bool   YfBuildDrumVertices

 (

     Yreal                   radius,

     Yreal                   assistRadius,

     Yuint                   slices,

     Yuint                   stacks,

     YeOriginPose            originPose,

     Yuint                   vertexStriding,

     Yuint                   vertexPos,

     void*                   pVerticesBuffer

 )

 {

     if (slices <  || stacks <  || !pVerticesBuffer)

     {

         return false;

     }

     Yuint numVertices  = slices * stacks + ;

     // 顶点赋值

     char* vertexPtr   = (char*)pVerticesBuffer + vertexPos;

     YsVector3* curVertexPtr   = NULL;

     Yuint nOffset = ;

     Yreal originOffsetY = 0.0f;

     if (originPose == YE_ORIGIN_POSE_TOP)

     {

         originOffsetY = -radius;

     }

     else if (originPose == YE_ORIGIN_POSE_BOTTOM)

     {

         originOffsetY = radius;

     }

     Yreal* pSinList = YD_NEW_ARRAY(Yreal, slices);

     Yreal* pCosList = YD_NEW_ARRAY(Yreal, slices);

     Yreal angleXZ;

     for (Yuint j = ; j < slices; j++)

     {

         angleXZ = YD_REAL_TWAIN_PI * j / slices;

         pSinList[j] = yf_sin(angleXZ);

         pCosList[j] = yf_cos(angleXZ);

     }

     // 赋值

     {

         // 第一个顶点

         {

             nOffset = ;

             curVertexPtr = (YsVector3*)(vertexPtr + nOffset);

             curVertexPtr->x = 0.0f;

             curVertexPtr->y = radius + originOffsetY;

             curVertexPtr->z = 0.0f;

         }

         // 最后一个顶点

         {

             nOffset = (numVertices - ) * vertexStriding;

             curVertexPtr = (YsVector3*)(vertexPtr + nOffset);

             curVertexPtr->x = 0.0f;

             curVertexPtr->y = -radius + originOffsetY;

             curVertexPtr->z = 0.0f;

         }

         for (Yuint i = ; i < stacks; i++)

         {

             Yreal angleY = YD_REAL_PI * i / (stacks - );

             Yreal posY = radius * yf_cos(angleY);

             Yreal radiusXZ = assistRadius + radius * yf_sin(angleY);

             Yreal posX, posZ;

             for (Yuint j = ; j < slices; j++)

             {

                 posX = radiusXZ * pSinList[j];

                 posZ = radiusXZ * pCosList[j];

                 nOffset = (i * slices + j + ) * vertexStriding;

                 curVertexPtr = (YsVector3*)(vertexPtr + nOffset);

                 curVertexPtr->x = posX;

                 curVertexPtr->y = posY + originOffsetY;

                 curVertexPtr->z = posZ;

             }

         }

     }

     YD_SAFE_DELETE_ARRAY(pSinList);

     YD_SAFE_DELETE_ARRAY(pCosList);

     return true;

 }

 bool   YfBuildDrumTriIndices

 (

     Yuint                   slices,

     Yuint                   stacks,

     YeIndexType             indexType,

     Yuint                   indexStriding,

     Yuint                   indexPos,

     void*                   pTriIndicesBuffer

 )

 {

     return YfBuildSphereTriIndices(

         slices,

         stacks + ,

         indexType,

         indexStriding,

         indexPos,

         pTriIndicesBuffer);

 }

 bool   YfBuildDrumWireIndices

 (

     Yuint                   slices,

     Yuint                   stacks,

     YeIndexType             indexType,

     Yuint                   indexStriding,

     Yuint                   indexPos,

     void*                   pWireIndicesBuffer

 )

 {

     return YfBuildSphereWireIndices(

         slices,

         stacks + ,

         indexType,

         indexStriding,

         indexPos,

         pWireIndicesBuffer);

 }