Question

我有一个基于Visual Studio的Windows8-DirectX模板的应用程序，我正在尝试使用以下D3D11_BLEND_DESC的alpha通道绘制纹理：

D3D11_BLEND_DESC blendDesc{};
blendDesc.RenderTarget[0].BlendEnable = TRUE;
blendDesc.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;
blendDesc.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;

blendDesc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_INV_DEST_ALPHA;
blendDesc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ONE;

blendDesc.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
blendDesc.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;

blendDesc.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;

ThrowIfFailed(device->CreateBlendState(&blendDesc, &_blendState));

我以这种方式绑定这个混合状态：

float blendFactor[4] = { 0.0f, 0.0f, 1.0f, 1.0f };
UINT sampleMask = 0xffffffff;
context->OMSetBlendState(_blendState.Get(), blendFactor, sampleMask);

这是我的顶点着色器：

cbuffer ModelViewProjectionConstantBuffer : register(b0)
{
    matrix model;
    matrix view;
    matrix projection;
};

struct VertexShaderInput
{
    float3 pos : POSITION;
    float2 texcoord : TEXCOORD;
};

struct PixelShaderInput
{
    float4 pos : SV_POSITION;
    float2 texcoord : TEXCOORD;
};

PixelShaderInput main(VertexShaderInput input)
{
    PixelShaderInput output;
    float4 pos = float4(input.pos, 1.0f);

    pos = mul(pos, model);
    pos = mul(pos, view);
    pos = mul(pos, projection);
    output.pos = pos;

    output.texcoord = input.texcoord;

    return output;
}

Pixel Shader：

Texture2D tex0;
SamplerState s0;

struct PixelShaderInput
{
    float4 pos : SV_POSITION;
    float2 texcoord : TEXCOORD;
};

float4 main(PixelShaderInput input) : SV_TARGET
{
    float4 color = tex0.Sample(s0, input.texcoord);
    return  color;
}

这就是我的纹理：

D3D11_TEXTURE2D_DESC textureDesc{};
textureDesc.Width = width;
textureDesc.Height = height;
textureDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM;
textureDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
textureDesc.MipLevels = textureDesc.ArraySize = 1;
textureDesc.SampleDesc.Count = 1;

ThrowIfFailed(device->CreateTexture2D(&textureDesc, NULL, &_texture));
ThrowIfFailed(device->CreateShaderResourceView(_texture.Get(), NULL, &_textureView));

但问题是混合效果不正常。纹理仅与背景混合，但不与其他纹理混合，例如。如果我用蓝色作为第三个参数调用ClearRenderTargetView方法，那么部分透明的纹理将会偏蓝，但不会与重叠纹理混合。

DirectX alpha混合在UWP中不起作用

0 个答案: