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ICADDemo is a demonstration version of IntroCAD 2.1.
Copyright (C) 1987, 1988 Tim Mooney
ICADDemo and the accompanying files IntroCAD.txt and ICADDemo.doc are
freely distributable, but are nevertheless protected by copyright. They
are not to be sold, although you may charge a nominal copying/hassle fee
for distributing them.
--------------------------------------------------------------------------
The following text is taken from the IntroCAD Owner's Manual.
--------------------------------------------------------------------------
***********************
OBJECT-ORIENTED DRAWING
IntroCAD is an OBJECT-ORIENTED drawing program. It might be easiest to
explain what that means by comparing IntroCAD to the PIXEL-ORIENTED drawing
programs (e.g., GraphiCraft and Deluxe Paint) with which you may be more
familiar. The major difference, as you will see, is in the way information
is stored.
Pixel-oriented programs store essentially all of the information which
describes the picture you are drawing right on the screen in front of you.
Each little dot on the screen--each pixel--has a color; your job, as drawer,
is to change the colors of selected pixels.
Now, for some purposes, the screen is not an ideal place
to store picture information. A computer screen is a
relatively low-resolution device when compared to most
printers and plotters; you normally can't use the higher
resolution of these output devices if the picture
information is stored on the screen. Some numbers: the
highest resolution achievable on the Amiga is approximately
75 dots per inch (DPI) horizontally, by 60 dpi vertically
(with the standard Amiga monitor.) In contrast, the best
resolution of one medium-priced dot matrix printer is 240 by
216 dpi. Laser printers routinely achieve 300 by 300 dpi.
Object-oriented programs, on the other hand, store information in a
drawing list--kept in memory which is separate from the screen's
memory--and use the screen only to exchange information with you. The
screen is optimized for quick transmission of information to your monitor,
while the drawing list is optimized for faithful recording of your drawing.
Your job, in using an object-oriented program, is to tell the program where
the lines which make up your drawing begin and end, what color the lines
are, whether they are solid or dashed, etc. You tell IntroCAD these things
by drawing the objects, just as if you were using a pixel-oriented program.
IntroCAD responds by showing you a picture of what you're drawing. In
IntroCAD, what actually is stored are the coordinates of the *POINTS* of
the objects you draw. A line segment, for example, is stored simply as two
points--two pairs of coordinates.
IntroCAD can use the full resolution of any output
device it knows how to talk to because the picture
information is stored--as floating-point numbers--in a drawing
list rather than on a screen. IntroCAD could effectively use
an output device with a resolution of well over one million
dots per inch, (although no such device exists, nor is one
likely to become generally available in the near future.)
This ability is one major advantage enjoyed by object-oriented
drawing programs.
A second difference between object-oriented and pixel-oriented programs
is the way they behave when you draw one object on top of another. In
pixel-oriented drawing, the covered object is gone forever; all memory of
it has been erased and replaced by the new object. (But most
pixel-oriented programs provide a means of recovering the obscured object
by "undoing" the drawing motion which erased it.) In object-oriented
drawing, nothing is ever erased by drawing on top of it; objects are
remembered unless they are explicitly erased.
The biggest difference becomes clear when you begin to modify a drawing.
Let's say you have drawn a box on the screen and then, later, drawn a
circle overlapping it. An object-oriented program allows you to move the
box, or modify its shape without changing the circle in any way. Normally,
you can also group the box and circle together and move or modify them as a
unit. A pixel-oriented program normally doesn't allow you to move or
modify overlapping objects separately. Instead, you modify sections of the
screen--with whatever objects, or parts of objects happen to lie on those
sections.
In pointing out some of the advantages of object-oriented drawing, I
don't mean at all to represent it as "better" in any absolute sense than
pixel-oriented drawing. It simply is different, with different advantages
and disadvantages. A major disadvantage of object- oriented drawing, for
example, is that the drawing list grows, consuming more memory, as more
objects are drawn. A very complex drawing may not fit in your computer's
memory space. In contrast, a pixel-oriented drawing always takes up the
same amount of memory--regardless of the drawing's complexity.
****************
INVOKING IntroCAD
-------------
From the WorkBench:
There are three methods:
1) Double-click on the IntroCAD icon.
2) Press and hold the shift key.
Click on the icon of an IntroCAD Drawing.
Double-click on the IntroCAD icon.
Release the shift key.
This will open IntroCAD and cause it to also open the Drawing
you selected.
