cajeta.math.Transform — a TRS (translate / rotate / scale) rigid+scale transform, the object-placement value type a scene graph and a renderer’s model matrix are built from. A value type over the builtin Vector<float32,3> (translation, scale) and Quaternion<float32> (rotation): stack-allocated, no heap, no drop chain. Applied to a point the order is scale, then rotate, then translate; transformVector drops the translation. Compose and inverse keep the TRS form exactly for uniform scale — a non-uniform scale combined with a rotation is not closed under TRS (a documented limitation).

package snip.transform;

import cajeta.math.Transform;
import cajeta.math.Rotation;

public final class Demo {
    public static void run() {
        Vector<float32,3> tr = stack Vector<float32,3>(0.0f, 0.0f, 5.0f);
        Quaternion<float32> rot = Rotation.identity();
        Vector<float32,3> sc = stack Vector<float32,3>(2.0f, 2.0f, 2.0f);
        Transform t = stack Transform(tr, rot, sc);
        Vector<float32,3> p = stack Vector<float32,3>(1.0f, 0.0f, 0.0f);
        Vector<float32,3> w = t.transformPoint(p);   // (2, 0, 5)
        return;
    }
}

Methods

Signature
`Transform(Vector<float32,3> translation, Quaternion<float32> rotation, Vector<float32,3> scale)` ⚑	Build a transform from its translation, rotation, and scale components
`static Transform identity()` ⚑	The identity transform: no translation, no rotation, unit scale
`Vector<float32,3> translation()`	The translation component
`Quaternion<float32> rotation()`	The rotation component (a unit quaternion)
`Vector<float32,3> scale()`	The scale component
`Vector<float32,3> transformPoint(Vector<float32,3> p)`	Map a point through the transform: translate(rotate(scale(p)))
`Vector<float32,3> transformVector(Vector<float32,3> v)`	Map a direction: rotate(scale(v)) — no translation
`Transform compose(Transform child)`	The transform that applies `child` first, then `this` (exact for uniform scale)
`Transform inverse()`	The inverse transform: `inverse().transformPoint(transformPoint(p)) == p` (exact for uniform scale)

⚑ = @EntryPoint

Transform

Methods

See also