I would like to zoom in on an object for as long as I hold the right mouse button down. The issue right now is that I have to click it every time I want to zoom. Is there a way I can modify my code so that it will zoom while I hold the button, rather than clicking it?
void mouse(int button, int state, int x, int y)
{
// Save the left button state
if (button == GLUT_LEFT_BUTTON)
{
leftMouseButtonDown = (state == GLUT_DOWN);
zMovement += 0.1f;
}
else if (button == GLUT_RIGHT_BUTTON)
{
leftMouseButtonDown = (state == GLUT_DOWN);
zMovement -= 0.1f;
}
// Save the mouse position
mouseXPos = x;
mouseYPos = y;
}
The state variable of your function tells you what type of mouse-button event had happened: It can either be GLUT_DOWN or GLUT_UP.
Knowing this, you can store this state in an extra variable outside of the mouse function and zoom as long as the state is set to true (this has to be done somewhere in every frame). The code could look like the following:
void mouse(int button, int state, int x, int y)
{
// Save the left button state
if (button == GLUT_LEFT_BUTTON)
{
leftMouseButtonDown = (state == GLUT_DOWN);
}
else if (button == GLUT_RIGHT_BUTTON)
{
// \/ right MouseButton
rightMouseButtonDown = (state == GLUT_DOWN);
}
// Save the mouse position
mouseXPos = x;
mouseYPos = y;
}
void callThisInEveryFrame()
{
if (leftMouseButtonDown)
zMovement += 0.1f;
if (rightMouseButtonDown)
zMovement -= 0.1f;
}
Related
In a basic variable and Button setup on an Arduino software, the idea is that if you press a button, you gain one on a variable. Theoretically, holding the button shouldn't cause the variable to increase more than one until the release and repressing of the button. However, I could not make this happen. How is this supposed to be done?
I tried using an else around a delay (because the adding one to a variable code was inside an "if" statement) so it would not delay unless the button and released and would not count multiple button inputs, but this resulted in a larger increase when a button was clicked rather than just a one increase.
const int buttonPin = 8;
int number = 0;
int numbertwo = 0;
int buttonState = 0;
void setup()
{
pinMode(buttonPin, INPUT);
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW){
numbertwo = ++number;
delay(100);
}
(Can use any method to determine variable, like on an LCD)
As mentioned above, I expected the variable to only increase by one when a button is pressed and not to continue increasing until the button is released and re-pressed, but what actually happened was the variable kept increasing in value as the button was held.
I'm assuming you want the variable "number" increase by 1 per press. I think you are looking for something like this:
const int buttonPin = 8;
int number = 0;
int buttonState = 0;
void setup() {
pinMode(buttonPin, INPUT);
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW){
++number;
// This loop is to make sure not to count up until button is released
do {
delay(5);
buttonState = digitalRead(buttonPin);
} while (buttonState == LOW);
}
}
If you don't like the loop based implementation, here's a state based implementation for you:
const int buttonPin = 8;
int number = 0;
int buttonState = 0;
int prevState = -1;
void setup() {
pinMode(buttonPin, INPUT);
prevState = -1;
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW && prevState != buttonState){
++number;
prevState = buttonState;
}
delay(5);
}
For developing a side-scrolling platform 2D game I want to implement a moving camera class, the reason of using the class instead of moving the whole map is that I'll have to use too many objects at once witch will cause a lag. I cannot let that happen.
There's a nice algorithm for handling the camera, when player is moving further than the width of the screen then camera moves on players direction until he is once again in the middle of the screen, I've been working several days for making this algorithm work however there's been no success.
