109 lines
2.7 KiB
Plaintext
109 lines
2.7 KiB
Plaintext
var collision2d = {}
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collision2d.body = function(config) {
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var c = config || {}
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return {
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type: c.type || 'aabb',
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width: c.width || 0,
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height: c.height || 0,
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radius: c.radius || 0,
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offset: c.offset || {x: 0, y: 0},
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layer: c.layer || 0,
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mask: c.mask || 0xFFFF
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}
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}
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function body_center(body, pos) {
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return {
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x: pos.x + body.offset.x,
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y: pos.y + body.offset.y
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}
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}
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function test_aabb_aabb(a, ap, b, bp) {
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var ac = body_center(a, ap)
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var bc = body_center(b, bp)
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var ahw = a.width * 0.5
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var ahh = a.height * 0.5
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var bhw = b.width * 0.5
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var bhh = b.height * 0.5
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return abs(ac.x - bc.x) < ahw + bhw && abs(ac.y - bc.y) < ahh + bhh
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}
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function test_circle_circle(a, ap, b, bp) {
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var ac = body_center(a, ap)
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var bc = body_center(b, bp)
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var dx = ac.x - bc.x
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var dy = ac.y - bc.y
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var r = a.radius + b.radius
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return dx * dx + dy * dy < r * r
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}
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function test_aabb_circle(aabb, ap, circ, cp) {
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var ac = body_center(aabb, ap)
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var cc = body_center(circ, cp)
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var hw = aabb.width * 0.5
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var hh = aabb.height * 0.5
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var cx = max(ac.x - hw, min(cc.x, ac.x + hw))
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var cy = max(ac.y - hh, min(cc.y, ac.y + hh))
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var dx = cc.x - cx
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var dy = cc.y - cy
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return dx * dx + dy * dy < circ.radius * circ.radius
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}
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collision2d.test = function(a, a_pos, b, b_pos) {
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if (a.layer & b.mask == 0 || b.layer & a.mask == 0)
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return false
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if (a.type == 'aabb' && b.type == 'aabb')
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return test_aabb_aabb(a, a_pos, b, b_pos)
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if (a.type == 'circle' && b.type == 'circle')
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return test_circle_circle(a, a_pos, b, b_pos)
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if (a.type == 'aabb' && b.type == 'circle')
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return test_aabb_circle(a, a_pos, b, b_pos)
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if (a.type == 'circle' && b.type == 'aabb')
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return test_aabb_circle(b, b_pos, a, a_pos)
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return false
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}
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collision2d.overlap = function(body, pos, others) {
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var results = []
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var i = 0
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var other = null
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for (i = 0; i < length(others); i++) {
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other = others[i]
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if (collision2d.test(body, pos, other.body, other.pos))
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results[] = other
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}
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return results
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}
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collision2d.overlap_point = function(point, bodies) {
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var results = []
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var i = 0
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var b = null
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var c = null
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var hw = 0
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var hh = 0
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var dx = 0
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var dy = 0
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for (i = 0; i < length(bodies); i++) {
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b = bodies[i]
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c = body_center(b.body, b.pos)
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if (b.body.type == 'aabb') {
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hw = b.body.width * 0.5
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hh = b.body.height * 0.5
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if (abs(point.x - c.x) < hw && abs(point.y - c.y) < hh)
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results[] = b
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} else if (b.body.type == 'circle') {
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dx = point.x - c.x
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dy = point.y - c.y
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if (dx * dx + dy * dy < b.body.radius * b.body.radius)
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results[] = b
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}
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}
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return results
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}
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return collision2d
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