Direct基础学习系列3 绘制+实例

3.1.1顶点缓存 索引缓存

放置在显存中能够加快绘制速度

创建顶点缓存

HRESULT CreateVertexBuffer(
  UINT Length,    //为缓存分配的字节数
  DWORD Usage,    //缓存附加属性，可为0
  DWORD FVF,      //顶点格式
  D3DPOOL Pool,   //缓存的内存池
  IDirect3DVertexBuffer9** ppVertexBuffer, //返回的结构
  HANDLE* pSharedHandle  //不用 设置为0
);

创建索引缓存

HRESULT CreateIndexBuffer(
  UINT Length,
  DWORD Usage,
  D3DFORMAT Format,
  D3DPOOL Pool,
  IDirect3DIndexBuffer9** ppIndexBuffer,
  HANDLE* pSharedHandle
);

Usage ！= D3DUSAGE_DYNAMIC 放置在静态缓存中，适合处理运行中不需要修改的数据

Usage = D3DUSAGE_DYNAMIC 放置在动态缓存，适合频繁更新内容，如粒子系统，动态缓存放置在内存AGP区域，可以很快的被更新

3.1.2访问数据

HRESULT Lock( 

UINT OffsetToLock,   //缓存中的起始点
UINT SizeToLock,   //需要锁定的数目

VOID ** ppbData,     //返回的被锁定的缓存区起始位置
DWORD Flags          //锁定方式：

);

BOOL Unlock();

3.1.3获得顶点缓存信息

typedef struct D3DVERTEXBUFFER_DESC {
    D3DFORMAT Format;
    D3DRESOURCETYPE Type;
    DWORD Usage;
    D3DPOOL Pool;
    UINT Size;
    DWORD FVF;
} D3DVERTEXBUFFER_DESC, *LPD3DVERTEXBUFFER_DESC;

typedef struct D3DINDEXBUFFER_DESC {
    D3DFORMAT Format;
    D3DRESOURCETYPE Type;
    DWORD Usage;
    D3DPOOL Pool;
    UINT Size;
} D3DINDEXBUFFER_DESC, *LPD3DINDEXBUFFER_DESC;

IDirect3DIndexBuffer9::GetDesc（）；

3.2 绘制状态

HRESULT SetRenderState(
  [in]  D3DRENDERSTATETYPE State,
  [in]  DWORD Value
);

3.3绘制准备工作

（1）制定数据流输入源

HRESULT SetStreamSource(
  UINT StreamNumber,      //数据流 可以是多个
  IDirect3DVertexBuffer9 * pStreamData,//建立数据流的缓存
  UINT OffsetInBytes,  //被传送到绘制流水线顶点数据的起始位置
  UINT Stride   //顶点缓存的大小
);

（2）设置顶点格式

HRESULT SetFVF(  DWORD FVF); 顶点格式如下：

（3）设置使用的索引，任意时刻只能有一个索引缓存，如果不同索引绘制物体时，必须进行切换

HRESULT SetIndices(
  IDirect3DIndexBuffer9 * pIndexData
);

3.4 绘制方法

使用顶点绘制

HRESULT DrawPrimitive(  

D3DPRIMITIVETYPE PrimitiveType,  //绘制的图元类型，TRIANGLELIST 

UINT StartVertex,  //绘制起点索引
UINT PrimitiveCount  //绘制的图元数量

);

采用索引绘制

HRESULT DrawIndexedPrimitive(
  D3DPRIMITIVETYPE Type,
  INT BaseVertexIndex,  //物体顶点在全局缓存中的起始位置偏移
  UINT MinIndex,
  UINT NumVertices,
  UINT StartIndex,
  UINT PrimitiveCount
);

绘制在下列函数之间进行

IDirect3DDevice9::BeginScene（）

IDirect3DDevice9::EndScene（）

实例：看完代码之后 多的一层了解：

（1）世界变换矩阵，取景变换矩阵，投影变换矩阵设置后 在绘图中起作用

（2）缓存中其实就在准备数据

   1:   

   2:  #include "d3dUtility.h"

   3:   

   4:  IDirect3DDevice9* Device = 0; 

