https://github.com/stavenko/nim-glm

glm library to operate vectors and matrices(inspired by https://github.com/g-truc/glm)
https://github.com/stavenko/nim-glm

Last synced: about 2 months ago
JSON representation

glm library to operate vectors and matrices(inspired by https://github.com/g-truc/glm)

• Host: GitHub
• URL: https://github.com/stavenko/nim-glm
• Owner: stavenko
• License: other
• Created: 2015-07-01T20:40:20.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2021-06-24T21:39:19.000Z (about 3 years ago)
• Last Synced: 2024-05-12T10:35:33.029Z (4 months ago)
• Language: Nim
• Homepage:
• Size: 256 KB
• Stars: 92
• Watchers: 10
• Forks: 18
• Open Issues: 3
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• awesome-nim - glm - Port of the popular glm C++ library to Nim. (Game Development / Game Libraries)

README

        
#Nim-glm port for matrix-vector algebra with shader like syntax.

Nim-glm has vector constructors:

Here's some examples

    var

        v = vec3(1.0, 5.0, 6.0)

        a = vec3(2.0, 2.0, 5.0)

        v4 = vec4(v, 1.0)

        c = cross(v,a)

        m = rotate(mat4d(), 5.0, vec3(1.0, 0.0, 0.0))

        r = v4 * m

Also, this version has basics for common matrices creations:

    var

        eye = vec3(50.0, 50.0, 10.0)

        center = vec3(0.0)

        up = vec3(0.0, 1.0, 0.0)

        viewMatrix = lookAt(eye, center, up)

        projectionMat = perspective(math.PI/2, 1.0, 0.01, 100.0)

    echo viewMatrix * projectionMat

Use it in OpenGL environment:

    var modelView = mat4f(1)

      .rotate(alpha, n.x, n.y, n.z)

      .scale(4,5,6)

      .translate(1,2,3)

    glUniformMatrix4fv(_uniformLocation, 1, false, modelView.caddr)

There is swizzling support:

    var pos1,pos2: Vec4f

    pos1.xyz = pos2.zww

    pos1.yz += pos2.ww

    var texcoord: Vec2f

    echo texcoord.st

    var color: Vec4f

    color.rgb = color.bgr

matrices can be printed with echo, because they have the `$` operator

implemented. By default they use nice unicode characters for best

visual representation.  But if you have probmles with them, you can

pass ``-d:noUnicode`` to the compiler and the ``$`` functions will use

a pure ASCII representation.

          ASCII            unicode

     / 3  7   3   0 \   ⎡3  7   3   0⎤

    |  0  2  -1   1  |  ⎢0  2  -1   1⎥

    |  5  4   3   2  |  ⎢5  4   3   2⎥

     \ 6  6   4  -1 /   ⎣6  6   4  -1⎦

perlin noise:

    import glm/vec

    import glm/noise

    var line = newStringOfCap(80)

    for y in 0 ..< 20:

      for x in 0 ..< 40:

        let n = perlin(vec2f(float32(x), float32(y)) * 0.1'f32)

        let i = int(floor((n + 1) * 5))

        line.add "  .:+=*%#@"[i]

      echo line

      line.setLen(0)

    # expected output:

    #

    #  =+++:::::+======++++==*%%%%**==++++++++=

    #  ===++::::++====++::++=*%%%%%*===++++:+++

    #  ***=+::.::+====++:::+==*%%%%***==++:::::

    #  ***=+:...:++===++:::++==**%%*****=++:...

    #  **=+::...::+====++:::+++==********=+:.

    #  *==+:....::+=====++:::::++==******=+:.

    #  ==+:..  .::+=****=++:::::::+==*****=+:.

    #  =+:..   .:++=*%%**=++::....:+==**%**=+:.

    #  ++:.   ..:+=*%%%%**=+:..   .:+=**%%**=+:

    #  ++:.   .::+=*%###%*=+::.   .:+==*%%%**=+

    #  =+:..  .:+==*%###%*==+:.   .:+==*%%%%*==

    #  =++:....:+=**%###%**=+:.    .:+=*%%#%%*=

    #  ==+::..:++=*%%####%*=+:.    .:+=*%%#%%**

    #  *==+:::++==*%%####%**=+:.   .:+==*%%%%**

    #  **==++++==***%%##%%%**=+:....::+=*****==

    #  %**======******%%%%%%**=+:....:++=***==+

    #  ***===*****====****%%%*=+::...:++====+++

    #  **===*****==++++==******=+::.::++====++:

    #  *====*****=++:::++==****=+::::+++====++:

    #  ==++==***==+::..::+======++::+++======++

* Changes regarding based to C++glm and glsl

  - the `mod` function is called `floorMod` instead. `mod` is already

    an operator in Nim and has it's own meaning that is very different

    to the meaning of the `mod` function in glsl. The name `fmod` is

    not good either, because `fmod` in c++ has a different meaning as well.

    The function `floorMod` from the ``math`` package has the same

    meaning as the `mod` function in glsl. Therefore `mod` is simply

    named `floorMod` to be at least consistent with the Nim standard

    library.  The `mod` operator always rounds towards zero, I personally

    recommend to never use this operator.

  - swizzle support. Unlike c++, Nim allows pretty well to implement

    swizzling. So it is implemented with the least amount of surprise.

  - simd instructions are not implemented.  You could hope that some

    day the C compiler will be smart enough to inject them, but I would

    not bet on it.

  - glm in c++ has a lot more extensions that are not yet ported over

    to the Nim version. They are added when needed. On the other hand,

    this library is feature complete in terms of featurs that come from GLSL.