bspline stuff

src/app/page.tsx

@@ -6,6 +6,7 @@ import { Paths, Poses } from "@/hooks/use-visualizer";
 import PoseControls from "@/components/pose-controls";
 import DrawPaths from "@/components/path-overlay";
 
+
 export default function Home() {
   const {
     poses,
@@ -57,7 +58,7 @@ export default function Home() {
               id="field"
             />
           </div>
-          <DrawPaths poses={poses} />
+          <DrawPaths poses={poses} paths={paths}/>
         </ResizablePanel>
         <ResizableHandle withHandle />
         <ResizablePanel maxSize="1000px" minSize="350px" collapsible>

src/components/path-overlay.tsx

@@ -1,12 +1,16 @@
 'use client';
 
-import { useEffect, useRef } from "react";
+import { bspline } from "@/lib/bspline";
+import { useEffect, useRef, useState } from "react";
 
 interface PathDrawProps {
   poses: Pose[];
+  paths: Path[];
 }
 
-export default function DrawPaths({ poses }: PathDrawProps) {
+export default function DrawPaths({ poses, paths}: PathDrawProps) {
+
+
   const canvasRef = useRef<HTMLCanvasElement>(null);
 
   useEffect(() => {

src/lib/bspline.tsx

@@ -0,0 +1,201 @@
+import { useState } from "react";
+
+export function bspline(poses:Pose[]){
+
+
+    const CMatrix = [
+                    [-1.0 / 6.0, 3.0 / 6.0, -3.0 / 6.0, 1.0 / 6.0],
+                    [3.0 / 6.0, -6.0 / 6.0, 3.0 / 6.0, 0.0],
+                    [-3.0 / 6.0, 0.0, 3.0 / 6.0, 0.0],
+                    [1.0 / 6.0, 4.0 / 6.0, 1.0 / 6.0, 0.0]
+                    ]
+
+    //first, make sure all of the poses have valid values(kinda copied from path-overlay)
+
+    poses.forEach((pose) => {
+      if (pose.x === null || pose.y === null) return;
+    });
+
+    //then, make sure the list has a valid amount of poses
+
+    if(poses.length<2) return;
+
+    //convert all poses to vectors
+
+    const [poseVector,setPoseVector] = useState<Vector[]>([]);
+    poses.forEach((pose) => {
+
+        const temp:Vector = {
+            x:pose.x ?? 0, // if pose.x is null, give a value of 0. Our filter above will automatically 
+            // return if any of the values are null, so this will never happen, it just lets the Vector class have pure number types instead
+            // of  number | null
+            y:pose.y ?? 0
+        };
+
+        setPoseVector((prevVectors)=>{
+
+            return [...prevVectors, temp]
+        })
+
+    });
+
+
+    //the first thing we need to do is to get the ghost points
+
+    //the formula is P_0+(-1(P_1-P_0)) where P_0 is the axis point(that you reflect across, otherwise known as the endpoint) 
+    // and P_1 is the point being reflected(otherwise known as the second, or second to last point)
+
+
+
+
+    const [ghostPoints,setGhostPoints] = useState<Vector[]>([]);// make a list for the ghost points
+
+    const neg1 = poses.length-1
+    const neg2 = poses.length-2
+
+    //will give error cus the value "might be null" even though we filtered for it already, so just add an if statement
+    if((poseVector[0].x!=null && poseVector[1].x!=null && poseVector[neg1].x!=null && poseVector[neg2].x!=null 
+        && poseVector[0].y!=null && poseVector[1].y!=null && poseVector[neg1].y!=null && poseVector[neg2].y!=null)
+    ){
+        setGhostPoints([
+            {
+                x:poseVector[0].x+((poseVector[1].x - poseVector[0].x) * -1),
+                y:poseVector[0].y+((poseVector[1].y - poseVector[0].y) * -1)
+            },
+            {
+                x:poseVector[neg1].x+((poseVector[neg2].x - poseVector[neg1].x) * -1),
+                y:poseVector[neg1].y+((poseVector[neg2].y - poseVector[neg1].y) * -1)
+
+            }
+        ])
+    }
+
+    //now that our ghost points are sorted out, we can make the array that will be put into the spline
+    const [splinePoints,setSplinePoints] = useState<Vector[]>([]);
+    // loop twice more than the poseVector array because we have 2 ghost points
+    for(let i = 0; i<poseVector.length +2; i++){
