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Cannot get textured quad visible

Started by Luke Cragg May 8, 2013 at 5:34 PM 3 replies 2.2k views

Original Post

May 8, 2013 at 5:34 PM

Hi all.

I just wanted to do a simple 2D game using directx11 (as I have been using direct 9 mostly).

I set up a 2D sprite class which was to render 2 triangles making a square and giving it a texture to represent the sprite.

Now all this compiles but I cannot get the sprite visible on screen.

The directx breakdown on PIX is attached. It's showing that all my vertices are correct and the vertex shader is doing what it's supposed to.

[attachment=15626:PIX.png]

So can only assume it is something to do with the rasterizer or output merger as I have tried just outputting a colour from my pixel shader instead of a texture sample.

My rasterizer state is


D3D11_RASTERIZER_DESC rastDesc;
	ZeroMemory( &rastDesc, sizeof( rastDesc ) );
	rastDesc.FillMode =  D3D11_FILL_SOLID ;
	rastDesc.CullMode =  D3D11_CULL_NONE   ;
	rastDesc.FrontCounterClockwise = false;
    rastDesc.DepthBias = 0.0f;
	rastDesc. DepthBiasClamp = 0.0f;
	rastDesc. SlopeScaledDepthBias = 0.0f;
	rastDesc.DepthClipEnable = true;
	rastDesc.ScissorEnable = false;
	rastDesc.MultisampleEnable = false;
	rastDesc.AntialiasedLineEnable = false;

	Program::GetInstance()->GetD3DDevice()->CreateRasterizerState(&rastDesc, & m_rasterizerState);
	Program::GetInstance()->GetD3DDeviceContext()->RSSetState(m_rasterizerState);

My blender state is


D3D11_BLEND_DESC blendDesc;
    ZeroMemory( &blendDesc, sizeof( blendDesc ) );
    blendDesc.RenderTarget[0].BlendEnable = TRUE;
    blendDesc.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
    blendDesc.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;
    blendDesc.RenderTarget[0].DestBlend = D3D11_BLEND_ONE;
    blendDesc.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;
    blendDesc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_SRC1_ALPHA;
    blendDesc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_INV_SRC1_ALPHA;
    blendDesc.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;

    float blendFactor[4] = { 0.0f, 0.0f, 0.0f, 0.0f };

    Program::GetInstance()->GetD3DDevice()->CreateBlendState( &blendDesc, &alphaBlendState_ );
    Program::GetInstance()->GetD3DDeviceContext()->OMSetBlendState( alphaBlendState_, &blendFactor, 0xFFFFFFFF );

Im using this projection matrix also as it's 2D.

Matrix projection = XMMatrixOrthographicOffCenterLH( 0.0f, 1000.0f, 0.0f, 1000.0f, 0.0f, 2.0f );

I am all out of ideas as to what the issue could be.

Thanks

Jason Z

May 8, 2013 at 10:54 PM

Have you tried to debug a pixel that should be affected by that sprite in PIX? It should show you if the pixel was generated (i.e. it made it past the rasterizer stage) and also why it was discarded (i.e. depth/stencil test) or if it was blended (in which case it would be a blend issue).

Just right click on the pixel in your output render target and you should be able to debug what is going on.

ankhd

May 9, 2013 at 3:10 AM

Hello. It looks like it is small

Luke Cragg

May 9, 2013 at 4:04 PM

Thanks, I was looking how to debug a pixel rather than a vertex.

It has told me that it is discarded because it has failed the depth test.

The vertices have a depth of 0.25 post vertex shader. Meaning they should be visible. Plus it is the only geometry being rendered so it cant be underneath anything else.

So it must either be my raster code


D3D11_RASTERIZER_DESC rastDesc;
	ZeroMemory( &rastDesc, sizeof( rastDesc ) );
	rastDesc.FillMode =  D3D11_FILL_SOLID ;
	rastDesc.CullMode =  D3D11_CULL_NONE   ;
	rastDesc.FrontCounterClockwise = false;
    rastDesc.DepthBias = 0.0f;
	rastDesc. DepthBiasClamp = 0.0f;
	rastDesc. SlopeScaledDepthBias = 0.0f;
	rastDesc.DepthClipEnable = true;
	rastDesc.ScissorEnable = false;
	rastDesc.MultisampleEnable = false;
	rastDesc.AntialiasedLineEnable = false;

	Program::GetInstance()->GetD3DDevice()->CreateRasterizerState(&rastDesc, & m_rasterizerState);
	Program::GetInstance()->GetD3DDeviceContext()->RSSetState(m_rasterizerState);

Or the projection Matrix's final two values.


Matrix view = XMMatrixIdentity( );
Matrix projection = XMMatrixOrthographicOffCenterLH( 0.0f, 1000.0f, 0.0f, 1000.0f, 0.0f, 2.0f );
m_viewProj = XMMatrixMultiply( view, projection );

But I thought what I had wrote meant anything between 0.0 and 2.0 in world space would be visible.

Luke Cragg

May 9, 2013 at 4:56 PM

I've sorted it. I wasn't clearing the depth buffer.

Although to be fair I thought this would have just rendered the image first frame then stuck like that.

Obviously being a problem once other objects had to be rendered.

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