第十章 DiffuseDemo核心代码

DiffuseDemo.cpp

//=============================================================================
// DiffuseDemo.cpp by Frank Luna (C) 2005 All Rights Reserved.
//
// Demonstrates diffuse lighting.
//
// Controls: Use mouse to orbit and zoom; use the 'W' and 'S' keys to 
//           alter the height of the camera.
//=============================================================================

#include "d3dApp.h"
#include "DirectInput.h"
#include <crtdbg.h>
#include "GfxStats.h"
#include <list>
#include "Vertex.h"

class DiffuseDemo : public D3DApp
{
public:
	DiffuseDemo(HINSTANCE hInstance, std::string winCaption, D3DDEVTYPE devType, DWORD requestedVP);
	~DiffuseDemo();

	bool checkDeviceCaps();
	void onLostDevice();
	void onResetDevice();
	void updateScene(float dt);
	void drawScene();

	// Helper methods
	void buildFX();
	void buildViewMtx();
	void buildProjMtx();

private:
	GfxStats* mGfxStats;
	
	ID3DXMesh*   mTeapot;
	ID3DXEffect* mFX;
	D3DXHANDLE   mhTech;
	D3DXHANDLE   mhWVP;
	D3DXHANDLE   mhWorldInverseTranspose;
	D3DXHANDLE   mhLightVecW;
	D3DXHANDLE   mhDiffuseMtrl;
	D3DXHANDLE   mhDiffuseLight;

	D3DXVECTOR3 mLightVecW;
	D3DXCOLOR   mDiffuseMtrl;
	D3DXCOLOR   mDiffuseLight;

	float mCameraRotationY;
	float mCameraRadius;
	float mCameraHeight;

	D3DXMATRIX mWorld;
	D3DXMATRIX mView;
	D3DXMATRIX mProj;
};


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance,
				   PSTR cmdLine, int showCmd)
{
	// Enable run-time memory check for debug builds.
	#if defined(DEBUG) | defined(_DEBUG)
		_CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
	#endif

	DiffuseDemo app(hInstance, "Diffuse Demo", D3DDEVTYPE_HAL, D3DCREATE_HARDWARE_VERTEXPROCESSING);
	gd3dApp = &app;

	DirectInput di(DISCL_NONEXCLUSIVE|DISCL_FOREGROUND, DISCL_NONEXCLUSIVE|DISCL_FOREGROUND);
	gDInput = &di;

    return gd3dApp->run();
}

DiffuseDemo::DiffuseDemo(HINSTANCE hInstance, std::string winCaption, D3DDEVTYPE devType, DWORD requestedVP)
: D3DApp(hInstance, winCaption, devType, requestedVP)
{
	if(!checkDeviceCaps())
	{
		MessageBox(0, "checkDeviceCaps() Failed", 0, 0);
		PostQuitMessage(0);
	}

	mGfxStats = new GfxStats();

	mCameraRadius    = 10.0f;
	mCameraRotationY = 1.2 * D3DX_PI;
	mCameraHeight    = 5.0f;

	mLightVecW    = D3DXVECTOR3(0.0, 0.0f, -1.0f);
	mDiffuseMtrl  = D3DXCOLOR(0.0f, 0.0f, 1.0f, 1.0f);
	mDiffuseLight = D3DXCOLOR(1.0f, 1.0f, 1.0f, 1.0f);

	D3DXMatrixIdentity(&mWorld);

	HR(D3DXCreateTeapot(gd3dDevice, &mTeapot, 0));
	buildFX();

	onResetDevice();

	InitAllVertexDeclarations();
}

DiffuseDemo::~DiffuseDemo()
{
	delete mGfxStats;
	ReleaseCOM(mTeapot);
	ReleaseCOM(mFX);

	DestroyAllVertexDeclarations();
}

bool DiffuseDemo::checkDeviceCaps()
{
	D3DCAPS9 caps;
	HR(gd3dDevice->GetDeviceCaps(&caps));

	// Check for vertex shader version 2.0 support.
	if( caps.VertexShaderVersion < D3DVS_VERSION(2, 0) )
		return false;

	// Check for pixel shader version 2.0 support.
	if( caps.PixelShaderVersion < D3DPS_VERSION(2, 0) )
		return false;

	return true;
}

void DiffuseDemo::onLostDevice()
{
	mGfxStats->onLostDevice();
	HR(mFX->OnLostDevice());
}

void DiffuseDemo::onResetDevice()
{
	mGfxStats->onResetDevice();
	HR(mFX->OnResetDevice());


	// The aspect ratio depends on the backbuffer dimensions, which can 
	// possibly change after a reset.  So rebuild the projection matrix.
	buildProjMtx();
}

void DiffuseDemo::updateScene(float dt)
{
	mGfxStats->setVertexCount(mTeapot->GetNumVertices());
	mGfxStats->setTriCount(mTeapot->GetNumFaces());
	mGfxStats->update(dt);

	// Get snapshot of input devices.
	gDInput->poll();

	// Check input.
	if( gDInput->keyDown(DIK_W) )	 
		mCameraHeight   += 25.0f * dt;
	if( gDInput->keyDown(DIK_S) )	 
		mCameraHeight   -= 25.0f * dt;

	// Divide by 50 to make mouse less sensitive. 
	mCameraRotationY += gDInput->mouseDX() / 100.0f;
	mCameraRadius    += gDInput->mouseDY() / 25.0f;

