summaryrefslogtreecommitdiff
path: root/src/newgrf_commons.cpp
blob: f52c1442ae5cf70bf20324259ceb4320bb4cc6fc (plain)
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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/* $Id$ */

/** @file newgrf_commons.cpp Implementation of the class OverrideManagerBase
 * and its descendance, present and futur
 */

#include "stdafx.h"
#include "openttd.h"
#include "town.h"
#include "industry.h"
#include "newgrf.h"
#include "newgrf_commons.h"

/** Constructor of generic class
 * @param offset end of original data for this entity. i.e: houses = 110
 * @param maximum of entities this manager can deal with. i.e: houses = 512
 * @param invalid is the ID used to identify an invalid entity id
 */
OverrideManagerBase::OverrideManagerBase(uint16 offset, uint16 maximum, uint16 invalid)
{
	max_offset = offset;
	max_new_entities = maximum;
	invalid_ID = invalid;

	mapping_ID = CallocT<EntityIDMapping>(max_new_entities);
	entity_overrides = MallocT<uint16>(max_offset);
	memset(entity_overrides, invalid, sizeof(entity_overrides));
}

/** Destructor of the generic class.
 * Frees allocated memory of constructor
 */
OverrideManagerBase::~OverrideManagerBase()
{
	free(mapping_ID);
	free(entity_overrides);
}

/** Since the entity IDs defined by the GRF file does not necessarily correlate
 * to those used by the game, the IDs used for overriding old entities must be
 * translated when the entity spec is set.
 * @param local_id id in grf file
 * @param entity_type original entity type
 */
void OverrideManagerBase::Add(uint8 local_id, uint entity_type)
{
	assert(entity_type < max_offset);
	entity_overrides[entity_type] = local_id;
}

/** Resets the mapping, which is used while initializing game */
void OverrideManagerBase::ResetMapping()
{
	memset(mapping_ID, 0, (max_new_entities - 1) * sizeof(EntityIDMapping));
}

/** Resets the override, which is used while initializing game */
void OverrideManagerBase::ResetOverride()
{
	for (uint16 i = 0; i < max_offset; i++) {
		entity_overrides[i] = invalid_ID;
	}
}

/** Return the ID (if ever available) of a previously inserted entity.
 * @param grf_local_id ID of this enity withing the grfID
 * @param grfid ID of the grf file
 * @return the ID of the candidate, of the Invalid flag item ID
 */
uint16 OverrideManagerBase::GetID(uint8 grf_local_id, uint32 grfid)
{
	const EntityIDMapping *map;

	for (uint16 id = max_offset; id < max_new_entities; id++) {
		map = &mapping_ID[id];
		if (map->entity_id == grf_local_id && map->grfid == grfid) {
			return id;
		}
	}
	return invalid_ID;
}

/** Reserves a place in the mapping array for an entity to be installed
 * @param grf_local_id is an arbitrary id given by the grf's author.  Also known as setid
 * @param grfid is the id of the grf file itself
 * @param substitute_id is the original entity from which data is copied for the new one
 * @return the proper usable slot id, or invalid marker if none is found
 */
uint16 OverrideManagerBase::AddEntityID(byte grf_local_id, uint32 grfid, byte substitute_id)
{
	uint16 id = this->GetID(grf_local_id, grfid);
	EntityIDMapping *map;

	/* Look to see if this entity has already been added. This is done
	 * separately from the loop below in case a GRF has been deleted, and there
	 * are any gaps in the array.
	 */
	if (id != invalid_ID) {
		return id;
	}

	/* This entity hasn't been defined before, so give it an ID now. */
	for (id = max_offset; id < max_new_entities; id++) {
		map = &mapping_ID[id];

		if (map->entity_id == 0 && map->grfid == 0) {
			map->entity_id     = grf_local_id;
			map->grfid         = grfid;
			map->substitute_id = substitute_id;
			return id;
		}
	}

	return invalid_ID;
}

/** Gives the substitute of the entity, as specified by the grf file
 * @param entity_id of the entity being queried
 * @return mapped id
 */
uint16 OverrideManagerBase::GetSubstituteID(byte entity_id)
{
	return mapping_ID[entity_id].substitute_id;
}

/** Install the specs into the HouseSpecs array
 * It will find itself the proper slot onwhich it will go
 * @param hs HouseSpec read from the grf file, ready for inclusion
 */
void HouseOverrideManager::SetEntitySpec(const HouseSpec *hs)
{
	HouseID house_id = this->AddEntityID(hs->local_id, hs->grffile->grfid, hs->substitute_id);

	if (house_id == invalid_ID) {
		grfmsg(1, "House.SetEntitySpec: Too many houses allocated. Ignoring.");
		return;
	}

	memcpy(&_house_specs[house_id], hs, sizeof(*hs));

	/* Now add the overrides. */
	for (int i = 0; i != max_offset; i++) {
		HouseSpec *overridden_hs = GetHouseSpecs(i);

		if (entity_overrides[i] != hs->local_id) continue;

		overridden_hs->override = house_id;
		entity_overrides[i] = invalid_ID;
	}
}