Directx11学习笔记【十一】 画一个简单的三角形--effect框架的使用

这里不再介绍effect框架的具体使用，有关effect框架使用可参考http://www.cnblogs.com/zhangbaochong/p/5475961.html

实现的功能依然是画一个简单的三角形，只不过使用了effect框架。

为了体现使用effect框架方便变量绑定的优点，我们对着色器代码做了修改，增加了一个常量float4x4 gWorldViewProj

cbuffer cbPerObject
{
    float4x4 gWorldViewProj; 
};

float4 VS_Main( float4 pos : POSITION ) : SV_POSITION  
  
{    
    pos = mul(pos,gWorldViewProj);
    return pos;  
  
}  
  
float4 PS_Main( float4 pos : SV_POSITION ) : SV_TARGET  
  
{  
  
    return float4( 1.0f, 0.0f, 0.0f, 1.0f );  
  
} 

technique11 ColorTech
{
    pass P0
    {
        SetVertexShader( CompileShader( vs_5_0, VS_Main() ) );
        SetGeometryShader( NULL );
        SetPixelShader( CompileShader( ps_5_0, PS_Main() ) );
    }
}

由于代码很简单，这里不再给出解释，直接看代码吧！

下面是修改后的TriangleDemo.h

#pragma once

#include "Dx11DemoBase.h"
#include "d3dx11effect.h"

class TriangleDemo : public Dx11DemoBase
{
public:
    TriangleDemo();
    ~TriangleDemo();

    bool LoadContent() override;
    void UnLoadContent() override;

    void Update(float dt) override;
    void Render() override;

private:
    ID3D11Buffer *m_pVertexBuffer;
    ID3D11InputLayout *m_pInputLayout;

    ID3DX11Effect *m_pFx;
    ID3DX11EffectTechnique *m_pTechnique;
    ID3DX11EffectMatrixVariable *m_pFxWorldViewProj;
    XMFLOAT4X4 m_world;
    XMFLOAT4X4 m_view;
    XMFLOAT4X4 m_proj;

};

TriangleDemo.cpp

#include "TriangleDemo.h"


struct VertexPos
{
    XMFLOAT3 pos;
};

TriangleDemo::TriangleDemo() 
: m_pInputLayout(0), m_pVertexBuffer(0)
{
    XMMATRIX I = XMMatrixIdentity();
    XMStoreFloat4x4(&m_world, I);
    XMStoreFloat4x4(&m_view, I);
    XMStoreFloat4x4(&m_proj, I);
}


TriangleDemo::~TriangleDemo()
{
}

void TriangleDemo::UnLoadContent()
{
    if (m_pVertexBuffer)
        m_pVertexBuffer->Release();
    if (m_pInputLayout)
        m_pInputLayout->Release();
    if (m_pFx)
        m_pFx->Release();
    m_pVertexBuffer = 0;
    m_pInputLayout = 0;
    m_pFx = 0;
}

bool TriangleDemo::LoadContent()
{
    HRESULT result;
    VertexPos vertices[] =
    {
        XMFLOAT3(0.5f, 0.5f, 0.5f),
        XMFLOAT3(0.5f, -0.5f, 0.5f),
        XMFLOAT3(-0.5f, -0.5f, 0.5f)
    };

    D3D11_BUFFER_DESC vertexDesc;
    ZeroMemory(&vertexDesc, sizeof(vertexDesc));
    vertexDesc.Usage = D3D11_USAGE_DEFAULT;
    vertexDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
    vertexDesc.ByteWidth = sizeof(VertexPos)* 3;

    D3D11_SUBRESOURCE_DATA resourceData;
    ZeroMemory(&resourceData, sizeof(resourceData));
    resourceData.pSysMem = vertices;

    result = m_pd3dDevice->CreateBuffer(&vertexDesc, &resourceData, &m_pVertexBuffer);
    if (FAILED(result))
    {
        return false;
    }


    DWORD shaderFlags = D3DCOMPILE_ENABLE_STRICTNESS;
#if defined _DEBUG || defined DEBUG
    shaderFlags = D3DCOMPILE_DEBUG;
#endif

    ID3D10Blob *compiledShader = 0;
    ID3D10Blob *compilationMsgs = 0;
    result = D3DX11CompileFromFile("SolidColor.fx", 0, 0, 0, "fx_5_0", shaderFlags,
        0, 0, &compiledShader, &compilationMsgs, 0);
    if (compilationMsgs != 0)
    {
        MessageBox(0, (char*)compilationMsgs->GetBufferPointer(), 0, 0);
        compilationMsgs->Release();
        compilationMsgs = 0;
    }
    if (FAILED(result))
    {
        MessageBox(0, "载入着色器错误", 0, 0);
        return false;
    }

    result = D3DX11CreateEffectFromMemory(compiledShader->GetBufferPointer(), compiledShader->GetBufferSize(),
        0, m_pd3dDevice, &m_pFx);
    compiledShader->Release();
    if (FAILED(result))
    {
        MessageBox(0, "载入着色器失败", 0, 0);
        return false;
    }
    m_pTechnique = m_pFx->GetTechniqueByName("ColorTech");
    m_pFxWorldViewProj = m_pFx->GetVariableByName("gWorldViewProj")->AsMatrix();
    
    D3D11_INPUT_ELEMENT_DESC solidColorLayout[] =
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 }
    };
    UINT numLayoutElements = ARRAYSIZE(solidColorLayout);
    D3DX11_PASS_DESC passDesc;
    m_pTechnique->GetPassByIndex(0)->GetDesc(&passDesc);

    result = m_pd3dDevice->CreateInputLayout(solidColorLayout, numLayoutElements, passDesc.pIAInputSignature,
        passDesc.IAInputSignatureSize, &m_pInputLayout);
    
    return true;
}



void TriangleDemo::Update(float dt)
{

}

void TriangleDemo::Render()
{
    if (m_pImmediateContext == 0)
        return;
    //清除渲染目标视图
    float clearColor[4] = { 0.5f, 0.5f, 0.5f, 1.0f };//背景颜色
    m_pImmediateContext->ClearRenderTargetView(m_pRenderTargetView, clearColor);

    UINT stride = sizeof(VertexPos);
    UINT offset = 0;
    //设置数据信息格式控制信息
    m_pImmediateContext->IASetInputLayout(m_pInputLayout);
    //设置要绘制的几何体信息
    m_pImmediateContext->IASetVertexBuffers(0,1,&m_pVertexBuffer,&stride,&offset);
    //指明如何绘制三角形
    m_pImmediateContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);

    //设置常量 
    XMMATRIX world = XMLoadFloat4x4(&m_world);
    XMMATRIX view = XMLoadFloat4x4(&m_view);
    XMMATRIX proj = XMLoadFloat4x4(&m_proj);
    XMMATRIX worldViewProj = world*view*proj;
    m_pFxWorldViewProj->SetMatrix(reinterpret_cast<float*>(&worldViewProj));

    D3DX11_TECHNIQUE_DESC techDesc;
    m_pTechnique->GetDesc(&techDesc);
    for (UINT i = 0; i < techDesc.Passes; ++i)
    {
        m_pTechnique->GetPassByIndex(i)->Apply(0, m_pImmediateContext);
        m_pImmediateContext->Draw(3, 0);
    }
    //马上输出
    m_pSwapChain->Present(0, 0);
}

运行结果同之前的一样，不再贴图了