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Annotation of 43BSDTahoe/new/X/libibm/bitblt/README, revision 1.1.1.1

1.1       root        1: General information about Bitblt:
                      2: 
                      3: If you look at the Makefile you will see that there are five defines
                      4: used during the compilation of bitblt. The Makefile is distributed this
                      5: way so that bitblt is able to run on all of the currently available IBM
                      6: displays. Lets take a closer look at each define.
                      7: 
                      8: APA16          The bltter is compiled to run on the apa16 display.
                      9:                (Note: The apa16 has hardware cursor support)
                     10: 
                     11: USE_APA16_HDWR The bltter will use apa16 hardware features to
                     12:                do screen to screen copies and and selected tiling
                     13:                operations. Note that it only makes sense to define 
                     14:                this when APA16 is also defined.
                     15: 
                     16: APA8           The bltter is compiled to run on the apa8 display.
                     17:                (Note: The apa8 and apa8c have software cursors)
                     18: 
                     19: APA8C          The bltter is compiled to run on the apa8C display.
                     20:                (NOTE: FULL COLOR SUPPORT IS NOT PROVIDED)
                     21: 
                     22: AED            The bltter is compiled to run on the aed display.
                     23:                (Note: The aed has hardware cursor support)
                     24: 
                     25: Note: 
                     26:        When none of the above are defined this creates a bltter that
                     27:        will work on any bitmap display (within limits). This includes
                     28:        the PQD. That is why no define was provided for it.
                     29: 
                     30: It should be noted that only those defines that relate to your hardware
                     31: configuration need be used (or none at all). This would in most cases reduced
                     32: code size and improve performace by 0 - 5 percent. Since the performance hit
                     33: for having the bltter compiled to run on all displays is minimal, consideration
                     34: should be given to the flexability provided by doing so.
                     35: 
                     36: 
                     37: Now lets review the source files.
                     38: 
                     39: bitblt.c       This is the code that actually does the the blt.
                     40: 
                     41: bitblt_apa16.c These two files make up the apa16 hardware support.
                     42: bitblt_apa16.h
                     43: 
                     44: bitblt_aed.c   These two files make up the aed microcode support.
                     45: bitblt_aed.h
                     46: 
                     47: bitblt_subr.c  This file contains the code required to convert the 
                     48:                extrenal bitblt data structure to and internal structre
                     49:                for easy processing.
                     50: 
                     51: bitblt_cur.c   This file contains the software cursor support. The code
                     52:                that removes the cursor from the screen and puts it back
                     53:                is in the kernel. The code that informs the kernel of where
                     54:                the current blt is taking place is in this source file.
                     55: 
                     56:                Note: Since hardware cursors are not removed from
                     57:                      the screen during a blt the support can be done
                     58:                      in the kernel. Therefore, the code is not included
                     59:                      in this source file.
                     60: 
                     61:                Before the bltter is used bitblt_init() must be called
                     62:                to set the cursor type and bitmap address. The cursor
                     63:                types are SOFT_CURSOR and HARD_CURSOR.
                     64: 
                     65: bitblt_int.h   This file contains the internal data structures.
                     66: 
                     67: bitblt_ext.h   this file contains the external data structures.
                     68: 
                     69: 
                     70: For more information on bitblt see bitblt.paper in the doc directory.
                     71: 
                     72:                                
                     73:                                                -- Scott --

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