//----------------------------------------------------------------------------
void DxRenderer::Draw (const ProjectedTexture& rkPTexture)
{
float fNear, fFar, fLeft, fRight, fTop, fBottom;
D3DXMATRIX kMatrixViewCamera;
D3DXMATRIX kMatrixInverseViewCamera;
D3DXMATRIX kMatrixViewProjector;
D3DXMATRIX kMatrixProjectionProjector;
D3DXMATRIX kMatTmp1, kMatTmp2;
D3DXMATRIX kMatrixTextureProjector;
// If multitexturing is not supported, then we cannot render a
// projected texture onto the objects. But render the objects anyway.
if ( !m_bCapMultitexture )
{
Renderer::Draw(rkPTexture.GetObjects());
return;
}
// Reserve an available texture unit, but use one on at the end of the
// sequence to allow room for the model if it needs to use any
// texture units prior to the ProjectedTexture texture. If one is
// not available, then we cannot render a projected texture onto
// the objects. But render the objects anyway.
int iUnit = RequestTextureUnit();
if ( iUnit < 0 )
{
Renderer::Draw(rkPTexture.GetObjects());
return;
}
// Fill the texture state object and bind it.
Texture* pkTexture = rkPTexture.GetTexture();
TextureState* pkTS = rkPTexture.GetTextureState();
pkTS->Set(iUnit,pkTexture);
SetTextureState(pkTS);
pkTS->Remove(iUnit);
// Setup the inverse for the current camera viewing transform. -
// Texture coordinates will be obtained from camera space position,
// but that camera viewing transform needs to be undone to get
// back to world coordinates.
ms_hResult = m_pqDevice->GetTransform(D3DTS_VIEW,&kMatrixViewCamera);
WML_DX_ERROR_CHECK(GetTransform);
D3DXMatrixInverse(&kMatrixInverseViewCamera,NULL,&kMatrixViewCamera);
// Setup viewing transform for the projector.
// Setup a lookat matrix using the projected texture camera
// viewpoint and view direction.
const Vector3f& rkCameraLoc = rkPTexture.GetCamera()->GetLocation();
const Vector3f& rkCameraDir = rkPTexture.GetCamera()->GetDirection();
const Vector3f& rkCameraUp = rkPTexture.GetCamera()->GetUp();
const Vector3f& rkCameraLookAt = rkCameraLoc + rkCameraDir;
D3DXVECTOR3 kProjectorEye(rkCameraLoc.X(),rkCameraLoc.Y(),
rkCameraLoc.Z());
D3DXVECTOR3 kProjectorUp(rkCameraUp.X(),rkCameraUp.Y(),rkCameraUp.Z());
D3DXVECTOR3 kProjectorLookAt(rkCameraLookAt.X(),rkCameraLookAt.Y(),
rkCameraLookAt.Z());
D3DXMatrixLookAtRH(&kMatrixViewProjector,&kProjectorEye,&kProjectorLookAt,
&kProjectorUp);
// Setup the projection transform for the projector - ProjectionProjector.
// Setup a right-handed off-center perspective projection matrix using
// the projected texture camera frustrum.
rkPTexture.GetCamera()->GetFrustum(fNear,fFar,fLeft,fRight,fTop,fBottom);
D3DXMatrixPerspectiveOffCenterRH(&kMatrixProjectionProjector,fLeft,fRight,
fBottom,fTop,fNear,fFar);
// Bias and scale the texture so that it covers the near plane.
// Note that integral screen coordinates represent pixel centers
// whereas integral texture coordinates represent texel boundaries.
// We also need to know the dimensions of the texture being projected.
Image* pkTextureImage = pkTexture->GetImage();
float fOffsetX = 0.5f + (0.5f / pkTextureImage->GetWidth());
float fOffsetY = 0.5f + (0.5f / pkTextureImage->GetHeight());
D3DXMATRIX kMatrixScaleBiasTexture(
0.5f,0.0f,0.0f,0.0f,
0.0f,0.5f,0.0f,0.0f,
0.0f,0.0f,1.0f,0.0f,
fOffsetX,fOffsetY,0.0f,1.0f);
// Create the projected texture transform by combining the
// following transformations in the given order (left to right):
// . kMatrixInverseViewCamera
// . kMatrixViewProjector
// . kMatrixProjectionProjector
// . kMatrixScaleBiasTexture
D3DXMatrixMultiply(&kMatrixTextureProjector,
D3DXMatrixMultiply(&kMatTmp1,&kMatrixInverseViewCamera,
&kMatrixViewProjector),
D3DXMatrixMultiply(&kMatTmp2,&kMatrixProjectionProjector,
&kMatrixScaleBiasTexture));
ms_hResult = m_pqDevice->SetTransform(
D3DTRANSFORMSTATETYPE(D3DTS_TEXTURE0+iUnit),&kMatrixTextureProjector);
WML_DX_ERROR_CHECK(SetTransform);
// Use the texture coordinate set defined for this stage, but the
// texture coordinates for this stage are based on the transformed
// vertex position.
ms_hResult = m_pqDevice->SetTextureStageState(iUnit,D3DTSS_TEXCOORDINDEX,
D3DTSS_TCI_CAMERASPACEPOSITION|iUnit);
WML_DX_ERROR_CHECK(SetTextureStageState);
// All four dimenions of the texture transform are processed.
// The coordinates are then dealt with as a projected texture.
ms_hResult = m_pqDevice->SetTextureStageState(iUnit,
D3DTSS_TEXTURETRANSFORMFLAGS,D3DTTFF_COUNT4|D3DTTFF_PROJECTED);
WML_DX_ERROR_CHECK(SetTextureStageState);
// Draw the objects as usual
Renderer::Draw(rkPTexture.GetObjects());
// No longer need the reserved texture unit.
ReleaseTextureUnit(iUnit);
}
