glEnable

NAME

glEnable, glDisable -- enable or disable GL capabilities 启动光照

C SPECIFICATION

void glEnable(GLenum cap)

PARAMETERS

cap

Specifies a symbolic constant indicating a GL capability.

C SPECIFICATION

void glDisable(GLenum cap)

PARAMETERS

cap

Specifies a symbolic constant indicating a GL capability.

DESCRIPTION

glEnable and glDisable enable and disable various capabilities. Use glIsEnabled or glGet to determine the current setting of any capability.

Both glEnable and glDisable take a single argument, cap, which can assume one of the following values:

GL_ALPHA_TEST

If enabled, do alpha testing. See glAlphaFunc.

AUTO_NORMAL

If enabled, compute surface normal vectors analytically when either GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4 is used to generate vertices. See glMap2.

GL_BLEND

If enabled, blend the incoming RGBA color values with the values in the color buffers. See glBlendFunc.

GL_CLIP_PLANEi

If enabled, clip geometry against user-defined clipping plane i. See glClipPlane.

GL_COLOR_MATERIAL

If enabled, have one or more material parameters track the current color. See glColorMaterial.

GL_CULL_FACE

If enabled, cull polygons based on their winding in window coordinates. See glCullFace.

GL_DEPTH_TEST

If enabled, do depth comparisons and update the depth buffer. See glDepthFunc and glDepthRange.

GL_DITHER

If enabled, dither color components or indices before they are written to the color buffer.

GL_FOG

If enabled, blend a fog color into the posttexturing color. See glFog.

GL_LIGHTi

If enabled, include light i in the evaluation of the lighting equation. See glLightModel and glLight.

GL_LIGHTING

If enabled, use the current lighting parameters to compute the vertex color or index. Otherwise, simply associate the current color or index with each vertex. See glMaterial, glLightModel and glLight.

GL_LINE_SMOOTH

If enabled, draw lines with correct filtering. Otherwise, draw aliased lines. See glLineWidth.

GL_LINE_STIPPLE

If enabled, use the current line stipple pattern when drawing lines. See glLineStipple.

GL_LOGIC_OP

If enabled, apply the currently selected logical operation to the incoming and and color buffer indices. See glLogicOp.

GL_MAP1_COLOR_4

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate RGBA values. See glMap1.

GL_MAP1_INDEX

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate color indices. See glMap1.

GL_MAP1_NORMAL

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate normals. See glMap1.

GL_MAP1_TEXTURE_COORD_1

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate s texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_2

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate s and t texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_3

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate s, t and r texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_4

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate s, t, r and q texture coordinates. See glMap1.

GL_MAP1_VERTEX_3

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate x, y and z vertex coordinates. See glMap1.

GL_MAP1_VERTEX_4

If enabled, calls to glEvalCoord1, glEvalMesh1 and glEvalPoint1 will generate homogeneous x, y, z and w vertex coordinates. See glMap1.

GL_MAP2_COLOR_4

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate RGBA values. See glMap2.

GL_MAP2_INDEX

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate color indices. See glMap2.

GL_MAP2_NORMAL

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate normals. See glMap2.

GL_MAP2_TEXTURE_COORD_1

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate s texture coordinates. See glMap2.

GL_MAP2_TEXTURE_COORD_2

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate s and t texture coordinates. See glMap2.

GL_MAP2_TEXTURE_COORD_3

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate s, t and r texture coordinates. See glMap2.

GL_MAP2_TEXTURE_COORD_4

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate s, t, r and q texture coordinates. See glMap2.

GL_MAP2_VERTEX_3

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate x, y and z vertex coordinates. See glMap2.

GL_MAP2_VERTEX_4

If enabled, calls to glEvalCoord2, glEvalMesh2 and glEvalPoint2 will generate homogeneous x, y, z and w vertex coordinates. See glMap2.

GL_NORMALIZE

If enabled, normal vectors specified with glNormal are scaled to unit length after transformation. See glNormal.

GL_POINT_SMOOTH

If enabled, draw points with proper filtering. Otherwise, draw aliased points. See glPointSize.

GL_POLYGON_SMOOTH

If enabled, draw polygons with proper filtering. Otherwise, draw aliased polygons. See glPolygonMode.

GL_POLYGON_STIPPLE

If enabled, use the current polygon stipple patttern when rendering polygons. See glPolygonStipple.

GL_SCISSOR_TEST

If enabled, discard fragments that are outside the scissor rectangle. See glScissor.

GL_STENCIL_TEST

If enabled, do stencil testing and update the stencil buffer. See glStencilFunc and glStencilOp.

GL_TEXTURE_1D

If enabled, one-dimensional texturing is performed (unless two-dimensional texturing is also enabled). See glTexImage1D.

GL_TEXTURE_2D

If enabled, two-dimensional texturing is performed. See glTexImage2D.

GL_TEXTURE_GEN_Q

If enabled, the q texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current q texture coordinate is used. See glTexGen.

GL_TEXTURE_GEN_R

If enabled, the r texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current r texture coordinate is used. See glTexGen.

GL_TEXTURE_GEN_S

If enabled, the s texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current s texture coordinate is used. See glTexGen.

GL_TEXTURE_GEN_T

If enabled, the t texture coordinate is computed using the texture generation function defined with glTexGen. Otherwise, the current t texture coordinate is used. See glTexGen.

ERRORS

GL_INVALID_ENUM is generated if cap is not one of the values listed above.

GL_INVALID_OPERATION is generated if glEnable is called between a call to glBegin and the corresponding call to glEnd.