3) Double-click on a Drawing's icon.
This will do the same thing as method #2, and is a nice short-cut.
But this method requires that:
a) IntroCAD hasn't been renamed.
b) IntroCAD is located in the top drawer of a disk (also) named
IntroCAD.
In other words, IntroCAD's FULL name must be "IntroCAD:IntroCAD".
Experienced users sometimes call the part up to and including the colon
the "path", while the rest is the "name".
If you've copied IntroCAD to a hard-disk or ram disk, you can't
cause the path to be "IntroCAD:", but you can do the next best thing:
Say, for example, you've copied IntroCAD to the directory "DH0:cad".
You can open a CLI window and type:
Assign IntroCAD: DH0:cad
From now until you reboot the machine or turn it off, the WorkBench
will act as though IntroCAD were located on a disk named "IntroCAD".
-------------
From the CLI:
Type IntroCAD
or IntroCAD filename
where "filename" is the name of a drawing or part file that you want to
create or edit.
**************************
DRAWING WITH IntroCAD
Here's how to draw some simple objects with IntroCAD:
--------------------------
BOX:
Select "Box" from the "Draw" menu.
Position the mouse pointer where you want one corner of the box to be.
Click the left mouse button once.
Move the mouse pointer until the box you see is the box you want.
Click the left mouse button once.
So you see what's going on here: Your first mouse click puts an
imaginary pen down on the page; your second one picks it back up and makes
the box part of your drawing. (All that hideous stuff--about coordinates
of points being somehow entered into a drawing list--you might have
imagined while reading the "Object-Oriented Drawing" section has just been
done for you. You can think about the box; IntroCAD will take care of the
drawing list.)
--------------------------
CIRCLE: Much like drawing a box.
Select "Circle" from the "Draw" menu.
Position the mouse pointer where you want the center of the circle to be.
Click the left mouse button once.
Move the mouse pointer until the circle you see is the circle you want.
Click the left mouse button once.
--------------------------
LINE: This one's a little different.
Select "Line" from the "Draw" menu.
Position the mouse pointer where you want the line to begin.
Click the left mouse button once.
Move the mouse pointer until the line you see is the line you want.
Click the left mouse button *twice* (don't move the mouse between clicks.)
Why do you have to click twice to end a line? Because the "Line" tool is
also used to draw a set of connected lines. A single click with this tool
means "end this line and start another." There's a limit to the number of
connected lines you can draw at once, but you'll probably never reach it.
For concreteness, here's an example of two connected lines:
SET OF TWO CONNECTED LINES:
Select "Line" from the "Draw" menu.
Position the mouse pointer where you want the line to begin.
Click the left mouse button once.
Move the mouse pointer until the line you see is the line you want.
Click the left mouse button once.
Move the mouse pointer until the line you see is the line you want.
Click the left mouse button *twice* (don't move the mouse between clicks.)
--------------------------
FREEHAND: Different from all the others in that you hold the mouse button
down while you draw.
Select "FreeHand" from the "Draw" menu.
Position the mouse pointer where you want the freehand figure to begin.
Press and hold the left mouse button.
Move the mouse pointer to draw the figure.
Release the left mouse button.
--------------------------
ARC: Like a circle, but with one extra click.
Select "Arc" from the "Draw" menu.
Position the mouse pointer where you want the center of the arc to be.
Click the left mouse button once.
Move the mouse pointer to set the radius and starting angle of the arc.
Click the left mouse button once.
Move the mouse pointer until the arc you see is the arc you want.
Click the left mouse button once.
--------------------------
TEXT: Just as you might expect.
Type a letter at the keyboard.
That's it. (You can do this at any time. You never need to make a menu
selection before typing text into your drawing.)
You can set the text size very simply:
Select "TextSize" from the "Draw" menu.
Draw a box. (It doesn't matter where you draw the box;
only its size matters.)
You can set the text location very simply as well:
Select "Cursor" from the "Draw" menu.
Position the mouse pointer where you want the lower
left hand corner of the next letter to begin.
Click the left mouse button once.
**************************
IntroCAD'S SCREEN
There are a number of features IntroCAD can put on the screen on top of
your drawing. All of these are intended to give you information of one
sort or another. All are controlled by selections from the "Options" menu.
RULERS
These are the numbered bars which occur at the left and bottom
edges of the screen. The rulers are marked out in inches. You can
toggle display of the rulers with the menu item "Rulers".
