diff options
| -rw-r--r-- | README | 2 | ||||
| -rw-r--r-- | xd.c | 159 |
2 files changed, 159 insertions, 2 deletions
@@ -1,6 +1,6 @@ BUILDING -------- -To build just run 'make'. To run, just type 'xd'. +To build just run 'make'. To run, just type './xd'. DESCRIPTION @@ -169,10 +169,11 @@ static void TriangleDemo(void); static void TriangleDemo2(void); static void FollowDemo(void); static void CatwalkDemo(void); +static void GravityDemo(void); /* ---------------------------------------- GLOBAL VARS */ -#define NO_DEMOS 17 +#define NO_DEMOS 18 static int demo=NO_DEMOS-1; @@ -265,6 +266,11 @@ static DemoInfo demotbl[NO_DEMOS]= CatwalkDemo, UsesPixmap }, + { + "Gravity Demo (LMB to reset, RMB to move central mass)", + GravityDemo, + UsesPixmap + }, }; /* ---------------------------------------- X11 VARS @@ -3895,4 +3901,155 @@ static void CatwalkDemo(void) #undef TRENCH_Z_MIN +/* ---------------------------------------- GRAVITY DEMO + */ + +#define GRAV_OBJ 20 +#define GRAV_TRAIL 200 +#define GRAV_SIZE 4 + +static void GravityDemo(void) +{ + static int init = FALSE; + + typedef struct + { + double x,y,dx,dy; + int col; + int mass; + double tx[GRAV_TRAIL]; + double ty[GRAV_TRAIL]; + } GravObj; + + static GravObj gravobj[GRAV_OBJ]; + + int f,r; + + if (!init || mouse_b&Button1Mask) + { + for(f = 0; f < GRAV_OBJ; f++) + { + if (f == 0) + { + gravobj[f].x = centre_x; + gravobj[f].y = centre_y; + gravobj[f].dx = 0; + gravobj[f].dy = 0; + gravobj[f].mass = 80; + } + else + { + int a; + int d; + + a = RND(3600); + d = RND2(400,200); + + gravobj[f].x = centre_x + sintab[a] * d; + gravobj[f].y = centre_y + costab[a] * d; + + a = (a + 900) % 3600; + + gravobj[f].dx = sintab[a] * 10; + gravobj[f].dy = costab[a] * 10; + + /* + gravobj[f].x = RND(width); + gravobj[f].y = RND(height); + gravobj[f].dx = (double)RND(10)/10.0; + gravobj[f].dy = (double)RND(10)/10.0; + */ + + gravobj[f].mass = RND2(10, 2); + } + + gravobj[f].col = GetCol(RND2(255,128), + RND2(255,100), + RND2(255,100)); + + for(r = 0; r < GRAV_TRAIL; r++) + { + gravobj[f].tx[r] = gravobj[f].x; + gravobj[f].ty[r] = gravobj[f].y; + } + } + + init=TRUE; + } + + Cls(); + + if (mouse_b & Button3Mask) + { + gravobj[0].x = mouse_x; + gravobj[0].y = mouse_y; + } + + for(f = 1; f < GRAV_OBJ; f++) + { + for(r = 0; r < GRAV_OBJ; r++) + { + if (f != r) + { + double d; + double g; + double dx; + double dy; + + dx = gravobj[f].x - gravobj[r].x; + dy = gravobj[f].y - gravobj[r].y; + + d = sqrt(dx*dx + dy*dy); + + g = 1.0 / d*d; + + g /= 100.0; + g /= gravobj[f].mass; + + dx /= d; + dy /= d; + + dx *= g; + dy *= g; + + gravobj[f].dx -= dx; + gravobj[f].dy -= dy; + } + } + } + + for(f = 0; f < GRAV_OBJ; f++) + { + gravobj[f].x += gravobj[f].dx / 50.0; + gravobj[f].y += gravobj[f].dy / 50.0; + + for(r = GRAV_TRAIL - 1; r > 0; r--) + { + gravobj[f].tx[r] = gravobj[f].tx[r-1]; + gravobj[f].ty[r] = gravobj[f].ty[r-1]; + } + + gravobj[f].tx[0] = gravobj[f].x; + gravobj[f].ty[0] = gravobj[f].y; + + for(r = 0; r < GRAV_TRAIL - 1; r++) + { + Line(gravobj[f].tx[r], gravobj[f].ty[r], + gravobj[f].tx[r+1], gravobj[f].ty[r+1], + gravobj[f].col); + } + } + + for(f = 0; f < GRAV_OBJ; f++) + { + FCircle(gravobj[f].x, gravobj[f].y, + gravobj[f].mass/GRAV_SIZE, gravobj[f].col); + } +} + +#undef GRAV_OBJ +#undef GRAV_TRAIL +#undef GRAV_SIZE + + /* END OF FILE */ |