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aJamDonut/gist:65a8ffa34de93d3747176a1f94cf65cf

Last active August 10, 2021 02:40
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Revisions

  1. aJamDonut revised this gist Aug 10, 2021. 1 changed file with 2 additions and 2 deletions.
    4 changes: 2 additions & 2 deletions gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -28,7 +28,7 @@ ddaWalk(x, y, endX, endY) {
    //Setup initial variables

    if (rayDir.x < 0) {
    step.x - 1;
    step.x = -1;
    rayLength1D.x = (rayStart.x - mapCheck.x) * rayUnitStepSize.x;
    } else {
    step.x = 1;
    @@ -65,7 +65,7 @@ ddaWalk(x, y, endX, endY) {
    //This is the meat, do your checks here, I just use it to reduce a rays length
    if (mapCheck.x >= 0 && mapCheck.x < mapSize.x && mapCheck.y >= 0 && mapCheck.y < mapSize.y) {
    if(this.isBlocked(mapCheck.x*64, mapCheck.y*64)) {
    return {x: mapCheck.x*64, y:mapCheck.y*64};//Vision blocked here so return this location.
    tileFound = true;
    }
    }
    }
  2. aJamDonut revised this gist Aug 9, 2021. No changes.
  3. aJamDonut revised this gist Aug 9, 2021. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -10,7 +10,7 @@ ddaWalk(x, y, endX, endY) {

    let rayStart = Vector.create(x, y);

    let rayEnd = new Vector.create(endX, endY);
    let rayEnd = Vector.create(endX, endY);

    let rayDir = Vector.normalise(Vector.sub(rayEnd, rayStart))
    // Lodev.org also explains this additional optimistaion (but it's beyond scope of video)
  4. aJamDonut created this gist Aug 9, 2021.
    72 changes: 72 additions & 0 deletions gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,72 @@
    ddaWalk(x, y, endX, endY) {

    //DDA Algorithm https://lodev.org/cgtutor/raycasting.html
    //https://www.youtube.com/watch?v=NbSee-XM7WA
    //https://github.com/OneLoneCoder/olcPixelGameEngine

    const Vector = Matter.Vector; //Replace with whatever Vector class you use

    let mapSize = Vector.create(100, 100); //Grid size in cell size

    let rayStart = Vector.create(x, y);

    let rayEnd = new Vector.create(endX, endY);

    let rayDir = Vector.normalise(Vector.sub(rayEnd, rayStart))
    // Lodev.org also explains this additional optimistaion (but it's beyond scope of video)
    // olc::vf2d vRayUnitStepSize = { abs(1.0f / vRayDir.x), abs(1.0f / vRayDir.y) };
    let rayUnitStepSize = Vector.create(
    Math.sqrt(1 + (rayDir.y / rayDir.x) * (rayDir.y / rayDir.x)),
    Math.sqrt(1 + (rayDir.x / rayDir.y) * (rayDir.x / rayDir.y))
    );

    let mapCheck = Vector.create(rayStart.x, rayStart.y);

    let rayLength1D = Vector.create();
    let step = Vector.create();

    //Setup initial variables

    if (rayDir.x < 0) {
    step.x - 1;
    rayLength1D.x = (rayStart.x - mapCheck.x) * rayUnitStepSize.x;
    } else {
    step.x = 1;
    rayLength1D.x = (mapCheck.x + 1 - rayStart.x) * rayUnitStepSize.x;
    }

    if (rayDir.y < 0) {
    step.y = -1;
    rayLength1D.y = (rayStart.y - mapCheck.y) * rayUnitStepSize.y;
    } else {
    step.y = 1;
    rayLength1D.y = (mapCheck.y + 1 - rayStart.y) * rayUnitStepSize.y;
    }

    //Start walking

    let tileFound = false;
    let maxDistance = 10; //Max distance to walk in 'cells'
    let distance = 0;
    let maxIterations = 100; //Just for safety, don't crash browsers!
    let iterations = 0;
    while (!tileFound && distance < maxDistance && iterations < maxIterations) {
    iterations++;
    if (rayLength1D.x < rayLength1D.y) { //Staying true to javids demo here but if u want X to be dominant change < to <=
    mapCheck.x += step.x;
    distance = rayLength1D.x;
    rayLength1D.x += rayUnitStepSize.x;
    } else {
    mapCheck.y += step.y;
    distance = rayLength1D.y;
    rayLength1D.y += rayUnitStepSize.y;
    }

    //This is the meat, do your checks here, I just use it to reduce a rays length
    if (mapCheck.x >= 0 && mapCheck.x < mapSize.x && mapCheck.y >= 0 && mapCheck.y < mapSize.y) {
    if(this.isBlocked(mapCheck.x*64, mapCheck.y*64)) {
    return {x: mapCheck.x*64, y:mapCheck.y*64};//Vision blocked here so return this location.
    }
    }
    }
    }