#include <u.h>#include <libc.h>#include <draw.h>#include <memdraw.h>#include <geometry.h> #include "scene.h" Obj *scene0(void){	Obj *objs, *o; 	objs = newplane((Point3){0, -1, 0, 0}, (Point3){0, 1, 0, 0});	o = newsphere((Point3){0, -0.5, -1, 0}, 0.5);	objs->next = o;	o->next = newsphere((Point3){1.5, 0, -2, 0}, 0.5);	o = o->next;	o->next = newsphere((Point3){-2, 2, -3, 0}, 1);	o = o->next;	o->next = newlight((Point3){3, 3, 0, 0}, 1, (Point3){-3, -3, -1, 0}, (Colour){0.40, 0.6, 0.6});	o = o->next;	o->next = newlight((Point3){-2, 4, 2, 0}, 1, (Point3){1, -3, -1, 0}, (Colour){0.4, 0.3, 0.40});	o = o->next;	o->next = newlight((Point3){-4, 6, -10, 0}, 1, (Point3){2, -4, 1, 0}, (Colour){0.5, 0.7, 0.4}); 	return objs;} Obj *scene1(void){	Obj *objs, *o; 	objs = newplane((Point3){0, -1, 0, 0}, (Point3){0, 1, 0, 0});	o = newplane((Point3){-5, 0, 0, 0}, (Point3){1, 0, 0, 0});	objs->next = o;	o->next = newsphere((Point3){-3, 3, -5, 0}, 0.75);	o = o->next;	o->next = newlight((Point3){-2, 10, -5, 0}, 1, (Point3){0.5, -2, 1, 0}, (Colour){0.6, 0.8, 0.8});	o = o->next;	o->next = newlight((Point3){2, 10, 5, 0}, 1, (Point3){-0.5, -1, -1, 0}, (Colour){0.8, 0.8, 0.6});	o = o->next;	o->next = newsphere((Point3){1, 0.5, -6, 0}, 4); 	return objs;} Obj *scene2(void){	Obj *objs, *o;	int i; 	objs = newplane((Point3){0, -1, -2, 0}, (Point3){0, 1, 0, 0});	objs->next = newlight((Point3){3, 3, 3, 0}, 1, (Point3){-3, -3, -3, 0}, (Colour){0.8, 0.7, 0.8});	o = objs->next;	o->next = newlight((Point3){-3, 3, 3, 0}, 1, (Point3){3, -3, -3, 0}, (Colour){0.9, 0.9, 0.7});	o = o->next;	for(i = 0; i < 10; ++i){		o->next = newsphere((Point3){i-3, 1, -5+((double)i/2.0), 0}, 0.5);		o = o->next;	} 	return objs;} Scene *newscene(int scnid, int w, int h){	Scene *scene;	Obj *o; 	scene = malloc(sizeof(Scene));	if(scene == nil)		exits("malloc"); 	scene->img = allocmemimage(Rect(0, 0, w, h), RGB24);	if(scene->img == nil)		exits("malloc"); 	if(scnid == 1)		scene->objs = scene1();	else if(scnid == 2)		scene->objs = scene2();	else		scene->objs = scene0(); 	scene->e = (Point3){0, 0, 1, 0};	scene->u = (Point3){1, 0, 0, 0};	scene->v = (Point3){0, -1, 0, 0};	scene->w = (Point3){0, 0, 1, 0};	scene->d = 1.0;	scene->l = -1;	scene->r = 1;	scene->t = 1;	scene->b = -1;	scene->s = (Point){w, h}; 	return scene;} Point3eyeray(Scene *scene, int x, int y){	double u, v;	Point3 ray; 	u = scene->l + (scene->r - scene->l) * ((double)x + 0.5) / (double)scene->s.x;	v = scene->b + (scene->t - scene->b) * ((double)y + 0.5) / (double)scene->s.y; 	if(nsamples > 1){		u += (0.5 - frand()) / 100.0;		v += (0.5 - frand()) / 100.0;	} 	ray = mul3(scene->w, -scene->d);	ray = add3(ray, mul3(scene->u, u));	ray = add3(ray, mul3(scene->v, v)); 	return ray;} doubleclamp(double x){	if(x > 1) return 1;	if(x < 0) return 0;	return x;} Memimage *render(Scene *scene, int id){	Colour c;	int i, j, s;	uchar *px; 	for(j = 0; j < scene->s.y; ++j){		if((j % nproc) != id)			continue;		for(i = 0; i < scene->s.x; ++i){			c = trace(0, scene->objs, scene->e, eyeray(scene, i, j));			for(s = 1; s < nsamples; ++s){				c = csum(c, trace(0, scene->objs, scene->e, eyeray(scene, i, j)));			}			c = cscale(c, 1.0/(double)nsamples);			px = byteaddr(scene->img, (Point){i, j});			px[0] = clamp(c.b) * 255;			px[1] = clamp(c.g) * 255;			px[2] = clamp(c.r) * 255;		}	} 	return scene->img;}