implementation of p5.Camera.set() function

[inaridarkfox4231]

Implement the set() function of p5.Camera.

This function copies the argument camera information to the target camera, just like p5.Vector's set().
The information to be copied is the view matrix and its parameters, projection matrix and its parameters, and cameraType.
There is no particular meaning in transferring the cameraType, but since this information is determined in a way related to how the projection is set, I thought it would be appropriate to copy it.
If the target camera is active, the renderer's view and projection matrices are updated with the same matrices.

Resolves #6238

Example

p5.Camera.set()_DEMO

let cam, initialCam;

function setup() {
  createCanvas(400, 400, WEBGL);
  strokeWeight(3);

  // Set the initial state to initialCamera and set it to the camera
  // used for drawing. Then set cam to be the active camera.
  cam = createCamera();
  initialCam = createCamera();
  initialCam.camera(100, 100, 100, 0, 0, 0, 0, 0, -1);
  cam.set(initialCam);

  setCamera(cam);
}

function draw() {
  orbitControl();
  background(255);
  box(50);
  translate(0, 0, -25);
  plane(100);
}

function doubleClicked(){
  // Double-click to return the camera to its initial position.
  cam.set(initialCam);
}

2023-06-27.22-23-39.mp4

When double-clicked, the camera whose initial state is registered is set as the active camera by set(), and the screen state is reset. As it stands now, this requires resetting the initial state somehow. setCamera() cannot be used because the active camera will change. With this function, you can restore only the settings without changing the active camera.

PR Checklist

• npm run lint passes
• Inline documentation is included / updated
• Unit tests are included / updated

[inaridarkfox4231]

I wanted to create this function because I wanted to make it easier to write code for smooth camera switching.
Check out the demo below.
p5.Camera.set_DEMO

2023-06-29.01-38-10.mp4

In this demo, 4 cameras are prepared and can be switched by pressing a button.
When switching cameras, a certain function is used so that the camera changes smoothly. I'd like to implement this function someday, but I'm using set() internally, so I'll think about it after this function is implemented.

For that we need the first and last camera, and set() is used to populate that information. However, if only the attached camera is used, the assignment operation is actually sufficient and the set() is not necessary.

This demo allows the camera to be manipulated with orbitControl() after switching cameras. Therefore, setCamera() cannot be used. This is because the information of the prepared camera will be rewritten. Also, if you use substitution when preparing the starting camera, the starting camera will change, so substitution cannot be used. So set() is used effectively. set() is very useful for treating the camera as a data-only object.

If this kind of thing can be done without using set(), we don't need this function. I tried to explain the usefulness as much as possible, but I don't know if I did it well. If the implementation is allowed, please give me a review.

[davepagurek]

Looks good, great example too!

[inaridarkfox4231]

Thanks for review and merge! ('ω')
I have one more pull request left that I want to pass by 1.7.0, so I'll do my best...

[Qianqianye]

Thanks @inaridarkfox4231 for working on it and @davepagurek for reviewing it!