excalidraw/src/galines.ts
Michal Srb 26f67d27ec
Allow binding linear elements to other elements (#1899)
* Refactor: simplify linear element type

* Refactor: dedupe scrollbar handling

* First step towards binding - establish relationship and basic test for dragged lines

* Refactor: use zoom from appstate

* Refactor: generalize getElementAtPosition

* Only consider bindable elements in hit test

* Refactor: pull out pieces of hit test for reuse later

* Refactor: pull out diamond from hit test for reuse later

* Refactor: pull out text from hit test for reuse later

* Suggest binding when hovering

* Give shapes in regression test real size

* Give shapes in undo/redo test real size

* Keep bound element highlighted

* Show binding suggestion for multi-point elements

* Move binding to its on module with functions so that I can use it from actions, add support for binding end of multi-point elements

* Use Id instead of ID

* Improve boundary offset for non-squarish elements

* Fix localStorage for binding on linear elements

* Simplify dragging code and fix elements bound twice to the same shape

* Fix binding for rectangles

* Bind both ends at the end of the linear element creation, needed for focus points

* wip

* Refactor: Renames and reshapes for next commit

* Calculate and store focus points and gaps, but dont use them yet

* Focus points for rectangles

* Dont blow up when canceling linear element

* Stop suggesting binding when a non-compatible tool is selected

* Clean up collision code

* Using Geometric Algebra for hit tests

* Correct binding for all shapes

* Constant gap around polygon corners

* Fix rotation handling

* Generalize update and fix hit test for rotated elements

* Handle rotation realtime

* Handle scaling

* Remove vibration when moving bound and binding element together

* Handle simultenous scaling

* Allow binding and unbinding when editing linear elements

* Dont delete binding when the end point wasnt touched

* Bind on enter/escape when editing

* Support multiple suggested bindable elements in preparation for supporting linear elements dragging

* Update binding when moving linear elements

* Update binding when resizing linear elements

* Dont re-render UI on binding hints

* Update both ends when one is moved

* Use distance instead of focus point for binding

* Complicated approach for posterity, ignore this commit

* Revert the complicated approach

* Better focus point strategy, working for all shapes

* Update snapshots

* Dont break binding gap when mirroring shape

* Dont break binding gap when grid mode pushes it inside

* Dont bind draw elements

* Support alt duplication

* Fix alt duplication to

* Support cmd+D duplication

* All copy mechanisms are supported

* Allow binding shapes to arrows, having arrows created first

* Prevent arrows from disappearing for ellipses

* Better binding suggestion highlight for shapes

* Dont suggest second binding for simple elements when editing or moving them

* Dont steal already bound linear elements when moving shapes

* Fix highlighting diamonds and more precisely highlight other shapes

* Highlight linear element edges for binding

* Highlight text binding too

* Handle deletion

* Dont suggest second binding for simple linear elements when creating them

* Dont highlight bound element during creation

* Fix binding for rotated linear elements

* Fix collision check for ellipses

* Dont show suggested bindings for selected pairs

* Bind multi-point linear elements when the tool is switched - important for mobile

* Handle unbinding one of two bound edges correctly

* Rename boundElement in state to startBoundElement

* Dont double account for zoom when rendering binding highlight

* Fix rendering of edited linear element point handles

* Suggest binding when adding new point to a linear element

* Bind when adding a new point to a linear element and dont unbind when moving middle elements

* Handle deleting points

* Add cmd modifier key to disable binding

* Use state for enabling binding, fix not binding for linear elements during creation

* Drop support for binding lines, only arrows are bindable

* Reset binding mode on blur

* Fix not binding lines
2020-08-08 21:04:15 -07:00

63 lines
1.8 KiB
TypeScript

import * as GA from "./ga";
import { Line, Point } from "./ga";
/**
* A line is stored as an array `[0, c, a, b, 0, 0, 0, 0]` representing:
* c * e0 + a * e1 + b*e2
*
* This maps to a standard formula `a * x + b * y + c`.
*
* `(-b, a)` correponds to a 2D vector parallel to the line. The lines
* have a natural orientation, corresponding to that vector.
*
* The magnitude ("norm") of the line is `sqrt(a ^ 2 + b ^ 2)`.
* `c / norm(line)` is the oriented distance from line to origin.
*/
// Returns line with direction (x, y) through origin
export function vector(x: number, y: number): Line {
return GA.normalized([0, 0, -y, x, 0, 0, 0, 0]);
}
// For equation ax + by + c = 0.
export function equation(a: number, b: number, c: number): Line {
return GA.normalized([0, c, a, b, 0, 0, 0, 0]);
}
export function through(from: Point, to: Point): Line {
return GA.normalized(GA.join(to, from));
}
export function orthogonal(line: Line, point: Point): Line {
return GA.dot(line, point);
}
// Returns a line perpendicular to the line through `against` and `intersection`
// going through `intersection`.
export function orthogonalThrough(against: Point, intersection: Point): Line {
return orthogonal(through(against, intersection), intersection);
}
export function parallel(line: Line, distance: number): Line {
const result = line.slice();
result[1] -= distance;
return (result as unknown) as Line;
}
export function parallelThrough(line: Line, point: Point): Line {
return orthogonal(orthogonal(point, line), point);
}
export function distance(line1: Line, line2: Line): number {
return GA.inorm(GA.meet(line1, line2));
}
export function angle(line1: Line, line2: Line): number {
return Math.acos(GA.dot(line1, line2)[0]);
}
// The orientation of the line
export function sign(line: Line): number {
return Math.sign(line[1]);
}