Vertices not rendering - DirectX

Question

我正在学习DirectX，并试图确定我在理解函数在做什么之后，继续创建索引缓冲区（这就是为什么我使用重复顶点而不是特定索引）的原因。我想渲染一个正方形，但我只有一个三角形显示。我确信这是我误解了排序顺序，或者在传递给着色器时抵消了这些值，但我无法找到问题所在。以下是当前的相关代码和运行时的结果。

void RenderFrame(void) { 

// Clear BackBuffer to a color 
devContext->ClearRenderTargetView(backbuffer, D3DXCOLOR(0.0f, 0.2f, 0.4f, 1.0f)); 

// select which vertex buffer to display 
UINT stride = sizeof(Vertex); 
UINT offset = 0; 
devContext->IASetVertexBuffers(0, 1, &pVBuffer, &stride, &offset); 

// select which primtive type we are using 
devContext->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELST); 

// draw the vertex buffer to the back buffer 
devContext->Draw(6, 0); 

// swap buffers 
swapchain->Present(0, 0); 
} 

void ParseGraphics() { 

// Create a triangle with the Vertex Struct 
Vertex square[] = 
{ 
    { 0.2f, 0.5f, 0.5f, D3DXCOLOR(0.0f, 0.0f, 1.0f, 1.0f) }, //top-right 
    { 0.2f, -0.5f, 0.5f, D3DXCOLOR(0.0f, 0.0f, 0.0f, 1.0f) }, //bottom-right 
    { -0.2f, -0.5f, 0.5f, D3DXCOLOR(1.0f, 0.0f, 0.0f, 1.0f) }, //bottom-left 
    { 0.2f, -0.5f, 0.5f, D3DXCOLOR(0.0f, 0.0f, 0.0f, 1.0f) }, //bottom-right 
    { -0.2f, -0.5f, 0.5f, D3DXCOLOR(1.0f, 0.0f, 0.0f, 1.0f) }, //bottom-left 
    { -0.2f, 0.5f, 0.5f, D3DXCOLOR(0.0f, 1.0f, 0.0f, 1.0f) }, //top-left 


}; 

// Create Vertex Buffer 
D3D11_BUFFER_DESC bd; 
ZeroMemory(&bd, sizeof(bd)); 

bd.Usage = D3D11_USAGE_DYNAMIC; 
bd.ByteWidth = sizeof(Vertex) * 6; 
bd.BindFlags = D3D11_BIND_VERTEX_BUFFER; 
bd.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE; 

dev->CreateBuffer(&bd, NULL, &pVBuffer); 

// copy vertices into buffer 
D3D11_MAPPED_SUBRESOURCE msr; 
devContext->Map(pVBuffer, NULL, D3D11_MAP_WRITE_DISCARD, NULL, &msr); 
memcpy(msr.pData, square, sizeof(square)); 
devContext->Unmap(pVBuffer, NULL); 

} 

void BuildPipeline() { 
// Load and Compile Shaders 
ID3D10Blob *VS, *PS; 
D3DX11CompileFromFile(L"shaders.shader", 0, 0, "VShader", "vs_5_0", 0, 0, 0, &VS, 0, 0); 
D3DX11CompileFromFile(L"shaders.shader", 0, 0, "PShader", "ps_5_0", 0, 0, 0, &PS, 0, 0); 

// Create shaders from the data in the Blobs Buffer 
dev->CreateVertexShader(VS->GetBufferPointer(), VS->GetBufferSize(), NULL, &pVS); 
dev->CreatePixelShader(PS->GetBufferPointer(), PS->GetBufferSize(), NULL, &pPS); 

// Apply Shaders to the device context 
devContext->VSSetShader(pVS, 0, 0); 
devContext->PSSetShader(pPS, 0, 0); 

// Define the layout of the input given to the shaders 
D3D11_INPUT_ELEMENT_DESC ied[] = 
{ 
    {"POSITION", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0}, 
    {"COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 24, D3D11_INPUT_PER_VERTEX_DATA, 0}, 

}; 

dev->CreateInputLayout(ied, 2, VS->GetBufferPointer(), VS->GetBufferSize(), &pLayout); 
devContext->IASetInputLayout(pLayout); 

} 

Answer 1

{ “POSITION”，0，DXGI_FORMAT_R32G32B32 A32 _FLOAT，0，0，D3D11_INPUT_PER_VERTEX_DATA，0}

应DXGI_FORMAT_R32G32B32_FLOAT作为位置仅具有三个成员。 AlignedByteOffset可以设置为12（4x3）。

Answer 2

对于拓扑，您可以指定D3D10_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP，所以顶点数据有望形成一个triangle strip。但是，你所提供的数据指定了两个独立的三角形（即三角形列表），所以你应该使用

devContext->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST); 

基本的错误似乎是在Draw（）调用：您指定要总共绘制3个顶点，而您实际上想从缓冲区中绘制所有6个顶点。即

devContext->Draw(6, 0); 

您的Color元素描述的字节偏移量也是错误的。该位置需要3个单精度浮点数（3 * 4 = 12个字节），紧接着是颜色数据。

{"COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0},