# glviewportindexed(3g) [centos man page]

GLVIEWPORTINDEXED(3G) OpenGL Manual GLVIEWPORTINDEXED(3G)NAME

glViewportIndexed - set a specified viewportC SPECIFICATION

void glViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h); void glViewportIndexedfv(GLuint index, const GLfloat *v);PARAMETERS

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.DESCRIPTION

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 (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. 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); }ERRORS

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.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_BITSSEE ALSO

glDepthRange(), glViewport(), glViewportArray()COPYRIGHT

Copyright (C) 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/.AUTHORS

opengl.orgopengl.org06/10/2014 GLVIEWPORTINDEXED(3G)

## Check Out this Related Man Page

GLDEPTHRANGEARRAY(3G) OpenGL Manual GLDEPTHRANGEARRAY(3G)NAME

glDepthRangeArray - specify mapping of depth values from normalized device coordinates to window coordinates for a specified set of viewportsC SPECIFICATION

void glDepthRangeArrayv(GLuint first, GLsizei count, const GLdouble *v);PARAMETERS

first Specifies the index of the first viewport whose depth range to update. count Specifies the number of viewports whose depth range to update. v Specifies the address of an array containing the near and far values for the depth range of each modified viewport.DESCRIPTION

After clipping and division by w, depth coordinates range fromto 1, corresponding to the near and far clipping planes. Each viewport has an independent depth range specified as a linear mapping of the normalized depth coordinates in this range to window depth coordinates. Regardless of the actual depth buffer implementation, window coordinate depth values are treated as though they range from 0 through 1 (like color components). glDepthRangeArray specifies a linear mapping of the normalized depth coordinates in this range to window depth coordinates for each viewport in the range [first, first + count). Thus, the values accepted by glDepthRangeArray are both clamped to this range before they are accepted. The first parameter specifies the index of the first viewport whose depth range to modify and must be less than the value of GL_MAX_VIEWPORTS. count specifies the number of viewports whose depth range to modify. first + count must be less than or equal to the value of GL_MAX_VIEWPORTS. v specifies the address of an array of pairs of double precision floating point values representing the near and far values of the depth range for each viewport, in that order. The setting of (0,1) maps the near plane to 0 and the far plane to 1. With this mapping, the depth buffer range is fully utilized.-1NOTES

It is not necessary that the near plane distance be less than the far plane distance. Reverse mappings such as near = 1, and far = 0 are acceptable. The type of the v parameter was changed from GLclampd to GLdouble. This change is transparent to user code and is described in detail on the removedTypes() page.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.ASSOCIATED GETS

glGet() with argument GL_DEPTH_RANGESEE ALSO

glDepthFunc(), glDepthRange(), glDepthRangeIndexed(), glPolygonOffset(), glViewportArray(), glViewport(), removedTypes()COPYRIGHT

Copyright (C) 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/.AUTHORS

opengl.orgopengl.org06/10/2014 GLDEPTHRANGEARRAY(3G)