51 lines
1.1 KiB
JavaScript
51 lines
1.1 KiB
JavaScript
const entity = require("../utilities/entity.js");
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function wallslide(ent, map, x = 0, y = 0) {
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let tiles;
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let tileEdge;
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const bounds = entity.bounds(ent);
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// Final amounts of movement to allow
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let xo = x;
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let yo = y;
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// Check vertical movement
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if (y !== 0) {
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tiles = map.tilesAtCorners(bounds, 0, yo);
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const [tl, tr, bl, br] = tiles.map(t => t && t.frame.walkable);
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// Hit your head
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if (y < 0 && !(tl && tr)) {
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tileEdge = tiles[0].pos.y + tiles[0].h;
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yo = tileEdge - bounds.y;
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}
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// Hit your feet
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if (y > 0 && !(bl && br)) {
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tileEdge = tiles[2].pos.y - 1;
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yo = tileEdge - (bounds.y + bounds.h);
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}
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}
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// Check horizontal movement
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if (x !== 0) {
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tiles = map.tilesAtCorners(bounds, xo, yo);
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const [tl, tr, bl, br] = tiles.map(t => t && t.frame.walkable);
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// Hit left edge
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if (x < 0 && !(tl && bl)) {
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tileEdge = tiles[0].pos.x + tiles[0].w;
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xo = tileEdge - bounds.x;
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}
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// Hit right edge
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if (x > 0 && !(tr && br)) {
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tileEdge = tiles[1].pos.x - 1;
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xo = tileEdge - (bounds.x + bounds.w);
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}
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}
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// xo & yo contain the amount we're allowed to move by.
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return { x: xo, y: yo };
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}
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module.exports = {
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wallslide
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}; |