protected void updateHardwareBuffers()
{
if (mChainElementList.Count < 2)
{
return;
}
// Here. we need to compute the position of the camera in the coordinate system of the billboard chain.
Vector3 eyePos = this.ParentNode._getDerivedOrientation().Inverse() *
(mCamera.GetDerivedPosition() - this.ParentNode._getDerivedPosition());
IntPtr ptrBuff;
uint buffIdx = 0;
int chainSize = mChainElementList.Count;
mVD.vertexCount = (uint)chainSize * 2;
// Setup the vertex coordinates
HardwareVertexBufferSharedPtr pPosBuffer = mVD.vertexBufferBinding.getBuffer(POSITION_BINDING);
ptrBuff = pPosBuffer.Get().Lock(HardwareBuffer.LockOptions.HBL_DISCARD);
// Compute the position of the vertices in the chain
for (int i = 0; i < chainSize; i++)
{
myBillBoardChainElement bbe = (myBillBoardChainElement)mChainElementList[i];
Vector3 chainTangent;
if (i == 0)
{
chainTangent = bbe.position - ((myBillBoardChainElement)mChainElementList[0]).position;
}
else if (i == chainSize - 1)
{
chainTangent = ((myBillBoardChainElement)mChainElementList[chainSize - 1]).position -
((myBillBoardChainElement)mChainElementList[chainSize - 2]).position;
}
else
{
chainTangent = ((myBillBoardChainElement)mChainElementList[i + 1]).position -
((myBillBoardChainElement)mChainElementList[i - 1]).position;
}
Vector3 p1 = bbe.position;
Vector3 vP1ToEye = eyePos - p1;
Vector3 vPerpendicular = chainTangent.Cross(vP1ToEye);
vPerpendicular.Normalize();
vPerpendicular *= bbe.width;
Vector3 pos0 = p1 - vPerpendicular;
Vector3 pos1 = p1 + vPerpendicular;
// Update the buffer with the 2 vertex positions
MeshBuilderHelper.SetVertexFloat(ptrBuff, mVBVertexSize, buffIdx++, mVBPostOff,
pos0.x, pos0.y, pos0.z);
MeshBuilderHelper.SetVertexFloat(ptrBuff, mVBVertexSize, buffIdx++, mVBPostOff,
pos1.x, pos1.y, pos1.z);
}
pPosBuffer.Get().Unlock();
// Setup the diffuse color of the vertex
HardwareVertexBufferSharedPtr pVertexColorBuffer = mVD.vertexBufferBinding.getBuffer(DIFFUSE_COLOR_BINDING);
ptrBuff = pVertexColorBuffer.Get().Lock(HardwareBuffer.LockOptions.HBL_DISCARD);
buffIdx = 0;
for (int i = 0; i < chainSize; i++)
{
Color col = ((myBillBoardChainElement)mChainElementList[i]).colour;
MeshBuilderHelper.SetVertexFloat(ptrBuff, mVCBVertexSize, buffIdx++, mVCBrgbaOff,
((float)col.R / 255.0f), ((float)col.G / 255.0f), ((float)col.B / 255.0f), ((float)col.A / 255.0f));
MeshBuilderHelper.SetVertexFloat(ptrBuff, mVCBVertexSize, buffIdx++, mVCBrgbaOff,
((float)col.R / 255.0f), ((float)col.G / 255.0f), ((float)col.B / 255.0f), ((float)col.A / 255.0f));
}
pVertexColorBuffer.Get().Unlock();
// Setup the texture coordinates
HardwareVertexBufferSharedPtr pTexCoordBuffer = mVD.vertexBufferBinding.getBuffer(TEXCOORD_BINDING);
ptrBuff = pTexCoordBuffer.Get().Lock(HardwareBuffer.LockOptions.HBL_DISCARD);
buffIdx = 0;
for (int i = 0; i < chainSize; i++)
{
myBillBoardChainElement bbe = (myBillBoardChainElement)mChainElementList[i];
MeshBuilderHelper.SetVertexFloat(ptrBuff, mTCVertexSize, buffIdx++, mTCBuvOff,
bbe.uTexCoord, 0.0f);
MeshBuilderHelper.SetVertexFloat(ptrBuff, mTCVertexSize, buffIdx++, mTCBuvOff,
bbe.uTexCoord, 1.0f);
}
pTexCoordBuffer.Get().Unlock();
}
/// <summary>
/// createGrassMesh
/// This demonstrates how to create a manual mesh
/// only use static members of MeshBuilderHelper to help set vertex and index data.
