NAME¶
glViewportArray - set multiple viewports
C SPECIFICATION¶
void
glViewportArrayv(GLuint first,
GLsizei count,
const GLfloat *v);
PARAMETERS¶
first
Specify the first viewport to set.
count
Specify the number of viewports to set.
v
Specify the address of an array containing the
viewport parameters.
DESCRIPTION¶
glViewportArrayv specifies the parameters for multiple viewports
simulataneously.
first specifies the index of the first viewport to
modify and
count specifies the number of viewports to modify.
first must be less than the value of
GL_MAX_VIEWPORTS, and
first +
count must be less than or equal to the value of
GL_MAX_VIEWPORTS. Viewports whose indices lie outside the range [
first,
first +
count) are not modified.
v contains
the address of an array of floating point values specifying the left (x),
bottom (y), width (w), and height (h) of each viewport, in that order. x and y
give the location of the viewport's lower left corner, and w and h give the
width and height of the viewport, respectively. The viewport specifies the
affine transformation of x and y from normalized device coordinates to window
coordinates. Let x nd y nd be normalized device coordinates. Then the window
coordinates x w y w are computed as follows:
x w = x nd + 1 width 2 + x
y w = y nd + 1 height 2 + y
The location of the viewport's bottom left corner, given by (x, y) is clamped to
be within the implementaiton-dependent viewport bounds range. The viewport
bounds range [min, max] 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.
ERRORS¶
GL_INVALID_VALUE is generated if
first is greater than or equal to
the value of
GL_MAX_VIEWPORTS.
GL_INVALID_VALUE is generated if
first +
count is greater
than or equal to the value of
GL_MAX_VIEWPORTS.
GL_INVALID_VALUE is generated if either
width or
height is
negative.
ASSOCIATED GETS¶
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
SEE ALSO¶
glDepthRange(),
glViewport(),
glViewportIndexed()
COPYRIGHT¶
Copyright © 2010 Khronos Group. This material may be distributed subject to
the terms and conditions set forth in the Open Publication License, v 1.0, 8
June 1999.
http://opencontent.org/openpub/.