There is nothing special about the screen regions occupied by the rulers.
You can (and should not hesitate to) draw right on top of them. IntroCAD
normally doesn't bother to refresh the screen when the rulers are scribbled
on because this can happen frequently and, for a complex drawing, a screen
refresh can take several seconds. You can, however, cause IntroCAD to
refresh the screen each time the drawing changes by selecting the menu item
"ReDraw/Auto" ("Auto" is a sub-item of "ReDraw") from the "Options" menu.
GRID
These lines are drawn behind your drawing. You can choose from several
different kinds of grid. You can also make the grid invisible. The menu
item "Grid" is used for these selections. You can make the grid mesh
finer or coarser with the menu item "Grid Mesh".
CURRENT TOOL
At the upper left-hand corner of the screen, IntroCAD prints the
abbreviated name of the *tool* you are currently using. (Examples of tools
are the "Line" tool, with which you draw lines; the "Erase" tool, with
which you erase objects; and the "Group" tool, with which you group objects
together.) Display of this feature is controlled with the menu item
"ShowTool".
COORDINATE READOUT
When the menu item "ShowXY" is active, IntroCAD prints four numbers at
the lower left-hand corner of the screen. The display might look like:
00.00:2.00 0.00:5.00 L:3.00 A:0.00
The first two numbers in the display are the current X (horizontal) and
Y (vertical) coordinates of the mouse pointer. The next two numbers are
the X and Y distances from the pointer to the position of the most recent
SELECT click. The number which follows "L:" is the length of the line
connecting the point of the most recent SELECT click and the current
position of the mouse. The number following the "A:" is the angle of that
line.
FREE MEMORY
When the menu item "ShowMem" is active, IntroCAD prints the total amount
of computer memory which has not been allocated by any process. The display
occurs near the middle bottom of the screen. The number is in kilobytes.
GRID SPACING
While a "Plain" or "Projection" grid is selected, IntroCAD prints the
spacing between grid lines at the lower right-hand corner of the screen.
**************************
IntroCAD OBJECTS & GROUPS
In this manual, the words OBJECT, GROUP, and PRIMITIVE will occur
frequently. These words have special meanings here; they refer to parts of
your drawing.
To IntroCAD, an *OBJECT* is either of:
1) The result of a single complete drawing motion. A box,
for example, is an object. So is a set of connected line
segments all drawn "at the same time." So are circles,
letters, etc. These objects are also called *PRIMITIVE*s.
2) A grouped set of primitives. Such an object is also
be called a *GROUP*. There is no limit to the number
of primitives in a group, or to the number of groups
in a drawing.
A few notes about groups:
The grouping of objects need not be permanent. You can
dismember ("UnGroup") a group into primitives at any time.
IntroCAD doesn't ever change the group structure of a
drawing on it's own, however. When a drawing is saved to
disk, the group structure is saved with it.
No object can be in more than one group at a time. If
you try to group objects which are already members of
different groups, IntroCAD will assume you want the entire
*groups* grouped together.
Although you can group groups together, groups are not
hierarchical. In other words, IntroCAD does not keep track
of groups within groups. When a group is "UnGrouped", the
result is always a collection of primitives.
It is not an error to attempt to ungroup a primitive. (It
doesn't work, though.)
*********
THE MOUSE
In IntroCAD, the mouse does mostly what you're accustomed to from drawing
programs like "Deluxe Paint". There are a few differences, however.
(Here, and throughout this manual, the *SELECT* button is the left mouse
button; the *MENU* button is the right mouse button.)
1) In IntroCAD, you are called on to select objects, e. g., for
treatment with one of the editing tools. Since IntroCAD can't know for
which of two or more overlapping objects your *SELECT* click was intended,
it runs through a list of all the possibilities, highlighting each in turn.
In this context, a *MENU* click means "No, not that one", a *SELECT* click
means "Yes, the highlighted object is the one I want". (See "Selecting
Objects" for more detail.)
2) While drawing an object (exception: text) or editing (exceptions:
coloring, setting line type, rotating by 90 degrees), IntroCAD gives you a
chance to abort the whole operation. In this context, a *MENU* click means
"Abort", a *SELECT* click means "The highlighted object is drawn as I want
it, make it permanent."
3) Certain editing functions, "Point" for example, require additional
information and indicate this by drawing highlighted objects. You are
asked to click on (*SELECT* button) e. g., one of the objects.
