glViewportIndexed — set a specified viewport
void glViewportIndexedf( | GLuint index, |
GLfloat x, | |
GLfloat y, | |
GLfloat w, | |
GLfloat h) ; |
void glViewportIndexedfv( | GLuint index, |
const GLfloat *v) ; |
index
Specify the first viewport to set.
x
, y
For glViewportIndexedf
, specifies the lower left corner of the viewport rectangle, in pixels. The initial value is (0,0).
width
, height
For glViewportIndexedf
, specifies the width and height of the viewport. When a GL context is first attached to a window, width
and height
are set to the dimensions of that window.
v
For glViewportIndexedfv
, specifies the address of an array containing the viewport parameters.
glViewportIndexedf
and glViewportIndexedfv
specify the parameters for a single viewport. index
specifies the index of the viewport to modify. index
must be less than the value of GL_MAX_VIEWPORTS
. For glViewportIndexedf
, x
, y
, w
, and h
specify the left, bottom, width and height of the viewport in pixels, respectively. For glViewportIndexedfv
, v
contains the address of an array of floating point values specifying the left (), bottom (), width (), and height () of each viewport, in that order. and give the location of the viewport's lower left corner, and and give the width and height of the viewport, respectively. The viewport specifies the affine transformation of and from normalized device coordinates to window coordinates. Let be normalized device coordinates. Then the window coordinates are computed as follows:
The location of the viewport's bottom left corner, given by (, ) is clamped to be within the implementaiton-dependent viewport bounds range. The viewport bounds range [, ] can be determined by calling glGet with argument GL_VIEWPORT_BOUNDS_RANGE
. Viewport width and height are silently clamped to a range that depends on the implementation. To query this range, call glGet with argument GL_MAX_VIEWPORT_DIMS
.
The precision with which the GL interprets the floating point viewport bounds is implementation-dependent and may be determined by querying the impementation-defined constant GL_VIEWPORT_SUBPIXEL_BITS
.
Calling glViewportIndexedfv
is equivalent to calling glViewportArray with first
set to index
, count
set to 1 and v
passsed directly. glViewportIndexedf
is equivalent to:
void glViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h) { const float v[4] = { x, y, w, h }; glViewportArrayv(index, 1, v); }
GL_INVALID_VALUE
is generated if index
is greater than or equal to the value of GL_MAX_VIEWPORTS
.
GL_INVALID_VALUE
is generated if either width
or height
is negative.
glGet with argument GL_VIEWPORT
glGet with argument GL_MAX_VIEWPORT_DIMS
glGet with argument GL_VIEWPORT_BOUNDS_RANGE
glGet with argument GL_VIEWPORT_SUBPIXEL_BITS
OpenGL Version | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
glViewportIndexedf | - | - | - | - | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ |
glViewportIndexedfv | - | - | - | - | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ |
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