1 /*
2 Open Asset Import Library (assimp)
3 ----------------------------------------------------------------------
4 
5 Copyright (c) 2006-2017, assimp team
6 
7 All rights reserved.
8 
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10 with or without modification, are permitted provided that the
11 following conditions are met:
12 
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14   copyright notice, this list of conditions and the
15   following disclaimer.
16 
17 * Redistributions in binary form must reproduce the above
18   copyright notice, this list of conditions and the
19   following disclaimer in the documentation and/or other
20   materials provided with the distribution.
21 
22 * Neither the name of the assimp team, nor the names of its
23   contributors may be used to endorse or promote products
24   derived from this software without specific prior
25   written permission of the assimp team.
26 
27 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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38 
39 ----------------------------------------------------------------------
40 */
41 
42 /** @file  MakeLeftHandedProcess.h
43  *  @brief Defines a bunch of post-processing steps to handle
44  *    coordinate system conversions.
45  *
46  *  - LH to RH
47  *  - UV origin upper-left to lower-left
48  *  - face order cw to ccw
49  */
50 #ifndef AI_CONVERTTOLHPROCESS_H_INC
51 #define AI_CONVERTTOLHPROCESS_H_INC
52 
53 #include <assimp/types.h>
54 #include "BaseProcess.h"
55 
56 struct aiMesh;
57 struct aiNodeAnim;
58 struct aiNode;
59 struct aiMaterial;
60 
61 namespace Assimp    {
62 
63 // -----------------------------------------------------------------------------------
64 /** @brief The MakeLeftHandedProcess converts all imported data to a left-handed
65  *   coordinate system.
66  *
67  * This implies a mirroring of the Z axis of the coordinate system. But to keep
68  * transformation matrices free from reflections we shift the reflection to other
69  * places. We mirror the meshes and adapt the rotations.
70  *
71  * @note RH-LH and LH-RH is the same, so this class can be used for both
72  */
73 class MakeLeftHandedProcess : public BaseProcess
74 {
75 
76 
77 public:
78     MakeLeftHandedProcess();
79     ~MakeLeftHandedProcess();
80 
81     // -------------------------------------------------------------------
82     bool IsActive( unsigned int pFlags) const;
83 
84     // -------------------------------------------------------------------
85     void Execute( aiScene* pScene);
86 
87 protected:
88 
89     // -------------------------------------------------------------------
90     /** Recursively converts a node and all of its children
91      */
92     void ProcessNode( aiNode* pNode, const aiMatrix4x4& pParentGlobalRotation);
93 
94     // -------------------------------------------------------------------
95     /** Converts a single mesh to left handed coordinates.
96      * This means that positions, normals and tangents are mirrored at
97      * the local Z axis and the order of all faces are inverted.
98      * @param pMesh The mesh to convert.
99      */
100     void ProcessMesh( aiMesh* pMesh);
101 
102     // -------------------------------------------------------------------
103     /** Converts a single material to left-handed coordinates
104      * @param pMat Material to convert
105      */
106     void ProcessMaterial( aiMaterial* pMat);
107 
108     // -------------------------------------------------------------------
109     /** Converts the given animation to LH coordinates.
110      * The rotation and translation keys are transformed, the scale keys
111      * work in local space and can therefore be left untouched.
112      * @param pAnim The bone animation to transform
113      */
114     void ProcessAnimation( aiNodeAnim* pAnim);
115 };
116 
117 
118 // ---------------------------------------------------------------------------
119 /** Postprocessing step to flip the face order of the imported data
120  */
121 class FlipWindingOrderProcess : public BaseProcess
122 {
123     friend class Importer;
124 
125 public:
126     /** Constructor to be privately used by Importer */
127     FlipWindingOrderProcess();
128 
129     /** Destructor, private as well */
130     ~FlipWindingOrderProcess();
131 
132     // -------------------------------------------------------------------
133     bool IsActive( unsigned int pFlags) const;
134 
135     // -------------------------------------------------------------------
136     void Execute( aiScene* pScene);
137 
138 protected:
139     void ProcessMesh( aiMesh* pMesh);
140 };
141 
142 // ---------------------------------------------------------------------------
143 /** Postprocessing step to flip the UV coordinate system of the import data
144  */
145 class FlipUVsProcess : public BaseProcess
146 {
147     friend class Importer;
148 
149 public:
150     /** Constructor to be privately used by Importer */
151     FlipUVsProcess();
152 
153     /** Destructor, private as well */
154     ~FlipUVsProcess();
155 
156     // -------------------------------------------------------------------
157     bool IsActive( unsigned int pFlags) const;
158 
159     // -------------------------------------------------------------------
160     void Execute( aiScene* pScene);
161 
162 protected:
163     void ProcessMesh( aiMesh* pMesh);
164     void ProcessMaterial( aiMaterial* mat);
165 };
166 
167 } // end of namespace Assimp
168 
169 #endif // AI_CONVERTTOLHPROCESS_H_INC
170