initial push

This commit is contained in:
zongor 2022-09-03 23:30:01 -04:00
parent c6f5045702
commit c49b9d37ea
5 changed files with 237 additions and 1 deletions

110
9ray.c Executable file
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#include "vec3.h"
#include "ray.h"
#include <draw.h>
#include <event.h>
void
eresized(int new)
{
if(new&& getwindow(display, Refnone) < 0)
sysfatal("can't reattach to window");
}
double
hit_sphere(vec3 centr, double rad, ray r)
{
vec3 oc = vecsub(r.origin, centr);
double a = length_sq(r.direction);
double h_b = dot(oc, r.direction);
double c = length_sq(oc) - rad*rad;
double dis = h_b*h_b - a*c;
if (dis < 0) {
return -1.0;
} else {
return (-h_b - sqrt(dis) ) / a;
}
}
vec3
ray_color(ray r)
{
double t = hit_sphere(point3(0,0,-1), 0.5, r);
if (t > 0.0) {
vec3 N = unit_vector(vecsub(at(r, t), point3(0,0,-1)));
N.e[0] += 1;
N.e[1] += 1;
N.e[2] += 1;
vec3 col = vecscale(0.5, N);
return col;
}
vec3 u_dir = unit_vector(r.direction);
t = 0.5 * (u_dir.e[1] + 1.0);
vec3 o = vecadd(vecscale((1.0-t), color(1.0, 1.0, 1.0)), vecscale(t, color(0.5, 0.7, 1.0)));
return o;
}
void
main(int argc, char* argv[])
{
USED(argc, argv);
Mouse m;
Image *color;
Point min, max;
int i, j;
unsigned int ir, ig, ib, rgb;
double u, v;
// Camera
vec3 llc = {-2.0, -1.0, -1.0};
vec3 hor = {4.0, 0.0, 0.0};
vec3 ver = {0.0, 2.0, 0.0};
vec3 ori = {0.0, 0.0, 0.0};
vec3 dir = {0.0, 0.0, 0.0};
ray r;
r.origin = ori;
r.direction = dir;
initdraw(0, 0, "Plan9 Raytracer");
eresized(0);
einit(Emouse);
min = screen->r.min;
max = screen->r.max;
for(j = max.y; j >= min.y; --j)
{
for(i = min.x; i < max.x; ++i)
{
u = (double)(i - min.x)/(double)(max.x - min.x);
v = (double)(j - min.y)/(double)(max.y - min.y);
r.origin = ori;
r.direction = vecsub(vecadd(vecadd(llc, vecscale(u,hor)), vecscale(v,ver)), ori);
vec3 rc = ray_color(r);
ir = (unsigned char)255.99*rc.e[0];
ig = (unsigned char)255.99*rc.e[1];
ib = (unsigned char)255.99*rc.e[2];
rgb = ((ir & 0xFF) << 24) + ((ig & 0xFF) << 16) + ((ib & 0xFF) << 8) + (255 & 0xFF);
color = allocimage(display, Rect(0,0,1,1), RGBA32, 1, rgb);
draw(screen, Rect(i, j, i+1, j+1), color, nil, ZP);
freeimage(color);
}
}
flushimage(display, Refnone);
/* Main loop */
for(;;) {
m = emouse();
if(m.buttons & 4)
break;
}
}

3
README.md Normal file → Executable file
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# 9ray This is a raytracer implemented from the book [Ray Tracing In One Weekend](https://raytracing.github.io/books/RayTracingInOneWeekend.html) for the plan9 operating system.
It uses the plan9 dialect of C as well as the plan9 make system

15
mkfile Executable file
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</$objtype/mkfile
TARG=9ray
OFILES=\
9ray.$O\
HFILES=\
vec3.h\
ray.h\
hittable.h\
sphere.h\
BIN=/usr/$user/bin/$objtype
</sys/src/cmd/mkone

19
ray.h Executable file
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#ifndef RAY_H
#define RAY_H
#include "vec3.h"
typedef struct ray ray;
struct ray
{
vec3 origin;
vec3 direction;
};
inline vec3
at(ray r, double t)
{
return vecadd(r.origin, vecscale(t, r.direction));
}
#endif

91
vec3.h Executable file
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#ifndef VEC3_H
#define VEC3_H
#include <u.h>
#include <libc.h>
typedef struct vec3 vec3;
struct vec3
{
double e[3];
};
inline double
length_sq(vec3 v)
{
return v.e[0]*v.e[0] + v.e[1]*v.e[1] + v.e[2]*v.e[2];
}
inline double
length(vec3 v)
{
return sqrt(length_sq(v));
}
inline vec3
vecscale(double t, vec3 v)
{
vec3 o = {t*v.e[0], t*v.e[1], t*v.e[2]};
return o;
}
inline vec3
vecadd(vec3 v1, vec3 v2)
{
vec3 o = {v1.e[0] + v2.e[0], v1.e[1] + v2.e[1], v1.e[2] + v2.e[2]};
return o;
}
inline vec3
vecsub(vec3 v1, vec3 v2)
{
vec3 o = {v1.e[0] - v2.e[0], v1.e[1] - v2.e[1], v1.e[2] - v2.e[2]};
return o;
}
inline vec3
vecmul(vec3 v1, vec3 v2)
{
vec3 o = {v1.e[0] * v2.e[0], v1.e[1] * v2.e[1], v1.e[2] * v2.e[2]};
return o;
}
inline double
dot(vec3 u, vec3 v)
{
return u.e[0] * v.e[0] + u.e[1] * v.e[1] + u.e[2] * v.e[2];
}
inline vec3
cross(vec3 u, vec3 v)
{
vec3 o = {(u.e[1] * v.e[2] - u.e[2] * v.e[1]),
(u.e[2] * v.e[0] - u.e[0] * v.e[2]),
(u.e[0] * v.e[1] - u.e[1] * v.e[0])};
return o;
}
inline vec3
unit_vector(vec3 v)
{
double len = length(v);
return vecscale((1/len), v);
}
inline vec3
color(double r, double g, double b)
{
vec3 o = {r, g, b};
return o;
}
inline vec3
point3(double x, double y, double z)
{
vec3 o = color(x, y, z);
return o;
}
#endif