   5:   

   6:  const int Width  = 640;

   7:  const int Height = 480;

   8:   

   9:  IDirect3DVertexBuffer9* VB = 0;

  10:  IDirect3DIndexBuffer9*  IB = 0;

  11:   

  12:  //顶点格式定义

  13:  struct Vertex

  14:  {

  15:      Vertex(){}

  16:      Vertex(float x, float y, float z)

  17:      {

  18:          _x = x;  _y = y;  _z = z;

  19:      }

  20:      float _x, _y, _z;

  21:      static const DWORD FVF;

  22:  };

  23:  //全局定点格式

  24:  const DWORD Vertex::FVF = D3DFVF_XYZ;

  25:   

  26:  //

  27:  // Framework Functions

  28:  //

  29:  bool Setup()

  30:  {

  31:      // Create vertex and index buffers.

  32:      Device->CreateVertexBuffer(

  33:          8 * sizeof(Vertex), 

  34:          D3DUSAGE_WRITEONLY,

  35:          Vertex::FVF,

  36:          D3DPOOL_MANAGED,

  37:          &VB,

  38:          0);

  39:      Device->CreateIndexBuffer(

  40:          36 * sizeof(WORD),

  41:          D3DUSAGE_WRITEONLY,

  42:          D3DFMT_INDEX16,

  43:          D3DPOOL_MANAGED,

  44:          &IB,

  45:          0);

  46:   

  47:   

  48:      // 填充数据

  49:      Vertex* vertices;

  50:      VB->Lock(0, 0, (void**)&vertices, 0);

  51:   

  52:      // vertices of a unit cube

  53:      vertices[0] = Vertex(-1.0f, -1.0f, -1.0f);

  54:      vertices[1] = Vertex(-1.0f,  1.0f, -1.0f);

  55:      vertices[2] = Vertex( 1.0f,  1.0f, -1.0f);

  56:      vertices[3] = Vertex( 1.0f, -1.0f, -1.0f);

  57:      vertices[4] = Vertex(-1.0f, -1.0f,  1.0f);

  58:      vertices[5] = Vertex(-1.0f,  1.0f,  1.0f);

  59:      vertices[6] = Vertex( 1.0f,  1.0f,  1.0f);

  60:      vertices[7] = Vertex( 1.0f, -1.0f,  1.0f);

  61:   

  62:      VB->Unlock();

  63:   

  64:      // define the triangles of the cube:

  65:      WORD* indices = 0;

  66:      IB->Lock(0, 0, (void**)&indices, 0);

  67:   

  68:      // front side

  69:      indices[0]  = 0; indices[1]  = 1; indices[2]  = 2;

  70:      indices[3]  = 0; indices[4]  = 2; indices[5]  = 3;

  71:   

  72:      // back side

  73:      indices[6]  = 4; indices[7]  = 6; indices[8]  = 5;

  74:      indices[9]  = 4; indices[10] = 7; indices[11] = 6;

  75:   

  76:      // left side

  77:      indices[12] = 4; indices[13] = 5; indices[14] = 1;

  78:      indices[15] = 4; indices[16] = 1; indices[17] = 0;

  79:   

  80:      // right side

  81:      indices[18] = 3; indices[19] = 2; indices[20] = 6;

  82:      indices[21] = 3; indices[22] = 6; indices[23] = 7;

  83:   

  84:      // top

  85:      indices[24] = 1; indices[25] = 5; indices[26] = 6;

  86:      indices[27] = 1; indices[28] = 6; indices[29] = 2;

  87:   

  88:      // bottom

  89:      indices[30] = 4; indices[31] = 0; indices[32] = 3;

  90:      indices[33] = 4; indices[34] = 3; indices[35] = 7;

  91:   

  92:      IB->Unlock();

  93:   

  94:      D3DXVECTOR3 position(0.0f, 0.0f, -5.0f);

  95:      D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);

  96:      D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);

  97:      D3DXMATRIX V;

  98:   

  99:      D3DXMatrixLookAtLH(&V, &position, &target, &up);

 100:      //设置取景变换矩阵

 101:      Device->SetTransform(D3DTS_VIEW, &V);

 102:   

 103:      // Set the projection matrix.

