snoopy/include/colour.h

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#pragma once
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#include "rtweekend.h"
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// for writing to stdout
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#include <iostream>
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// for writing to socket
#include <unistd.h>
const colour pink(254.0/255.0, 226.0/255.0, 170.0/255.0);
const colour grey(0.133, 0.133, 0.133);
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void correct_gamma(colour& pixel_colour, int samples)
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{
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double r = pixel_colour.x();
double g = pixel_colour.y();
double b = pixel_colour.z();
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// divide the colour total by the number of samples and gamma-correct for gamma=2.0
auto scale = 1.0 / samples;
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r = sqrt(scale * r);
g = sqrt(scale * g);
b = sqrt(scale * b);
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pixel_colour = colour(r, g, b);
}
int format_component(double component)
{
return int(256 * math::clamp(component, 0.0, 0.999));
}
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void write_colour_to_stream(std::ostream &out, colour pixel_colour, int samples_per_pixel)
{
correct_gamma(pixel_colour, samples_per_pixel);
auto r = pixel_colour.x();
auto g = pixel_colour.y();
auto b = pixel_colour.z();
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// write the translated [0,255] value of each colour component.
out << format_component(r) << ' '
<< format_component(g) << ' '
<< format_component(b) << '\n';
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}
void write_colour_to_socket(int sockfd, colour pixel_colour, int samples_per_pixel)
{
correct_gamma(pixel_colour, samples_per_pixel);
int r = format_component(pixel_colour.x());
int g = format_component(pixel_colour.y());
int b = format_component(pixel_colour.z());
// pack values
int len = 3;
char s[len];
sprintf(s, "%c%c%c", r, g, b);
int written = write(sockfd, s, len);
if (written < 0)
{
error("ERROR writing colour to socket");
}
}