10

	int8 delta_x; // 0x80 is sequence terminator

    23

// Iterate through all DrawTileSeqStructs in DrawTileSprites.

    29

    30

struct SpriteGroup;

    31

    32

struct RealSpriteGroup {

    50

/* Shared by deterministic and random groups. */

    51

enum VarSpriteGroupScope {

    52

	VSG_SCOPE_SELF,

    53

	// Engine of consists for vehicles, city for stations.

    54

	VSG_SCOPE_PARENT,

    55

};

    56

    57

struct DeterministicSpriteGroupRanges;

    58

    59

struct DeterministicSpriteGroup {

    60

	// Take this variable:

    61

	enum VarSpriteGroupScope var_scope;

    62

	byte variable;

    63

    64

	// Do this with it:

    65

	byte shift_num;

    66

	byte and_mask;

    67

    68

	// Then do this with it:

    69

	enum DeterministicSpriteGroupOperation {

    70

		DSG_OP_NONE,

    71

		DSG_OP_DIV,

    72

		DSG_OP_MOD,

    73

	} operation;

    74

	byte add_val;

    75

	byte divmod_val;

    76

    77

	// And apply it to this:

    78

	byte num_ranges;

    79

	struct DeterministicSpriteGroupRanges *ranges; // Dynamically allocated

    80

    81

	// Dynamically allocated, this is the sole owner

    82

	struct SpriteGroup *default_group;

    83

};

    84

    85

struct SpriteGroup {

    86

	enum SpriteGroupType {

    87

		SGT_REAL,

    88

		SGT_DETERMINISTIC,

    89

		SGT_RANDOM, /* TODO */

    90

	} type;

    91

    92

	union {

    93

		struct RealSpriteGroup real;

    94

		struct DeterministicSpriteGroup determ;

    95

	} g;

    96

};

    97

    98

struct DeterministicSpriteGroupRanges {

    99

	struct SpriteGroup group;

   100

	byte range_low;

   101

	byte range_high;

   102

};

   103

   104

/* This is a temporary helper for SpriteGroup users not supporting variational

   105

 * sprite groups yet - it just traverses those cowardly, always taking the

   106

 * default choice until it hits a real sprite group, returning it. */

   107

static struct RealSpriteGroup *TriviallyGetRSG(struct SpriteGroup *sg);

   108

   109

   110

   111

/**** Inline functions ****/

   112

   113

static INLINE struct RealSpriteGroup *TriviallyGetRSG(struct SpriteGroup *sg)

   114

{

   115

	if (sg->type == SGT_REAL)

   116

		return &sg->g.real;

   117

	return TriviallyGetRSG(sg->g.determ.default_group);

   118

}

   119