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| #include "../3rdParty/svpng/svpng.inc"
#include "../Chapter5/Sphere.h"
#include "../Chapter5/CollisibleList.h"
#include "Camera.h"
#include <cstdio>
#include <limits>
#include <random>
#include <functional>
const int WIDTH = 640;
const int HEIGHT = 480;
using byte = unsigned char;
void paint(byte *d, int x, int y, Color3f color, float alpha) {
d += 4 * ((HEIGHT - y - 1) * WIDTH + x);
d[0] = 255 * color.r;
d[1] = 255 * color.g;
d[2] = 255 * color.b;
d[3] = 255 * alpha;
}
Color3f mix(const Color3f &a, const Color3f &b, float t) { return a * (1.0f - t) + b * t; }
Color3f paint(const Ray &r, const Collisible &obj) {
CollideRecord rec;
if (obj.collide(r, 0.0f, std::numeric_limits<float>::max(), rec))
return 0.5f * (rec.normal + Vector3f(1.0f, 1.0f, 1.0f));
Vector3f dir = r.getDir();
float t = 0.5f * (dir.y + 1.0f);
return mix({1.0f, 1.0f, 1.0f}, {0.5f, 0.7f, 1.0f}, t);
}
int main() {
byte d[4 * WIDTH * HEIGHT];
FILE *f = fopen("ch6.png", "wb");
Camera camera({0.0f, 0.0f, 0.0f}, {-2.0f, -1.5f, -1.0f}, {4.0f, 0.0f, 0.0f},
{0.0f, 3.0f, 0.0f});
std::uniform_real_distribution<float> dis;
std::mt19937 engine;
auto gen = std::bind(dis, engine);
CollisibleList list;
Collisible *obj[2];
obj[0] = new Sphere({0, 0, -1}, 0.5);
obj[1] = new Sphere({0, -100.5, -1}, 100);
list.add(obj[0]);
list.add(obj[1]);
const int SAMPLE_TIMES = 100;
for (int x = 0; x < WIDTH; x++) {
for (int y = 0; y < HEIGHT; y++) {
Color3f col;
for (int i = 0; i < SAMPLE_TIMES; i++) {
float u = (float)(x + gen()) / WIDTH;
float v = (float)(y + gen()) / HEIGHT;
col += paint(camera.getRay(u, v), list);
}
col /= SAMPLE_TIMES;
paint(d, x, y, col, 1.0f);
}
}
delete obj[0];
delete obj[1];
svpng(f, WIDTH, HEIGHT, d, 1);
fclose(f);
}
|
