#define USE_FORGE_CPU_COPY_HELPERS
#include <complex>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <vector>
#include <iostream>
const unsigned IMGW = 256;
const unsigned IMGH = 256;
const unsigned DIMX = 1000;
const unsigned DIMY = 800;
const unsigned NBINS = 256;
using namespace std;
struct Bitmap {
unsigned char *ptr;
unsigned width;
unsigned height;
};
class PerlinNoise
{
private:
float base[IMGW][IMGH];
float perlin[IMGW][IMGH];
public:
PerlinNoise();
float noise(float u, float v);
};
Bitmap createBitmap(unsigned w, unsigned h);
void destroyBitmap(Bitmap& bmp);
void kernel(Bitmap& bmp);
void populateBins(Bitmap& bmp, int *hist_array, const unsigned nbins, float *hist_cols);
int main(void)
{
Bitmap bmp = createBitmap(IMGW, IMGH);
wnd.makeCurrent();
chart.setAxesLimits(0, 1, 0, IMGW*IMGH/(float)(NBINS/4.0));
do {
kernel(bmp);
std::vector<int> histArray(NBINS, 0);
std::vector<float> colArray(3*NBINS, 0.0f);
populateBins(bmp, histArray.data(), NBINS, colArray.data());
wnd.draw(2, 3, 0, img, "Dynamic Perlin Noise" );
wnd.draw(2, 3, 1, img, "Dynamic Perlin Noise" );
wnd.draw(2, 3, 2, img, "Dynamic Perlin Noise" );
wnd.draw(2, 2, 2, chart, "Histogram of Noisy Image");
wnd.draw(2, 2, 3, chart, "Histogram of Noisy Image");
wnd.swapBuffers();
} while(!wnd.close());
releaseGLBuffer(handles[0]);
releaseGLBuffer(handles[1]);
releaseGLBuffer(handles[2]);
return 0;
}
float interp(float x0, float x1, float alpha)
{
return x0 * (1 - alpha) + alpha * x1;
}
PerlinNoise::PerlinNoise()
{
std::srand((unsigned)(std::time(0)));
for(unsigned i=0; i < IMGW; i++)
{
for(unsigned j=0; j < IMGH; j++)
{
base[i][j] = std::rand()/(float)(RAND_MAX);
perlin[i][j] = 0;
}
}
float persistence = 0.5f;
float amp = 1.0f;
float tamp = 0.0f;
for (int octave=6; octave>=0; --octave)
{
int period = 1 << octave;
float freq = 1.0f / period;
for(unsigned i=0; i < IMGW; i++)
{
int si0 = (i/period) * period;
int si1 = (si0 + period) % IMGW;
float hblend = (i - si0) * freq;
for(unsigned j=0; j < IMGH; j++)
{
int sj0 = (j/period) * period;
int sj1 = (sj0 + period) % IMGH;
float vblend = (j - sj0) * freq;
float top = interp(base[si0][sj0], base[si1][sj0], hblend);
float bot = interp(base[si0][sj1], base[si1][sj1], hblend);
perlin[i][j] += (amp * interp(top, bot, vblend));
}
}
tamp += amp;
amp *= persistence;
}
for(unsigned i=0; i < IMGW; i++)
for(unsigned j=0; j < IMGH; j++)
perlin[i][j] /= tamp;
}
float PerlinNoise::noise(float u, float v)
{
return perlin[(unsigned)(IMGW*u)][(unsigned)(IMGH*v)];
}
Bitmap createBitmap(unsigned w, unsigned h)
{
Bitmap retVal;
retVal.width = w;
retVal.height= h;
retVal.ptr = new unsigned char[4*w*h];
return retVal;
}
void destroyBitmap(Bitmap& bmp)
{
delete[] bmp.ptr;
}
void kernel(Bitmap& bmp)
{
PerlinNoise perlin;
for (unsigned y=0; y<bmp.height; ++y) {
for (unsigned x=0; x<bmp.width; ++x) {
int offset = x + y * bmp.width;
float u = x/(float)(bmp.width);
float v = y/(float)(bmp.height);
unsigned char noiseVal = (unsigned char)(255 * perlin.noise(u, v));
bmp.ptr[offset*4 + 0] = noiseVal;
bmp.ptr[offset*4 + 1] = noiseVal;
bmp.ptr[offset*4 + 2] = noiseVal;
bmp.ptr[offset*4 + 3] = 255;
}
}
}
void populateBins(Bitmap& bmp, int *hist_array, const unsigned nbins, float *hist_cols)
{
for (unsigned y=0; y<bmp.height; ++y) {
for (unsigned x=0; x<bmp.width; ++x) {
int offset = x + y * bmp.width;
unsigned char noiseVal = bmp.ptr[offset*4];
unsigned idx = (int)((float)noiseVal/255.f * nbins);
hist_array[idx]++;
}
}
for (unsigned b=0; b<nbins; ++b) {
hist_cols[3*b+0] = std::rand()/(float)RAND_MAX;
hist_cols[3*b+1] = std::rand()/(float)RAND_MAX;
hist_cols[3*b+2] = std::rand()/(float)RAND_MAX;
}
}