Provided by: opengl-4-man-doc_1.0~svn33624-1_all
NAME
glPolygonOffset - set the scale and units used to calculate depth values
C SPECIFICATION
void glPolygonOffset(GLfloat factor, GLfloat units);
PARAMETERS
factor Specifies a scale factor that is used to create a variable depth offset for each polygon. The initial value is 0. units Is multiplied by an implementation-specific value to create a constant depth offset. The initial value is 0.
DESCRIPTION
When GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE, or GL_POLYGON_OFFSET_POINT is enabled, each fragment's depth value will be offset after it is interpolated from the depth values of the appropriate vertices. The value of the offset is factor × DZ + r × units, where DZ is a measurement of the change in depth relative to the screen area of the polygon, and r is the smallest value that is guaranteed to produce a resolvable offset for a given implementation. The offset is added before the depth test is performed and before the value is written into the depth buffer. glPolygonOffset is useful for rendering hidden-line images, for applying decals to surfaces, and for rendering solids with highlighted edges.
ASSOCIATED GETS
glIsEnabled() with argument GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE, or GL_POLYGON_OFFSET_POINT. glGet() with argument GL_POLYGON_OFFSET_FACTOR or GL_POLYGON_OFFSET_UNITS.
VERSION SUPPORT
┌────────────────┬───────────────────────────────────────────────────────────────────────┐ │ │ OpenGL Version │ ├────────────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤ │Function │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │ │/ │ │ │ │ │ │ │ │ │ │ │ │ │ │Feature │ │ │ │ │ │ │ │ │ │ │ │ │ │Name │ │ │ │ │ │ │ │ │ │ │ │ │ ├────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤ │glPolygonOffset │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ └────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
SEE ALSO
glDepthFunc(), glEnable(), glGet(), glIsEnabled()
COPYRIGHT
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.
COPYRIGHT
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group [FIXME: source] 01/03/2018 GLPOLYGONOFFSET(3G)