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	VideoControl -- Modify the operation of a ViewPort's ColorMap (V36)
VideoControlTags -- varargs stub for VideoControl (V36)


	error = VideoControl( cm , tags )
d0 a0 a1
ULONG VideoControl( struct ColorMap *, struct TagItem * );
error= VideoControlTags(cm, tags,...);


	Process the commands in the VideoControl command TagItem buffer 
using cm as the target, with respect to its "attached" ViewPort.
viewport commands:
VTAG_ATTACH_CM [_SET | _GET] -- set/get attached viewport
VTAG_VIEWPORTEXTRA [_SET | _GET] -- set/get attached vp_extra
VTAG_NORMAL_DISP [_SET | _GET] -- set/get DisplayInfoHandle
(natural mode)
VTAG_COERCE_DISP [_SET | _GET] -- set/get DisplayInfoHandle
(coerced mode)
VTAG_PF1_BASE [_SET | _GET] -- set/get color base for
first playfield. (V39)
VTAG_PF2_BASE [_SET | _GET] -- set/get color base for
second playfield. (V39)
VTAG_SPODD_BASE [_SET | _GET] -- set/get color base for odd
sprites. (V39)
VTAG_SPEVEN_BASE [_SET | _GET] -- set/get color base for even
sprites. (V39)
VTAG_BORDERSPRITE [_SET | _GET] -- on/off/inquire sprites in
borders. (V39)
VTAG_SPRITERESN [_SET | _GET] -- set/get sprite resolution
(legal values are SPRITERESN_ECS/_140NS/_70NS/_35NS.
see graphics/view.h) (V39)
VTAG_PF1_TO_SPRITEPRI [_SET | _GET] -- set/get playfield1 priority
with respect to sprites (V39)
VTAG_PF2_TO_SPRITEPRI [_SET | _GET] -- set/get playfield2 priority
with respect to sprites (V39)
(These two require that the ColorMap is attached to a ViewPort to be
genlock commands:
VTAG_BORDERBLANK [_SET | _CLR | _GET] -- on/off/inquire blanking
VTAG_BORDERNOTRANS [_SET | _CLR | _GET] -- on/off/inquire notransparency
VTAG_CHROMAKEY [_SET | _CLR | _GET] -- on/off/inquire chroma mode
VTAG_BITPLANEKEY [_SET | _CLR | _GET] -- on/off/inquire bitplane mode
VTAG_CHROMA_PEN [_SET | _CLR | _GET] -- set/clr/get chromakey pen #
VTAG_CHROMA_PLANE [_SET | | _GET] -- set/get bitplanekey plane #
control commands:
VTAG_IMMEDIATE - normally, VideoControl changes do not occur until the
next MakeVPort. Using this tag, some changes can be made to
happen immediately. The tag data is a pointer to a longword
flag variable which will be cleared if all changes happened
immediately. See the example. (V39)
VTAG_FULLPALETTE [_SET | _CLR | _GET] -- enable/disable loading of all
colors in the copper list.
Normally, graphics will only load the color which are necessary
for the viewport, based upon the screen depth and mode. In order
to use the color palette banking features, you may need to use
this tag to tell graphics to load ALL colors, regardless of
screen depth. (V39)
When set, graphics will update the intermediate copper
lists on colour changes. When FALSE, graphics won't update
the intermediate copperlists, so ScrollVPort(),
ChangeVPBitMap() and colour loading functions will be faster.
This value is TRUE by default. (V40)
When set, only colour 0 will be loaded for this ViewPort,
hence the inter-ViewPort gap will be smaller. The colours for
this ViewPort are inherited from the next higher ViewPort. The
results are undefined if this is the first or only ViewPort in
the display, and undefined when used in conjunction with
This value is FALSE by default. (V40)
When set, disables the setting of the dual-playfield
bit in bplcon0. When used with a dual-playfield mode
screen, this allows using separate scroll and bitmaps
for the odd and even bitplanes, without going through
the normal dual-playfield priority and palette selection.
With appropriate palette setup, this can be used for
transparency effects, etc.
copper commands
VTAG_USERCLIP [_SET | _CLR | _GET] -- on/off/inquire clipping of
UserCopperList at bottom
edge of ColorMap->cm_vp
(defaults to off)
buffer commands:
VTAG_NEXTBUF_CM -- link to more VTAG commands
VTAG_END_CM -- terminate command buffer
batch mode commands:
(if you want your videocontrol taglist to be processed in "batch"
mode, that is, at the next MakeVPort() for the ColorMap->cm_vp;
you may install a static list of videocontrol TagItems into the
ColorMap with the BATCH_ITEMS_SET command; and then enable/disable
batch mode processing of those items via the BATCH_CM control
VTAG_BATCH_CM [_SET | _CLR | _GET] -- on/off/inquire batch mode
VTAG_BATCH_ITEMS [_SET | _ADD | _GET] -- set/add/get batched TagLists
private commands (used internally by intuition -- do not call):
VTAG_VPMODEID [_SET | _CLR | _GET] -- force GetVPModeID() return


	cm   = pointer to struct ColorMap obtained via GetColorMap().
tags = pointer to a table of videocontrol tagitems.


	error = NULL if no error occurred in the control operation.
(non-NULL if bad colormap pointer, no tagitems or bad tag)
The operating characteristics of the ColorMap and its attached
ViewPort are modified. The result will be incorporated into the
ViewPort when its copper lists are reassembled via MakeVPort().
Note that you must NOT change colors in the viewport (via SetRGB4(),
LoadRGB4(), SetRGB4(), etc.) after changing any of the color palette
offsets (VTAG_PF1_BASE, etc), without first remaking the ViewPort.


	Sprite resolutions is controlled by two sets of tags, SPRITERESN
and DEFSPRITERESN. If you don't set the sprite resolution, it will
follow the intuition-controlled "default" sprite resolution. Setting
the sprite resolution to one of the SPRITERESN_ values will allow the
application to override intuition's control of it.
This function will modify the contents of the TagList you pass to it by
changing _GET tags to the corresponding _SET or _CLR tag. The
exceptions to this rule are documented as such above (such as
The new tags added for V40 have the prefix VC_ instead of VTAG_. These
tags work in the same manner as all other tags in the system, and will
not be modified by VideoControl().


if (must_remake) { MakeVPort(myview,myvp); MrgCop(myview); }


	struct TagItem VCTags[] =
BOOL bblank = FALSE;
if (VideoControl(cm, VCTags) == NULL)
bblank = (VCTags[0].ti_Tag == VTAG_BORDERBLANK_SET);


	struct TagItem VCTags[] =
{VC_NoColorPaletteLoad_Query, NULL},
ULONG query;
VCTags[0].ti_Data = (ULONG)&query;
if (VideoControl(cm, VCTags) == NULL)
printf("Palette loading is %s\n", (query ? "off" : "on"));



<graphics/videocontrol.h>, GetColorMap(), FreeColorMap()


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