[DefaultType] fix rigidcoord compilation

[bakpaul]

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[fredroy]

I dont think the fix is good ; the "toMatrix()" is available for Mat3x3 but not for Mat4x4 (there was a toMatrix for Mat4x4 but it was deleted and replace with toHomogenousMatrix() ). This RigidCoord::toMatrix() is templated on the Mat type actually, and is really ill-formed (no assert on the size of the given matrix, etc). I think the solution is to either:

• test if the matrix is 3x3 or 4x4 (and failed to compile with a message with a static assert) and calling the respective toMatrix() or toHomogenousMatrix ()
• or remove the template, force it to Mat3x3 and create an other toHomogenousMatrix in RigidCoord. Consisntent with Quat but duplicating code and breaking.

I am more for the first solution.

Thanks for your contribution. I wonder how it was not detected before

I guess this was not detected before because nobody was calling RigidCoord::toMatrix with a Mat4x4 with the code compiled on the CI. Actually, nobody calls RigidCoord::toMatrix, either with mat3 or mat4 apparently.

[alxbilger]

The changes I suggested are here: https://github.com/mimesis-inria/sofa/pull/18