DirectX9 SDK Samples(10) HLSLwithoutEffects Sample

最新推荐文章于 2018-06-07 22:57:29 发布

HowdChow

最新推荐文章于 2018-06-07 22:57:29 发布

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分类专栏： DirectX SDK Samples 文章标签： shader output float constants function null

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这个例子没有用效果框架的接口，只用了顶点着色器。

OnCreateDevice函数中，载入顶点着色器。

    WCHAR strPath[512];
    LPD3DXBUFFER pCode;

    D3DVERTEXELEMENT9 decl[] =
    {
        { 0, 0, D3DDECLTYPE_FLOAT2, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_POSITION, 0 },
        D3DDECL_END()
    };

    V_RETURN( pd3dDevice->CreateVertexDeclaration( decl, &g_pVertexDeclaration ) );

    // Find the vertex shader file
    V_RETURN( DXUTFindDXSDKMediaFileCch( strPath, 512, L"HLSLwithoutEffects.vsh" ) );

这一次终于用到了顶点描述表。

    V_RETURN( D3DXCompileShaderFromFile( strPath, NULL, NULL, "Ripple",
                                         "vs_2_0", dwShaderFlags, &pCode,
                                         NULL, &g_pConstantTable ) );

    // Create the vertex shader
    hr = pd3dDevice->CreateVertexShader( ( DWORD* )pCode->GetBufferPointer(),
                                         &g_pVertexShader );

载入并且创建顶点着色器。

OnResetDevice函数，创建顶点缓冲和索引缓冲。具体代码就不贴了。

OnFrameMove函数，设置着色器参数

    // Set up the vertex shader constants
    D3DXMATRIXA16 mWorldViewProj;
    D3DXMATRIXA16 mWorld;
    D3DXMATRIXA16 mView;
    D3DXMATRIXA16 mProj;

    mWorld = *g_Camera.GetWorldMatrix();
    mView = *g_Camera.GetViewMatrix();
    mProj = *g_Camera.GetProjMatrix();

    mWorldViewProj = mWorld * mView * mProj;

    g_pConstantTable->SetMatrix( DXUTGetD3D9Device(), "mWorldViewProj", &mWorldViewProj );
    g_pConstantTable->SetFloat( DXUTGetD3D9Device(), "fTime", ( float )fTime );

OnFrameRender函数~注意这里直接使用了SetVertexDeclaration和SetVertexShader函数。

    if( SUCCEEDED( pd3dDevice->BeginScene() ) )
    {
        pd3dDevice->SetVertexDeclaration( g_pVertexDeclaration );
        pd3dDevice->SetVertexShader( g_pVertexShader );
        pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof( D3DXVECTOR2 ) );
        pd3dDevice->SetIndices( g_pIB );

        V( pd3dDevice->DrawIndexedPrimitive( D3DPT_TRIANGLELIST, 0, 0, g_dwNumVertices,
                                             0, g_dwNumIndices / 3 ) );

        RenderText();
        V( g_HUD.OnRender( fElapsedTime ) );

        V( pd3dDevice->EndScene() );
    }

5RenderText()，这个函数在这个例子中并不占主要地位，但这里用到了txtHelper，DXUT中用这个来输出文字，因此提及一下，具体代码看例子。

至于HLSL文件就只列出代码不解释了，比较简单。

//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
float4x4 mWorldViewProj;  // World * View * Projection transformation
float fTime;			  // Time parameter. This keeps increasing


//-----------------------------------------------------------------------------
// Vertex shader output structure
//-----------------------------------------------------------------------------
struct VS_OUTPUT
{
    float4 Position   : POSITION;   // vertex position 
    float4 Diffuse    : COLOR0;     // vertex diffuse color
};


//-----------------------------------------------------------------------------
// Name: Ripple
// Type: Vertex shader                                      
// Desc: This shader ripples the vertices
//-----------------------------------------------------------------------------
VS_OUTPUT Ripple( in float2 vPosition : POSITION )
{
	VS_OUTPUT Output;
	
    float fSin, fCos;   
    float x = length( vPosition ) * sin( fTime ) * 15.0f;
    
    // This HLSL intrinsic computes returns both the sine and cosine of x
    sincos( x, fSin, fCos );

	// Change the y of the vertex position based on a function of time 
	// and transform the vertex into projection space. 
    Output.Position = mul( float4( vPosition.x, fSin * 0.1f, vPosition.y, 1.0f ), mWorldViewProj );
    
    // Output the diffuse color as function of time and 
    // the vertex's object space position
    Output.Diffuse = 0.5f - 0.5f * fCos;
    
    return Output;
}