*
* Global definitions for "view" program.
*
* This thing is starting to grow, so I figured I'd put all the
*  global variables in one file for easy reference.
* Note: root.a initializes all variables to zero, before it sets up
*   the explicitly initialized variables.  So, all DP vars not explicitly
*   initialized will be set to zero.  By not including explicit initializations
*   for such variables, we actually save on code size, since initializing
*   constants are stored in the module (by RLink).
*

* stacksize has to be global, because view_io.a uses it to calculate the
*  amount of buffer space it can use.  If some format needs a lot of
*  stack space (for large dynamic data structures, or recursive routines),
*  then this value will have to be changed.
stk equ 200 Stack space.  This should be enough for everything.

* This seems a good compromise between keeping a large buffer for efficient
*  throughput, and keeping a small buffer so we don't stall so long on
*  slowly growing (i.e. downloading) files.
buffer equ 2000    Space for input buffering and free pool.

   psect  view_global_a,0,0,0,stk+buffer,0

* !"$# RMA won't make something global unless it's in a PSect, so...
stacksize: equ stk

*   Constant internal codes for various screen formats.
 csect 0
 rmb 1        We can't have a zero format code.
VEFFormat: rmb 1
VEFSqFormat: rmb 1 VEF Squash format, only used by Save routine.
MGEFormat: rmb 1   Color Max 3
MGE640Format: rmb 1  Color Max 3: 640x200x4color
CM3Format: rmb 1   CoCo Max 3
CLPFormat: rmb 1   MVCanvas/OS9 CLP clipboard format
PIXFormat: rmb 1   DS69 16-level 256x256 and 128x128 pictures
PIX256Format: rmb 1 Force us to interpret it as 256x256
PIX128Format: rmb 1 as above, 128x128.
IMGFormat: rmb 1   Rascan IMG format
RATFormat: rmb 1   RAT format
P00Format: rmb 1   Support for various Pmodes.
P01Format: rmb 1
P10Format: rmb 1   First digit is "Pmode" type, second is 0 or 1
P11Format: rmb 1   for standard or alternate color set.
P20Format: rmb 1
P21Format: rmb 1
P30Format: rmb 1
P31Format: rmb 1
P40Format: rmb 1
P41Format: rmb 1
MAXFormat: equ P41Format   Non-artifacted Pmode-4 pictures (Color Max 2)
ARTFormat: rmb 1   Artifacted Pmode-4 pictures     (Color Max 2)
MAXCMPFormat: rmb 1 MAXCMP/PIXCMP
ARTCMPFormat: rmb 1 Above, with artifacting
RLEFormat: rmb 1   CIS RLE format
STFormat:  rmb 1   Degas ST format
MACFormat: rmb 1   Macintosh MacPaint format
GIFFormat: rmb 1   GIF format
GIFBWFormat: rmb 1 GIF with B/W rendering.
PUBFormat: rmb 1   Home publisher clipart format
 endsect

 csect 128
MButton:  rmb 1   signal to return on mouse click (by SS.MsSig)
KButton:  rmb 1   signal to return on keypress.   (by SS.SSig)
 endsect

 vsect dp
PID:        rmb 1       Holds Process ID, for Get/Put buffer stuff
outpath:    fcb 1       Holds path number for current output screen
format:     rmb 1       Current format code. $ff -> none.

*
* For better handling of slowly growing files (i.e. viewing files while
*   they are downloading), set this small (i.e. 100), which will limit
*   the size of disk reads.
MaxBuff:    fdb $ffff

* Routines that need large tables can allocate them by moving up
* MemTop and decreasing MemSiz.  Note that the I/O routines use up
* all of this when the input file is opened, so such allocation
* should be done very early.
MemTop:     rmb 2       Top of allocated data = bottom of free pool
MemSiz:     rmb 2       Size of free pool

*
* These are used by view_gfx.a routines for setting up new screens.
*  Note: for multi-screen displays, "Samescreen" only affects
*   the first call to "setscreen".
Samescreen: rmb 1       T = Use same screen, rather than making new one.
type:       rmb 1       Type of window.  Set before calling "setscreen"
border:     rmb 1       Border palette to use for this window.

* View sets up a signal trap at the beginning, and sets this variable.
*  It also sets a mouse signal (MButton).
*  This variable instructs the signal handler to abort the program
*  (through the _abort vector in view.a) if a signal occurs.
* If you want to use the signal, you should clear this variable first.
*  The keywait routine clears it in order to handle mouse clicks and
*  such.
SigCode:    rmb 1       Signal value received by Signal handler. 0=no signal
abort:      rmb 1       T= abort on any signal.

* For use with slideshow-type programs, the -signal # # option will
*   set these variables, which will cause VIEW to send the specified
*   signal rather than ringing the terminal bell.
SigPID:     rmb 1
SigOut:     rmb 1

*
* These are set by command line parameters.
*   If used by a picture format, it should first check for out-of-range
*   values.  In particular, if Skiplines is $ffff, it should be re-set
*   to an appropriate default value.  Ditto for Skipcols
Skiplines:  fdb $ffff   Number of lines to skip. $ffff -> not set.
Skipcols:   fdb $ffff   Number of cols to skip.  Used by very wide formats.

* This determines the size of the picture display.  The following
* values are used:  0=Small (fits on one screen), 1=Big (normal size)
* 2=Huge (show as much detail as possible, for non-CoCo formats).
Size:       fcb $ff     $ff -> Use "default" size.

* Variables for various animation effects.
*   "cycling" refers to rotating a group of palettes
*       (What CM3 calls "animation)
*   "extra" variables control rotating several colors through one palette.
*   To disable cycling, set cyclestart=cycleend
*   To disable extra rotation, set extranum = 0
*
cycle:      rmb 1       T = All animation effects enabled.
cyclestart: fcb 8       First palette for palette cycling.
cycleend:   fcb 15      Last palette for palette cycling.
cyclerate:  fdb 5       Time in ticks between palette cycles.
extraslot:  rmb 1       Palette slot for color rotation
extranum:   rmb 1       Number of colors to rotate through that slot
extrarate:  fdb 5       Time in ticks between color rotation.

*
*  Flipping is a technique of quickly switching several screens in order
*    to provide the appearance of a wider palette.
*  Setting flipping disables all other animation effects.
*    This variable is ignored if numscreens < 2.  (see view_gfx.a)
*  Multi-screen displays can set fliprate high (like 100 to 200) to
*    allow automatic slow cycling between the screens (CM3, for example)
flipping:   rmb 1       T = multiple screen flipping should be used.
fliprate:   fdb 2       2 gives best performance for most.

*
* Set by -q option to 60 times the number of seconds.
*  counted down by the keywait routine to timeout the display.
*  the default of 65,536 ticks is a little over 18 minutes.
* View ends when this variable hits zero.  In reality, due to overhead
*  in "keywait", the actual delay time tends to be longer than is
*  actually set here, especially if animation effects are on.
MaxTime:    fdb $ffff   Max number of ticks to show picture.

* Used by malloc to dynamically request/return memory from the system
*
oldmemsize: rmb 2
newmemsize: rmb 2
 endsect

*
* Large buffers.
 vsect
extrapals:  rmb 16      Palette codes to rotate through one palette register.
palette:    rmb 48      Palette codes to be used by "setpals" call.
linebuff:   rmb 1024    Space for storing lines of graphics to be output.
altbuff:    rmb 1024    Extra buffer for various uses.
alt2buff:   rmb 1024    Extra buffer for various uses.
 endsect

 endsect