4) In certain circumstances, IntroCAD prompts you for a mouse motion by
making a suggestive little pictogram with the mouse pointer. The meanings
of the pictograms are as follows:
A) CIRCLE WITH A SLASH THROUGH IT:
Wait. IntroCAD is busy with some calculations and is not
looking for input from you. However, Intuition--the Amiga's user
interface--is *always* attentive to the mouse and keyboard and
will "stack up" mouse clicks and key presses for later handling
by IntroCAD. You should not assume, then, that the mouse and
keyboard are ignored while the "Wait" pointer is displayed.
B) ARROW WITH A QUESTION MARK:
This is a "Select Something" mouse pointer.
Point at something and click the *SELECT* button. Typically, you
will position the mouse pointer over some object on the screen
and click to direct IntroCAD's attention to the object.
C) ARROW WITH A BOX:
This is a "Draw Region" mouse pointer.
Draw a box. (For "Zooming" only, clicking twice in the
same spot is equivalent to drawing a box twice the size
of the screen. See "Zoom" in the section which describes
the "Options" menu.)
D) QUESTION MARK WITH A "Y" ON THE LEFT AND A "N" ON THE RIGHT:
This is a "Yes/No" mouse pointer.
Say "Yes" by clicking the *SELECT* button, or "No" by clicking
the *MENU* button.
So, generally, when the mouse buttons don't have their Intuition
meanings, the *SELECT* button means "Yes/THAT one/Do it", and the *MENU*
button means "No/Not THAT one/Get me out of this!". This follows the
generally accepted convention that "left" breaks new ground while "right"
is conservative and safe. If you get lost in, or called away in the middle
of, a sequence of mouse clicks, some number of *MENU* button clicks will
ALWAYS get you out of it.
One last thing about mouse buttons: Since IntroCAD appropriates the
*MENU* button for things like selecting objects and aborting, there are
times when you can't (immediately) make menu selections with this button.
If you truly DO want to make a menu selection, and IntroCAD seems
uncooperative, just click the *MENU* button repeatedly until the menu bar
flashes at the top of the screen, and then make your menu selection.
**************************
SELECTING OBJECTS
To edit, clone, or save an object to disk, you must first specify the
object by selecting it. (This is true even if there is only one possible
object.) There is no explicit tool--no menu item--for this purpose since
IntroCAD always knows when a selection is required. At the appropriate
time, IntroCAD will ask you to specify an object by giving you the "Select
Something" mouse pointer (an arrow with a question mark above it.)
When IntroCAD gives you the "Select Something" mouse pointer, you should
point to the object of your choice and click the *SELECT* button. IntroCAD
will make a list of all the objects you might possibly be referring to
(let's call this list the *SELECT LIST*), and highlight the first one in
the list by re-drawing it in the highlight color. (The highlight color is
color #15. IntroCAD causes this color to change continuously whenever it's
waiting for input from you.) After highlighting an object, IntroCAD will
give you the "Yes/No" mouse pointer. If the highlighted object is the one
you want, say "Yes" by clicking the *SELECT* button; if not, say "No" by
clicking the *MENU* button and IntroCAD will "unhighlight" the object and
highlight the next object in the list. If you get all the way through the
Select List without saying "Yes" to any of the objects, IntroCAD will
invite you to make another selection by again giving you the "Select
Something" mouse pointer. You can, of course, ignore the invitation and
make a menu selection instead.
It may help you to know how IntroCAD infers, from the
position of the mouse pointer at the time of your *SELECT*
click, which object you are specifying. For each
primitive, IntroCAD maintains a *REGION-RECTANGLE*. This
is the smallest rectangle, having horizontal and vertical
sides, which completely encloses all points of the
primitive. (A vertical line, then, has a region-rectangle
one pixel wide. You can't be that precise? Well, actually,
IntroCAD allows a little slop here.) If your click lands in
an object's region-rectangle, that object goes into the
Select List because it might be the one you have in mind. If
the object is part of a group, the whole group goes into the
list as a single object.
There is a potential problem with this method of
selecting objects: What if you draw, for example, a circle
with some objects inside it, and then zoom inside the circle
so that none of it is visible on the screen? If you now try
to select one of the objects inside the circle, you're
*SELECT* click can't help but be inside the circle's region-
rectangle. IntroCAD will dutifully include the circle in
the Select List, and highlight it in its turn. You won't be
able to see the highlighted circle because it's off-screen,
BUT IntroCAD WILL NOT REALIZE THIS. Your job is to say "No"
whenever you get the "Yes/No" mouse pointer, but don't see a
highlighted object.
