From 16bd81ffad8a1d4ea9a9c62a468185d543826c10 Mon Sep 17 00:00:00 2001
From: Armin Burgmeier <armin@arbur.net>
Date: Fri, 10 Jul 2009 21:57:11 +0200
Subject: [PATCH] Implemented StdMeshInstance

---
 standard/inc/StdMesh.h   | 19 ++++++---
 standard/src/StdMesh.cpp | 91 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 103 insertions(+), 7 deletions(-)

diff --git a/standard/inc/StdMesh.h b/standard/inc/StdMesh.h
index e190c4835..8195652d4 100644
--- a/standard/inc/StdMesh.h
+++ b/standard/inc/StdMesh.h
@@ -114,12 +114,10 @@ public:
   // *this = trans * *this
   void Transform(const StdMeshMatrix& trans);
 
-#if 0
   // *this *= f;
   void Mul(float f);
   // *this += other;
   void Add(const StdMeshVertex& other);
-#endif
 };
 
 class StdMeshFace
@@ -150,6 +148,7 @@ private:
 class StdMeshAnimation
 {
   friend class StdMesh;
+  friend class StdMeshInstance;
 public:
   StdMeshAnimation() {}
   StdMeshAnimation(const StdMeshAnimation& other);
@@ -166,6 +165,7 @@ private:
 
 class StdMesh
 {
+  friend class StdMeshInstance;
 public:
   StdMesh();
   ~StdMesh();
@@ -184,7 +184,7 @@ public:
   const StdMeshBone& GetBone(unsigned int i) const { return *Bones[i]; }
   unsigned int GetNumBones() const { return Bones.size(); }
 
-  const StdMeshAnimation& GetAnimationByName(const char* name);
+  const StdMeshAnimation* GetAnimationByName(const StdStrBuf& name) const;
   const StdMeshMaterial& GetMaterial() const { return *Material; }
 
 private:
@@ -214,17 +214,26 @@ class StdMeshInstance
 public:
   StdMeshInstance(const StdMesh& mesh);
 
-  void SetAnimation(const StdStrBuf& animation);
-  const StdMeshAnimation& GetAnimation() const;
+  void SetAnimation(const StdStrBuf& animation_name);
+  void UnsetAnimation();
+
+  const StdMeshAnimation* GetAnimation() const { return Animation; }
 
   void SetPosition(float position);
+  float GetPosition() const { return Position; }
 
   // Get vertex of instance, with current animation applied. This needs to
   // go elsewhere if/when we want to calculate this on the hardware.
   const StdMeshVertex& GetVertex(unsigned int i) const { return Vertices[i]; }
   unsigned int GetNumVertices() const { return Vertices.size(); }
 
+  const StdMesh& Mesh;
+
 protected:
+  const StdMeshAnimation* Animation;
+  float Position;
+
+  std::vector<StdMeshMatrix> BoneTransforms;
   std::vector<StdMeshVertex> Vertices;
 };
 
diff --git a/standard/src/StdMesh.cpp b/standard/src/StdMesh.cpp
index 9e3d0b5e9..a583ca714 100644
--- a/standard/src/StdMesh.cpp
+++ b/standard/src/StdMesh.cpp
@@ -224,7 +224,6 @@ void StdMeshVertex::Transform(const StdMeshMatrix& trans)
   nz = trans(2,0)*old.nx + trans(2,1)*old.ny + trans(2,2)*old.nz;
 }
 
-#if 0
 void StdMeshVertex::Mul(float f)
 {
   x *= f;
@@ -249,7 +248,6 @@ void StdMeshVertex::Add(const StdMeshVertex& other)
   ny += other.ny;
   nz += other.nz;
 }
-#endif
 
 StdMeshMatrix StdMeshTrack::GetTransformAt(float time) const
 {
@@ -610,4 +608,93 @@ void StdMesh::AddMasterBone(StdMeshBone* bone)
     AddMasterBone(bone->Children[i]);
 }
 
+const StdMeshAnimation* StdMesh::GetAnimationByName(const StdStrBuf& name) const
+{
+  std::map<StdStrBuf, StdMeshAnimation>::const_iterator iter = Animations.find(name);
+  if(iter == Animations.end()) return NULL;
+  return &iter->second;
+}
+
+StdMeshInstance::StdMeshInstance(const StdMesh& mesh):
+  Mesh(mesh), Animation(NULL), Position(0.0f),
+  BoneTransforms(Mesh.GetNumBones()), Vertices(Mesh.GetNumVertices())
+{
+  for(unsigned int i = 0; i < Mesh.GetNumVertices(); ++i)
+    Vertices[i] = Mesh.GetVertex(i);
+}
+
+void StdMeshInstance::SetAnimation(const StdStrBuf& animation_name)
+{
+  Animation = Mesh.GetAnimationByName(animation_name);
+  SetPosition(0.0f);
+}
+
+void StdMeshInstance::UnsetAnimation()
+{
+  Animation = NULL;
+
+  // Reset instance vertices
+  for(unsigned int i = 0; i < Mesh.GetNumVertices(); ++i)
+    Vertices[i] = Mesh.GetVertex(i);
+}
+
+void StdMeshInstance::SetPosition(float position)
+{
+  assert(Animation);
+  Position = position;
+
+  // Compute transformation matrix for each bone.
+  for(unsigned int i = 0; i < BoneTransforms.size(); ++i)
+  {
+    StdMeshTrack* track = Animation->Tracks[i];
+    if(track)
+    {
+      BoneTransforms[i] = track->GetTransformAt(position);
+    }
+    else
+    {
+      // No track for this bone, so use parent transformation
+      const StdMeshBone* parent = Mesh.GetBone(i).GetParent();
+      if(parent)
+      {
+        // Parent should already have been processed, because the bone indices
+        // are supposed to be hierarchically ordered.
+        assert(parent->Index < i);
+        BoneTransforms[i] = BoneTransforms[parent->Index];
+      }
+      else
+      {
+        BoneTransforms[i].SetIdentity();
+      }
+    }
+  }
+
+  // Compute transformation for each vertex. We could later think about
+  // doing this on the GPU using a vertex shader. This would then probably
+  // need to go to CStdGL::PerformMesh and CStdD3D::PerformMesh.
+  for(unsigned int i = 0; i < Vertices.size(); ++i)
+  {
+    const StdMesh::Vertex& vertex = Mesh.Vertices[i];
+    if(!vertex.BoneAssignments.empty())
+    {
+      Vertices[i].x = Vertices[i].y = Vertices[i].z = 0.0f;
+      Vertices[i].nx = Vertices[i].ny = Vertices[i].nz = 0.0f;
+      Vertices[i].u = vertex.u; Vertices[i].v = vertex.v;
+
+      for(unsigned int j = 0; j < vertex.BoneAssignments.size(); ++j)
+      {
+        const StdMeshVertexBoneAssignment& assignment = vertex.BoneAssignments[j];
+        StdMeshVertex vtx = vertex;
+        vtx.Transform(BoneTransforms[assignment.BoneIndex]);
+        vtx.Mul(assignment.Weight);
+        Vertices[i].Add(vtx);
+      }
+    }
+    else
+    {
+      Vertices[i] = vertex;
+    }
+  }
+}
+
 // vim: et ts=2 sw=2