Starbase Functionality

The raw parameter for the block_read and block_write commands is used to enable the use of the bit per pixel mode specified via the R_BIT_MODE gescape. The raw parameter for the block_write command is used to enable the use of the skipcount specified via the BLOCK_WRITE_SKIPCOUNT gescape.

4×4 is the largest supported pattern.

Because of per-window double-buffering and multiple color maps, this utility is only supported for printing one window at a time for these devices. Attempts to print pixels outside this one window may result in a wrong color or pixels from the wrong buffer being printed.

The color map mode may be selected, but shading cannot be turned on. Dithering is available through the hp98735 or hp98765 driver for 12-bit indexing mode.

Only STROKE_TEXT precision is supported.

The use parameter must be zero, any extra coordinates supplied will be ignored.

The raw parameter for these commands is used to enable the use of the bit per pixel mode specified via the R_BIT_MODE gescape. The raw parameter for block_write can also be used to enable use of the skipcount specified via the BLOCK_WRITE_SKIPCOUNT gescape.

If bank_switch (see the section "Changes to bank_switch()" in Chapter 1) is used to select bank 3 (the Z-bank), all subsequent block writes and block reads will be done using word per pixel mode. This means that block_write and block_read will assume that the data is organized in 32 bit words, and (w * h) words will be transferred between the Z-buffer and system memory. The buffer address should be point to a word boundary. Words that are read from the the Z-buffer will contain the Z-buffer data in the 3 most significant bytes of each word, with the least significant byte undefined. Similarly, data being written to the Z-buffer should contain the data to be written in the three most significant bytes of each word.

An HP 98766 device running the HP 98766 device driver, will report 〈image_banks〉 as four, since the system has 24 display planes and 24 Z-buffer planes (the Z-buffer behaves as one bank even though it is 24 planes deep). The dedicated Z-buffer can be accessed with block_write, block_read, and block_move. The Z-buffer may also be selected for read/write using bank_switch (see the section "Changes to bank_switch()" in Chapter 1). The Z-buffer may not be displayed. The graphics accelerator cannot render polygons or other drawing primitives to the Z-buffer.

When rendering lines of width greater than 0, the current position is not valid. Set line_width to zero (0) and perform a move2d to ensure the current position is valid.

If the polygon fill type is INT_HATCH then the following functionality will not work correctly:

Splines, polyhedra, quadrilateral meshes, and triangular strips will not be hatched. Performance is also degraded in this mode.

Because of per-window double-buffering and multiple color maps, this utility is only supported for printing one window at a time for these devices. Attempts to print pixels outside this one window may result in a wrong color or pixels from the wrong buffer being printed.

Dithering is not available in CMAP_MONOTONIC 12 bit indexing mode. Attempting to dither with more than one color in this mode will yield the same results as dithering with one color. Dithering is available through the hp98735 or hp98765 drivers for 12 bit indexing mode.

Only STROKE_TEXT precision is supported.