GLGETTEXENV(3gl)GLGETTEXENV(3gl)NAME
glGetTexEnvfv, glGetTexEnviv - return texture environment parameters
C SPECIFICATION
void glGetTexEnvfv( GLenum target,
GLenum pname,
GLfloat *params )
void glGetTexEnviv( GLenum target,
GLenum pname,
GLint *params )
PARAMETERS
target Specifies a texture environment. Must be GL_TEXTURE_ENV.
pname Specifies the symbolic name of a texture environment parameter.
Accepted values are GL_TEXTURE_ENV_MODE and GL_TEX‐
TURE_ENV_COLOR.
params Returns the requested data.
DESCRIPTION
glGetTexEnv returns in params selected values of a texture environment
that was specified with glTexEnv. target specifies a texture environ‐
ment. Currently, only one texture environment is defined and sup‐
ported: GL_TEXTURE_ENV.
pname names a specific texture environment parameter, as follows:
GL_TEXTURE_ENV_MODE
params returns the single-valued texture environment mode, a
symbolic constant. The initial value is GL_MODULATE.
GL_TEXTURE_ENV_COLOR
params returns four integer or floating-point values that are
the texture environment color. Integer values, when
requested, are linearly mapped from the internal floating-
point representation such that 1.0 maps to the most positive
representable integer, and -1.0 maps to the most negative
representable integer. The initial value is (0, 0, 0, 0).
GL_COMBINE_RGB_ARB
params returns the single-valued texture environment combine
rgb mode, a symbolic constant. The initial value is GL_MODU‐
LATE.
GL_COMBINE_ALPHA_ARB
params returns the single-valued texture environment combine
alpha mode, a symbolic constant. The initial value is GL_MOD‐
ULATE.
GL_SOURCE0_RGB_ARB
params returns the single-valued texture combine rgb source
mode for Arg0, a symbolic constant. The initial value is
GL_TEXTURE.
GL_SOURCE1_RGB_ARB
params returns the single-valued texture combine rgb source
mode for Arg1, a symbolic constant. The initial value is
GL_PREVIOUS_ARB.
GL_SOURCE2_RGB_ARB
params returns the single-valued texture combine rgb source
mode for Arg2, a symbolic constant. The initial value is
GL_CONSTANT_ARB.
GL_SOURCE0_ALPHA_ARB
params returns the single-valued texture combine alpha source
mode for Arg0, a symbolic constant. The initial value is
GL_TEXTURE.
GL_SOURCE1_ALPHA_ARB
params returns the single-valued texture combine alpha source
mode for Arg1, a symbolic constant. The initial value is
GL_PREVIOUS_ARB.
GL_SOURCE2_ALPHA_ARB
params returns the single-valued texture combine alpha source
mode for Arg2, a symbolic constant. The initial value is
GL_CONSTANT_ARB.
GL_OPERAND0_RGB_ARB
params returns the single-valued texture combine rgb source
operand for Arg0, a symbolic constant. The initial value is
GL_SRC_COLOR.
GL_OPERAND1_RGB_ARB
params returns the single-valued texture combine rgb source
operand for Arg1, a symbolic constant. The initial value is
GL_SRC_COLOR.
GL_OPERAND2_RGB_ARB
params returns the single-valued texture combine rgb source
operand for Arg2, a symbolic constant. The initial value is
GL_SRC_ALPHA.
GL_OPERAND0_ALPHA_ARB
params returns the single-valued texture combine alpha source
operand for Arg0, a symbolic constant. The initial value is
GL_SRC_ALPHA.
GL_OPERAND1_ALPHA_ARB
params returns the single-valued texture combine alpha source
operand for Arg1, a symbolic constant. The initial value is
GL_SRC_ALPHA.
GL_OPERAND2_ALPHA_ARB
params returns the single-valued texture combine alpha source
operand for Arg2, a symbolic constant. The initial value is
GL_SRC_ALPHA.
GL_RGB_SCALE_ARB
params returns the rgb scale value, a floating-point value.
The initial value is 1.0.
GL_ALPHA_SCALE_ARB
params returns the alpha scale value, a floating-point value.
The initial value is 1.0.
NOTES
If an error is generated, no change is made to the contents of params.
ERRORS
GL_INVALID_ENUM is generated if target or pname is not an accepted
value.
GL_INVALID_OPERATION is generated if glGetTexEnv is executed between
the execution of glBegin and the corresponding execution of glEnd.
SEE ALSO
glTexEnv
15 Mar 97 GLGETTEXENV(3gl)