unsigned int TextureLoader::CreateNoiseTexture(double alpha, double beta, int n, int side) {
Perlin perlin;
float* data = new float[side*side*side];
double step = 1.0/(side-1.0);
int index = 0;
for (double x = 0; x <= 1; x += step) {
for (double y = 0; y <= 1; y += step) {
for(double z = 0; z <= 1; z += step) {
float noise = static_cast<float>(perlin.PerlinNoise3D(x, y, z, alpha, beta, n));
data[index] = noise;
index++;
}
}
}
//create the OpenGL texture
unsigned int gl_texture_object;
glGenTextures(1, &gl_texture_object);
glBindTexture(GL_TEXTURE_3D, gl_texture_object);
//filtering
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_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_LINEAR);
float maxAnisotropy;
glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAnisotropy);
glTexParameterf(GL_TEXTURE_3D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy);
//when we work with textures of sizes not divisible by 4 we have to use the line reader
//which loads the textures in OpenGL so as it can work with a 1 alligned memory (default is 4)
//glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
//Generates texture
glTexImage3D(GL_TEXTURE_3D, 0, GL_R32F, side, side, side, 0, GL_RED, GL_FLOAT, data);
//eliminates the array from the RAM
delete data;
//creates the mipmap hierarchy
glGenerateMipmap(GL_TEXTURE_3D);
//returns the texture object
return gl_texture_object;
}
