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65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
5 months ago
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#ifndef VIEW_H
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#define VIEW_H
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#include "random.h"
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#include "vec3.h"
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#include <cmath>
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struct View
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{
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static constexpr auto lookat = point3(0, 0, -1); // Point camera is looking at
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static constexpr auto vup = vec3(0, 1, 0); // Camera-relative "up" direction
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float fieldOfView = 90.f;
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float focalLength;
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float viewportHeight;
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float viewportWidth;
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point3 camera;
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vec3 viewportX;
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vec3 viewportY;
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vec3 pixelDX;
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vec3 pixelDY;
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vec3 viewportUL;
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vec3 pixelUL;
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View() {
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recalculate();
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}
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void recalculate() {
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focalLength = (camera - lookat).length();
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viewportHeight = 2 * std::tan(fieldOfView * 3.14159265 / 180.0 / 2.0) * focalLength;
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viewportWidth = viewportHeight * Aspect;
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const auto w = (camera - lookat).normalize();
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const auto u = cross(vup, w).normalize();
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const auto v = cross(w, u);
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viewportX = viewportWidth * u;
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viewportY = -viewportHeight * v;
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pixelDX = viewportX / Width;
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pixelDY = viewportY / Height;
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viewportUL = camera - focalLength * w - viewportX / 2 - viewportY / 2;
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pixelUL = viewportUL + 0.5 * (pixelDX + pixelDY);
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}
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ray getRay(int x, int y, bool addRandom = false) const {
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double X = x;
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double Y = y;
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if (addRandom) {
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X += randomN() - 0.5;
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Y += randomN() - 0.5;
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}
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auto pixel = pixelUL + X * pixelDX + Y * pixelDY;
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return ray(camera, pixel - camera);
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}
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};
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#endif // VIEW_H
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