GLCLEARPARAMETEREXT(3gl)GLCLEARPARAMETEREXT(3gl)NAME
glClearParameterfEXT, glClearParameteriEXT, glClearParameterfvEXT,
glClearParameterivEXT - set gradient clear parameters
C SPECIFICATION
void glClearParameterfEXT( GLenum pname,
const GLfloat param )
void glClearParameteriEXT( GLenum pname,
const GLint param )
PARAMETERS
pname Specifies the symbolic name of a single-value gradient clear
parameter, must be GL_GRADIENT_CLEAR_X_EXT, GL_GRADI‐
ENT_CLEAR_Y_EXT, GL_GRADIENT_CLEAR_WIDTH_EXT or GL_GRADI‐
ENT_CLEAR_HEIGHT_EXT.
param Specifies the value of pname.
C SPECIFICATION
void glClearParameterfvEXT( GLenum pname,
const GLfloat *params )
void glClearParameterivEXT( GLenum pname,
const GLint *params )
PARAMETERS
pname Specifies the symbolic name of a gradient clear parameter, must
be GL_GRADIENT_CLEAR_X_EXT, GL_GRADIENT_CLEAR_Y_EXT, GL_GRADI‐
ENT_CLEAR_WIDTH_EXT, GL_GRADIENT_CLEAR_HEIGHT_EXT, GL_GRADI‐
ENT_CLEAR_COLOR_TOP_EXT or GL_GRADIENT_CLEAR_COLOR_BOTTOM_EXT.
params Specifies a pointer to an array where the value or values of
pname are stored
DESCRIPTION
The gradient clear extension allows the an application to clear a
region of the color buffer to a gradient color that varies linearly in
the vertical direction. The color gradient is specified by the values
GL_GRADIENT_CLEAR_COLOR_TOP_EXT and GL_GRADIENT_CLEAR_COLOR_BOTTOM_EXT
which define the colors at the top and bottom of the clear region. The
lower left corner of the clear region is specified in window relative
coordinates by GL_GRADIENT_CLEAR_X_EXT and GL_GRADIENT_CLEAR_Y_EXT.
The width and height of the clear region are set by GL_GRADI‐
ENT_CLEAR_WIDTH_EXT and GL_GRADIENT_CLEAR_HEIGHT_EXT
glClearParameter assigns the value or values in params to the gradient
clear parameter specified as pname. The following symbols are accepted
for pname:
GL_GRADIENT_CLEAR_X_EXT
Window relative x coordinate of lower left of clear region.
GL_GRADIENT_CLEAR_Y_EXT
Window relative y coordinate of lower left of clear region.
GL_GRADIENT_CLEAR_WIDTH_EXT
Width of clear region in window coordinates.
GL_GRADIENT_CLEAR_HEIGHT_EXT
Height of clear region in window coordinates.
GL_GRADIENT_CLEAR_COLOR_TOP_EXT
RGBA of color at top of clear region.
GL_GRADIENT_CLEAR_COLOR_BOTTOM
RBGA of color at bottom of clear region.
NOTESERRORS
GL_INVALID_ENUM is generated if pname is not one of the accepted
defined values.
ASSOCIATED GETS
glGet
SEE ALSO
glClearColor, glClearColorModeEXT.
24 September 02 GLCLEARPARAMETEREXT(3gl)
