46 lines
1.4 KiB
Lua
46 lines
1.4 KiB
Lua
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--
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-- Anaglym std library
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--
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-- History:
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-- 2009-11-02 Josh Holtrop Initial Revision
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--
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std = {}
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-- Compute the cross product of two vectors
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-- Input:
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-- vec1: the first vector (table; indices 1..3)
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-- vec2: the second vector (table; indices 1..3)
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-- Output:
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-- The cross product vector (table; indices 1..3)
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std.crossProduct = function(vec1, vec2)
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local vec_result = {}
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vec_result[1] = vec1[2] * vec2[3] - vec1[3] * vec2[2]
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vec_result[2] = vec1[3] * vec2[1] - vec1[1] * vec2[3]
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vec_result[3] = vec1[1] * vec2[2] - vec1[2] * vec2[1]
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return vec_result
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end
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-- Compute the dot product of two vectors
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-- Input:
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-- vec1: the first vector (table; indices 1..3)
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-- vec2: the second vector (table; indices 1..3)
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-- Output:
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-- The dot product scalar
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std.dotProduct = function(vec1, vec2)
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return vec1[1] * vec2[1] + vec1[2] * vec2[2] + vec1[3] * vec2[3]
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end
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-- Create a plane
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-- Input:
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-- x, y, z: coordinates of a point on the plane
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-- nx, ny, nz: normal vector of the plane
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-- Output:
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-- Plane object (returned from ag.createPlane())
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std.createPlanePointNormal = function(x, y, z, nx, ny, nz)
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-- calculate the d plane parameter based on the point coordinates
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-- invoke the ag routine to create a plane based on a, b, c, d parameters
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return ag.createPlane(nx, ny, nz, nx * x, ny * y, nz * z)
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end
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