//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------

#include "ts/tsSortedMesh.h"
#include "dgl/dgl.h"
#include "math/mMath.h"
#include "ts/tsShapeInstance.h"

// Not worth the effort, much less the effort to comment, but if the draw types
// are consecutive use addition rather than a table to go from index to command value...
#if ((GL_TRIANGLES+1==GL_TRIANGLE_STRIP) && (GL_TRIANGLE_STRIP+1==GL_TRIANGLE_FAN))
   #define getDrawType(a) (GL_TRIANGLES+(a))
#else
   U32 drawTypes[] = { GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN };
   #define getDrawType(a) (drawTypes[a])
#endif

// found in tsmesh
extern void forceFaceCamera();
extern void forceFaceCameraZAxis();

//-----------------------------------------------------
// TSSortedMesh render methods
//-----------------------------------------------------

void TSSortedMesh::render(S32 frame, S32 matFrame, TSMaterialList * materials)
{
   if (getFlags(Billboard))
   {
      if (getFlags(BillboardZAxis))
         forceFaceCameraZAxis();
      else
         forceFaceCamera();
   }

   MatrixF toCam;
   dglGetModelview(&toCam);
   toCam.inverse();
   Point3F cameraCenter;
   toCam.getColumn(3,&cameraCenter);

   S32 firstVert  = firstVerts[frame];
   S32 vertCount  = numVerts[frame];
   // note on the following:  a TSSortedMesh can animate frame or matFrame but not both.
   // The reason for this is simple:  the number of verts change depending on frame, so
   // if both varied then there would have to be a new set of tverts for every (frame x matFrame)
   // combination, rather than for every matFrame as for other mesh types.  However, either frame
   // or matFrame is allowed to vary, accounting for the following odd looking statement.
   S32 firstTVert = firstTVerts[matFrame ? matFrame : frame];

   // set up vertex arrays -- already enabled in TSShapeInstance::render
   glVertexPointer(3,GL_FLOAT,0,&verts[firstVert]);
   glNormalPointer(GL_FLOAT,0,getNormals(firstVert));
   glTexCoordPointer(2,GL_FLOAT,0,&tverts[firstTVert]);
   if (TSShapeInstance::smRenderData.detailMapMethod == TSShapeInstance::DETAIL_MAP_MULTI_1 ||
       TSShapeInstance::smRenderData.detailMapMethod == TSShapeInstance::DETAIL_MAP_MULTI_2)
   {
      glClientActiveTextureARB(GL_TEXTURE0_ARB + TSShapeInstance::smRenderData.detailMapTE);
      glTexCoordPointer(2,GL_FLOAT,0,&tverts[firstTVert]);
      glClientActiveTextureARB(GL_TEXTURE0_ARB + TSShapeInstance::smRenderData.baseTE);
   }

   // lock...
   bool lockArrays = dglDoesSupportCompiledVertexArray();
   if (lockArrays)
      glLockArraysEXT(0,vertCount);

   if (alwaysWriteDepth)
      glDepthMask(GL_TRUE);

   Cluster * cluster;
   S32 nextCluster = startCluster[frame];
   do
   {
      // the cluster...
      cluster = &clusters[nextCluster];

      // render the cluster...
      for (S32 i=cluster->startPrimitive; i<cluster->endPrimitive; i++)
      {
         TSDrawPrimitive & draw = primitives[i];
         AssertFatal((draw.matIndex & TSDrawPrimitive::Indexed)!=0,"TSSortedMesh::render: rendering of non-indexed meshes no longer supported");

         // material change?
         if ( (TSShapeInstance::smRenderData.materialIndex ^ draw.matIndex) & (TSDrawPrimitive::MaterialMask|TSDrawPrimitive::NoMaterial))
         {
            setMaterial(draw.matIndex,materials);
            if (alwaysWriteDepth)
               glDepthMask(GL_TRUE);
         }

         S32 drawType  = getDrawType(draw.matIndex>>30);

         glDrawElements(drawType,draw.numElements,GL_UNSIGNED_SHORT,&indices[draw.start]);
      }

      // determine next cluster...
      if (cluster->frontCluster!=cluster->backCluster)
         nextCluster = (mDot(cluster->normal,cameraCenter) > cluster->k) ? cluster->frontCluster : cluster->backCluster;
      else
         nextCluster = cluster->frontCluster;
   } while (nextCluster>=0);

   // unlock...
   if (lockArrays)
      glUnlockArraysEXT();

   if ((TSShapeInstance::smRenderData.materialFlags & TSMaterialList::Translucent) && alwaysWriteDepth)
      glDepthMask(GL_FALSE);
}

void TSSortedMesh::renderFog(S32 frame)
{
   if (getFlags(Billboard))
   {
      if (getFlags(BillboardZAxis))
         forceFaceCameraZAxis();
      else
         forceFaceCamera();
   }

