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Sample.cpp
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Sample.cpp
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#define _CRT_RAND_S
#include "Sample.h"
#include "Vector2D.h"
#include <math.h>
#include <stdlib.h>
void random(Vector2D* samples, int num_samples)
{
for (int i= 0; i< num_samples; i++) {
samples[i].setX(((double) rand() / (RAND_MAX)));
samples[i].setY(((double) rand() / (RAND_MAX)));
}
}
void jitter(Vector2D* samples, int num_samples)
{
int sqrt_samples = (int) (sqrt(num_samples));
for(int i=0; i <sqrt_samples; i++)
for(int j=0; j<sqrt_samples; j++)
{
float x = ((double) i + ((double) rand() / (RAND_MAX))) / (double) sqrt_samples;
float y = ((double) j + ((double) rand() / (RAND_MAX))) / (double) sqrt_samples;
(samples[i*sqrt_samples + j]).setX(x);
(samples[i*sqrt_samples + j]).setY(y);
}
}
void nrooks(Vector2D * samples, int num_samples )
{
for( int i=0; i< num_samples; i++)
{
samples[i].setX(((double) i + ((double) rand() / (RAND_MAX)) ) / (double) num_samples);
samples[i].setY(((double) i + ((double) rand() / (RAND_MAX)) ) / (double) num_samples);
}
for (int i = num_samples - 2; i >= 0; i--)
{
int target = int(((double) rand() / (RAND_MAX)) *(double)i);
float temp = samples[i+1].getX();
samples[i+1].setX(samples[target].getX());
samples[target].setX(temp);
}
}
void multiJitter(Vector2D* samples, int num_samples)
{
int sqrt_samples = (int) sqrt(num_samples);
float subcell_width = 1.0f/(float(num_samples));
for (int i = 0; i <sqrt_samples; i++)
for (int j=0; j<sqrt_samples; j++)
{
samples[i*sqrt_samples + j].setX(i*sqrt_samples*subcell_width + j*subcell_width +
((double) rand() / (RAND_MAX)) *subcell_width);
samples[i*sqrt_samples + j].setY(j*sqrt_samples*subcell_width + i*subcell_width +
((double) rand() / (RAND_MAX)) *subcell_width);
}
// shuffle x coordinates withing each column and y coordinates within each row
for (int i=0; i <sqrt_samples; i++)
for (int j=0; j<sqrt_samples; j++)
{
int k = j + int (((double) rand() / (RAND_MAX)) * (sqrt_samples - j -1));
float t = samples[i*sqrt_samples + j].getX();
samples[i*sqrt_samples + j].setX(samples[i*sqrt_samples + k].getX());
samples[i* sqrt_samples + k].setX(t);
}
}
void shuffle(Vector2D* samples, int num_samples)
{
for (int i=num_samples -2; i >= 0; i--)
{
int target = int(((double) rand() / (RAND_MAX)) * (double) i);
Vector2D temp = samples[i+1];
samples[i+1] = samples[target];
samples[target] = temp;
}
}
void boxFilter(Vector2D* samples, int num_samples)
{
for(int i=0; i < num_samples; i++) {
samples[i].setX(samples[i].getX() - 0.5f);
samples[i].setY(samples[i].getY() - 0.5f);
}
}
void tentFilter(Vector2D* samples, int num_samples)
{
for (int i=0; i < num_samples; i++)
{
float x = samples[i].getX();
float y = samples[i].getY();
if (x < 0.5f)
samples[i].setX((float) sqrt(2.0*(double) x) -1.0f);
else
samples[i].setX(1.0f - (float)sqrt(2.0 -2.0 * (double) x));
if (y < 0.5f)
samples[i].setY((float) sqrt(2.0*(double) y) -1.0f);
else
samples[i].setY(1.0f - (float)sqrt(2.0 -2.0 * (double) y));
}
}
void cubicSplineFilter(Vector2D * samples, int num_samples)
{
for (int i = 0; i < num_samples; i++)
{
float x = samples[i].getX();
float y = samples[i].getY();
samples[i].setX(cubicFilter(x));
samples[i].setY(cubicFilter(y));
}
}
void random(float * samples, int num_samples)
{
for(int i = 0; i <num_samples; i++)
samples[i] = ((double) rand() / (RAND_MAX));
}
void jitter(float * samples, int num_samples)
{
for (int i = 0; i <num_samples; i++)
samples[i] = ((double) i + ((double) rand() / (RAND_MAX))) / (double) num_samples;
}
void shuffle(float * samples, int num_samples)
{
for (int i = num_samples -2; i >= 0; i--)
{
int target = int (((double) rand() / (RAND_MAX)) * (double) i);
float temp = samples[i+1];
samples[i+1] = samples[target];
samples[target] = temp;
}
}