ch17p2_wipetransition.cpp

游戏开发特殊技巧-special.effects.game.programming

#include "Ch17p2_WipeTransition.h"

CWipeTransition::CWipeTransition(LPDIRECT3DDEVICE8 pDev, LPDIRECT3DTEXTURE8 pOrigTexture, 
                                 LPDIRECT3DTEXTURE8 pSecondImage, WipeDir direction)
{
  m_pSecondImage = pSecondImage;
  m_pd3dDevice = pDev;
  m_fFadeTime = 0;
  m_pOrigImage = pOrigTexture;
  m_Direction = direction;
  if (direction == Random) {
    switch (RandomNumber(0, 3)) {
      case 0: m_Direction = Left; break;
      case 1: m_Direction = Right; break;
      case 2: m_Direction = Up; break;
      case 3: m_Direction = Down; break;
    }
  }

  // create vertex buffer for one quad
  if (FAILED(CreateQuad(&m_pVB, D3DPOOL_MANAGED, 2, 0, pDev))) {
    throw("Error creating vertex buffer!");
  }
}

CWipeTransition::~CWipeTransition()
{
  SAFE_RELEASE(m_pVB);
}

void CWipeTransition::DoTransition(float fTransTime)
{
  m_fFadeTime += fTransTime;
}


void CWipeTransition::CalcQuadVerts()
{
  HRESULT hr;
  VERTEX_XYZ_DIFFUSE_TEX1* pVertices;

  float fRatio = m_fFadeTime / m_fDuration;

  float fNewVertX1, fNewVertY1, fNewVertX2, fNewVertY2;
  float fNewU1, fNewV1, fNewU2, fNewV2;

  switch(m_Direction) {
    case Up:
      fNewVertX1 = -1.0f; fNewVertX2 = 1.0f; fNewVertY2 = -1.0f;
      fNewVertY1 = -1.0f + (2.0f * fRatio);
      fNewU1 = 0.0f; fNewU2 = 1.0f; fNewV1 = 1.0f - (1.0f * fRatio); fNewV2 = 1.0f;
      break;
    case Down:
      fNewVertX1 = -1.0f; fNewVertX2 = 1.0f; fNewVertY1 = 1.0f;
      fNewVertY2 = 1.0f - (2.0f * fRatio);
      fNewU1 = 0.0f; fNewU2 = 1.0f; fNewV1 = 0.0f; fNewV2 = 1.0f * fRatio;
      break;
    case Left:
      fNewVertY1 = 1.0f; fNewVertY2 = -1.0f; fNewVertX1 = -1.0f;
      fNewVertX2 = -1.0f + (2.0f * fRatio);
      fNewV1 = 0.0f; fNewV2 = 1.0f; fNewU1 = 0.0f; fNewU2 = 1.0f * fRatio;
      break;
    case Right:
      fNewVertY1 = 1.0f; fNewVertY2 = -1.0f; fNewVertX2 = 1.0f;
      fNewVertX1 = 1.0f - (2.0f * fRatio);
      fNewV1 = 0.0f; fNewV2 = 1.0f; fNewU1 = 1.0f - (1.0f * fRatio); fNewU2 = 1.0f;
      break;
  };

  if( FAILED( hr = m_pVB->Lock( 0, 6*sizeof(VERTEX_XYZ_DIFFUSE_TEX1), (BYTE**)&pVertices, 0 ) ) )
      return;

  pVertices[0].position = D3DXVECTOR3(fNewVertX1, fNewVertY1, 0.0f);
  pVertices[0].tu = fNewU1; pVertices[0].tv = fNewV1;
                                                    
  pVertices[1].position = D3DXVECTOR3(fNewVertX2, fNewVertY1, 0.0f);
  pVertices[1].tu = fNewU2; pVertices[1].tv = fNewV1;

  pVertices[2].position = D3DXVECTOR3(fNewVertX2, fNewVertY2, 0.0f);
  pVertices[2].tu = fNewU2; pVertices[2].tv = fNewV2;

