An interactive Javascript Plotting Boilerplate

   # Installs the package
   $ npm i plotboilerplate

<canvas id="my-canvas"> Your browser does not support the canvas tag. </canvas>

var pb = new PlotBoilerplate({
  canvas: document.getElementById("my-canvas"),
  fullSize: true
});

<svg id="my-svg"></svg>

var pb = new PlotBoilerplate({
  canvas: document.getElementById("my-svg"),
  fullSize: true
});

// Create two points:
//   The origin is at the visual center by default.
var pointA = new Vertex(-100, -100);
var pointB = new Vertex(100, 100);
pb.add(new Line(pointA, pointB));

// When point A is moved by the user
//   then move point B in the opposite direction
pointA.listeners.addDragListener(function (e) {
  pointB.sub(e.params.dragAmount);
  pb.redraw();
});

// and when point B is moved
//   then move point A
pointB.listeners.addDragListener(function (e) {
  pointA.sub(e.params.dragAmount);
  pb.redraw();
});

// Usage with Typescript could look like this
import { PlotBoilerplate, Vertex, Line } from "plotboilerplate";

globalThis.addEventListener("load", () => {
  const pointA: Vertex = new Vertex(100, -100);
  const pointB: Vertex = new Vertex(-100, 100);
  console.log(pointA, pointB);

  const line: Line = new Line(pointA, pointB);

  const pb: PlotBoilerplate = new PlotBoilerplate({
    canvas: document.getElementById("my-canvas"),
    fullSize: true
  });

  pb.add(line);
});

var pb = new PlotBoilerplate({
  // HTMLCanvasElement | SVGElement | string
  //   Your canvas element in the DOM (required).
  canvas: document.getElementById("my-canvas"),

  // boolean
  //   If set to true the canvas will gain full window size.
  fullSize: true,

  // boolean
  //   If set to true the canvas will gain the size of its parent
  //   container.
  // @overrides fullSize
  fitToParent: true,

  // float
  //   The initial zoom. Default is 1.0.
  scaleX: 1.0,
  scaleY: 1.0,

  // float
  //   The initial offset. Default is 0.0. Note that autoAdjustOffset=true overrides these values.
  offsetX: 0.0,
  offsetY: 0.0,

  // Specifies if the raster should be drawn.
  drawGrid: true,

  // If set to true the background grid will be drawn rastered.
  rasterGrid: true,

  // float
  //    The exponential limit for wrapping down the grid.
  //    (2.0 means: halve the grid each 2.0*n zoom step).
  rasterAdjustFactor: 2.0,

  // Draw a crosshair at (0,0).
  drawOrigin: false,

  // boolean
  //   When set to true then the origin of the XY plane will
  //   be re-adjusted automatically (see the params
  //    offsetAdjust{X,Y}Percent for more).
  autoAdjustOffset: true,
  // float
  //   The x- and y- fallback position for the origin after
  //   resizing the canvas.
  offsetAdjustXPercent: 50,
  offsetAdjustYPercent: 50,

  // int
  //   The canvas size fallback if no automatic resizing
  //   is switched on.
  defaultCanvasWidth: 1024,
  defaultCanvasHeight: 768,

  // float
  //   Two scaling factors (width and height) upon the canvas size.
  //   In combination with cssScale{X,Y} this can be used to obtain
  //   sub pixel resolutions for retina displays.
  canvasWidthFactor: 1.0,
  canvasHeightFactor: 1.0,

  // float
  //   Visually resize the canvas using CSS transforms (scale).
  cssScaleX: 1.0,
  cssScaleY: 1.0,

  // boolean
  //   If set to true only cssScaleX applies for both dimensions.
  cssUniformScale: true,

  // boolean
  //   When set to true (default) the canvas will try to use the display's pixel ratio.
  autoDetectRetina: true,

  // string
  //   A background color (CSS string) for the canvas.
  backgroundColor: "#ffffff",

  // boolean
  //   Switch auto-redrawing on resize on/off (some applications
  //   might want to prevent automatic redrawing to avoid data
  //   loss from the drae buffer).
  redrawOnResize: true,

