Am 04.12.2011 01:38, schrieb dsimcha:
I don't know much about computer graphics but I take it that a sane
design for a matrix/vector library geared towards graphics is completely
different from one geared towards general numerics/scientific computing?
I'm trying to understand whether SciD (which uses BLAS/LAPACK and
expression templates) overlaps with this at all.

On 12/2/2011 5:36 PM, David wrote:
Hello,

I am currently working on gl3n - https://bitbucket.org/dav1d/gl3n - gl3n
provides all the math you need to work with OpenGL, DirectX or just
vectors and matrices (it's mainly targeted at graphics - gl3n will never
be more then a pure math library). What it supports:

* vectors
* matrices
* quaternions
* interpolation (lerp, slerp, hermite, catmull rom, nearest)
* nearly all glsl functions (according to spec 4.1)
* some more cool features, like templated types (vectors, matrices,
quats), cool ctors, dynamic swizzling

And the best is, it's MIT licensed ;). Unfortunatly there's no
documentation yet, but it shouldn't be hard to understand how to use it,
if you run anytime into troubles just take a look into the source, I did
add to every part of the lib unittests, so you can see how it works when
looking at the unittests, furthermore I am very often at #D on freenode.
But gl3n isn't finished! My current plans are to add more interpolation
functions and the rest of the glsl defined functions, but I am new to
graphics programming (about 4 months I am now into OpenGL), so tell me
what you're missing, the chances are good that I'll implement and add
it. So let me know what you think about it.

Before I forget it, a bit of code to show you how to use gl3n:

------------------------------------------------------------------------
vec4 v4 = vec4(1.0f, vec3(2.0f, 3.0f, 4.0f));
vec4 v4 = vec4(1.0f, vec4(1.0f, 2.0f, 3.0f, 4.0f).xyz)); // "dynamic"
swizzling with opDispatch
vec3 v3 = my_3dvec.rgb;
float[] foo = v4.xyzzzwzyyxw // not useful but possible!
glUniformMatrix4fv(location, 1, GL_TRUE, mat4.translation(-0.5f, -0.54f,
0.42f).rotatex(PI).rotatez(PI/2).value_ptr); // yes they are row major!
mat3 inv_view = view.rotation;
mat3 inv_view = mat3(view);
mat4 m4 = mat4(vec4(1.0f, 2.0f, 3.0f, 4.0f), 5.0f, 6.0f, 7.0f, 8.0f,
vec4(…) …);

struct Camera {
vec3 position = vec3(0.0f, 0.0f, 0.0f);
quat orientation = quat.identity;

Camera rotatex(real alpha) { orientation.rotatex(alpha); return this; }
Camera rotatey(real alpha) { orientation.rotatey(alpha); return this; }
Camera rotatez(real alpha) { orientation.rotatez(alpha); return this; }

Camera move(float x, float y, float z) {
position += vec3(x, y, z);
return this;
}
Camera move(vec3 s) {
position += s;
return this;
}

@property camera() {
//writefln("yaw: %s, pitch: %s, roll: %s",
degrees(orientation.yaw), degrees(orientation.pitch),
degrees(orientation.roll));
return mat4.translation(position.x, position.y, position.z) *
orientation.to_matrix!(4,4);
}
}

glUniformMatrix4fv(programs.main.view, 1, GL_TRUE,
cam.camera.value_ptr);
glUniformMatrix3fv(programs.main.inv_rot, 1, GL_TRUE,
cam.orientation.to_matrix!(3,3).inverse.value_ptr);
------------------------------------------------------------------------

I hope this gave you a little introduction of gl3n.

- dav1d

We talked yesterday about this topic a bit (freenode.#D):


klickverbot dav1d: Just to clear up the confusion, scientific linear algebra stuff is a completely different beast than game math. Games is fast 4x4 matrices, numerics is intricate algorithms for 1000x1000 matrices (read: larger than you ever need in gamedev, even when your game uses string theory)

klickverbot dav1d: I don't know gl3n specifically, but trust me, no gaming linear algebra lib is ever going to be a viable choice for science-y things and vice versa

klickverbot dav1d: I mean, a gaming lib would e.g. never have LU, Cholesky, and all other different kinds of decomposition algorithms


Well, I don't know a lot about this topic (scientific linear algebra), but it seems that they have different aims.



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