source/renderer/MikktspaceWrap.cpp

   1 /* Copyright (C) 2021 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "precompiled.h"
  19
  20 #include "renderer/MikktspaceWrap.h"
  21
  22 MikkTSpace::MikkTSpace(const CModelDefPtr& m, std::vector<float>& v, bool gpuSkinning) : m_Model(m),
  23                         m_NewVertices(v), m_GpuSkinning(gpuSkinning)
  24 {
  25         // ensure that m_NewVertices is empty
  26         m_NewVertices.clear();
  27
  28         // set up SMikkTSpaceInterface struct
  29         m_Interface.m_getNumFaces = GetNumFaces;
  30         m_Interface.m_getNumVerticesOfFace = GetNumVerticesOfFace;
  31         m_Interface.m_getPosition = GetPosition;
  32         m_Interface.m_getNormal = GetNormal;
  33         m_Interface.m_getTexCoord = GetTexCoord;
  34         m_Interface.m_setTSpaceBasic = nullptr;
  35         m_Interface.m_setTSpace = SetTSpace;
  36
  37         // set up SMikkTSpaceContext struct
  38         m_Context.m_pInterface = &m_Interface;
  39         m_Context.m_pUserData = static_cast<void*>(this);
  40 }
  41
  42 void MikkTSpace::Generate()
  43 {
  44         genTangSpaceDefault(&m_Context);
  45 }
  46
  47 int MikkTSpace::GetNumFaces(const SMikkTSpaceContext* pContext)
  48 {
  49         return GetUserDataFromContext(pContext)->m_Model->GetNumFaces();
  50 }
  51
  52 int MikkTSpace::GetNumVerticesOfFace(const SMikkTSpaceContext* UNUSED(pContext), const int UNUSED(iFace))
  53 {
  54         return 3;
  55 }
  56
  57 void MikkTSpace::GetPosition(const SMikkTSpaceContext* pContext,
  58                 float* fvPosOut, const int iFace, const int iVert)
  59 {
  60         const CVector3D& position = GetVertex(pContext, iFace, iVert).m_Coords;
  61
  62         fvPosOut[0] = position.X;
  63         fvPosOut[1] = position.Y;
  64         fvPosOut[2] = position.Z;
  65 }
  66
  67
  68 void MikkTSpace::GetNormal(const SMikkTSpaceContext* pContext,
  69                 float* fvNormOut, const int iFace, const int iVert)
  70 {
  71         const CVector3D& normal = GetVertex(pContext, iFace, iVert).m_Norm;
  72
  73         fvNormOut[0] = normal.X;
  74         fvNormOut[1] = normal.Y;
  75         fvNormOut[2] = normal.Z;
  76 }
  77
  78
  79 void MikkTSpace::GetTexCoord(const SMikkTSpaceContext* pContext,
  80                 float* fvTexcOut, const int iFace, const int iVert)
  81 {
  82         const MikkTSpace* userData = GetUserDataFromContext(pContext);
  83         const SModelFace& face = userData->m_Model->GetFaces()[iFace];
  84         const size_t numberOfUVPerVertex = userData->m_Model->GetNumUVsPerVertex();
  85
  86         // The tangents are calculated according to the 'default' UV set
  87         const CVector2D& uv = userData->m_Model->GetUVCoordinates()[face.m_Verts[iVert] * numberOfUVPerVertex];
  88         fvTexcOut[0] = uv.X;
  89         fvTexcOut[1] = 1.0 - uv.Y;
  90 }
  91
  92
  93 void MikkTSpace::SetTSpace(const SMikkTSpaceContext* pContext, const float* fvTangent,
  94         const float* UNUSED(fvBiTangent), const float UNUSED(fMagS), const float UNUSED(fMagT),
  95         const tbool bIsOrientationPreserving, const int iFace, const int iVert)
  96 {
  97         const MikkTSpace* userData = GetUserDataFromContext(pContext);
  98         const SModelFace& face = userData->m_Model->GetFaces()[iFace];
  99         const SModelVertex& vertex = userData->m_Model->GetVertices()[face.m_Verts[iVert]];
 100
 101         const CVector3D& p = vertex.m_Coords;
 102         userData->m_NewVertices.push_back(p.X);
 103         userData->m_NewVertices.push_back(p.Y);
 104         userData->m_NewVertices.push_back(p.Z);
 105
 106         const CVector3D& n = vertex.m_Norm;
 107         userData->m_NewVertices.push_back(n.X);
 108         userData->m_NewVertices.push_back(n.Y);
 109         userData->m_NewVertices.push_back(n.Z);
 110
 111         userData->m_NewVertices.push_back(fvTangent[0]);
 112         userData->m_NewVertices.push_back(fvTangent[1]);
 113         userData->m_NewVertices.push_back(fvTangent[2]);
 114         userData->m_NewVertices.push_back(bIsOrientationPreserving != 0 ? 1.f : -1.f);
 115
 116         if (userData->m_GpuSkinning)
 117         {
 118                 for (u8 j = 0; j < 4; ++j)
 119                 {
 120                         userData->m_NewVertices.push_back(vertex.m_Blend.m_Bone[j]);
 121                         userData->m_NewVertices.push_back(255.f * vertex.m_Blend.m_Weight[j]);
 122                 }
 123         }
 124
 125         const size_t numberOfUVPerVertex = userData->m_Model->GetNumUVsPerVertex();
 126         for (size_t UVset = 0; UVset < numberOfUVPerVertex; ++UVset)
 127         {
 128                 const CVector2D& uv = userData->m_Model->GetUVCoordinates()[face.m_Verts[iVert] * numberOfUVPerVertex + UVset];
 129                 userData->m_NewVertices.push_back(uv.X);
 130                 userData->m_NewVertices.push_back(1.f - uv.Y);
 131         }
 132 }
 133
 134 MikkTSpace* MikkTSpace::GetUserDataFromContext(const SMikkTSpaceContext* pContext)
 135 {
 136         return static_cast<MikkTSpace*>(pContext->m_pUserData);
 137 }
 138
 139 SModelVertex MikkTSpace::GetVertex(const SMikkTSpaceContext* pContext, const int iFace, const int iVert)
 140 {
 141         const MikkTSpace* userData = GetUserDataFromContext(pContext);
 142         const SModelFace& f = userData->m_Model->GetFaces()[iFace];
 143         return userData->m_Model->GetVertices()[f.m_Verts[iVert]];
 144 }