added games/mole

sys/src/games/mkfile

@@ -8,6 +8,7 @@ TARG=4s\
 	juggle\
 	life\
 	memo\
+	mole\
 
 OFILES=
 HFILES=

sys/src/games/mole.c

@@ -0,0 +1,190 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <event.h>
+
+int N = 20, refresh = 0;
+
+double dt = 0.01,
+	xmin = -40,
+	xmax = 40,
+	ymin = -40,
+	ymax = 40,
+	v0 = 0.1;
+	
+#define mini(a,b) (((a)<(b))?(a):(b))
+
+typedef struct Particle Particle;
+struct Particle {
+	double x, y;
+	double vx, vy;
+	double ax, ay;
+	double prevx, prevy;
+	Image* col;
+};
+
+int colors[] = {
+              DBlack,
+              DRed,
+              DGreen,
+              DBlue,
+              DCyan,
+              DMagenta,
+              DDarkyellow,
+              DDarkgreen,
+              DPalegreen,
+              DMedgreen,
+              DDarkblue,
+              DPalebluegreen,
+              DPaleblue,
+              DBluegreen,
+              DGreygreen,
+              DPalegreygreen,
+              DYellowgreen,
+              DMedblue,
+              DGreyblue,
+              DPalegreyblue,
+              DPurpleblue
+};
+
+Particle *A, *B;
+Particle *prev, *cur;
+
+void
+reset(void)
+{
+	int j, grid = sqrt(N)+0.5;
+	Particle *p;
+	draw(screen, screen->r, display->white, 0, ZP);
+	for(j=0;j<N;j++) {
+		p = prev+j;
+		p->x = 2*(j%grid)+frand()/2;
+		p->y = 2*(j/grid)+frand()/2;
+		p->vx = 1.*v0*frand();
+		p->vy = 1.*v0*frand();
+		p->prevx = p->x - p->vx * dt;
+		p->prevy = p->y - p->vy * dt;
+		p->col = allocimage(display, Rect(0,0,1,1), screen->chan, 1, colors[rand()%(sizeof(colors)/sizeof(int))]);
+		if(!p->col) sysfatal("allocimage");
+	}
+}
+
+void
+usage(void)
+{
+	print("USAGE: mole options\n");
+	print(" -N number of particles [20]\n");
+	print(" -x left boundary [-40]\n");
+	print(" -X right boundary [40]\n");
+	print(" -y top boundary [-40]\n");
+	print(" -Y bottom boundary [40]\n");
+	print(" -t time step [0.01]\n");
+	print(" -v maximum start velocity [0.1]\n");
+	print(" -F clear every <n> frames (0:off) [0]\n");	
+	exits("usage");
+}
+
+void
+main(int argc, char** argv)
+{
+	int i, j;
+	Particle *p, *q;
+	double dx, dx1, dx2, dy, dy1, dy2, R, F;
+	char* f;
+	
+	#define FARG(c, v) case c: if(!(f=ARGF())) usage(); v = atof(f); break;
+	ARGBEGIN {
+	case 'N': if(!(f=ARGF())) usage(); N = atoi(f); break;
+	case 'F': if(!(f=ARGF())) usage(); refresh = atoi(f); break;
+	FARG('v', v0);
+	FARG('x', xmin);
+	FARG('X', xmax);
+	FARG('y', ymin);
+	FARG('Y', ymax);
+	FARG('t', dt);
+	default: usage();
+	} ARGEND;
+	
+	A = calloc(sizeof(Particle), N);
+	B = calloc(sizeof(Particle), N);
+	prev = A;
+	cur = B;
+	srand(time(0));
+	initdraw(0, 0, "Molecular Dynamics");
+	einit(Emouse | Ekeyboard);
+	reset();
+
+	i=0;
+	while(1) {
+		if(refresh && ((++i)%refresh)==0) draw(screen, screen->r, display->white, 0, ZP);
+		memset(cur, 0, sizeof(Particle) * N);
+		for(p=prev;p<prev+N;p++) {
+			for(q=prev;q<p;q++) {
+				dx1 = fabs(p->x - q->x);
+				dx2 = xmax - xmin - dx1;
+				dx = mini(dx1, dx2);
+				dy1 = fabs(p->y - q->y);
+				dy2 = ymax - ymin - dy1;
+				dy = mini(dy1, dy2);
+				R = dx*dx + dy*dy;
+				if(R >= 9) continue;
+				R = 1/sqrt(R);
+				double R2, R4, R6, R12;
+				R2 = R * R;
+				R4 = R2 * R2;
+				R6 = R4 * R2;
+				R12 = R6 * R6;
+				F = 24*(2*R12 - R6);
+				if(p->x < q->x) dx = -dx;
+				if(p->y < q->y) dy = -dy;
+				if(dx1 > dx2) dx = -dx;
+				if(dy1 > dy2) dy = -dy;
+				dx *= F;
+				dy *= F;
+				(p-prev+cur)->ax += dx;
+				(p-prev+cur)->ay += dy;
+				(q-prev+cur)->ax -= dx;
+				(q-prev+cur)->ay -= dy;
+			}
+		}
+		for(j=0;j<N;j++) {
+			int x, y;
+			p = prev+j;
+			q = cur+j;
+			q->x = 2*p->x - p->prevx + q->ax * dt*dt;
+			q->y = 2*p->y - p->prevy + q->ay * dt*dt;
+			q->vx = (q->x - p->prevx) / (2*dt);
+			q->vy = (q->y - p->prevy) / (2*dt);
+			q->prevx = p->x;
+			q->prevy = p->y;
+			if(q->x > xmax) {q->x -= xmax - xmin; q->prevx -= xmax - xmin;}
+			if(q->x < xmin) {q->x += xmax - xmin; q->prevx += xmax - xmin;}
+			if(q->y > ymax) {q->y -= ymax - ymin; q->prevy -= ymax - ymin;}
+			if(q->y < ymin) {q->y += ymax - ymin; q->prevy += ymax - ymin;}
+			q->col = p->col;
+			x = (screen->r.max.x - screen->r.min.x) * (q->x - xmin) / (xmax - xmin) + screen->r.min.x;
+			y = (screen->r.max.y - screen->r.min.y) * (q->y - ymin) / (ymax - ymin) + screen->r.min.y;
+			draw(screen, Rect(x, y, x+1, y+1), p->col, 0, ZP);
+		}
+
+		Particle* tmp = prev;
+		prev = cur;
+		cur = tmp;
+		flushimage(display, 1);
+		
+		
+		if(ecankbd()) {
+			switch(ekbd()) {
+				case 'q': exits(0); break;
+				case 'r': reset(); break;
+				case 'f': draw(screen, screen->r, display->white, 0, ZP); break;
+			}
+		}
+	}
+}
+
+void
+eresized(int new)
+{
+	if(new) getwindow(display, Refnone);
+}