// Main
public class Camera
{
protected float _zoom;
protected Matrix _transform;
protected Matrix _inverseTransform;
//The zoom scalar (1.0f = 100% zoom level)
public float Zoom
{
get { return _zoom; }
set { _zoom = value; }
}
// Camera View Matrix Property
public Matrix Transform
{
get { return _transform; }
set { _transform = value; }
}
// Inverse of the view matrix,
// can be used to get
// objects screen coordinates
// from its object coordinates
public Matrix InverseTransform
{
get { return _inverseTransform; }
}
public Vector2 Pos;
// Constructor
public Camera()
{
_zoom = 2.4f;
Pos = new Vector2(0, 0);
}
// Update
public void Update(GameTime gameTime)
{
//Clamp zoom value
_zoom = MathHelper.Clamp(_zoom, 0.0f, 10.0f);
//Create view matrix
_transform = Matrix.CreateScale(new Vector3(_zoom, _zoom, 1)) *
Matrix.CreateTranslation(Pos.X, Pos.Y, 0);
//Update inverse matrix
_inverseTransform = Matrix.Invert(_transform);
}
}
This is the camera class I made for handling the screen, it's main purpose is to resize the screen, more precisely to zoom in and out whenever I want to change my screen, (Title screen, Playing screen, Game over, and like that.)
Moving the camera is quite simple with keys, like this.
if (keyState.IsKeyDown(Keys.D))
Cam.Pos.X -= 20;
if (keyState.IsKeyDown(Keys.A))
Cam.Pos.X += 20;
if (keyState.IsKeyDown(Keys.S))
Cam.Pos.Y -= 20;
if (keyState.IsKeyDown(Keys.W))
Cam.Pos.Y += 20;
And ofc. the drawing method witch apply the camera.
spriteBatch.Begin(SpriteSortMode.Texture, BlendState.AlphaBlend, null, null, null, null, Cam.Transform);
Here comes the part when I stop, so what I want to do is make something like 2 2D rooms. By Room I mean the place where I usually place objects. like this "Vector2(74, 63)" So I want to create a place where I could draw items that would stick to the screen and wouldn't move, and make the screen bounds that would make my algorithm to work, witch will be always on screen and as an addition it will check if one of the borders of the screen "room" reaches the certain coordinates of the map "room".
I think that the reason for that would be obvious because I don't want player to move camera outside the map when he reaches the wall, otherwise the player would already see a part of the next map where he will be transformed.
The reason of drawing both maps next to each other is again to reduce the loading time so player wouldn't have to wait for playing the next map.
Alright, so I've run into more troubles than I expected so I'll add extra information and will start with the player class:
// Main
public class Player
{
public Texture2D AureliusTexture;
public Vector2 position;
public Vector2 velocity;
public Vector2 PosForTheCam; // Variable that holds value for moving the camera
protected Vector2 dimensions;
protected CollisionPath attachedPath;
const float GRAVITY = 18.0f;
const float WALK_VELOCITY = 120f;
const float JUMP_VELOCITY = -425.0f;
// Constructor
public Player()
{
dimensions = new Vector2(23, 46);
position = new Vector2(50, 770);
}
public void Update(float deltaSeconds, List<CollisionPath> collisionPaths)
{
#region Input handling
KeyboardState keyState = Keyboard.GetState();
if (keyState.IsKeyDown(Keys.Left))
{
velocity.X = -WALK_VELOCITY;
}
else if (keyState.IsKeyDown(Keys.Right))
{
velocity.X = WALK_VELOCITY;
}
else
{
velocity.X = 0;
}
if (attachedPath != null && keyState.IsKeyDown(Keys.Space))
{
velocity.Y = JUMP_VELOCITY;
attachedPath = null;
}
velocity.Y += GRAVITY;
#endregion
#region Region of handling the camera based on Player
PosForTheCam.X = velocity.X;
#endregion
#region Collision checking
if (velocity.Y >= 0)
{
if (attachedPath != null)
{
position.X += velocity.X * deltaSeconds;
position.Y = attachedPath.InterpolateY(position.X) - dimensions.Y / 2;
velocity.Y = 0;
if (position.X < attachedPath.MinimumX || position.X > attachedPath.MaximumX)
{
attachedPath = null;
}
}
else
{
Vector2 footPosition = position + new Vector2(0, dimensions.Y / 2);
Vector2 expectedFootPosition = footPosition + velocity * deltaSeconds;
CollisionPath landablePath = null;
float landablePosition = float.MaxValue;
foreach (CollisionPath path in collisionPaths)
{
if (expectedFootPosition.X >= path.MinimumX && expectedFootPosition.X <= path.MaximumX)
{
float pathOldY = path.InterpolateY(footPosition.X);
float pathNewY = path.InterpolateY(expectedFootPosition.X);
if (footPosition.Y <= pathOldY && expectedFootPosition.Y >= pathNewY && pathNewY < landablePosition)
{
landablePath = path;
landablePosition = pathNewY;
}
}
}
if (landablePath != null)
{
velocity.Y = 0;
footPosition.Y = landablePosition;
attachedPath = landablePath;
position.X += velocity.X * deltaSeconds;
position.Y = footPosition.Y - dimensions.Y / 2;
}
else
{
position = position + velocity * deltaSeconds;
}
}
}
else
{
position += velocity * deltaSeconds;
attachedPath = null;
}
#endregion
}
}
So I state it clear that I asked my friend to do most of it because I wanted to handle the gravity and the slopes so we made it work similar like in Unity. And he happened to know how to do that.
