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小弟刚开始学OpenGL ,在编写顶点拾取程序时，发现我通过鼠标拾取的名字始终是第一个定点的名字，而且，我没有加入名字列表的点也能拾取到第一个顶点的名字，郁闷。
我把代码贴出来，请大哥们帮忙指点一下。
extern CWTPSApp theApp;
int GraphType = 0;
static int gs_iCurName = 1; //当前的名字
/************************************************************************/
void DrawSence(GLenum mode)
{
COpenGL *pGL = theApp.m_pOpenGL;
CGLVertex origin;
origin.x = 0.0f;
origin.y = 0.0f;
origin.z = 0.0f;
// pGL->DrawAxis(origin);
// glScalef(pGL->m_fScaleX,pGL->m_fScaleY,pGL->m_fScaleZ);
int Count = pGL->GetDSCount();
if(mode == GL_SELECT)//是否为选择模式
{
glInitNames();
glPushName(0);
gs_iCurName = 1;
}
for(int i=0;i<Count ;i++)
{
if(mode == GL_SELECT)
{
DrawSelectableVertex(pGL->m_pDS);
}
DrawLineStrip(pGL->m_pDS);
}
}
/*************************************************************************/
// 功能说明://画可通过鼠标选择的顶点
// 参数说明:
// 作 者: ZRB
// 修改纪录: 2005-11-17 create;
/************************************************************************/
void DrawSelectableVertex(CGLDataSet &DS)
{
COpenGL *pGL = theApp.m_pOpenGL;
int Count = DS.GetVertexCount();
float *pfVertex = NULL;
TVertex *pVertex = NULL;
float x,y,z;
for(int i=0;i<Count;i++)
{
DS.m_Vertexs.NameID = gs_iCurName;
glPushMatrix();
glLoadName(gs_iCurName++);
glColor4fv(DS.m_pfColor);
glPointSize(5);
glBegin(GL_POINTS);
pfVertex = DS.m_Vertexs.Coord;
x = pfVertex[0];
y = pfVertex[1];
z = pfVertex[2];
glVertex3f(x,y,z);
//glVertex3fv(pfVertex);
glEnd();
glPopMatrix();
}
}
///////////////////////////////////////////////////////////
// Process the mouse click
void MouseCallback(int button, int state, int x, int y)
{
if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
ProcessSelection(x, y);
}
#define BUFFER_LENGTH 64 //1024
void ProcessSelection(int xPos,int yPos)
{
GLfloat fAspect;
COpenGL *pGL = theApp.m_pOpenGL;
// 选择缓冲区的空间
GLuint selectBuff[BUFFER_LENGTH];
// 点击计数器和视口存储
GLint hits, viewport[4];
// Setup selection buffer
glSelectBuffer(BUFFER_LENGTH, selectBuff);
// Get the viewport
glGetIntegerv(GL_VIEWPORT, viewport);
// Switch to projection and save the matrix
glMatrixMode(GL_PROJECTION);
glPushMatrix();
// Change render mode
hits = glRenderMode(GL_SELECT);
// 围绕鼠标点建立新的单位立方体裁减区，
//并在水平和垂直方向扩展2个像素
glLoadIdentity();
gluPickMatrix(xPos, viewport[3] - yPos, 2,2, viewport);
pGL->reProject(viewport[3],viewport[4]);//相当于glOrtho(-5,5,-5,5,-1,1);
// Draw the scene
DrawSence(GL_SELECT);
// Restore the projection matrix
glMatrixMode(GL_PROJECTION);
glPopMatrix();
// 恢复到模型视图，以便进行正常的渲染
glMatrixMode(GL_MODELVIEW);
// 收集点击纪录
hits = glRenderMode(GL_RENDER);
ProcessHits(hits,selectBuff);
}
//////////////////////////////////////////////////////////////////////////////
//处理点击事件
void ProcessHits(GLint hits,GLuint buffer[])
{
COpenGL *pGL = theApp.m_pOpenGL;
TVertex *pVertex = NULL;
int Count = 0 ,Name = -1;
Count = buffer[0];
if(Count > 1)
AfxMessageBox("有多个测压点被选中，无法进行修改压力值");
else
{
Name = buffer[3];
//pVertex = pGL->GetVertex(Name);
CString temp ;
temp.Format("Name : %d",Name);
//if(pVertex)
AfxMessageBox(temp);
}
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发表于 2005-11-19 16:26:00
楼主