glClearStencil example c/c++ java

Name

glClearStencil - specify the clear value for the stencil buffer

C Specification

void glClearStencil(GLint s)

Parameters

s

Specifies the index used when the stencil buffer is cleared. The initial value is 0.

Description

glClearStencil specifies the index used by glClear to clear the stencil buffer. s is masked with 2^m - 1, where m is the number of bits in the stencil buffer.

Associated Gets

glGetInteger with argument GL_STENCIL_BITS

Copyright

Copyright © 2003 Silicon Graphics, Inc.
This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

See Also

glClear, glClearColor, glClearDepth, glGetInteger, glStencilFunc, glStencilOp, glStencilMask

Example of glClearStencil

void RenderScence(void)
{
   GLdouble dRadius = 0.1;
   GLdouble dAngle;

   glClearColor(0.0f,0.0f,1.0f,0.0f);
   glClearStencil(0.0f);

  glEnable(GL_STENCIL_TEST);

  glClear(GL_COLOR_BUFFER | GL_STENCIL_BUFFER_BIT);

  glStencilFunc(GL_NEVER,0x0,0x0);
  glStencilOp(GL_INCR , GL_INCR , GL_INCR);

   glColor3f(1.0f,1.0f,1.0f);

   glBegin(GL_LINE_STRIP);
      for( dAngle = 0 ; dAngle < 400 ; dAngle += 0.1)
      {
          glVertex2d( dRadius * cos(dAngle) , dRadius * sin( dAngle));
          dRadius *= 1.002;
      }
   glEnd();

   glStencilFunc(GL_NOTEQUAL , 0x1, 0x1 );
   glStencilOp(GL_KEEP,GL_KEEP,GL_KEEP);

   glColor3f(1.0f,0.0f,0.0f);
   glRectf(x,y, x + rsize, y - rsize);

   glSwapBuffer();
}