// copied from the orange book
GlTexture* NoiseGenerator::make3Dnoise(int size, float ampStart, float ampDiv, int startFrequency)
{
int f, i, j, k, inc;
//int startFrequency = 4;
int numOctaves = NUM_OCT; //4;
double ni[3];
double inci, incj, inck;
int frequency = startFrequency;
double amp = ampStart;
double minn = 100.0, maxn = -100.0;
// uint bufsize = noise3DTexSize * noise3DTexSize * noise3DTexSize * 4;
// if ((noise3DTexPtr = (GLubyte *) malloc(bufsize)) == nullptr)
// {
// printf("ERROR: Could not allocate 3D noise texture - %d bytes\n", bufsize);
// return nullptr;
// }
Space3D<Vec4b> noise3DTexPtr(size, size, size);
byte *ptr = noise3DTexPtr.ptr()->v;
for (f = 0, inc = 0; f < numOctaves; ++f, frequency *= 2, ++inc, amp *= ampDiv)
{
setNoiseFrequency(frequency);
ni[0] = ni[1] = ni[2] = 0;
inci = 1.0 / (size / frequency);
for (i = 0; i < size; ++i, ni[0] += inci)
{
incj = 1.0 / (size / frequency);
for (j = 0; j < size; ++j, ni[1] += incj)
{
inck = 1.0 / (size / frequency);
for (k = 0; k < size; ++k, ni[2] += inck, ptr+= 4)
{
double ns = noise3(ni) * N_FACT;
*(ptr+inc) = (GLubyte)(((ns+1.0) * amp)*255.0);
if (ns > maxn)
maxn = ns;
if (ns < minn)
minn = ns;
}
}
}
}
//GlTexture *tex = new GlTexture();
//tex->init(GL_TEXTURE_3D, QSize(size, size), size, GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE,
// noise3DTexPtr, GL_LINEAR, GL_LINEAR, GL_REPEAT); //GL_NEAREST
printf("%lf - %lf = %lf\n", maxn, minn, maxn - minn);
Vec2i sz2d;
uchar* buf2d = saveto2D(noise3DTexPtr, size, size/4, 8, &sz2d);
GlTexture *tex = new GlTexture();
tex->init(GL_TEXTURE_2D, Vec2i(sz2d.x, sz2d.y), 1, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, buf2d, GL_LINEAR, GL_LINEAR, GL_CLAMP_TO_EDGE);
/*
QImage img(buf2d, sz2d.x, sz2d.y, QImage::Format_ARGB32);
img.save("c:/temp/cubeTex.jpg");
*/
delete[] buf2d;
return tex;
}