	// If we rotate over 360 degrees, just roll back to 0
	if( fabsf(mCameraRotationY) >= 2.0f * D3DX_PI ) 
		mCameraRotationY = 0.0f;

	// Don't let radius get too small.
	if( mCameraRadius < 5.0f )
		mCameraRadius = 5.0f;

	// The camera position/orientation relative to world space can 
	// change every frame based on input, so we need to rebuild the
	// view matrix every frame with the latest changes.
	buildViewMtx();
}


void DiffuseDemo::drawScene()
{
	// Clear the backbuffer and depth buffer.
	HR(gd3dDevice->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0xffeeeeee, 1.0f, 0));

	HR(gd3dDevice->BeginScene());

	// Setup the rendering FX
	HR(mFX->SetTechnique(mhTech));

	HR(mFX->SetMatrix(mhWVP, &(mWorld*mView*mProj)));
	D3DXMATRIX worldInverseTranspose;
	D3DXMatrixInverse(&worldInverseTranspose, 0, &mWorld);
	D3DXMatrixTranspose(&worldInverseTranspose, &worldInverseTranspose);
	HR(mFX->SetMatrix(mhWorldInverseTranspose, &worldInverseTranspose));
	HR(mFX->SetValue(mhLightVecW, &mLightVecW, sizeof(D3DXVECTOR3)));
	HR(mFX->SetValue(mhDiffuseMtrl, &mDiffuseMtrl, sizeof(D3DXCOLOR)));
	HR(mFX->SetValue(mhDiffuseLight, &mDiffuseLight, sizeof(D3DXCOLOR)));

	// Begin passes.
	UINT numPasses = 0;
	HR(mFX->Begin(&numPasses, 0));
	for(UINT i = 0; i < numPasses; ++i)
	{
		HR(mFX->BeginPass(i));
		HR(mTeapot->DrawSubset(0));
		HR(mFX->EndPass());
	}
	HR(mFX->End());

	
	mGfxStats->display();

	HR(gd3dDevice->EndScene());

	// Present the backbuffer.
	HR(gd3dDevice->Present(0, 0, 0, 0));
}

void DiffuseDemo::buildFX()
{
	// Create the FX from a .fx file.
	ID3DXBuffer* errors = 0;
	HR(D3DXCreateEffectFromFile(gd3dDevice, "diffuse.fx", 
		0, 0, D3DXSHADER_DEBUG, 0, &mFX, &errors));
	if( errors )
		MessageBox(0, (char*)errors->GetBufferPointer(), 0, 0);

	// Obtain handles.
	mhTech                  = mFX->GetTechniqueByName("DiffuseTech");
	mhWVP                   = mFX->GetParameterByName(0, "gWVP");
	mhWorldInverseTranspose = mFX->GetParameterByName(0, "gWorldInverseTranspose");
	mhLightVecW             = mFX->GetParameterByName(0, "gLightVecW");
	mhDiffuseMtrl           = mFX->GetParameterByName(0, "gDiffuseMtrl");
	mhDiffuseLight          = mFX->GetParameterByName(0, "gDiffuseLight");
}

void DiffuseDemo::buildViewMtx()
{
	float x = mCameraRadius * cosf(mCameraRotationY);
	float z = mCameraRadius * sinf(mCameraRotationY);
	D3DXVECTOR3 pos(x, mCameraHeight, z);
	D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);
	D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);
	D3DXMatrixLookAtLH(&mView, &pos, &target, &up);
}

void DiffuseDemo::buildProjMtx()
{
	float w = (float)md3dPP.BackBufferWidth;
	float h = (float)md3dPP.BackBufferHeight;
	D3DXMatrixPerspectiveFovLH(&mProj, D3DX_PI * 0.25f, w/h, 1.0f, 5000.0f);
}

 

diffuse.fx

 

//=============================================================================
// diffuse.fx by Frank Luna (C) 2004 All Rights Reserved.
//
// Does basic diffuse lighting.
//=============================================================================

uniform extern float4x4 gWorldInverseTranspose;
uniform extern float4x4 gWVP;

uniform extern float4 gDiffuseMtrl;
uniform extern float4 gDiffuseLight;
uniform extern float3 gLightVecW;
 
struct OutputVS
{
    float4 posH  : POSITION0;
    float4 color : COLOR0;
};

OutputVS DiffuseVS(float3 posL : POSITION0, float3 normalL : NORMAL0)
{
    // Zero out our output.
	OutputVS outVS = (OutputVS)0;
	
	// Transform normal to world space.
	float3 normalW = mul(float4(normalL, 0.0f), gWorldInverseTranspose).xyz;
	normalW = normalize(normalW);
	
	// Compute the color: Equation 10.1.
	float s = max(dot(gLightVecW, normalW), 0.0f);
	outVS.color.rgb = s*(gDiffuseMtrl*gDiffuseLight).rgb;
	outVS.color.a   = gDiffuseMtrl.a;
	
	// Transform to homogeneous clip space.
	outVS.posH = mul(float4(posL, 1.0f), gWVP);
	
	// Done--return the output.
    return outVS;
}

float4 DiffusePS(float4 c : COLOR0) : COLOR
{
    return c;
}

technique DiffuseTech
{
    pass P0
    {
        // Specify the vertex and pixel shader associated with this pass.
        vertexShader = compile vs_2_0 DiffuseVS();
        pixelShader  = compile ps_2_0 DiffusePS();
    }
}