Why might render target in DirectX9 fail to work?

Question

I'm trying to render to a texture, but nothing is being drawn. Everything before SetRenderTarget is rendered properly, everything after second SetRenderTarget is visible on the screen. Just the part that should have been rendered to a texture is ignored.

Below is a Delphi code showing what I'm doing. What am I missing?

//Random texture size, non-power-of-two textures supported by card
//Tried with 512x512, same results
FStaticWidth := 806;
FStaticHeight := 413;

//Error checking code left out for clarity
//But every operation is checked

//Create texture
dev.CreateTexture(FStaticWidth, FStaticHeight, 1, D3DUSAGE_RENDERTARGET, D3DFMT_X8R8G8B8, D3DPOOL_DEFAULT, FStaticText, nil);
FStaticText.GetSurfaceLevel(0, surf);

//Save everything;
dev.GetViewport(oldVp);
dev.GetRenderTarget(0, oldTarget);

//Change render target
dev.EndScene;
dev.SetRenderTarget(0, surf);
dev.BeginScene;

//Reset viewport
vp.X := 0;
vp.Y := 0;
vp.Width := FStaticWidth;
vp.Height := FStaticHeight;
vp.MinZ := -1000;
vp.MaxZ := 1000;
dev.SetViewport(vp);

//Draw
dev.Clear(0, nil, D3DCLEAR_TARGET or D3DCLEAR_ZBUFFER, $FF112233, 1.0, 0);

//...whatever I do here, it's ignored.
//It doesn't appear neither on the surface, nor on the screen.
//Not even dev.Clear() above works.

//Restore render target
dev.EndScene;
dev.SetRenderTarget(0, OldTarget);
dev.BeginScene;

//Restore viewport
dev.SetViewport(oldVp);

//Dump the texture to a file
D3DXSaveSurfaceToFileW(PWideChar(AppFolder+'\static-surf.bmp'), D3DXIFF_BMP, surf, nil, nil);
//The file is a FStaticWidth x FStaticHeight bitmap,
//containing only black transparent ($00000000) pixels.

Here's how it looks like in PIX:

12570   <0x05AC9EA0> IDirect3DDevice9::GetViewport(0x0018FD40)
12571   <0x05AC9EA0> IDirect3DDevice9::GetRenderTarget(0x00000000, 0x0018FD80 --> 0x05ACA9B8)
12572   <0x05AC9EA0> IDirect3DDevice9::EndScene()
12573   <0x05AC9EA0> IDirect3DDevice9::SetRenderTarget(0x00000000, 0x05B53878)
12574   <0x05AC9EA0> IDirect3DDevice9::BeginScene()
12575   <0x05AC9EA0> IDirect3DDevice9::SetViewport(0x0018FD58)
12576   <0x05AC9EA0> IDirect3DDevice9::Clear(0x00000000, NULL, 0x00000003, D3DCOLOR_ARGB(0xff,0x11,0x22,0x33), 1.000f, 0x00000000)
12577   <0x05AC9EA0> IDirect3DDevice9::EndScene()
12578   <0x05AC9EA0> IDirect3DDevice9::SetRenderTarget(0x00000000, 0x05ACA9B8)
12579   <0x05AC9EA0> IDirect3DDevice9::BeginScene()
12580   <0x05AC9EA0> IDirect3DDevice9::SetViewport(0x0018FD40)

Render target 0x05B53878 remains empty (transparent black) after each event.

Answer 1

Solved. You have to set DepthStencil surface along with RenderTarget, and those have to be of the same dimensions and formats.

FStaticText.GetLevelDesc(0, desc);
dev.CreateDepthStencilSurface(FStaticWidth, FStaticHeight, D3DFMT_D16,
    desc.MultiSampleType, desc.MultiSampleQuality, true, FStaticStencil, nil);

//...
dev.GetDepthStencilSurface(oldStencil);
dev.SetDepthStencilSurface(FStaticStencil);

//...
dev.SetDepthStencilSurface(oldStencil);