Starbase Functionality

Calls not Supported

The following calls are not supported when using the CRX-48Z. When executed, these calls will produce no result (i.e. they are no-ops).

bf_texture_index
define_texture
texture_index
texture_viewport
texture_window

Conditional Support of Starbase Calls

The following calls are supported with the listed exceptions:

alpha_ transparency

Alpha only applies to filled areas such as polygons, quadrilateral meshes, triangular strips, and spline surfaces. Alpha per vertex is supported. Vector primitives are not rendered with alpha_transparency.

The alpha_transparency feature is limited toCMAP_FULL in the 24-plane configurations. Only the floating point version of these primitives will be rendered with alpha transparency; device coordinate primitives do NOT use alpha. The CRX-48Z does not support alpha transparency with attenuation. (See the Reference page for alpha_transparency for parameters in the Starbase Reference Manual).

block_read, block_write

The raw parameter for the block_read andblock_write commands is used by this driver to do plane-major reads and writes. It is enabled by the gescape R_BIT_MODE.

The storage supplied by the user as the source or destination must be organized as follows.

The data from each plane is packed with eight pixels per byte.
Each row must begin on a byte boundary. Thus the size of the rectangle as specified by the 〈length_x〉 and 〈length_y〉 parameters must correspond to an integral number of bytes.
The data for the next plane begins on the following byte boundary.
Clip to the screen limits.
The first pixel in the source rectangle is placed in the high-order bit of the first byte in each plane region.
When clipping, part of each plane region will not be displayed (block_read) or altered (block_write).

A bit mask selects the planes to read or write. The initial value of this mask is 1 (one) indicating that only plane 0 is to be accessed. The value of the mask may be changed using the R_BIT_MASK gescape. The planes selected by the mask are expected to reside in consecutive plane locations in the user storage area. This reduces the storage requirements to exactly what is needed but also presents the potential for addressing violations or undesirable results.

For example, if the plane mask is changed to specify more planes between a block_read and a following block_write from the same location, the block_write will attempt to access storage for planes that were not read (and perhaps not allocated). The application program must ensure consistency in these operations.

define_raster_echo

The hpcrx48z driver interprets pixel values of 0 in the raster echo definition to be the cursor background color. It interprets all non-zero pixel values to foreground color.

line_filter, perimeter_ filter

The antialiasing features are only available with the CMAP_FULL color map mode in the 24-plane configurations.

The CRX-48Z has two antialiasing modes that may be specified with the line_filter andperimeter_filter procedures. The index values are assigned as follows:

0

Anti-aliasing disabled, all vectors have one pixel wide output.

1

Anti-aliasing enabled, all vectors have three pixel wide output. Pixel values are multiplied by the alpha value and blended with the background according to the formula:

pixel_color= (new_pixel × α)+(old_pixel × (1-α));

2

Anti-aliasing enabled, all vectors have three pixel wide output. Pixel values are multiplied by the alpha value, and blended with the background according to the formula:

pixel_color = (new_pixel × α);

pattern_ define

The maximum pattern size is 4x4. If a pattern larger than 4x4 is specified, an error message is printed and the previous pattern is retained.

shade_mode

Shading is not supported on device coordinate primitives.

text_ precision

Only STROKE_TEXT precision is supported.

vertex_format

The 〈use〉 parameter must be zero. Any extra coordinate information will be ignored. If using PowerShade software, vertex_format is fully functional. Note that HCRX-8Z and HCRX-24Z configurations automatically use PowerShade.

with_data

The following routines are called with_data routines because they contain with_data in their routine names. These with_data routines are supported by the CRX family of graphics devices.

partial_polygon_with_data3d
polygon_with_data3d
polyhedron_with_data
polyline_with_data3d
polymarker_with_data3d
quadrilateral_mesh_with_data
triangle_strip_with_data

For detailed information on these routines, read the Starbase Reference. In some cases, you will be able to find the routines under their own name, but in other cases, you will need to use the first part of the routine name to locate these routines (e.g., polyline_with_data3d is described on the man page for polyline(3G)).

Supported Gescapes

The hpcrx48z driver supports the following gescape operations. Refer to Appendix A of this manual for details on gescapes.

BAD_SAMPLE_ON_DIFF_SCREEN — Restore the locator and choice sampling of the X11 pointer device.
BLOCK_WRITE_SKIPCOUNT — Specify byte skip count during block write.
CONTOUR_CONTROL — Specify alternative methods for interpolation of contour data.
CUBIC_POLYPOINT — Specify points to be rendered in a cubic volume specified in modeling coordinates.
DC_PIXEL_WRITE — Specify points to be rendered along a horizontal scan line.
DRAW_POINTS — Select different modes of rounding for rendered points.
GAMMA_CORRECTION — Enable/disable gamma correction.
GCRX_PIXEL_REPLICATE — Pan and zoom a raster image.
GR2D_PLANE_MASK — Overrides the bit mode mask.
IGNORE_RELEASE — Trigger only when button pressed.
ILLUMINATION_ENABLE — Turn on/off illumination bits.
LINEAR_POLYPOINT — Specify points to be rendered along a line specified in modeling coordinates.
LS_OVERFLOW_CONTROL — Set light source overflow handling.
OLD_SAMPLE_ON_DIFF_SCREEN — Inquire the locator and choice sampling of the X11 pointer device.
PLUG_ACCELERATED_PIPELINE — Controls the rendering of the graphics accelerators into the frame buffer.
POLYGON_TRANSPARENCY — Segment control over front/back face "screen door".
R_BIT_MASK — Select plane for reading and writing bit blocks.
R_BIT_MODE — Specify data format for bit/pixel block transfer operations..
R_DEF_ECHO_TRANS — Define transparency mask for raster echo.
R_ECHO_FG_BG_COLORS — Define color attributes.
R_ECHO_MASK — Turns on echo transparency mask.
R_GET_FRAME_BUFFER — Read the frame buffer and control space addresses.
R_LINE_TYPE — User defined line style and repeat length.
R_LOCK_DEVICE — Lock device.
R_UNLOCK_DEVICE — Unlock device.
READ_COLOR_MAP — Read color map.
STEREO — Activate stereo output mode.
SWITCH_SEMAPHORE — Semaphore Control.
TRANSPARENCY — Set screen door transparency mask (front face and back face).
TRIGGER_ON_RELEASE — Trigger only when button is released.
ZBANK_ACCESS — Enable/disable the Z-buffer bank for reading and writing.
ZWRITE_ENABLE — Enable/disable replacement of Z value.

Exceptions to Gescape Support




	NOTE: Because the gescape operations are device-dependent, the exceptions discussed below may be removed in future drivers.

GAMMA_CORRECTION - Enable/disable gamma correction. Gamma correction is implemented differently on the hpcrx48z than on older devices. It is implemented in the color map rather than in the frame buffer. For information on the gescape GAMMA_CORRECTION, refer to Appendix A.
R_ECHO_CONTROL - Regardless of what cursor is requested, hardware or software, the CRX-48Z will always return the arg2[0] value of 1 which indicates the hardware cursor is being used.

Starbase Functionality

Technical documentation

» Table of Contents

» Index

Calls not Supported

Conditional Support of Starbase Calls

Supported Gescapes

Exceptions to Gescape Support