Need help with D3DXMatrixOrthoLH

Hello,

I've been tearing my hair out for the past few days trying to do this.

I am trying to draw a rectangle enclosing a rotating 3D object. The rectangle position is fixed no matter where the camera is or how it rotates. The rectangle acts like a control panel to the 3D scene.

I am using D3DXMatrixOrthoLH to position the rectangle. But I am not sure what should I put in the w and h. Should I put the display resolution values such as 800, 600? Or the size of the display surface in pixels?

Is it true that if I use D3DXMatrixOrthoLH, its origin starts at the center, not the top left corner? How can I translate my line coordinates into the display surface? I can't seem to get the rectangle displayed no matter what coordinates I use.

Here's my code



Dim mode As D3DDISPLAYMODE
Dim matOrtho As D3DMATRIX
Dim matIdentity As D3DMATRIX

Dim oSurface As Direct3DSurface8
Dim SurfDesc As D3DSURFACE_DESC

Set oSurface = g_D3DDevice.GetRenderTarget
oSurface.GetDesc SurfDesc

' Get The current Display Mode format
g_d3d.GetAdapterDisplayMode D3DADAPTER_DEFAULT, mode

D3DXMatrixOrthoLH matOrtho, SurfDesc.width, SurfDesc.height, 0#, 1#
' D3DXMatrixOrthoLH matOrtho, mode.width, mode.height, 0#, 1#

D3DXMatrixIdentity matIdentity

g_D3DDevice.SetTransform D3DTS_PROJECTION, matOrtho
g_D3DDevice.SetTransform D3DTS_WORLD, matIdentity
g_D3DDevice.SetTransform D3DTS_VIEW, matIdentity

'Make sure that the z-buffer and lighting are disabled
g_D3DDevice.SetRenderState D3DRS_ZENABLE, D3DZB_FALSE
g_D3DDevice.SetRenderState D3DRS_LIGHTING, False

LineStripBox(0) = CreateTLVertex(2, 2, 1, 1, RGB(0, 255, 0), 0, 0, 0)
LineStripBox(1) = CreateTLVertex(390, 2,1, 1, RGB(0, 0, 0), 0, 0, 0)
LineStripBox(2) = CreateTLVertex(390, 400, 1, 1, RGB(0, 0, 0), 0, 0, 0)
LineStripBox(3) = CreateTLVertex(2, 400, 1, 1, RGB(0, 0, 255), 0, 0, 0)
LineStripBox(4) = CreateTLVertex(2, 2, 1, 1, RGB(0, 0, 0), 0, 0, 0)

g_D3DDevice.SetVertexShader FVF
g_D3DDevice.DrawPrimitiveUP D3DPT_LINESTRIP, 4, LineStripBox(0), Len(LineStripBox(0))

Do you still need help with this?

CreateTLVertex
Transformed vertices ignore all transformations, including the world, view and projection matrices.