/// </summary>
void createGrassMesh()
{
OgreDotNet.MeshPtr mp = MeshManager.Instance.CreateManual(GRASS_MESH_NAME, "General");
SubMesh sm = mp.Get().CreateSubMesh();
sm.useSharedVertices = false;
sm.vertexData = new VertexData();
sm.vertexData.vertexStart = 0;
sm.vertexData.vertexCount = 12;
//mIndexType = HardwareIndexBuffer::IT_16BIT;
VertexDeclaration dcl = sm.vertexData.vertexDeclaration;
UInt32 offset = 0;
UInt32 offPos = dcl.addElement(0, offset, VertexElementType.VET_FLOAT3, VertexElementSemantic.VES_POSITION).getOffset();
offset = VertexElement.getTypeSize(VertexElementType.VET_FLOAT3);
UInt32 offNorm = dcl.addElement(0, offset, VertexElementType.VET_FLOAT3, VertexElementSemantic.VES_NORMAL).getOffset();
offset += VertexElement.getTypeSize(VertexElementType.VET_FLOAT3);
UInt32 offUV = dcl.addElement(0, offset, VertexElementType.VET_FLOAT2, VertexElementSemantic.VES_TEXTURE_COORDINATES).getOffset();
offset += VertexElement.getTypeSize(VertexElementType.VET_FLOAT2);
UInt32 vertexsize = offset;
mLog.LogMessage(string.Format("createGrassMesh vertexsize={0}", vertexsize));
HardwareVertexBufferSharedPtr vbuf = HardwareBufferManager.getSingleton().createVertexBuffer(
vertexsize, 12, HardwareBuffer.Usage.HBU_STATIC_WRITE_ONLY);
IntPtr pV = vbuf.Get().Lock(HardwareBuffer.LockOptions.HBL_DISCARD);
Vector3 vec = new Vector3(GRASS_WIDTH / 2.0f, 0.0f, 0.0f);
Quaternion rot = Quaternion.FromAngleAxis(60, Vector3.UnitY);
uint i;
for (i = 0; i < 3; ++i)
{
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 0, offPos, -vec.x, GRASS_HEIGHT, -vec.z); //position
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 0, offNorm, 0.0f, 1.0f, 0.0f); //normal
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 0, offUV, 0.0f, 0.0f); //uv
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 1, offPos, vec.x, GRASS_HEIGHT, vec.z); //position
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 1, offNorm, 0.0f, 1.0f, 0.0f); //normal
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 1, offUV, 1.0f, 0.0f); //uv
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 2, offPos, -vec.x, 0.0f, -vec.z); //position
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 2, offNorm, 0.0f, 1.0f, 0.0f); //normal
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 2, offUV, 0.0f, 1.0f); //uv
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 3, offPos, vec.x, 0.0f, vec.z); //position
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 3, offNorm, 0.0f, 1.0f, 0.0f); //normal
OgreDotNet.MeshBuilderHelper.SetVertexFloat(pV, vertexsize, (i * 4) + 3, offUV, 1.0f, 1.0f); //uv
vec = rot * vec;
}
vbuf.Get().Unlock();
sm.vertexData.vertexBufferBinding.setBinding(0, vbuf);
sm.indexData.indexCount = 6 * 3;
sm.indexData.indexBuffer = HardwareBufferManager.getSingleton().createIndexBuffer(
HardwareIndexBuffer.IndexType.IT_16BIT, 6 * 3, HardwareBuffer.Usage.HBU_STATIC_WRITE_ONLY);
IntPtr pI = sm.indexData.indexBuffer.Get().Lock(HardwareBuffer.LockOptions.HBL_DISCARD);
for (i = 0; i < 3; ++i)
{
UInt16 off = (UInt16)(i * 4);
OgreDotNet.MeshBuilderHelper.SetIndex16bit(pI, (i * 2) + 0, (UInt16)(0 + off), (UInt16)(3 + off), (UInt16)(1 + off));
OgreDotNet.MeshBuilderHelper.SetIndex16bit(pI, (i * 2) + 1, (UInt16)(0 + off), (UInt16)(2 + off), (UInt16)(3 + off));
}
sm.indexData.indexBuffer.Get().Unlock();
sm.SetMaterialName(GRASS_MATERIAL);
mp.Get().Load();
}