SH fix for spz

[CedricGuillemet]

For reference, using uint32 instead of swizzled uint8. This should have no implication on the shader.

for (let i = 0; i < splatCount; i++) {
    const c = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
    for (let j = 0; j < 15; ++j) {
        c[j * 3] = ubuf[shIndexRead + i * shComponentCount + j * 3 + 0];
        c[j * 3 + 1] = ubuf[shIndexRead + i * shComponentCount + j * 3 + 1];
        c[j * 3 + 2] = ubuf[shIndexRead + i * shComponentCount + j * 3 + 2];
    }
    sh[0][i * 4 + 0] = (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
    sh[0][i * 4 + 1] = (c[4] << 24) | (c[5] << 16) | (c[6] << 8) | c[7];
    sh[0][i * 4 + 2] = (c[8] << 24) | (c[9] << 16) | (c[10] << 8) | c[11];
    sh[0][i * 4 + 3] = (c[12] << 24) | (c[13] << 16) | (c[14] << 8) | c[15];

    sh[1][i * 4 + 0] = (c[16] << 24) | (c[17] << 16) | (c[18] << 8) | c[19];
    sh[1][i * 4 + 1] = (c[20] << 24) | (c[21] << 16) | (c[22] << 8) | c[23];
    sh[1][i * 4 + 2] = (c[24] << 24) | (c[25] << 16) | (c[26] << 8) | c[27];
    sh[1][i * 4 + 3] = (c[28] << 24) | (c[29] << 16) | (c[30] << 8) | c[31];

    sh[2][i * 4 + 0] = (c[32] << 24) | (c[33] << 16) | (c[34] << 8) | c[35];
    sh[2][i * 4 + 1] = (c[36] << 24) | (c[37] << 16) | (c[38] << 8) | c[39];
    sh[2][i * 4 + 2] = (c[40] << 24) | (c[41] << 16) | (c[42] << 8) | c[43];
    sh[2][i * 4 + 3] = c[44] << 24;
}

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