  // boolean
  //   Indicates if Bézier curve handles should be drawn (used for
  //   editors, no required in pure visualizations).
  drawBezierHandleLines: true,

  // boolean
  //   Indicates if Bézier curve handle points should be drawn.
  drawBezierHandlePoints: true,

  // function
  //   A callback function that will be triggered just before the
  //   draw function clears the canvas (before anything else was drawn).
  preClear: function () {
    console.log("before clearing the canvas on redraw.");
  },

  // function
  //   A callback function that will be triggered just before the
  //   draw function starts.
  preDraw: function (draw, fill) {
    console.log("after clearing and before drawing.");
  },

  // function
  //   A callback function that will be triggered right after the
  //   drawing process finished.
  postDraw: function (draw, fill) {
    console.log("after drawing.");
  },

  // boolean
  //   Indicates if the application should handle mouse events for you.

  enableMouse: true,
  // boolean
  //   Indicates if the application should handle touch events for you.
  enableTouch: true,

  // boolean
  //   Indicates if the application should handle key events for you.
  enableKeys: true,

  // boolean
  //   Indicates if the application should handle mouse wheelevents for you.
  enableMouseWheel: true,

  // boolean (default true)
  //    Use this to disable panning completely.
  enablePan: true,

  // boolean (default true)
  //    Use this to disable zooming completely.
  enableZoom: true,

  // Indicates if the SVG export should be enabled (default is true).
  enableSVGExport: true,

  // boolean
  //   Indicates if the application should use the experimental WebGL features.
  enableGL: false
});

var vert = new Vertex(100, 100);
vert.listeners.addDragListener(function (e) {
  // e is of type Event.
  // You are encouraged to use the values in the object e.params
  console.log("vertex was dragged by: ", "x=" + e.params.dragAmount.x, "y=" + e.params.dragAmount.y);
});

 {
  // The canvas that fired the event.
  element : [HTMLElement],

  // The event name.
  //   Default: 'drag'
  name : string,

  // The current drag position.
  pos : { x : number, y : number },

  // A mouse button indicator (if mouse event).
  //    0=left, 1=middle, 2=right
  button : number,

  // A flag indicating if event comes from left mouse button.
  leftButton : boolean,

  // A flag indicating if event comes from middle mouse button.
  middleButton : boolean,

  // A flag indicating if event comes from right mouse button.
  rightButton : boolean,

  // A mouse-down-position: position where the dragging
  //   started. This will not change during one drag process.
  mouseDownPos : { x : number, y : number },

  // The most recent drag position (position before
  //   current drag step).
  draggedFrom : { x : number, y : number },

  // True if this is a drag event (nothing else available the moment).
  wasDragged : boolean,

  // The x-y-amount of the current drag step.
  //   This is the difference between the recent drag step
  //   and the actual drag position.
  dragAmount : { x : number, y : number }
 }

new KeyHandler({ trackAll: true })
  .down("enter", function () {
    console.log("ENTER was hit.");
  })
  .press("enter", function () {
    console.log("ENTER was pressed.");
  })
  .up("enter", function () {
    console.log("ENTER was released.");
  })
  .down("e", function () {
    console.log("e was hit. shift is pressed?", keyHandler.isDown("shift"));
  })
  .up("spacebar", function () {
    console.log("spacebar was released.");
  });

new MouseHandler(document.getElementById("mycanvas"))
  .drag(function (e) {
    console.log("Mouse dragged: " + JSON.stringify(e));
    if (e.params.leftMouse);
    else if (e.params.rightMouse);
  })
  .move(function (e) {
    console.log("Mouse moved: " + JSON.stringify(e.params));
  })
  .up(function (e) {
    console.log("Mouse up. Was dragged?", e.params.wasDragged);
  })
  .down(function (e) {
    console.log("Mouse down.");
  })
  .click(function (e) {
    console.log("Click.");
  })
  .wheel(function (e) {
    console.log("Wheel. delta=" + e.deltaY);
  });