And so I'll add the Update method that handles the camera from the Main Class.
MM.Update(gameTime); // Map Managher update function for map handling
Cam.Update(gameTime); // Camera update
Cam.Zoom = 2.4f; // Sets the zoom level for the title screen
// Takes the start position for camera in map and then turns off the update
// so the camera position can be changed. Else it would just keep an infinite
// loop and we couldn't change the camera.
if (StartInNewRoom)
{
Cam.Pos = MM.CameraPosition; // Applys the camera position value from the map manager class
StartInNewRoom = false;
}
I am unsure how to handle the camera, like I used your method and the result often ended up that camera moves by itself or it doesn't move at all.
If you don't want objects to move with the camera like a HUD you need a second spriteBatch.Begin() without your camera matrix which you draw after your actual scene.
To make the camera not move out of the map you could use some kind of collision detection. Just calculate the right border of your camera. It depends where the origin of your camera is.
Is your camera matrix working like this? Because the position should be negative or it will move in the wrong direction.
This is how mine looks like.
return Matrix.CreateTranslation(new Vector3(-camera.position.X, -camera.position.Y, 0)) *
Matrix.CreateRotationZ(Rotation) * Matrix.CreateScale(Zoom) *
Matrix.CreateTranslation(new Vector3(Viewport.Width * 0.5f, Viewport.Height * 0.5f, 0));
Viewport.Width/Height * 0.5 centers you camera.
You can also apply this behind your Pos.X/Y
To Camera follows player
public void Update(Player player)
{
//Clamp zoom value
_zoom = MathHelper.Clamp(_zoom, 0.0f, 10.0f);
//Create view matrix
_transform = Matrix.CreateScale(new Vector3(_zoom, _zoom, 1)) *
Matrix.CreateTranslation(player.Pos.X, player.Pos.Y, 0);
//Update inverse matrix
_inverseTransform = Matrix.Invert(_transform);
}
I've added InputListener to my actor and now I want to check if touchUp event is inside the actor.
Simple example: I'm starting draging mouse inside my actor and i'm finishing outside my actor.
I though that touchUp event will start only if mouse is inside my actor but it also start outside my actor (when touchDown event start inside my actor).
How to check if touchUp event is inside my actor only?
I see two solutions here:
To use some flag to check if the pointer is inside the actor and handle it with exit method:
image.addListener(new InputListener(){
boolean touched = false;
#Override
public boolean touchDown(InputEvent event, float x, float y, int pointer, int button)
{
touched = true;
System.out.println("TOUCH DOWN");
return true;
}
#Override
public void touchUp(InputEvent event, float x, float y, int pointer, int button)
{
if(touched)
{
touched = false;
System.out.println("TOUCH UP");
}
}
#Override
public void exit(InputEvent event, float x, float y, int pointer, Actor toActor)
{
touched = false;
}
});
To check if pointer is inside the actor inside touchUp
#Override
public void touchUp(InputEvent event, float x, float y, int pointer, int button)
{
Stage stage = event.getTarget().getStage();
Vector2 mouse = stage.screenToStageCoordinates( new Vector2(Gdx.input.getX(), Gdx.input.getY()) );
if(stage.hit(mouse.x, mouse.y, true) == event.getTarget())
{
System.out.println("TOUCH UP");
}
}
Both solutions need some extra code but both should be working fine.
