indexed triangle drawing

hw3d/Graphics.cpp

@@ -124,6 +124,9 @@ void Graphics::DrawTestTriangle()
 		{ 0.0f,0.5f,255,0,0,0 },
 		{ 0.5f,-0.5f,0,255,0,0 },
 		{ -0.5f,-0.5f,0,0,255,0 },
+		{ -0.3f,0.3f,0,255,0,0 },
+		{ 0.3f,0.3f,0,0,255,0 },
+		{ 0.0f,-0.8f,255,0,0,0 },
 	};
 	vertices[0].color.g = 255;
 	wrl::ComPtr<ID3D11Buffer> pVertexBuffer;
@@ -137,11 +140,35 @@ void Graphics::DrawTestTriangle()
 	D3D11_SUBRESOURCE_DATA sd = {};
 	sd.pSysMem = vertices;
 	GFX_THROW_INFO( pDevice->CreateBuffer( &bd,&sd,&pVertexBuffer ) );
-
+	
 	// Bind vertex buffer to pipeline
 	const UINT stride = sizeof( Vertex );
 	const UINT offset = 0u;
 	pContext->IASetVertexBuffers( 0u,1u,pVertexBuffer.GetAddressOf(),&stride,&offset );
+
+
+	// create index buffer
+	const unsigned short indices[] =
+	{
+		0,1,2,
+		0,2,3,
+		0,4,1,
+		2,1,5,
+	};
+	wrl::ComPtr<ID3D11Buffer> pIndexBuffer;
+	D3D11_BUFFER_DESC ibd = {};
+	ibd.BindFlags = D3D11_BIND_INDEX_BUFFER;
+	ibd.Usage = D3D11_USAGE_DEFAULT;
+	ibd.CPUAccessFlags = 0u;
+	ibd.MiscFlags = 0u;
+	ibd.ByteWidth = sizeof( indices );
+	ibd.StructureByteStride = sizeof( unsigned short );
+	D3D11_SUBRESOURCE_DATA isd = {};
+	isd.pSysMem = indices;
+	GFX_THROW_INFO( pDevice->CreateBuffer( &ibd,&isd,&pIndexBuffer ) );
+
+	// bind index buffer
+	pContext->IASetIndexBuffer( pIndexBuffer.Get(),DXGI_FORMAT_R16_UINT,0u );
 	
 
 	// create pixel shader
@@ -200,7 +227,7 @@ void Graphics::DrawTestTriangle()
 	pContext->RSSetViewports( 1u,&vp );
 
 
-	GFX_THROW_INFO_ONLY( pContext->Draw( (UINT)std::size( vertices ),0u ) );
+	GFX_THROW_INFO_ONLY( pContext->DrawIndexed( (UINT)std::size( indices ),0u,0u ) );
 }