DirectX 11 Sprite Alpha (Invalid? + Bad Quality)

Question

I have a bug with a texture font.

This is the texture file in photoshop:

This is the result I am getting:

The alpha from 0 and 1 shows weird artifacts as the final result, alongside the low quality of the image itself. How can i fix this?

blendStateDescription.RenderTarget[0].BlendEnable = TRUE;
blendStateDescription.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;
blendStateDescription.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;

blendStateDescription.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;
blendStateDescription.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_INV_DEST_ALPHA;
blendStateDescription.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ONE;
blendStateDescription.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
blendStateDescription.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;

float4 FontPixelShader(PixelInputType input) : SV_TARGET
{
   float4 color;

   // Sample the texture pixel at this location.
   color = shaderTexture.Sample(SampleType, input.tex);

   // If the color is black on the texture then treat this pixel as transparent.
   if(color.r == 0.0f)
   {
       color.a = 0.0f;
   }

   // If the color is other than black on the texture then this is a pixel in the font so draw it using the font pixel color.
   else
   {
       color.rgb = pixelColor.rgb;
       color.a = pixelColor.a;
   }

   return color;
}

// Create a texture sampler state description.
samplerDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
samplerDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
samplerDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
samplerDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
samplerDesc.MipLODBias = 0.0f;
samplerDesc.MaxAnisotropy = 1;
samplerDesc.ComparisonFunc = D3D11_COMPARISON_ALWAYS;
samplerDesc.BorderColor[0] = 0;
samplerDesc.BorderColor[1] = 0;
samplerDesc.BorderColor[2] = 0;
samplerDesc.BorderColor[3] = 0;
samplerDesc.MinLOD = 0;
samplerDesc.MaxLOD = D3D11_FLOAT32_MAX;

Answer 1

This is a rather odd setup for blend state:

// Default values
desc.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;
desc.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
desc.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;

// Blend setup
desc.RenderTarget[0].BlendEnable = TRUE;
desc.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;
desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_INV_DEST_ALPHA;
desc.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;
desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ONE;

Typically you'd use the following for 'straight' alpha:

// Blend setup
desc.RenderTarget[0].BlendEnable = TRUE;
desc.RenderTarget[0].SrcBlend =
desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_SRC_ALPHA;
desc.RenderTarget[0].DestBlend =
desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_INV_SRC_ALPHA;

And use this for premultiplied alpha:

// Blend setup
desc.RenderTarget[0].BlendEnable = TRUE;
desc.RenderTarget[0].SrcBlend =
desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_ONE;
desc.RenderTarget[0].DestBlend =
desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_INV_SRC_ALPHA;

And this for additive:

// Blend setup
desc.RenderTarget[0].BlendEnable = TRUE;
desc.RenderTarget[0].SrcBlend =
desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_SRC_ALPHA;
desc.RenderTarget[0].DestBlend =
desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ONE;