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I am quite confused over how GLM library is behaving or I am using it improperly. 

glm::vec2 testVec(6,-4);

float len = testVec.length();

I get the value 2 with the above code snippet. I believe I am trying to get the length of the vector defined by testVec. You know very well that it is not the correct length of the vector. What am I missing here?

Martin Ender
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sajis997
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1 Answers1

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Sorry folks for posting such a trivial issue! The issue is solved. I was using the wrong function. Here goes the correct one:

glm::vec2 testVec(6,-4);
float len  = glm::length(testVec);

The member function of the same name returns the number of components instead (i.e. vec2::length will always yield 2, vec3::length will always yield 3, etc.).

Martin Ender
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sajis997
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    Don't apologise, I think it's a fair question, seeing that GLM's function naming is quite misleading here. I expect this could be a useful (and concise) reference in the future. – Martin Ender Mar 01 '16 at 09:52
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    @MartinEnder it's not GLM who's guilty: the GLSL spec prescribes this confusion to exist: there's length(vecN) free function returning the norm of vecN, and vecN.length() method, returning dimension of vecN. See §5.5 Vector and Scalar Components and Length of GLSL 4.60 spec. – Ruslan Feb 15 '19 at 16:16
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    You are not alone. – Summer Sun Apr 11 '20 at 12:01
  • I too am a member of the "Wrong Length Function Anonymous" group. – nenchev Mar 16 '24 at 12:20