************************
RESPONDING TO REQUESTERS
When IntroCAD has a message for you that does not require a reply, it
normally doesn't make you reply just to get the requester off of your
screen. You can go on about your business; the requester will go away the
next time you click a mouse button. (But the mouse click which removes a
requester will not be used again for anything else.) Further, if pressing
the *SELECT* button brought the requester up, releasing the *SELECT* button
will remove it.
****************************************************************************
FIRST TIME THROUGH
This section is an introduction to some IntroCAD features. Not all
features are covered here. Neither are the covered features described in
glorious detail. The idea here is to give "The Big Picture" very quickly
and painlessly to users who dislike formal tutorials.
Some users like detailed move-by-move instructions and some don't.
If you're one who does, go through the section of this manual called
"Drawing with IntroCAD". The basic drawing motions are described in
that section. Another place to go for more detail is the section
called "Menus".)
1) Set up check.
Make a copy of the IntroCAD disk and put the master copy in a safe
place. (If you use the Workbench, the copied disk should, ideally, be
named "IntroCAD", just as the master copy was. If you use the CLI, the
disk name is irrelevant.)
If you use IntroCAD from the CLI, set your stack size to 10000 or more.
(You may know from experience with other programs that to set your stack
size to anything less than 10000 is to live dangerously. Some folks
recommend an even larger stack.) If you use IntroCAD from the
WorkBench, the stack size will be set to 10000 for you when you open
IntroCAD.
2) Get comfortable with your drawing environment:
Play around with the tools from the "Draw" menu until you have some
"stuff" on the screen (forget "TextSize", "Cursor", and "Clone" for now.)
You might have a hard time guessing that the only way to "end" a line
is to click twice in the same spot. The other Draw menu items are more
intuitive. Just bang away at those mouse buttons until your *fingers*
know how to draw the primitives.
Make a few selections from the "Options" menu and see what they do.
("Zoom", "Slide", and "Snap to" will be explained presently. You can
wait or not, as you like.)
3) Learn how to "drive" around in your drawing:
Select "Slide" from the "Options" menu act like you're drawing a line
with the mouse. When you've finished the line the picture will move in
the direction of your drawing motion.
Select "Zoom" from the same menu. The mouse pointer should now be an
arrow with a box above it. IntroCAD is asking you to draw a box.
When you do, the picture will expand to show you the region inside the
box. You can "zoom out" by clicking twice in the same spot instead of
drawing a box. Notice that you can't "squash" your drawing horizontally
or vertically with this tool.
Select "FullPict". IntroCAD immediately zooms out so that the entire
drawing is displayed.
Select "ReDraw/Now". IntroCAD refreshes the screen without zooming.
4) Be aware that the keyboard is active:
Type a couple of letters. (If no letters appear on the screen, do a
"FullPict".) You can choose the location of the next character with the
"Cursor" tool from the "Draw" menu: select that item and click somewhere
on the screen. You can choose the character size with the "TextSize"
tool, also from the "Draw" menu: select that item and draw a box. Notice
that "Cursor" and "TextSize" do not affect text already drawn. You can
use the "Edit" menu for that.
Try the DEL key. Notice that this key deletes the primitive most
recently drawn (whether or not that primitive was text.)
5) Editing
Select "Erase" from the "Edit" menu. The mouse pointer should now be
an arrow with a question mark above it. IntroCAD is asking you to select
an object by "pointing at it" and clicking the left mouse button.
Once you've selected an object, IntroCAD will "highlight" it and ask,
by changing the shape of the mouse pointer (to a question mark flanked by
"Y" and "N"), whether this is the object you had in mind. Click the left
mouse button for "Yes" and the object will be erased. If you click the
right button instead, IntroCAD will highlight another object if there is
one nearby. If not, the menu bar will flash at the top of the screen,
telling you that menu selections can now be made. At this point, you can
also select another object for treatment with the editing tool you are
using.
All of the editing tools begin work in the same way: you first select
an object, then confirm your selection. But with some of the editing
tools, there is more. Try the "Move" tool. Maybe you can guess how to
use this one. (If not, you get to play some more until you figure it
out--this is not a tutorial we're having here. You can, of course,
refer to the description in the "Menus" section of this manual, but you
lose points for doing so.)