+
+        //adds ghost points at beginning
+        if(i == 0){
+            setSplinePoints(
+                (prevPoints)=>{
+
+                    return[...prevPoints,ghostPoints[0]]
+
+                }
+            )
+        }
+        //adds ghost points at the end
+        else if(i == poseVector.length+1){// because its 0 indexed, the last loop will be when i is 1 less than poseVector.length+2
+
+            setSplinePoints(
+                (prevPoints)=>{
+
+                    return [...prevPoints,ghostPoints[1]]
+
+                }
+            )
+        }
+        else{
+
+            setSplinePoints(
+                (prevPoints)=>{
+
+                    return [...prevPoints,poseVector[i-1]]//since arrays are 0-indexed, and when the value of i is 0,
+                    // the ghost point is added, we need to subtract one to add all elements in the array
+
+                }
+            )
+        }
+    }
+
+
+
+    //now, the control points are in order. Let's make the actual b spline evaluate.
+
+
+    const numSegments = splinePoints.length-3
+    const [cx,setCx] = useState<number[][]>([])
+    const [cy,setCy] = useState<number[][]>([])
+
+
+    //create the b spline segments, 4 control points per segment, each contribute to the whole spline, keeping it 4th degree
+    //as joel's bspline class states in the pathing repo, "they are evaluated using a sliding 4-point window"
+
+    for(let i = 0; i<numSegments;i++){
+        const p0:Vector = splinePoints[i]
+        const p1:Vector = splinePoints[i + 1]
+        const p2:Vector = splinePoints[i + 2]
+        const p3:Vector = splinePoints[i + 3]
+
+
+        const xWindow = [p0.x,p1.x,p2.x,p3.x]
+        const yWindow = [p0.y,p1.y,p2.y,p3.y]
+
+        //multiply our blend matrix and x/y window for cx and cy
+        //made a function so its easier
+
+        //adding to the end of the array, a little different than java cus u cant specify the length and loop through it
+        const tempx:number[] = multiplyMatrices(CMatrix,xWindow)
+        setCx(
+            (prevCx)=>[...prevCx,tempx]
+        )
+        const tempy:number[] = multiplyMatrices(CMatrix,yWindow)
+        setCy(
+            (prevCy)=>[...prevCy,tempy]
+        )
+
+
+
+    }
+
+
+    //evaluate function
+    // copied from joels thing
+    const evaluate = (t:number)=>{
+
+        if (t >= 1.0) t = 0.999999;
+        if (t < 0.0) t = 0.0;
+
+        const continuousIndex = t * numSegments
+        const segment =  Math.trunc(continuousIndex) //should do the same thing as type casting to int
+        const localT = continuousIndex - segment
+
+
+        const cX = cx[segment]
+        const cY = cy[segment]
+
+
+        const x = ((cX[0] * localT + cX[1]) * localT + cX[2]) * localT + cX[3]
+        const y = ((cY[0] * localT + cY[1]) * localT + cY[2]) * localT + cY[3]
+
+        const returnValue:Vector = {
+            x:x,
+            y:y
+        }
+        return returnValue;
+    }
+
+    return {evaluate}
+}
+
+
+//this function is made specifically for multiplying the Cmatrix and the windows
+function multiplyMatrices(matrix:number[][], window:number[]){
+
+
+    const [result,setResult] = useState<number[]>([]);
+
+    for (let i = 0; i < matrix.length; i++) {
+        let sum:number = 0.0;
+        for (let j = 0; j < matrix[0].length; j++) {
+            sum += matrix[i][j] * window[j];
+        }
+        setResult((prevResults)=>{
+            return[...prevResults,sum]
+        })
+    }
+    return result;
+
+
+}

types/poses.ts

@@ -7,4 +7,11 @@ interface Pose {
   radius: number | null
   arcPose: boolean
   local: boolean
+}
+
+//this interface is for calculating the bspline, 
+// as it doesn't need the other things for poses which will just be plugged into the b spline
+interface Vector{
+  x:number //these two values are null to match the type of the poses, it will never actually be null
+  y:number 
 }