Sorry miss read your question noticed when you changed it.
Still, I would add a listener and simply check coordinates of actor. The x and y given with a clicklistener just return local coordinates of the actor so a simple check vs width and height is enough.
ClickListener cl = new ClickListener()
{
#Override
public void touchUp(InputEvent event, float x, float y, int pointer, int button) {
super.touchUp(event, x, y, pointer, button);
if (x > 0 && y > 0 && x < getWidth() && y < getHeight())
{
System.out.println("Released within actor");
}
}
};
actor.addListener(cl);
Thanks in advance for your help.
Scenario Overview
In the real world, I am using one button to open two mechanical valves, but one of those valves should close after a period of time that we will hard code into the sketch, and the other valve stays open for as long as the button is pushed. For proof of concept, I am lighting two LEDs as stand-ins for the valves.
Pseudocode
If Button One is pressed, Valve One should Open, and Valve Two should also Open for 200ms then Close.
Initial Solution
Within the main loop, I look for the button to be pushed as part of an if statement. When that condition is passed, I used a while loop and timer to keep "valve2" open until the time is up. LEDs work, and all is superficially great. However...
The Issue
When my partner starts putting the actual mechanicals together, valve2 doesn't open because the while loop is cycling so quickly that the voltage required to initiate the opening of the valve is not high enough.
My Question
Is it possible to isolate (without using delays) the loop & evaluation of the timer condition from the main loop in order to allow full power to be sent to the valve mechanism (or LED in this case)? Or am I overthinking this whole thing (likely the case)?
The Code
const int button1 = 2; //Pin for switch 1
const int button2 = 3; //Pin for switch 2
const int valve1 = 12; //Pin for relay 1
const int valve2 = 13; //Pin for relay 2
// variables will change:
int state1 = 0; // variable for reading the pushbutton status
int state2 = 0; // variable for reading the pushbutton status
//THIS IS THE TIME IN MILLISECONDS FOR valve2 WHEN button1 IS DEPRESSED
int valve2time = 200;
void setup() {
//switches
pinMode(button1,INPUT); //Set button1 as input
pinMode(button2, INPUT); //Set button2 as input
//relays
pinMode(valve1, OUTPUT); //Set valve1 as output
pinMode(valve2, OUTPUT); //Set valve2 as output
Serial.begin(9600);
}
void loop(){
state1 = digitalRead(button1); //state1 returns the state of button1, up or down.
state2 = digitalRead(button2); //state2 returns the state of button2, up or down.
int duration = switchTime(); //Create variable to capture duration of switch press
if (state1 == LOW && state2 == LOW){ //if no buttons are pressed
digitalWrite(valve1,LOW); //make sure valve1 is off
digitalWrite(valve2,LOW); //make sure valve2 is off
}
else if (state1 == HIGH && state2 == LOW) { //if JUST button one is pressed
digitalWrite(valve1,HIGH); //turn on valve1
while (duration <= valve2time){ //as long as the timer is below or = to what we defined up top....
digitalWrite(valve2,HIGH); //...Turn on valve2...
break; //...Then stop the while loop...
