glPassThrough
The glPassThrough function places a marker in the feedback buffer.
void glPassThrough(
GLfloat token);
Parameters
- token
A marker value to be placed in the feedback buffer. It is indicated with the following unique identifying value:Value Meaning GL_PASS_THROUGH_TOKEN The order of glPassThrough commands with respect to the specification of graphics primitives is maintained.
Remarks
Feedback is an OpenGL render mode selected by calling glRenderMode with GL_FEEDBACK. When OpenGL is in feedback mode, no pixels are produced by rasterization. Instead, information about primitives that would have been rasterized is fed back to the application by OpenGL. See glFeedbackBuffer for a description of the feedback buffer and the values in it.
The glPassThrough function inserts a user-defined marker in the feedback buffer when it is executed in feedback mode. The token parameter is returned as if it were a primitive.
The glPassThrough function is ignored if OpenGL is not in feedback mode.
The following function retrieves information related to glPassThrough:
glGet with argument GL_RENDER_MODE
Error Codes
The following is the error code and its condition.
| Error code | Condition |
|---|---|
| GL_INVALID_OPERATION | glPassThrough was called between a call to glBegin and the corresponding call to glEnd. |
Requirements
** Windows NT/2000:** Requires Windows NT 3.5 or later.
** Windows 95/98:** Requires Windows 95 or later. Available as a redistributable for Windows 95.
** Header:** Declared in Gl.h.
** Library:** Use Opengl32.lib.