Pollocks
An XCMD for painting colour lines, shapes and pictures directly on to the card window.
Pollocks XCMD. Version 3.2d3, by Sam Deane. Copyright ©1994 ULTRALAB. Compiled 15:53:43, 06/12/94. Debugging code included.
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Description
Back in the old days (when I were a lad), there was no way of displaying colour pictures in Hypercard, so I got out my copy of Turbo Pascal (those were the days eh?) and decided that it was time I had a go at this XCMD lark.
What resulted was an XCMD called DrawPICTs, which allowed you to paint PICT resources directly on to the card window. It worked, but looking back at the code I'm not sure how or why, since it was complete gibberish which broke every rule in Inside Mac!
Now that Hypercard 2's picture command exists, along with a whole load of clever stuff like Colourize Hypercard, HyperTint, and Ken Doyle's QTPict XCMD, there are rather more options available.
Nevertheless, DrawPICTs (now called Pollocks) has hung around, been improved now and then, and proven to be useful enough to get included in a number of our products.
In addition to displaying PICT resources, it now allows you to do basic PICT animations, to paint coloured shapes all over the place, and to fudge around with the clip region of hypercard's window.
Clipping
The main problem with painting pictures directly on to the card window like this, is that Hypercard doesn't know that they are there, and so it will obliterate them whenever it refreshes the screen. As this happens quite often, pictures have a habit of disappearing, or even worse getting partially wiped out.
A partial solution to this problem is to tell hypercard not to draw into the areas of the window that contain pictures. This can be done by modifying the window's clipping region.
The clipping region determines the area of the window into which hypercard can draw. Normally the clipping region covers the whole card. With the add, subtract and reset commands it is possible to modify the clipping region of the current card window, so that rectangular areas of the window are removed from it.
The remove command removes rectangles from the clip region, effectively masking out areas of the window. The add command puts areas back in.
The reset command can be used at any time to reset the clip region to its normal value, covering the whole of the window.
Æ NB: Removing an area from the clip region only prevents Hypercard from drawing into that area, it does not prevent the area from being obscured by another window (for example a palette window). When an obscuring window is removed, a white space will be left in it's wake. Hypercard will not be able to redraw your picture (since it doesn't know about it), and it won't even be able redraw the card graphics that it does know about (since you have prevented it from drawing into that area of it's window!).
To avoid this problem, it is best to clip out any pictures just before doing something that is likely to obliterate them (going from card to card for example) and to restore the clip region as soon as possible afterwards.
Commands
draw
The draw command is the simplest way of drawing a picture resource (PICT) on to the card.
The syntax is:
Pollocks draw,<name>,<left>,<top>
The <name> parameter should contain the name or id of a PICT resource somewhere in the current inheritance path.
The <left> and <top> parameters should contain the coordinates of the top left corner of the PICT. The picture will be displayed at this location in the window of the current stack. It will be clipped by the current clip-region of the card window.
Example script for draw
on mouseDown
Pollocks draw,"test",140,0
ClearWhenClicked
end mouseDown
list
The list command can be used to display up to 16 pictures in one go.
It has the following syntax:
Pollocks list,<picture> { ,<picture> {,...etc }}
where <picture> is a single item in the form "<name>,<left>,<top>".
The <name> parameter should contain the name or id of a PICT resource somewhere in the current inheritance path.
The <left> and <top> parameters should contain the coordinates of the top left corner of the PICT. The picture will be displayed at this location in the window of the current stack. It will be clipped by the current clip-region of the card window.
Example script for list
on mouseDown
Pollocks list,"test,140,0,test,140,100"
ClearWhenClicked
end mouseDown
sequence
The sequence command allows for basic animation, by displaying a numbered sequence of PICTs in quick succession.
The syntax of the command is:
Pollocks sequence,<name>,<left>,<top>,<frames>
This is the same syntax as the draw command, but with one extra parameter. The <frames> parameter should be a number saying how many frames there are in the PICT sequence.
The command will display the pictures "<name>1", "<name>2" ... "<name><frames>" in turn, producing a basic animation. Note that the speed of this animation is totally dependant on the hardware, which is not a good thing. For more sophisticated animation, it would be best to get into Quicktime.
into
The into command draws a picture into a rectangle, scaling the picture if necessary.
It has the following syntax:
Pollocks into,<name>,<rectangle>
The <name> parameter should contain the name or id of a PICT resource somewhere in the current inheritance path.
The <rectangle> parameter specifies the exact rectangle into which the picture should be drawn. The picture will be scaled as necessary to accomplish this.
Example script for into
on mouseDown
Pollocks into,"test",the rect of bg fld "text"
ClearWhenClicked
end mouseDown
add
The add command puts rectangular areas back in to the card's clipping region.
The syntax of this commands is:
Pollocks add,<rectangle>
where <rectangle> is the rectangle to add/remove from the clip region.
subtract
The subtract command removes rectangles from the clip region, effectively masking out areas of the window.
The syntax of this commands is:
Pollocks subtract,<rectangle>
where <rectangle> is the rectangle to add/remove from the clip region.
reset
The reset command can be used at any time to reset the clip region to its normal value, covering the whole of the window.
The syntax of this commands is:
Pollocks reset
foreground
The foreground command can be used to change the actual colour that hypercard uses to display "black" pixels. This is a bit of a kludge, as the colour can only be set to one of eight values.
The syntax is:
Pollocks foreground,<colour>
where <colour> is one of: black,white,red,green,blue, cyan,magenta,or yellow.
