How to initialize constant of type rs_matrix4x4?

Question

How to initialize constant of type rs_matrix4x4 using RenderScript?

Something like that

const rs_matrix4x4 xyz2rgb_m = {
     3.2406, -1.5372, -0.4986, 0.0000,
    -0.9689,  1.8758,  0.0415, 0.0000,
     0.0557, -0.2040,  1.0570, 0.0000,
     0.0000,  0.0000,  0.0000, 1.0000};

doesn't work. Compiler returns an error message:

Error:(11, 20) error: Reflection of initializer to variable 'xyz2rgb_m' (of type 'rs_matrix4x4') is unsupported currently.

Is element-by-element initialization the only way?

Answer 1

There is a set of functions named rsMatrixLoad for rs_matrix4x4 initialization. They can load matrix elements from an array or a matrix.

One can use this function for initialization by array values:

void rsMatrixLoad(rs_matrix2x2* destination, const float* array);

For example:

void init() {
    float rgb2xyz_m_data[] = {
         0.4124, 0.3576, 0.1805, 0.0000,
         0.2126, 0.7152, 0.0722, 0.0000,
         0.0193, 0.1192, 0.9505, 0.0000,
         0.0000, 0.0000, 0.0000, 1.0000};

    rsMatrixLoad(&rgb2xyz_m, rgb2xyz_m_data);
}

There is also a set of methods for loading special matrices (e.g. projection one).