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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
// Mixins.h
// Provides various mixins for easier cBlockHandler descendant implementations
/* The general use case is to derive a handler from these mixins, providing a suitable base to them:
class cBlockAir: public cBlockWithNoDrops<cBlockHandler>;
class cBlockLadder: public cMetaRotator<cClearMetaOnDrop, ...>
*/
#pragma once
#include "../Item.h"
#include "../Entities/Player.h"
// MSVC generates warnings for the templated AssertIfNotMatched parameter conditions, so disable it:
#ifdef _MSC_VER
#pragma warning(disable: 4127) // Conditional expression is constant
#endif
/** Mixin to clear the block's meta value when converting to a pickup. */
template <class Base>
class cClearMetaOnDrop :
public Base
{
public:
constexpr cClearMetaOnDrop(BLOCKTYPE a_BlockType):
Base(a_BlockType)
{
}
protected:
~cClearMetaOnDrop() = default;
private:
virtual cItems ConvertToPickups(const NIBBLETYPE a_BlockMeta, const cItem * const a_Tool) const override
{
// Reset the meta to zero:
return cItem(this->m_BlockType);
}
};
/** Mixin for rotations and reflections following the standard pattern of "apply mask, then use a switch".
Inherit from this class providing your base class as Base, the BitMask for the direction bits in bitmask and the masked value for the directions in North, East, South, West.
There is also an aptional parameter AssertIfNotMatched, set this if it is invalid for a block to exist in any other state. */
template <class Base, NIBBLETYPE BitMask, NIBBLETYPE North, NIBBLETYPE East, NIBBLETYPE South, NIBBLETYPE West, bool AssertIfNotMatched = false>
class cMetaRotator :
public Base
{
public:
constexpr cMetaRotator(BLOCKTYPE a_BlockType):
Base(a_BlockType)
{
}
protected:
~cMetaRotator() = default;
virtual NIBBLETYPE MetaRotateCCW(NIBBLETYPE a_Meta) const override
{
NIBBLETYPE OtherMeta = a_Meta & (~BitMask);
switch (a_Meta & BitMask)
{
case South: return East | OtherMeta;
case East: return North | OtherMeta;
case North: return West | OtherMeta;
case West: return South | OtherMeta;
}
if (AssertIfNotMatched)
{
ASSERT(!"Invalid Meta value");
}
return a_Meta;
}
virtual NIBBLETYPE MetaRotateCW(NIBBLETYPE a_Meta) const override
{
NIBBLETYPE OtherMeta = a_Meta & (~BitMask);
switch (a_Meta & BitMask)
{
case South: return West | OtherMeta;
case West: return North | OtherMeta;
case North: return East | OtherMeta;
case East: return South | OtherMeta;
}
if (AssertIfNotMatched)
{
ASSERT(!"Invalid Meta value");
}
return a_Meta;
}
virtual NIBBLETYPE MetaMirrorXY(NIBBLETYPE a_Meta) const override
{
NIBBLETYPE OtherMeta = a_Meta & (~BitMask);
switch (a_Meta & BitMask)
{
case South: return North | OtherMeta;
case North: return South | OtherMeta;
}
// Not Facing North or South; No change.
return a_Meta;
}
virtual NIBBLETYPE MetaMirrorYZ(NIBBLETYPE a_Meta) const override
{
NIBBLETYPE OtherMeta = a_Meta & (~BitMask);
switch (a_Meta & BitMask)
{
case West: return East | OtherMeta;
case East: return West | OtherMeta;
}
// Not Facing East or West; No change.
return a_Meta;
}
};
/** Mixin for blocks whose meta on placement depends on the yaw of the player placing the block. BitMask
selects the direction bits from the block's meta values. */
template <
class Base,
NIBBLETYPE BitMask = 0x07,
NIBBLETYPE North = 0x02,
NIBBLETYPE East = 0x05,
NIBBLETYPE South = 0x03,
NIBBLETYPE West = 0x04,
bool AssertIfNotMatched = false
>
class cYawRotator :
public cMetaRotator<Base, BitMask, North, East, South, West, AssertIfNotMatched>
{
using Super = cMetaRotator<Base, BitMask, North, East, South, West, AssertIfNotMatched>;
public:
using Super::Super;
/** Converts the rotation value as returned by cPlayer::GetYaw() to the appropriate metadata
value for a block placed by a player facing that way */
static NIBBLETYPE YawToMetaData(double a_Rotation)
{
if ((a_Rotation >= -135) && (a_Rotation < -45))
{
return East;
}
else if ((a_Rotation >= -45) && (a_Rotation < 45))
{
return South;
}
else if ((a_Rotation >= 45) && (a_Rotation < 135))
{
return West;
}
else // degrees jumping from 180 to -180
{
return North;
}
}
protected:
~cYawRotator() = default;
};
/** Mixin for blocks whose meta on placement depends on the pitch and yaw of the player placing the block. BitMask
selects the direction bits from the block's meta values. */
template <
class Base,
NIBBLETYPE BitMask = 0x07,
NIBBLETYPE North = 0x02,
NIBBLETYPE East = 0x05,
NIBBLETYPE South = 0x03,
NIBBLETYPE West = 0x04,
NIBBLETYPE Up = 0x00,
NIBBLETYPE Down = 0x01
>
class cPitchYawRotator:
public cYawRotator<Base, BitMask, North, East, South, West>
{
using Super = cYawRotator<Base, BitMask, North, East, South, West>;
public:
using Super::Super;
/** Converts the rotation and pitch values as returned by cPlayer::GetYaw() and cPlayer::GetPitch()
respectively to the appropriate metadata value for a block placed by a player facing that way */
static NIBBLETYPE PitchYawToMetaData(double a_Rotation, double a_Pitch)
{
if (a_Pitch >= 50)
{
return Up;
}
else if (a_Pitch <= -50)
{
return Down;
}
return Super::YawToMetaData(a_Rotation);
}
protected:
~cPitchYawRotator() = default;
virtual NIBBLETYPE MetaMirrorXZ(NIBBLETYPE a_Meta) const override
{
NIBBLETYPE OtherMeta = a_Meta & (~BitMask);
switch (a_Meta & BitMask)
{
case Down: return Up | OtherMeta; // Down -> Up
case Up: return Down | OtherMeta; // Up -> Down
}
// Not Facing Up or Down; No change.
return a_Meta;
}
};
|
