Name
glSecondaryColor — set the current secondary color
C Specification
void glSecondaryColor3b( | GLbyte | red, |
| | GLbyte | green, |
| | GLbyte | blue); |
void glSecondaryColor3s( | GLshort | red, |
| | GLshort | green, |
| | GLshort | blue); |
void glSecondaryColor3i( | GLint | red, |
| | GLint | green, |
| | GLint | blue); |
void glSecondaryColor3f( | GLfloat | red, |
| | GLfloat | green, |
| | GLfloat | blue); |
void glSecondaryColor3d( | GLdouble | red, |
| | GLdouble | green, |
| | GLdouble | blue); |
void glSecondaryColor3ub( | GLubyte | red, |
| | GLubyte | green, |
| | GLubyte | blue); |
void glSecondaryColor3us( | GLushort | red, |
| | GLushort | green, |
| | GLushort | blue); |
void glSecondaryColor3ui( | GLuint | red, |
| | GLuint | green, |
| | GLuint | blue); |
Parameters
red, green, blue
Specify new red, green, and blue values for the current secondary color.
C Specification
void glSecondaryColor3bv( | const GLbyte * | v); |
void glSecondaryColor3sv( | const GLshort * | v); |
void glSecondaryColor3iv( | const GLint * | v); |
void glSecondaryColor3fv( | const GLfloat * | v); |
void glSecondaryColor3dv( | const GLdouble * | v); |
void glSecondaryColor3ubv( | const GLubyte * | v); |
void glSecondaryColor3usv( | const GLushort * | v); |
void glSecondaryColor3uiv( | const GLuint * | v); |
Parameters
v
Specifies a pointer to an array that contains red, green, blue.
Description
The GL stores both a primary four-valued RGBA color and a
secondary four-valued RGBA color (where alpha is always set to 0.0) that is
associated with every vertex.
The secondary color is interpolated and applied to each fragment during
rasterization when GL_COLOR_SUM is enabled. When lighting is enabled,
and GL_SEPARATE_SPECULAR_COLOR is specified, the value of the
secondary color is assigned the value computed from the specular term of
the lighting computation. Both the primary and secondary current colors are
applied to each fragment, regardless of the state of GL_COLOR_SUM,
under such conditions. When GL_SEPARATE_SPECULAR_COLOR is specified,
the value returned from querying the current secondary color is undefined.
glSecondaryColor3b, glSecondaryColor3s, and
glSecondaryColor3i take three signed byte, short, or long integers as
arguments. When v is appended to the name, the color commands can
take a pointer to an array of such values.
Color values are stored in floating-point format, with
unspecified mantissa and exponent sizes. Unsigned integer color
components, when specified, are linearly mapped to floating-point values
such that the largest representable value maps to 1.0 (full intensity), and
0 maps to 0.0 (zero intensity). Signed integer color components, when
specified, are linearly mapped to floating-point values such that the most
positive representable value maps to 1.0, and the most negative
representable value maps to
-1.0
.
(Note that this mapping does not convert
0 precisely to 0.0). Floating-point values are mapped directly.
Neither floating-point nor signed integer values are clamped to the range
0
1
before the current color is updated. However, color components are
clamped to this range before they are interpolated or written into a color
buffer.
Notes
glSecondaryColor is available only if the GL version is 1.4 or greater.
The initial value for the secondary color is (0, 0, 0, 0).
The secondary color can be updated at any time. In particular, glSecondaryColor can
be called between a call to glBegin and the corresponding call to
glEnd.
Associated Gets
glGet with argument GL_CURRENT_SECONDARY_COLOR
glGet with argument GL_RGBA_MODE
glIsEnabled with argument GL_COLOR_SUM
Copyright
Copyright © 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.