GLAPI/glDepthRangeIndexed

From OpenGL.org
Jump to: navigation, search
glDepthRangeIndexed
Core in version 4.4
Core since version 4.1
Core ARB extension ARB_viewport_array

glDepthRangeIndexed: specify mapping of depth values from normalized device coordinates to window coordinates for a specified viewport

Function Definition

 void glDepthRangeIndexed(GLuint index​, GLdouble nearVal​, GLdouble farVal​);
index
Specifies the index of the viewport whose depth range to update.
nearVal
Specifies the mapping of the near clipping plane to window coordinates. The initial value is 0.
farVal
Specifies the mapping of the far clipping plane to window coordinates. The initial value is 1.

Description

After clipping and division by w, depth coordinates range from -1 to 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). glDepthRangeIndexed specifies a linear mapping of the normalized depth coordinates in this range to window depth coordinates for a specified viewport. Thus, the values accepted by glDepthRangeIndexed are both clamped to this range before they are accepted.

The index​ parameter specifies the index of first viewport whose depth range to modify and must be less than the value of GL_MAX_VIEWPORTS​. nearVal​ and farVal​ specify near and far values of the depth range for the specified viewport, respectively.

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.

Notes

It is not necessary that the near plane distance be less than the far plane distance. Reverse mappings such as nearVal = 1, and farVal = 0 are acceptable.

The type of the nearVal​ and farVal​ parameters was changed from GLclampd to GLdouble. This change is transparent to user code.

Errors

GL_INVALID_VALUE​ is generated if index​ is greater than or equal to the value of GL_MAX_VIEWPORTS​.

Associated Gets

glGet with argument GL_DEPTH_RANGE​

See Also

glDepthFunc, glDepthRange, glDepthRangeArray, glPolygonOffset, 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/.