HP c3700 - Workstation, Справочное руководство, Страница: 335 / 486

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glPixelTransfer
Chapter 14
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Each index is shifted GL_INDEX_SHIFT bits just as a color index is, then added to
GL_INDEX_OFFSET. If GL_MAP_STENCIL is true, each index is masked by 2
n
- 1,
where n is GL_PIXEL_MAP_S_TO_S_SIZE, then replaced by the contents of
GL_PIXEL_MAP_S_TO_S indexed by the masked value.
The following table gives the type, initial value, and range of valid values for each of the
pixel transfer parameters that are set with glPixelTransfer.
glPixelTransferf can be used to set any pixel transfer parameter. If the parameter type is
boolean, 0 implies false and any other value implies true. If pname is an integer
parameter, param is rounded to the nearest integer.
Likewise, glPixelTransferi can be used to set any of the pixel transfer parameters.
Boolean parameters are set to false if param is 0 and to true otherwise. param is
converted to floating point before being assigned to real-valued parameters.
Notes
If a glCopyPixels, glCopyTexImage1D,glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glDrawPixels, glReadPixels, glTexImage1D, glTexImage2D,
glTexSubImage1D, or glTexSubImage2D command is placed in a display list (see
glNewList and glCallList), the pixel transfer mode settings in effect when the display
list is executed are the ones that are used. They may be different from the settings when
the command was compiled into the display list.
pname Type
Initial
Value Valid
Range
GL_MAP_COLOR boolean false true/false
GL_MAP_STENCIL boolean false true/false
GL_INDEX_SHIFT integer 0
( -
∞,∞
)
GL_INDEX_OFFSET integer 0
( -
∞,∞
)
GL_RED_SCALE float 1
( -
∞,∞
)
GL_GREEN_SCALE float 1
( -
∞,∞
)
GL_BLUE_SCALE float 1
( -
∞,∞
)
GL_ALPHA_SCALE float 1
( -
∞,∞
)
GL_DEPTH_SCALE float 1
( -
∞,∞
)
GL_RED_BIAS float 0
( -
∞,∞
)
GL_GREEN_BIAS float 0
( -
∞,∞
)
GL_BLUE_BIAS float 0
( -
∞,∞
)
GL_ALPHA_BIAS float 0
( -
∞,∞
)
GL_DEPTH_BIAS float 0
( -
∞,∞
)