mirror of
https://github.com/cyberarm/cyberarm_engine.git
synced 2025-12-16 13:12:34 +00:00
57 lines
1.5 KiB
Ruby
57 lines
1.5 KiB
Ruby
module CyberarmEngine
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class Ray
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def initialize(origin, direction, range = Float::INFINITY)
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raise "Origin must be a Vector!" unless origin.is_a?(Vector)
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raise "Direction must be a Vector!" unless direction.is_a?(Vector)
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@origin = origin
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@direction = direction
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@range = range
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@inverse_direction = @direction.inverse
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end
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def intersect?(intersectable)
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if intersectable.is_a?(BoundingBox)
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intersect_bounding_box?(intersectable)
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else
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raise NotImplementedError, "Ray intersection test for #{intersectable.class} not implemented."
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end
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end
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# Based on: https://tavianator.com/fast-branchless-raybounding-box-intersections/
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def intersect_bounding_box?(box)
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tmin = -@range
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tmax = @range
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tx1 = (box.min.x - @origin.x) * @inverse_direction.x
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tx2 = (box.max.x - @origin.x) * @inverse_direction.x
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tmin = max(tmin, min(tx1, tx2))
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tmax = min(tmax, max(tx1, tx2))
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ty1 = (box.min.y - @origin.y) * @inverse_direction.y
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ty2 = (box.max.y - @origin.y) * @inverse_direction.y
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tmin = max(tmin, min(ty1, ty2))
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tmax = min(tmax, max(ty1, ty2))
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tz1 = (box.min.z - @origin.z) * @inverse_direction.z
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tz2 = (box.max.z - @origin.z) * @inverse_direction.z
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tmin = max(tmin, min(tz1, tz2))
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tmax = min(tmax, max(tz1, tz2))
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tmax >= max(tmin, 0.0)
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end
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def min(x, y)
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((x) < (y) ? x : y)
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end
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def max(x, y)
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((x) > (y) ? x : y)
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end
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end
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end
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