   MatrixF toCam;
   dglGetModelview(&toCam);
   toCam.inverse();
   Point3F cameraCenter;
   toCam.getColumn(3,&cameraCenter);

   S32 firstVert  = firstVerts[frame];
   S32 vertCount  = numVerts[frame];

   // set up vertex arrays -- already enabled in TSShapeInstance::render
   glVertexPointer(3,GL_FLOAT,0,&verts[firstVert]);

   // lock...
   bool lockArrays = dglDoesSupportCompiledVertexArray();
   if (lockArrays)
      glLockArraysEXT(0,vertCount);

   Cluster * cluster;
   S32 nextCluster = startCluster[frame];
   do
   {
      // the cluster...
      cluster = &clusters[nextCluster];

      // render the cluster...
      for (S32 i=cluster->startPrimitive; i<cluster->endPrimitive; i++)
      {
         TSDrawPrimitive & draw = primitives[i];
         glDrawElements(getDrawType(draw.matIndex>>30),draw.numElements,GL_UNSIGNED_SHORT,&indices[draw.start]);
      }

      // determine next cluster...
      if (cluster->frontCluster!=cluster->backCluster)
         nextCluster = (mDot(cluster->normal,cameraCenter) > cluster->k) ? cluster->frontCluster : cluster->backCluster;
      else
         nextCluster = cluster->frontCluster;
   } while (nextCluster>=0);

   // unlock...
   if (lockArrays)
      glUnlockArraysEXT();
}

//-----------------------------------------------------
// TSSortedMesh collision methods
//-----------------------------------------------------

bool TSSortedMesh::buildPolyList(S32 frame, AbstractPolyList * polyList, U32 & surfaceKey)
{
   frame, polyList, surfaceKey;
   return false;
}

bool TSSortedMesh::castRay(S32 frame, const Point3F & start, const Point3F & end, RayInfo * rayInfo)
{
   frame, start, end, rayInfo;
   return false;
}

bool TSSortedMesh::buildConvexHull()
{
   return false;
}

S32 TSSortedMesh::getNumPolys()
{
   S32 count = 0;
   S32 cIdx = !clusters.size() ? -1 : 0;
   while (cIdx>=0)
   {
      Cluster & cluster = clusters[cIdx];
      for (S32 i=cluster.startPrimitive; i<cluster.endPrimitive; i++)
      {
         if (primitives[i].matIndex & TSDrawPrimitive::Triangles)
            count += primitives[i].numElements / 3;
         else
            count += primitives[i].numElements - 2;
      }
      cIdx = cluster.frontCluster; // always use frontCluster...we assume about the same no matter what
   }
   return count;
}

//-----------------------------------------------------
// TSSortedMesh assembly/dissembly methods
// used for transfer to/from memory buffers
//-----------------------------------------------------

#define alloc TSShape::alloc

void TSSortedMesh::assemble(bool skip)
{
   bool save1 = TSMesh::smUseTriangles;
   bool save2 = TSMesh::smUseOneStrip;
   TSMesh::smUseTriangles = false;
   TSMesh::smUseOneStrip = false;

   TSMesh::assemble(skip);

   TSMesh::smUseTriangles = save1;
   TSMesh::smUseOneStrip = save2;

   S32 numClusters = alloc.get32();
   S32 * ptr32 = alloc.copyToShape32(numClusters*8);
   clusters.set(ptr32,numClusters);

   S32 sz = alloc.get32();
   ptr32 = alloc.copyToShape32(sz);
   startCluster.set(ptr32,sz);

   sz = alloc.get32();
   ptr32 = alloc.copyToShape32(sz);
   firstVerts.set(ptr32,sz);

   sz = alloc.get32();
   ptr32 = alloc.copyToShape32(sz);
   numVerts.set(ptr32,sz);

   sz = alloc.get32();
   ptr32 = alloc.copyToShape32(sz);
   firstTVerts.set(ptr32,sz);

   alwaysWriteDepth = alloc.get32()!=0;

   alloc.checkGuard();
}

void TSSortedMesh::disassemble()
{
   TSMesh::disassemble();

   alloc.set32(clusters.size());
   alloc.copyToBuffer32((S32*)clusters.address(),clusters.size()*8);

   alloc.set32(startCluster.size());
   alloc.copyToBuffer32((S32*)startCluster.address(),startCluster.size());

   alloc.set32(firstVerts.size());
   alloc.copyToBuffer32((S32*)firstVerts.address(),firstVerts.size());

   alloc.set32(numVerts.size());
   alloc.copyToBuffer32((S32*)numVerts.address(),numVerts.size());

   alloc.set32(firstTVerts.size());
   alloc.copyToBuffer32((S32*)firstTVerts.address(),firstTVerts.size());

   alloc.set32(alwaysWriteDepth ? 1 : 0);

   alloc.setGuard();
}