// vr-MIP-test.diderot
//
// test version of maximum intensity projection in Diderot
//

string dataFile = "../data/zimg.nrrd";
int dataSize = 9;
int imgSize = 200;
vec3 orig = [0.0, 0.0, 4.0];
vec3 cVec = [0.0, 1.0, 0.0];
vec3 rVec = [1.0, 0.0, 0.0];
image(3)[] img = load (dataFile);
field#2(3)[] F = img ⊛ bspln3;

strand RayCast (int row, int col)
{
    // HEY why doesn't rr or cc ever go negative?
    real rr = real(dataSize)*(real(row)+0.5)/real(imgSize) - 0.5;
    real cc = real(dataSize)*(real(col)+0.5)/real(imgSize) - 0.5;
    vec3 pos = orig + rr*rVec + cc*cVec;
    output real maxval = -∞; 

    update
    {
        maxval = rr;
        if (1 > 0) // HEY can't take this test out 
          stabilize;
    }

    /* render: output maxval */
}

initially [ RayCast(r, c) | r in 0..199, c in 0..199 ];