1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <time.h>

4 #include "db.h"

5

6

7 enum {

8 Nlast = 2,

9 };

10

11 enum { Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec };

12

13 struct weather {

14 float temp;

15 float sun;

16 float rain;

17 float wind;

18 float hum;

19 };

20

21 float mean_temp[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

22 float mean_sun[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

23 float mean_rain[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

24 float mean_wind[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

25 float mean_hum[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

26

27

28 /* generates random number between -limit and +limit */

29 float rand_limit(float limit) {

30 int r;

31

32 r = rand() / ( ((float) RAND_MAX + 1) / (2*limit) );

33 return r - limit;

34 }

35

36

37

38

39 void getlastweather(struct weather lastw[], int nlast) {

40 char query[512];

41 int i;

42

43 sprintf(query,

44 " select temp, sun, rain, wind, hum from weather "

45 " order by tick desc "

46 " limit %d "

47 , nlast

48 );

49 stmt = db_query(query);

50 for (i = 0; i < nlast && sqlite3_step(stmt) == SQLITE_ROW; i++) {

51 lastw[i].temp = sqlite3_column_double(stmt, 0);

52 lastw[i].sun = sqlite3_column_double(stmt, 1);

53 lastw[i].rain = sqlite3_column_double(stmt, 2);

54 lastw[i].wind = sqlite3_column_double(stmt, 3);

55 lastw[i].hum = sqlite3_column_double(stmt, 4);

56 }

57 sqlite3_finalize(stmt);

58 }

59

60

61 void genweather(struct weather* w, struct weather lastw[], int nlast, int month) {

62 w->temp = 0.2 * mean_temp[month] + 0.4 * lastw[0].temp + 0.2 * lastw[1].temp + 0.08 * rand_limit(10); // + 0.02 * rand_limit(100);

63 w->sun = 0.2 * mean_sun[month] + 0.4 * lastw[0].sun + 0.2 * lastw[1].sun + 0.08 * rand_limit(10); // + 0.02 * rand_limit(100);

64 w->rain = 0.2 * mean_rain[month] + 0.4 * lastw[0].rain + 0.2 * lastw[1].rain + 0.08 * rand_limit(10); // + 0.02 * rand_limit(100);

65 w->wind = 0.2 * mean_wind[month] + 0.4 * lastw[0].wind + 0.2 * lastw[1].wind + 0.08 * rand_limit(10); // + 0.02 * rand_limit(100);

66 w->hum = 0.2 * mean_hum[month] + 0.4 * lastw[0].hum + 0.2 * lastw[1].hum + 0.08 * rand_limit(10); // + 0.02 * rand_limit(100);

67 }

68

69

70 int setweather(struct weather* w) {

71 char query[512];

72 sprintf(query,

73 " insert into weather "

74 " (tick, temp, sun, rain, wind, hum) "

75 " values ('%d', '%f', '%f', '%f', '%f', '%f') "

76 , gametime, w->temp, w->sun, w->rain, w->wind, w->hum

77 );

78 if (!db_update(query)) {

79 db_error("weather insertion");

80 return 0;

81 }

82 return 1;

83 }

84

85

86 int weather(void) {

87 struct weather w;

88 struct weather lastn[Nlast];

89

90 getlastweather(lastn, Nlast);

91 genweather(&w, lastn, Nlast, May);

92 return setweather(&w);

93 /* FIXME: include all functions in return value */

94 }