 104:      D3DXMATRIX proj;

 105:      D3DXMatrixPerspectiveFovLH(

 106:              &proj,

 107:              D3DX_PI * 0.5f, // 90 - degree

 108:              (float)Width / (float)Height,

 109:              1.0f,

 110:              1000.0f);

 111:   

 112:      //设置投影变换矩阵

 113:      Device->SetTransform(D3DTS_PROJECTION, &proj);

 114:   

 115:      //设置绘图模式

 116:      Device->SetRenderState(D3DRS_FILLMODE, D3DFILL_WIREFRAME);

 117:   

 118:      return true;

 119:  }

 120:   

 121:  void Cleanup()

 122:  {

 123:      d3d::Release<IDirect3DVertexBuffer9*>(VB);

 124:      d3d::Release<IDirect3DIndexBuffer9*>(IB);

 125:  }

 126:   

 127:  bool Display(float timeDelta)

 128:  {

 129:      if( Device )

 130:      {

 131:          // spin the cube:

 132:          D3DXMATRIX Rx, Ry;

 133:   

 134:          // rotate 45 degrees on x-axis

 135:          D3DXMatrixRotationX(&Rx, 3.14f / 4.0f);

 136:   

 137:          // incremement y-rotation angle each frame

 138:          static float y = 0.0f;

 139:          D3DXMatrixRotationY(&Ry, y);

 140:          y += timeDelta;     // 每帧增加旋转量

 141:   

 142:          // reset angle to zero when angle reaches 2*PI

 143:          if( y >= 6.28f )

 144:              y = 0.0f;

 145:   

 146:          // combine x- and y-axis rotation transformations.

 147:          D3DXMATRIX p = Rx * Ry;

 148:   

 149:          //设置世界变换矩阵

 150:          Device->SetTransform(D3DTS_WORLD, &p);

 151:   

 152:          //

 153:          // draw the scene:

 154:   

 155:          //清除背景

 156:          Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0xffffffff, 1.0f, 0);

 157:          Device->BeginScene();

 158:   

 159:          //设置数据源

 160:          Device->SetStreamSource(0, VB, 0, sizeof(Vertex));

 161:   

 162:          //设置使用的索引

 163:          Device->SetIndices(IB);

 164:   

 165:          //

 166:          Device->SetFVF(Vertex::FVF);

 167:   

 168:          // Draw cube.

 169:          Device->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 8, 0, 12);

 170:   

 171:          Device->EndScene();

 172:          Device->Present(0, 0, 0, 0);

 173:      }

 174:      return true;

 175:  }

 176:   

 177:   

 178:  //

 179:  // WndProc

 180:  //

 181:  LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)

 182:  {

 183:      switch( msg )

 184:      {

 185:      case WM_DESTROY:

 186:          ::PostQuitMessage(0);

 187:          break;

 188:          

 189:      case WM_KEYDOWN:

 190:          if( wParam == VK_ESCAPE )

 191:              ::DestroyWindow(hwnd);

 192:          break;

 193:      }

 194:      return ::DefWindowProc(hwnd, msg, wParam, lParam);

 195:  }

 196:   

 197:  //

 198:  // WinMain

 199:  //

 200:  int WINAPI WinMain(HINSTANCE hinstance,

 201:                     HINSTANCE prevInstance, 

 202:                     PSTR cmdLine,

 203:                     int showCmd)

 204:  {

 205:      if(!d3d::InitD3D(hinstance,

 206:          Width, Height, true, D3DDEVTYPE_HAL, &Device))

 207:      {

 208:          ::MessageBox(0, "InitD3D() - FAILED", 0, 0);

 209:          return 0;

 210:      }

 211:          

 212:      if(!Setup())

 213:      {

 214:          ::MessageBox(0, "Setup() - FAILED", 0, 0);

 215:          return 0;

 216:      }

 217:   

 218:      d3d::EnterMsgLoop( Display );

 219:   

 220:      Cleanup();

 221:   

 222:      Device->Release();

 223:   

 224:      return 0;

 225:  }