Example script for foreground
on mouseDown
put "black,white,red,green,blue,cyan,magenta,yellow" into cols
get Poppet(items,cols,0,the topLeft of the target,comma)
if it 0 then
Pollocks foreground,item 3 of it
end if
end mouseDown
rect
The rect command is used to paint or colour wash rectangular sections of the card. Like the picture drawing commands, the results of this permanent only until the next time Hypercard updates it's window.
The syntax for this command is not fixed yet, but is currently:
Pollocks rect,<rectangle>,<colour>,<size>,<mode>
The <colour> parameter is a three item RGB colour in the format "<red>,<green>,<blue>".
The <size> parameter is a number determines the thickness of the lines used to draw the rectangle. If "fill" is specified, instead of a number, the rectangle is filled.
The <mode> parameter is a number which specifies the Quickdraw pen mode to use when painting the rectangle. If "hilite" is passed, the special hilite mode will be used, which will result in a rectangle painted in the current hilite colour.
Example script for rect
on mouseDown
-- outline the section field
Pollocks rect,the rect of bg fld "section","20000,20000,20000",5,srccopy
-- hilite the text field rectangle
Pollocks rect,the rect of bg fld "text","10000,0,0",fill,hilite
ClearWhenClicked
end mouseDown
update
The update command is used to force Hypercard to re-draw a section of the card window. This can be useful if you know that a section of the window is likely to be invalid, as a result of previous messing around with the clip region of the window.
The syntax for the command is:
Pollocks update,<rectangle>
depth
The depth command returns the bit-depth of the deepest screen in the result.
Example script for depth
on mouseDown
Pollocks depth
answer "Max depth is: " & the result
end mouseDown
devices
The devices command returns a list giving the details of all the screens connected to the computer.
The syntax is:
Pollocks devices
A list is returned in the result, with one line for each screen.
The first item of each line is the depth of the screen. Items 2 to 5 give the localtion of the screen, in global coordinates.
Example script for devices
on mouseDown
Pollocks devices
answer "Number of screens: " & the number of lines in the result
end mouseDown
background
The background command can be used to change the actual colour that hypercard uses to display "white" pixels. This is a bit of a kludge, as the colour can only be set to one of eight values.
The syntax is:
Pollocks background,<colour>
where <colour> is one of: black,white,red,green,blue, cyan,magenta,or yellow.
Example script for background
on mouseDown
put "black,white,red,green,blue,cyan,magenta,yellow" into cols
get Poppet(items,cols,0,the topLeft of the target,comma)
if it 0 then
Pollocks background,item 3 of it
end if
end mouseDown
line
The line command is used to paint or colour wash lines onto the card. Like the picture drawing commands, the results of this permanent only until the next time Hypercard updates it's window.
The syntax for this command is not fixed yet, but is currently:
Pollocks "line",<start>,<path>,<colour>,<size>,<mode>
The <start> parameter gives the start point of the line. The <path> parameter gives the path of the line as a series of coordinates in the form x1,y1,x2,y2,x3,y3, etc..
The <colour> parameter is a three item RGB colour in the format "<red>,<green>,<blue>".
The <size> parameter is a number determines the thickness of the line.
The <mode> parameter is a number which specifies the Quickdraw pen mode to use when painting the line. If "hilite" is passed, the special hilite mode will be used, which will result in a line painted in the current hilite colour.
Example script for line
on mouseDown
put the topLeft of bg field "text" into tl
put the botRight of bg field "text" into br
repeat with n = 1 to 50
Pollocks line,tl,br,"30000,5000,5000",1,srccopy
subtract 5 from item 2 of br
end repeat
repeat with n = 1 to 50
Pollocks line,tl,br,"5000,30000,5000",1,srccopy
add 4 to item 2 of tl
end repeat
repeat with n = 1 to 50
Pollocks line,tl,br,"5000,5000,30000",1,srccopy
subtract 4 from item 1 of br
end repeat
ClearWhenClicked
end mouseDown
globalRect
Example script for globalRect
on mouseDown
-- outline the section field
Pollocks globalRect,the rect of bg fld "section","20000,20000,20000",5,srccopy
-- hilite the text field rectangle
Pollocks globalRect,the rect of bg fld "text","10000,0,0",fill,hilite
ClearWhenClicked
end mouseDown
globalLine
The line command is used to paint or colour wash lines onto the card. Like the picture drawing commands, the results of this permanent only until the next time Hypercard updates it's window.
The syntax for this command is not fixed yet, but is currently:
Pollocks "line",<start>,<end>,<colour>,<size>,<mode>
The <start> and <end> parameters give the start and end points of the line.
The <colour> parameter is a three item RGB colour in the format "<red>,<green>,<blue>".
The <size> parameter is a number determines the thickness of the line.
The <mode> parameter is a number which specifies the Quickdraw pen mode to use when painting the line. If "hilite" is passed, the special hilite mode will be used, which will result in a line painted in the current hilite colour.
Example script for globalLine
on mouseDown
put the topLeft of bg field "text" into tl
put the botRight of bg field "text" into br
repeat with n = 1 to 50
Pollocks globalLine,tl,br,"30000,5000,5000",1,srccopy
subtract 5 from item 2 of br
end repeat
repeat with n = 1 to 50
Pollocks globalLine,tl,br,"5000,30000,5000",1,srccopy
add 4 to item 2 of tl
end repeat
repeat with n = 1 to 50
Pollocks globalLine,tl,br,"5000,5000,30000",1,srccopy
subtract 4 from item 1 of br
end repeat
ClearWhenClicked
end mouseDown
draw file
list file
sequence file
into file
