void make3DNoiseTexture()
{
int f, i, j, k, inc;
int startFrequency = 4;
int numOctaves = 4;
double ni[3];
double inci, incj, inck;
int frequency = startFrequency;
GLubyte* ptr;
double amp = 0.5;
Noise3DTexPtr = (GLubyte*) malloc(Noise3DTexSize * Noise3DTexSize * Noise3DTexSize * 4);
for (f = 0, inc = 0; f < numOctaves; ++f, frequency *= 2, ++inc, amp *= 0.5)
{
SetNoiseFrequency(frequency);
ptr = Noise3DTexPtr;
ni[0] = ni[1] = ni[2] = 0;
inci = 1.0 / (Noise3DTexSize / frequency);
for (i = 0; i < Noise3DTexSize; ++i, ni[0] += inci)
{
incj = 1.0 / (Noise3DTexSize / frequency);
for (j = 0; j < Noise3DTexSize; ++j, ni[1] += incj)
{
inck = 1.0 / (Noise3DTexSize / frequency);
for (k = 0; k < Noise3DTexSize; ++k, ni[2] += inck, ptr += 4)
*(ptr + inc) = (GLubyte) (((noise3(ni) + 1.0) * amp) * 128.0);
}
}
}
}
//
// Create 3D noise texture
//
int CreateNoise3D(int unit)
{
int f,i,j,k,inc;
unsigned int id;
int numOctaves = 4;
double ni[3];
double inci,incj,inck;
int frequency = 4;
double amp = 0.5;
char* ptr;
char pix[size * size * size * 4];
for (f=0,inc=0; f<numOctaves; f++,frequency*=2,inc++,amp*=0.5)
{
SetNoiseFrequency(frequency);
ptr = pix;
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)
*(ptr + inc) = (char) (((noise3(ni) + 1.0) * amp) * 128.0);
}
}
}
// Select texture unit
glActiveTexture(unit);
// Generate 2D texture id and make current
glGenTextures(1,&id);
glBindTexture(GL_TEXTURE_2D,id);
// Copy noise to texture
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA8, size, size, size, 0, GL_RGBA, GL_UNSIGNED_BYTE, pix);
// Set texture parameters
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
// Select texture unit
glActiveTexture(GL_TEXTURE0);
return id;
}
void make3DNoiseTexture(void){
int f, i, j, k, inc;
int startFrequency = 4;
int numOctaves = 4;
double ni[3];
double inci, incj, inck;
int frequency = startFrequency;
GLubyte *ptr;
double amp = 0.5;
if ((noise3DTexPtr = (GLubyte *) malloc(noise3DTexSize *
noise3DTexSize *
noise3DTexSize * 4)) == NULL)
{
fprintf(stderr, "ERROR: Could not allocate 3D noise texture\n");
exit(1);
}
for (f=0, inc=0; f < numOctaves;
++f, frequency *= 2, ++inc, amp *= 0.5)
{
SetNoiseFrequency(frequency);
ptr = noise3DTexPtr;
ni[0] = ni[1] = ni[2] = 0;
inci = 1.0 / (noise3DTexSize / frequency);
for (i=0; i<noise3DTexSize; ++i, ni[0] += inci)
{
incj = 1.0 / (noise3DTexSize / frequency);
for (j=0; j<noise3DTexSize; ++j, ni[1] += incj)
{
inck = 1.0 / (noise3DTexSize / frequency);
for (k=0; k<noise3DTexSize; ++k, ni[2] += inck, ptr+= 4)
{
*(ptr+inc) = (GLubyte) (((noise3(ni)+1.0) * amp)*128.0);
}
}
}
}
}