}
digitalWrite(valve2,LOW); //...and finally turn off valve2
}
else if (state2 == HIGH){ //final condition, if button two is pressed
digitalWrite(valve1,HIGH); //turn on valve1
digitalWrite(valve2,HIGH); //turn on valve2
}
}
//return the time in ms that the switch has been pressed (LOW)
long switchTime(){
//these variables are static
static unsigned long startTime = 0; //the time the switch state was first detected
static boolean state; //the current state of the switch
if(digitalRead(button1) != state){ //check to see if the switch has changed state
state = ! state; //yes, invert the state
startTime = millis(); //store the time
}
if(state == HIGH){
return millis() - startTime; //switch pushed, return time in ms
}
else{
return 0; //return 0 if the switch is not pushed (in the HIGH state)
}
}
UPDATE: The working Code
//button pins
const int BUTTON1_PIN = 2;
const int BUTTON2_PIN = 3;
const int VALVE1_PIN = 0; //mml for tiny
const int VALVE2_PIN = 1; //mml for tiny
// IO Channels - Used to simulate arduino IO
boolean inputChannels[] = {LOW, LOW}; // digital input channels "Button1" and "Button2"
boolean outputChannels[] = {LOW, LOW}; // digital output channels "Valve1" and "Valve2"
// =============================================================================================================
// You can probably ignore everything above this line
// State machine variables
const int STATE_CLOSED = 0;
const int STATE_BUTTON1_PRESSED = 1;
const int STATE_BUTTON1_RELEASED = 2;
const int STATE_BUTTON2_PRESSED = 3;
const int STATE_BUTTON2_RELEASED = 4;
int currentState = 0;
int lastState = 0;
// button debounce time in ms
unsigned long BUTTON_DEBOUNCE = 200;
unsigned long BUTTON1_PRESSED_VALVE2_FLASH = 350;
unsigned long BUTTON1_RELEASE_VALVE2_FLASH = 1000;
// state tracking arrays
boolean buttonState[] = {LOW, LOW};
boolean buttonDebounce[] = {LOW, LOW};
unsigned long buttonTimers[] = {0, 0};
unsigned long valveTimers[] = {0, 0};
void setup(){
pinMode(BUTTON1_PIN, INPUT);
digitalWrite(BUTTON1_PIN, HIGH); //MML
pinMode(BUTTON2_PIN, INPUT);
digitalWrite(BUTTON2_PIN, HIGH); //MML
pinMode(VALVE1_PIN, OUTPUT);
pinMode(VALVE2_PIN, OUTPUT);
}
/**
* Main control loop
*/
void loop() {
switch (currentState) {
case STATE_CLOSED:
handleClosedState();
lastState = STATE_CLOSED;
break;
case STATE_BUTTON1_PRESSED:
handleButton1PressedState();
lastState = STATE_BUTTON1_PRESSED;
break;
case STATE_BUTTON1_RELEASED:
handleButton1ReleasedState();
lastState = STATE_BUTTON1_RELEASED;
break;
case STATE_BUTTON2_PRESSED:
handleButton2PressedState();
lastState = STATE_BUTTON2_PRESSED;
break;
case STATE_BUTTON2_RELEASED:
handleButton2ReleasedState();
lastState = STATE_BUTTON2_RELEASED;
break;
default:;
}
}
/**
* Handler method for STATE_CLOSED
*/
void handleClosedState() {
// ensure valves are closed
if (digitalRead(VALVE1_PIN) == HIGH) {
digitalWrite(VALVE1_PIN, LOW);
}
if (digitalRead(VALVE1_PIN) == HIGH) {
digitalWrite(VALVE2_PIN, LOW);
}
// wait for button1 press
if (LOW == debouncedDigitalRead(BUTTON1_PIN, BUTTON_DEBOUNCE)) {
buttonState[BUTTON1_PIN] = LOW;
currentState = STATE_BUTTON1_PRESSED;
}
}
/**
* Handler method for STATE_BUTTON1_PRESSED
*/
void handleButton1PressedState() {
// check for button1 release
if (HIGH == debouncedDigitalRead(BUTTON1_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON1_RELEASED;
return;
}
// open valve1
if (digitalRead(VALVE1_PIN) == LOW) {
valveTimers[VALVE1_PIN] = millis();
digitalWrite(VALVE1_PIN, HIGH);
}
// on state change open valve2
if (lastState != currentState) {
valveTimers[VALVE2_PIN] = millis();
digitalWrite(VALVE2_PIN, HIGH);
}
// and close it after 200 ms
else if ((millis() - valveTimers[VALVE2_PIN]) > BUTTON1_PRESSED_VALVE2_FLASH && digitalRead(VALVE2_PIN) == HIGH) {
digitalWrite(VALVE2_PIN, LOW);
}
// check for button2 press
if (LOW == debouncedDigitalRead(BUTTON2_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON2_PRESSED;
}
}
/**
* Handler method for STATE_BUTTON1_RELEASED
*/
void handleButton1ReleasedState() {
// open valve2
