textureGatherOffset — gathers four texels from a texture with offset
gvec4 textureGatherOffset( | gsampler2D | sampler, |
vec2 | P, | |
ivec2 | offset, | |
[int | comp]) ; |
gvec4 textureGatherOffset( | gsampler2DArray | sampler, |
vec3 | P, | |
ivec2 | offset, | |
[int | comp]) ; |
gvec4 textureGatherOffset( | gsampler2DRect | sampler, |
vec3 | P, | |
ivec2 | offset, | |
[int | comp]) ; |
vec4 textureGatherOffset( | gsampler2DShadow | sampler, |
vec2 | P, | |
float | refZ, | |
ivec2 | offset) ; |
vec4 textureGatherOffset( | gsampler2DArrayShadow | sampler, |
vec3 | P, | |
float | refZ, | |
ivec2 | offset) ; |
vec4 textureGatherOffset( | gsampler2DRectShadow | sampler, |
vec3 | P, | |
float | refZ, | |
ivec2 | offset) ; |
sampler
Specifies the sampler to which the texture from which texels will be retrieved is bound.
P
Specifies the texture coordinates at which texture will be sampled.
comp
Specifies the component of the source texture that will be used to generate the resulting vector.
refZ
Specifies the reference Z value used in the comparison for shadow forms.
offset
Specifies the offset from the specified texture coordinate P
from which the texels will be gathered.
textureGatherOffset
returns the value:
vec4(Sample_i0_j1(P + offset, base).comp, Sample_i1_j1(P + offset, base).comp, Sample_i1_j0(P + offset, base).comp, Sample_i0_j9(P + offset, base).comp);
It perfoms as textureGather but with offset
applied as described in textureOffset, except that the
implementation-dependent minimum and maximum offset values are given by GL_MIN_PROGRRAM_TEXTURE_GATHER_OFFSET
and GL_MAX_PROGRAM_TEXTURE_GATHER_OFFSET
, respectively.
If specified, the value of comp
must ba constant integer expression with a value
of 0, 1, 2, or 3, identifying the x, y, z or w component of the four-component vector lookup result for each
texel, respectively. If comp
is not specified, it is treated as 0, selecting the x
component of each texel to generate the result.
Function | Version 1.10 | Version 1.20 | Version 1.30 | Version 1.40 | Version 1.50 | Version 3.30 | Version 4.00 | Version 4.10 | Version 4.20 | Version 4.30 |
---|---|---|---|---|---|---|---|---|---|---|
textureGatherOffset | - | - | - | - | - | - | Y | Y | Y | Y |
texelFetch, texelFetchOffset, texture, textureGather, textureGatherOffsets, textureGrad, textureGradOffset, textureLod, textureLodOffset, textureOffset, textureProj, textureProjGrad, textureProjGradOffset, textureProjLod, textureProjLodOffset, textureProjOffset, textureQueryLod, textureSize
Copyright © 2011 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/.