Tweaked the stream classes, added an example, and the begining of a formula

parser.

1 files changed, 127 insertions, 0 deletions

diff --git a/parex/egg.h b/parex/egg.h
new file mode 100644
index 0000000..6830edd
--- /dev/null
+++ b/parex/egg.h
@@ -0,0 +1,127 @@
+/* 
+ *  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__ */
+