1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/*
* EGG.H - part of the EGG system.
*
* Global definitions and function prototypes.
*
* By Shawn Hargreaves.
*/
#ifndef __EGG_H__
#define __EGG_H__
#ifndef TRUE
#define TRUE -1
#define FALSE 0
#endif
#ifndef MIN
#define MIN(x,y) (((x) < (y)) ? (x) : (y))
#define MAX(x,y) (((x) > (y)) ? (x) : (y))
#define MID(x,y,z) MAX((x), MIN((y), (z)))
#endif
#ifndef ABS
#define ABS(x) (((x) >= 0) ? (x) : (-(x)))
#endif
#ifndef ALLEGRO_H
struct BITMAP;
#endif
/* possible particle commands (ie. language keywords) */
#define EGG_COMMAND_INIT 1
#define EGG_COMMAND_SET 2
#define EGG_COMMAND_IF 3
#define EGG_COMMAND_LAY 4
#define EGG_COMMAND_DIE 5
/* each particle is controlled by a command list */
typedef struct EGG_COMMAND
{
int type; /* command type */
int line; /* source line number */
char *var; /* variable to be set */
char *exp; /* arithmetic expression */
struct EGG_COMMAND *cmd; /* nested, child command list (if) */
struct EGG_COMMAND *cmd2; /* more child commands (else) */
struct EGG_COMMAND *next; /* linked list pointer */
} EGG_COMMAND;
/* each type of particle is defined by one of these structures */
typedef struct EGG_TYPE
{
char *name; /* type name */
EGG_COMMAND *cmd; /* command list */
struct EGG_TYPE *next; /* linked list pointer */
} EGG_TYPE;
/* particles store their state variables in these structures */
typedef struct EGG_VARIABLE
{
char *name; /* variable name */
double val; /* current value */
struct EGG_VARIABLE *next; /* linked list pointer */
} EGG_VARIABLE;
/* a specific particle instance */
typedef struct EGG_PARTICLE
{
int num; /* unique ID number */
EGG_TYPE *type; /* type information */
EGG_VARIABLE *var; /* list of variables */
struct EGG_PARTICLE *next; /* linked list pointer */
} EGG_PARTICLE;
/* everything you need to know about an EGG particle system */
typedef struct EGG
{
int frame; /* animation frame number */
int part_count; /* number of active particles */
int part_num; /* particle ID counter */
EGG_PARTICLE *part; /* list of particle instances */
EGG_TYPE *type; /* list of particle types */
EGG_VARIABLE *var; /* list of global variables */
} EGG;
/* script loading functions */
EGG *load_egg(char *filename, char *error);
EGG *use_egg(void *data, int length, char *error);
/* script unloading function */
void destroy_egg(EGG *egg);
/* script interpreter */
int update_egg(EGG *egg, char *error);
/* renders the current animation state into an Allegro bitmap */
void lay_egg(EGG *egg, struct BITMAP *bmp);
/* internal utility functions */
double evaluate(char *equation, int *error, double (*variable)(char *name));
int process_egg_cmd(EGG *egg, EGG_PARTICLE *part, EGG_PARTICLE *other, EGG_COMMAND *cmd, int init, int set, char *error);
void destroy_egg_cmd(EGG_COMMAND *cmd);
double get_egg_variable(EGG_PARTICLE *part, EGG_PARTICLE *other, EGG *egg, char *name);
void set_egg_variable(EGG_PARTICLE *part, EGG_PARTICLE *other, EGG *egg, char *name, double value);
#endif /* __EGG_H__ */
|