if (lastState != currentState) {
valveTimers[VALVE2_PIN] = millis();
digitalWrite(VALVE2_PIN, HIGH);
digitalWrite(VALVE1_PIN, LOW);
}
// and close valve2 after 1000ms
else if ((millis() - valveTimers[VALVE2_PIN] > BUTTON1_RELEASE_VALVE2_FLASH)) {
digitalWrite(VALVE2_PIN, LOW);
currentState = STATE_CLOSED;
}
}
/**
* Handler method for STATE_BUTTON2_PRESSED
*/
void handleButton2PressedState() {
// open valve2
if (digitalRead(VALVE2_PIN) == LOW){
digitalWrite(VALVE2_PIN, HIGH);
digitalWrite(VALVE1_PIN, HIGH);
}
// check for button1 release
if (HIGH == debouncedDigitalRead(BUTTON1_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON1_RELEASED;
}
// check for button2 release
else if (HIGH == debouncedDigitalRead(BUTTON2_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON2_RELEASED;
}
}
/**
* Handler method for STATE_BUTTON2_PRESSED
*/
void handleButton2ReleasedState() {
// open valve2
if (digitalRead(VALVE2_PIN) == HIGH){
digitalWrite(VALVE2_PIN, LOW);
digitalWrite(VALVE1_PIN, HIGH);
}
// check for button1 release
if (HIGH == debouncedDigitalRead(BUTTON1_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON1_RELEASED;
}
// check for button2 press
else if (LOW == debouncedDigitalRead(BUTTON2_PIN, BUTTON_DEBOUNCE)) {
currentState = STATE_BUTTON2_PRESSED;
}
}
/**
* Utility for debouncing input channels
* #param channel
* #param debounce
* #return
*/
boolean debouncedDigitalRead(int channel, unsigned long debounce) {
int input = digitalRead(channel);
if (input != buttonState[channel] && HIGH == buttonDebounce[channel]) {
buttonTimers[channel] = millis();
buttonDebounce[channel] = LOW;
}
if ((millis() - buttonTimers[channel]) > debounce) {
buttonState[channel] = input;
buttonDebounce[channel] = HIGH;
}
return buttonState[channel];
}
In order for the code to simultaneously a) keep looping to check the buttons, and b) achieve the desired behavior for valve2, you need a software state machine that keeps track of what valve2 is doing. In the code below, I renamed your state1 and state2 variables, so that I could introduce a new state variable that controls valve2.
The state variable is normally in the idle state.
When button1 is pressed
valve2 is turned on
a timestamp is taken
the state is changed to active
After a 200 msec delay
valve2 is turned off
the state is changed to done
The state will stay done until either button1 is released or button2 is pressed, since either of those actions resets the state to idle.
Here's what the code looks like
void loop()
{
int state = 0; //variable to keep track of valve2: 0=idle 1=active 2=done
unsigned long start; //variable to keep track of when valve2 was turned on
boolean pressed1 = (digitalRead(button1) == HIGH); //pressed1 is true if button1 is pressed
boolean pressed2 = (digitalRead(button2) == HIGH); //pressed2 is true if button2 is pressed
if ( !pressed1 && !pressed2 ) //if no buttons are pressed
{
digitalWrite(valve1,LOW); //make sure valve1 is off
digitalWrite(valve2,LOW); //make sure valve2 is off
state = 0; //clear valve2 state
}
else if ( pressed2 ) //if button2 is pressed
{
digitalWrite(valve1,HIGH); //turn on valve1
digitalWrite(valve2,HIGH); //turn on valve2
state = 0; //clear valve2 state
}
else //button1 is pressed
{
digitalWrite(valve1,HIGH); //turn on valve1
if ( state == 0 ) //if valve2 is idle
{
digitalWrite(valve2,HIGH); //turn on valve2
state = 1; //valve2 is active
start = millis(); //capture the start time
}
else if ( state == 1 ) //if valve2 is active
{
if ( millis() - start > 200 ) //has it been 200ms?
{
digitalWrite(valve2,LOW); //turn valve2 is off
state = 2; //valve2 is done
}
}
}
}
Is it possible that the axis scale outside the graph could be scale using the mouse event "mouse_down and hold" and move up or down in y-axis the same with the x-axis move left or right? ex. when I trigger MouseDownEvent and hold the x-axis scale 0.6 or at the space along with that scale and move it to the right, scale should scroll depend in the chartfraction? could you post an example? Thanks in advance!
