summaryrefslogtreecommitdiff
path: root/indra/newview/llphysicsshapebuilderutil.cpp
blob: 5bfe5c9941c470443abd6bd3e96170040c240a4a (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
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
/** 
 * @file llphysicsshapebuilder.cpp
 * @brief Generic system to convert LL(Physics)VolumeParams to physics shapes
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "llphysicsshapebuilderutil.h"

/* static */
void LLPhysicsShapeBuilderUtil::determinePhysicsShape( const LLPhysicsVolumeParams& volume_params, const LLVector3& scale, PhysicsShapeSpecification& specOut )
{
	const LLProfileParams& profile_params = volume_params.getProfileParams();
	const LLPathParams& path_params = volume_params.getPathParams();

	specOut.mScale = scale;

	const F32 avgScale = ( scale[VX] + scale[VY] + scale[VZ] )/3.0f;	

	// count the scale elements that are small
	S32 min_size_counts = 0;
	for (S32 i = 0; i < 3; ++i)
	{
		if (scale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
		{
			++min_size_counts;
		}
	}

	const bool profile_complete = ( profile_params.getBegin() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale ) &&
		( profile_params.getEnd() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) );

	const bool path_complete =	( path_params.getBegin() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale ) && 
		( path_params.getEnd() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) );

	const bool simple_params = ( volume_params.getHollow() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_HOLLOW/avgScale )
		&& ( fabs(path_params.getShearX()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_SHEAR/avgScale )
		&& ( fabs(path_params.getShearY()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_SHEAR/avgScale )
		&& ( !volume_params.isMeshSculpt() && !volume_params.isSculpt() );

	if (simple_params && profile_complete)
	{
		// Try to create an implicit shape or convexified
		bool no_taper = ( fabs(path_params.getScaleX() - 1.0f) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale )
			&& ( fabs(path_params.getScaleY() - 1.0f) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale );

		bool no_twist = ( fabs(path_params.getTwistBegin()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TWIST/avgScale )
			&& ( fabs(path_params.getTwistEnd()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TWIST/avgScale);

		// Box 
		if(
			( profile_params.getCurveType() == LL_PCODE_PROFILE_SQUARE )
			&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE )
			&& no_taper
			&& no_twist
			)
		{
			specOut.mType = PhysicsShapeSpecification::BOX;
			if ( path_complete )
			{
				return;
			}
			else
			{
				// Side lengths
				specOut.mScale[VX] = llmax( scale[VX], SHAPE_BUILDER_MIN_GEOMETRY_SIZE );
				specOut.mScale[VY] = llmax( scale[VY], SHAPE_BUILDER_MIN_GEOMETRY_SIZE );
				specOut.mScale[VZ] = llmax( scale[VZ] * (path_params.getEnd() - path_params.getBegin()), SHAPE_BUILDER_MIN_GEOMETRY_SIZE );

				specOut.mCenter.set( 0.f, 0.f, 0.5f * scale[VZ] * ( path_params.getEnd() + path_params.getBegin() - 1.0f ) );
				return;
			}
		}

		// Sphere 
		if(		path_complete
			&& ( profile_params.getCurveType() == LL_PCODE_PROFILE_CIRCLE_HALF )
			&& ( path_params.getCurveType() == LL_PCODE_PATH_CIRCLE )
			&& ( fabs(volume_params.getTaper()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale )
			&& no_twist
			)
		{
			if (   ( scale[VX] == scale[VZ] )
				&& ( scale[VY] == scale[VZ] ) )
			{
				// perfect sphere
				specOut.mType	= PhysicsShapeSpecification::SPHERE;
				specOut.mScale  = scale;
				return;
			}
			else if (min_size_counts > 1)
			{
				// small or narrow sphere -- we can boxify
				for (S32 i=0; i<3; ++i)
				{
					if (specOut.mScale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
					{
						// reduce each small dimension size to split the approximation errors
						specOut.mScale[i] *= 0.75f;
					}
				}
				specOut.mType  = PhysicsShapeSpecification::BOX;
				return;
			}
		}

		// Cylinder 
		if(	   (scale[VX] == scale[VY])
			&& ( profile_params.getCurveType() == LL_PCODE_PROFILE_CIRCLE )
			&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE )
			&& ( volume_params.getBeginS() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale )
			&& ( volume_params.getEndS() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) )
			&& no_taper
			)
		{
			if (min_size_counts > 1)
			{
				// small or narrow sphere -- we can boxify
				for (S32 i=0; i<3; ++i)
				{
					if (specOut.mScale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
					{
						// reduce each small dimension size to split the approximation errors
						specOut.mScale[i] *= 0.75f;
					}
				}

				specOut.mType = PhysicsShapeSpecification::BOX;
			}
			else
			{
				specOut.mType = PhysicsShapeSpecification::CYLINDER;
				F32 length = (volume_params.getPathParams().getEnd() - volume_params.getPathParams().getBegin()) * scale[VZ];

				specOut.mScale[VY] = specOut.mScale[VX];
				specOut.mScale[VZ] = length;
				// The minus one below fixes the fact that begin and end range from 0 to 1 not -1 to 1.
				specOut.mCenter.set( 0.f, 0.f, 0.5f * (volume_params.getPathParams().getBegin() + volume_params.getPathParams().getEnd() - 1.f) * scale[VZ] );
			}

			return;
		}
	}

	if (	(min_size_counts == 3 )
		// Possible dead code here--who wants to take it out?
		||	(path_complete
				&& profile_complete
				&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE ) 
				&& (min_size_counts > 1 ) ) 
		)
	{
		// it isn't simple but
		// we might be able to convexify this shape if the path and profile are complete
		// or the path is linear and both path and profile are complete --> we can boxify it
		specOut.mType = PhysicsShapeSpecification::BOX;
		specOut.mScale = scale;
		return;
	}

	// Special case for big, very thin objects - bump the small dimensions up to the COLLISION_TOLERANCE
	if (min_size_counts == 1		// One dimension is small
		&& avgScale > 3.f)			//  ... but others are fairly large
	{
		for (S32 i = 0; i < 3; ++i)
		{
			specOut.mScale[i] = llmax( specOut.mScale[i], COLLISION_TOLERANCE );
		}
	}

	if ( volume_params.shouldForceConvex() )
	{
		specOut.mType = PhysicsShapeSpecification::USER_CONVEX;
	}	
	// Make a simpler convex shape if we can.
	else if (volume_params.isConvex()			// is convex
			|| min_size_counts > 1 )			// two or more small dimensions
	{
		specOut.mType = PhysicsShapeSpecification::PRIM_CONVEX;
	}
	else if ( volume_params.isSculpt() ) // Is a sculpt of any kind (mesh or legacy)
	{
		specOut.mType = volume_params.isMeshSculpt() ? PhysicsShapeSpecification::USER_MESH : PhysicsShapeSpecification::SCULPT;
	}
	else // Resort to mesh 
	{
		specOut.mType = PhysicsShapeSpecification::PRIM_MESH;
	}
}