise, even if there are no events, it skips the if and goes through the other statements.
That means that the state of the keyboard won't be updated after the first key press if there are no events, but still you iterate over it.
See here for further details about how SDL_PollEvent works.
I changed the while loops to this:
while(isRunning){
while(SDL_PollEvent(&ev)){
if(ev.type == SDL_QUIT || ev.key.keysym.scancode == SDL_SCANCODE_ESCAPE)
return 0;
else if(ev.type == SDL_KEYDOWN){
if(ev.key.keysym.scancode == SDL_SCANCODE_LEFT){
--count;
std::cout << count << std::endl;
}
else if(ev.key.keysym.scancode == SDL_SCANCODE_RIGHT){
++count;
std::cout << count << std::endl;
}
}
}
}
If I understand it right, SDL_PollEvent fires only while address of object ev is true. If user presses a key down, it continues. If the key is left arrow, count goes down one. If key is right arrow, count increases one.
Now cout prints the way I hoped it would.
Output after I press right a few times:
0
1
2
3
4
Then left:
4
3
2
1
0

Simulating a Jump with keyDown Glut C++ not 100%

I'm controlling a sprite on screen using glutkeyboardfunc and keyDown's.
Eg. When I implement the following code the sprite successfully jumps up:
if(keyDown[119]){//w key = up
sprite_y +=40.0f;
spriteT=spriteJ;
}
Whilst in the air, the sprite returns using this code:
if(sprite_y>0){ gravity-=10*delta; sprite_y+=gravity; }
else{ gravity=0; }
The problem I'm having is, if you keep your finger down on the w key, the sprite jumps forever and keeps going up.
I understand this is because I'm using the keyDown method so I tried this:
if(keyDown[119]){//w key = up
sprite_y +=40.0f;
spriteT=spriteJ;
keyDown[119]=0;//reset keyDown to keyUp
}
But I had no luck...
Is there a way I can limit the keyDown to a certain time period or only act as if it was pressed once? Thanks.
edit I dont quite understand how this question is worthy of a vote down. Did you even read it?
You can use a variable to represent the previous state of the key, and then see if it has changed.
For example:
//Initialise a bool called keyWasDown to false
if (keyDown[119]){
if (!keyWasDown){
//Do jumping code
keyWasDown = true;
}
else {
keyWasDown = false;
}

SFML Input Not responsive at start

I am making a 2D game where we are supposed to control the character through arrow keys.
if((win.GetInput().IsKeyDown(sf::Key::Down)))
{
y = y + Speed;
}
if((win.GetInput().IsKeyDown(sf::Key::Left)))
{
x = x - Speed;
}
I have set Speed to 10. And then a i use the Sprite.SetPosition(x,y) to actually animate my character.
Everything works fine. But the problem is whenever i press an arrow key, the character moves for 1/2 seconds, stops for about 1/2 seconds and then moves again smoothly. This happens whenever i press any arrow key.
And yes, i am using a while loop on top to handle multiple events simultaneously.
I hope my question was clear enough. Please help me out!
Thanks.
I think you're not handling events the right way. What you're doing here is checking on each event (which could be keyboard input or not) whether the sf::Key::Down key is pressed (and the same for sf::Key::Left).
Firstly, it's not effective, because you don't get the result you want.
Secondly, it performs useless checks admitting that the events could be mouse moves, mouse clicks or anything else : checking whether those keys are pressed in such cases is pointless for your program.
I can't see your whole code, but you should try something of this taste as your main loop :
bool isMovingLeft = false;
bool isMovingDown = false;
sf::Event event;
while (win.IsOpen())
{
// While window catches events...
while(win.GetEvent(event))
{
// If the caught event is a click on the close button, close the window
if (event.Type == sf::Event::Closed)
win.Close();
// If it's a key press, check which key and move consequently
else if (event.Type == sf::Event::KeyPressed)
{
if(event.Key.Code == sf::Key::Left)
isMovingLeft = true;
else if(event.Key.Code == sf::Key::Down)
isMovingDown = true;
}
// If it's a key release, stop moving in the following direction
else if (event.Type == sf::Event::KeyReleased)
{
if(event.Key.Code == sf::Key::Left)
isMovingLeft = false;
else if(event.Key.Code == sf::Key::Down)
isMovingDown = false;
}
}
// Now that we have caught events, we move the lil' thing if we need to.
if(isMovingLeft)
x = x - SPEED;
if(isMovingDown)
y = y - SPEED;
win.Clear();
// Draw things on the screen...
win.Display();
}
In this code, the whole process is split in two parts :
We first intercept the user input to see if we need to change the moving state of the thing.
Then, once every event has been caught and thoroughly analyzed, we move the thing if it has to. It is done through two bools (that you may need to increase to four if you want a four-direction control. If you want to handle diagonal directions, it would be wiser to use an enum than eight bool, which begins to be rather memory-consuming for such a simple task.)
Note : you will maybe notice that I changed "Speed" to "SPEED". I can't see if it was a define, a const var or simply a var from the code you have given, but the best option would be one of the two first ones. I prefer using #define for such things, to make constants easily reachable (as they're put in the preprocessor) and the fully capped writing make it more differentiable from classic vars once in the code. But that's just coding style we're talking of here :)