Separately panning and zooming Y axises can be achieved using the mouse events of ZedGraph: MouseDownEvent, MouseMoveEvent, MouseUpEvent and MouseWheel events (credits go to a colleague of mine).
It works with multiple GraphPanes and multiple Y axises.
The MouseMoveEvent is used to shift the Min and the Max of an Y axis when the mouse is moved while its button is pressed. If not, it is used to get the reference of the Y axis object the mouse is hovering on.
The MouseDownEvent is used to initiate an axis pan operation.
The MouseWheel is used to perform a zoom on an Y axis.
And the MouseUpEvent is used to clean things when zooming and panning operations are finished.
Here is the code :
// The axis that is currently hovered by the mouse
YAxis hoveredYAxis;
// The graphpane that contains the axis
GraphPane foundPane;
// The scale of the axis before it is panned
double movedYAxisMin;
double movedYAxisMax;
// The Y on the axis when the panning operation is starting
float movedYAxisStartY;
void z_MouseWheel(object sender, MouseEventArgs e)
{
if (hoveredYAxis != null)
{
var direction = e.Delta < 1 ? -.05f : .05f;
var increment = direction * (hoveredYAxis.Scale.Max - hoveredYAxis.Scale.Min);
var newMin = hoveredYAxis.Scale.Min + increment;
var newMax = hoveredYAxis.Scale.Max - increment;
hoveredYAxis.Scale.Min = newMin;
hoveredYAxis.Scale.Max = newMax;
foundPane.AxisChange();
z.Invalidate();
}
}
bool z_MouseUpEvent(ZedGraphControl sender, MouseEventArgs e)
{
hoveredYAxis = null;
return false;
}
bool z_MouseMoveEvent(ZedGraphControl sender, MouseEventArgs e)
{
var pt = e.Location;
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
if (hoveredYAxis != null)
{
var yOffset = hoveredYAxis.Scale.ReverseTransform(pt.Y) - hoveredYAxis.Scale.ReverseTransform(movedYAxisStartY);
hoveredYAxis.Scale.Min = movedYAxisMin - yOffset;
hoveredYAxis.Scale.Max = movedYAxisMax - yOffset;
sender.Invalidate();
return true;
}
}
else
{
var foundObject = findZedGraphObject(null);
hoveredYAxis = foundObject as YAxis;
if (hoveredYAxis != null)
{
z.Cursor = Cursors.SizeNS;
return true;
}
else
{
if (z.IsShowPointValues)
{
z.Cursor = Cursors.Cross;
return false;
}
else
{
z.Cursor = Cursors.Default;
return true;
}
}
}
return false;
}
bool z_MouseDownEvent(ZedGraphControl sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
if (hoveredYAxis != null)
{
movedYAxisStartY = e.Location.Y;
movedYAxisMin = hoveredYAxis.Scale.Min;
movedYAxisMax = hoveredYAxis.Scale.Max;
return true;
}
}
return false;
}
This is a helper that factorizes a bit the object find operations of ZedGraph.
object findZedGraphObject(GraphPane pane = null)
{
var pt = zgc.PointToClient(Control.MousePosition);
if (pane == null)
{
foundPane = zgc.MasterPane.FindPane(pt);
if (foundPane != null)
{
object foundObject;
int forget;
using (var g = zgc.CreateGraphics())
if (foundPane.FindNearestObject(pt, g, out foundObject, out forget))
return foundObject;
}
}
return null;
}
If I understand your question correctly, here's my response:
zedgraph has got an in-built function called "Pan", you could change the scale of x & y axis.
Place the cursor within the 'chart area'
Hold the 'ctrl' button & move the mouse towards x & y directions to change the scale.
you could get back to original state by 'Un-Pan' (Context Menu)
Cheers..:)
Do You want to create a ScrollBar?
zedGraphControl1.IsShowHScrollbar = true;
//Set borders for the scale
zedGraphControl1.GraphPane.XAxis.Scale.Max = Xmax;
zedGraphControl1.GraphPane.XAxis.Scale.Min = Xmin;