It's probably pretty hard to guess how the "Size" and "Point" edit
tools work. A hint: tiny little boxes are for clicking on.
"Set Color" is used to set an object to the current color (which you
can select from the "Palette" menu.) Ditto for "SetLinTyp" and the
"LineType" menu.
6) Cloning, Parts
Although "Clone" is an item in the "Draw" menu, it *feels* to your hand
like an editing tool: it *feels*, in fact, exactly like the "Move" tool.
Sooner or later you're going to wish you could somehow Clone an object
you drew in some other IntroCAD session--as part of some other drawing, so
that you can include it in your current drawing without having to draw it
all over again. Well, you can, but we don't use the word "clone" to
describe the process.
Select "Open" from the "Part" menu. You will get a file requester.
The names listed are names of Parts--which live on disk. Click on one of
the names and then click on the "OK" gadget of the requester. Now your
situation is EXACTLY as it would be if you had selected an object in your
drawing using the Clone tool, but the object hanging off the end of your
mouse pointer came from disk.
When you've drawn an object you can't bear to part with, save it as a
Part: select "Save As" from the "Part" menu and select the object you
want to save (as if you were planning to use an editing tool on it.)
A file requester will come up. Type the name you want the Part to be
called and click the "OK" gadget. The object will be written to disk.
In case you were wondering... Yes, you can include an entire Drawing
in your current drawing by Opening it as a Part.
7) Groups:
This is relatively advanced stuff, but it's easy to use. You will
probably come to use groups a lot in drawing and editing.
Select "Group" from the "Part" menu and draw a box completely around
several objects. The enclosed objects are now grouped. You can ungroup
them at any time with the "UnGroup" tool, also from the "Part" menu.
(The "UnGroup" tool *feels* like an editing tool in that you begin using
it by selecting an object. Try it.)
As you might have expected, or at least hoped, you can treat a group of
objects EXACTLY as if it were a primitive: you can apply any of the
editing tools to a group; you can also Clone a group, and you can save it
to disk as a Part.
What if you group objects, some of which are already in different
groups? The groups merge into a single group; no object can be in more
than one group at a time.
8) Snapping to the grid:
Select a grid type from the "Options" menu. Select the drawing option
"Snap to/Grid" and draw some stuff.
Notice that circles and arcs aren't snapped point-by-point while
drawing (that would be kind of stupid, don't you agree?) The individual
mouse clicks which specify the center and radius of the circle or arc
*are* snapped, however, so you can, for example, center a circle on a
grid intersection. Text is not snapped at all (*that* would be
disastrous!). But, again, the mouse click used to place text (when you
use "Cursor" from the "Draw" menu) is snapped.
Also notice that grid snapping is usually suspended when you aren't
actually drawing anything. When you are grouping objects, for example,
snap would be annoying, and so is disabled.
Select the editing tool "Snap/Naively" and apply it to a couple of
different objects. Notice that EVERYTHING, even text, snaps
point-by-point to the grid when this tool is applied. This is a
*DANGEROUS* *TOOL*! We suggest you play with this tool a LOT before
you start a serious drawing. After this tool has trashed a couple of
your practice drawings, it will be a safer tool in your hands.
Select the editing tool "Snap/No Distort" and apply it to several
objects. This tool used in much the same way as the "Point" edit tool.
"Snap/No Distort" is much safer than "Snap/Naively". This is the way
to align, say, one corner of a box with the grid.
8) Snapping to the drawing:
Select "Snap to/Drawing" from the "Options" menu. Draw a line which
begins very near an existing object, and see if the line gets snapped.
You have to be fairly close--within several screen pixels--to trigger
the snap. The tolerance of this Option has been carefully set so that
you can do nearly normal drawing while "Snap to Drawing" is enabled.
Try, using the "Line" tool from the "Draw" menu, to draw a closed
triangle with and without "Snap to/Drawing". Try to draw the letter
"T" by hand.
You can snap an existing object to the drawing using the editing
tool "Snap/Naively" or "Snap/NoDistort". In the latter case, the point
nearest your confirming SELECT click is snapped; the rest of the object
is dragged along with it.
9) And the rest...
The "Palette" and "LineType" menus are left to your unassisted
exploration. They are completely described in the "Menus" section,
of course, and their names alone give you the degree of understanding
we are attempting to convey in this section.