OpenGL C bindings library: libGL.a
GLint glRenderMode(GLenum Mode)
| Mode | Specifies the rasterization mode. Three values are accepted: GL_RENDER, GL_SELECT, and GL_FEEDBACK. The default value is GL_RENDER. |
The glRenderMode subroutine sets the rasterization mode. It takes one argument, the Mode parameter, which can assume one of three predefined values:
| GL_RENDER | Render mode. Primitives are rasterized, producing pixel fragments, which are written into the frame buffer. This is the normal mode, and also the default mode. |
| GL_SELECT | Selection mode. No pixel fragments are produced, and no change to the frame buffer contents is made. Instead, a record of the names of primitives that would have been drawn if the render mode was GL_RENDER is returned in a select buffer, which must be created before selection mode is entered. (See the glSelectBuffer subroutine for information about establishing a buffer for selection mode values.) |
| GL_FEEDBACK | Feedback mode. No pixel fragments are produced, and no change to the frame buffer contents is made. Instead, the coordinates and attributes of vertices that would have been drawn had the render mode been GL_RENDER are returned in a feedback buffer, which must be created before feedback mode is entered. (See the glFeedbackBuffer subroutine for information about controlling the feedback mode.) |
The return value of glRenderMode is determined by the render mode at the time glRenderMode is called, rather than by the Mode parameter.
Refer to glSelectBuffer and glFeedbackBuffer for more details concerning selection and feedback operation.
If an error is generated, glRenderMode returns 0 (zero) regardless of the current render mode.
Associated gets for the glRenderMode subroutine are as follows. (See the glGet subroutine for more information.)
glGet with argument GL_RENDER_MODE.
| GL_RENDER | 0. |
| GL_SELECT | The number of hit records transferred to the select buffer. |
| GL_FEEDBACK | The number of values (not vertices) transferred to the feedback buffer. |
| /usr/include/GL/gl.h | Contains C language constants, variable type definitions, and ANSI function prototypes for OpenGL. |
The glBegin or glEnd subroutine, glFeedbackBuffer subroutine, glInitNames subroutine, glLoadName subroutine, glPassThrough subroutine, glPushName subroutine, glSelectBuffer subroutine.