  pVertices[3].position = D3DXVECTOR3(fNewVertX1, fNewVertY1, 0.0f);
  pVertices[3].tu = fNewU1; pVertices[3].tv = fNewV1;

  pVertices[4].position = D3DXVECTOR3(fNewVertX2, fNewVertY2, 0.0f);
  pVertices[4].tu = fNewU2; pVertices[4].tv = fNewV2;

  pVertices[5].position = D3DXVECTOR3(fNewVertX1, fNewVertY2, 0.0f);
  pVertices[5].tu = fNewU1; pVertices[5].tv = fNewV2;


  if( FAILED( hr = m_pVB->Unlock() ) ) return;
}

void CWipeTransition::ResetQuadVerts()
{
  HRESULT hr;
  VERTEX_XYZ_DIFFUSE_TEX1* pVertices;

  if( FAILED( hr = m_pVB->Lock( 0, 6*sizeof(VERTEX_XYZ_DIFFUSE_TEX1), (BYTE**)&pVertices, 0 ) ) )
      return;

  // first triangle
  pVertices[0].position = D3DXVECTOR3(-1.0f, 1.0f, 0.0f);
  pVertices[0].color    = 0;
  pVertices[0].tu       = 0.0f;
  pVertices[0].tv       = 0.0f;

  pVertices[1].position = D3DXVECTOR3(1.0f, 1.0f, 0.0f);
  pVertices[1].color    = 0;
  pVertices[1].tu       = 1.0f;
  pVertices[1].tv       = 0.0f;

  pVertices[2].position = D3DXVECTOR3(1.0f, -1.0f, 0.0f);
  pVertices[2].color    = 0;
  pVertices[2].tu       = 1.0f;
  pVertices[2].tv       = 1.0f;

  // second triangle
  pVertices[3].position = D3DXVECTOR3(-1.0f, 1.0f, 0.0f);
  pVertices[3].color    = 0;
  pVertices[3].tu       = 0.0f;
  pVertices[3].tv       = 0.0f;

  pVertices[4].position = D3DXVECTOR3(1.0f, -1.0f, 0.0f);
  pVertices[4].color    = 0;
  pVertices[4].tu       = 1.0f;
  pVertices[4].tv       = 1.0f;

  pVertices[5].position = D3DXVECTOR3(-1.0f, -1.0f, 0.0f);
  pVertices[5].color    = 0;
  pVertices[5].tu       = 0.0f;
  pVertices[5].tv       = 1.0f;

  if( FAILED( hr = m_pVB->Unlock() ) ) return;
}

void CWipeTransition::DoRender(D3DXMATRIX mFinalScale)
{
  m_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
  
  // set our texture active...
  m_pd3dDevice->SetTexture( 0, m_pOrigImage );

  // set up our texture stages for a simple texture copy...
  m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLOROP,   D3DTOP_SELECTARG1 );
  m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG1, D3DTA_TEXTURE );
  m_pd3dDevice->SetTextureStageState( 0, D3DTSS_COLORARG2, D3DTA_DIFFUSE );
  m_pd3dDevice->SetTextureStageState( 0, D3DTSS_ALPHAOP,   D3DTOP_SELECTARG1 );

  // draw our quad
  ResetQuadVerts();

  m_pd3dDevice->SetStreamSource( 0, m_pVB, sizeof(VERTEX_XYZ_DIFFUSE_TEX1) );
  m_pd3dDevice->SetVertexShader( D3DFVF_XYZ_DIFFUSE_TEX1 );
  m_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLELIST, 0, 2 );

  if (m_fFadeTime > 0.0f) {
    // put the correct colors into the quad's verts
    CalcQuadVerts();

    m_pd3dDevice->SetTexture( 0, m_pSecondImage );
    
    m_pd3dDevice->SetStreamSource(0, m_pVB, sizeof(VERTEX_XYZ_DIFFUSE_TEX1));
    m_pd3dDevice->SetVertexShader(D3DFVF_XYZ_DIFFUSE_TEX1);
    m_pd3dDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 2);
  }
}