Name

PCA3P − Divides a designated parallelogram into cells, and displays each cell in a specified color. 

Operating States: PHOP, ∗, STOP, ∗
PHIGS PLUS function
Creates a structure element

Syntax

PCA3P (CPXA, CPYA, CPZA, DIMX, DIMY, ISC, ISR, DX, DY, CTYPE,
NCC, COLIA, COLRA)

Argument        Data Type     Access   Description
---------------------------------------------------------------------------
CPXA(3),        Real          Read     Cell parallelogram (P, Q, R), in
CPYA(3),                               modeling coordinates
CPZA(3)
DIMX, DIMY      Integer       Read     Number of columns and rows in COLIA
                                       or COLRA
ISC, ISR        Integer       Read     Indexes of the starting column and
                                       starting row
DX, DY          Integer       Read     Number of columns, number of rows
CTYPE           Integer       Read     Color type
NCC             Integer       Read     Number of color value components
COLIA(DIMX,     Array of      Read     Color index array
DIMY)           integers
COLRA(NCC∗      Array of      Read     Color value array
DIMX∗DIMY)      reals
---------------------------------------------------------------------------

Constants

Defined Argument     Constant    Description
---------------------------------------------------------------------------
CTYPE                PINDIR      Indirect (indexed) color
                     PRGB        Direct specification of red, green, and
                                 blue
                     PCIE        Direct specification in the format of the
                                 Commission Internationale de l’Eclairage
                     PHSV        Direct specification of hue, saturation,
                                 and value
                     PHLS        Direct specification of hue, lightness,
                                 and saturation
---------------------------------------------------------------------------

Description

PCA3P divides a designated parallelogram into cells and displays each cell in a specified color.  This function allows for more direct color specification than the standard primitive. 

Depending on the current edit mode, this function either inserts the new structure element directly after the element indicated by the pointer or replaces the element indicated by the pointer.  The pointer then points to the new cell array 3 plus element. 

You pass a three-dimensional array containing color index values as one argument to this function. Digital PHIGS maps the color index values to corresponding cells within a parallelogram-shaped area of the workstation surface. 

There is a one-to-one correspondence between the number of specified array columns and rows, and the number of columns and rows by which Digital PHIGS divides the cell array parallelogram. Each of the columns within the parallelogram is of equal width, and each of the rows within the parallelogram is of equal height.  Digital PHIGS maps the color index values from each specified color index array element to the corresponding cell, moving from the starting point towards the diagonal point along the x-axis. The grid defined by the three parallelogram vertices and the number of columns and rows is subject to all transformations. 

For more information on the initial color index values for a given workstation, see the Device Specifics Reference Manual for DEC GKS and DEC PHIGS. 

To alter the color associated with a certain index value, you can use the function PSCR.  Refer to the figure in the hardcopy and Bookreader documentation.  The label DX refers to the argument DIMX, and DY refers to the argument DIMY. 

If Digital PHIGS is in immediate mode, it performs this function immediately, but the function does not create a structure element. 

Digital PHIGS Version 3.1 does not support this function.

See Also

PADS
PCA
PCA3
PSBRFM
PSBRFP
PSFCM
PSFDM
PSLSS
PSRFM
PSRFP