Hi all:
im coding a project using Glut, and im having a problem with my picking/rendering procedures:
[ol][li] the project consists of three sub windows…[] in one of them im drawing a menu with buttons[/li] and shapes.
(not using any graphic library at all)[li] now, all buttons and shapes are objects which[/li] have there own drawind/rendering methods.
(again, MY objects)[li] im having troubles with the “naming thing”…[] every object (a button or a shape) has its own _ID assigned to it at the main entry of the program… that _ID is used as the “name” for the selection mode.[*] Now here is my menu drawing procedure:[/li]
void drawMenu(GLenum mode)
{
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glOrtho(0.0,MAINWINX*WINRATIO,0.0,MAINWINY*WINRATIO,100.0,-100.0);
renderBackground(); //.................... Render the background area
if(mode==GL_SELECT)
{
glInitNames();
glPushName(0);
}
glTranslatef(30.0,5.0,0.0);
for(int btn=0; btn<MenuObjectsCounter; btn++)
if(Menu[btn])
Menu[btn]->Render(mode);
glTranslatef(-30.0,-5.0,0.0);
glPopMatrix();
glFlush();
glutSwapBuffers();
}
[li] every Render() procedure called with the current ‘mode’… so the objects can choose its own ‘Draw()’ method (either ‘pressed’ or ‘normal’.[*] Now the mouse call back function is as follows:[/li]
void pickMenu(int button,int state,int x,int y)
{
GLuint selectBuf[BUFSIZE];
GLint hits;
GLint viewport[4];
if( button==GLUT_LEFT_BUTTON && state==GLUT_DOWN)
displaySubWin3();// the menu window
glGetIntegerv(GL_VIEWPORT,viewport);
glSelectBuffer(BUFSIZE,selectBuf);
glRenderMode(GL_SELECT);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
gluPickMatrix( (GLdouble)x , (GLdouble)(viewport[3]-y) , 2.0 , 2.0, viewport );
glOrtho(0.0,MAINWINX*WINRATIO,0.0,MAINWINY*WINRATIO,100.0,-100.0);
drawMenu(GL_SELECT);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glFlush();
glutSwapBuffers();
hits = glRenderMode(GL_RENDER);
processHits(hits,selectBuf);
}
[li] HERE IS MY PROBLEM: I figured that no matter what i do ‘hits’ value is always ‘0’!!![/li]so i can’t process the hits!!![/ol]