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- !Example by Paul Field
- See !ReadMe for distribution/modification restrictions
-
- This program 'example' is provided as an example of how to use the euclid
- library. It 'plots' and displays various functions in various ways -
- most of which are under user control from menus.
-
- There are two environmental variables that are set in !Run.
- 'Example$Seperatecaches' determines whether each picture has a seperate drawing
- cache or not. If it is 'no' then all of the graphs will share a single drawing
- cache and so if several graphs want to draw at the same time they will do so
- sequentially. If is not a good idea to set this to 'no' if you are raytracing
- a picture.
- The cache size is determined by the environmental variable 'Example$Cachesize'.
- You should probably increase this if you want to ray trace.
-
- Known bugs:
- The palette is not defined properly when drawing sprites, so in some cases
- sprites will be drawn with strange colours.
- Drawing 256-colour sprites should always work.
- Drawing n-colour sprites in n-colour modes should always work.
- Otherwise expect problems.
-
-
- The icon bar menu
- =================
-
- Info gives information about the program.
- Graph1 }
- Graph2 } opens a window onto a particular graph (open graphs become ticked)
- Graph3 }
- Quit leaves the program
-
-
- The graph menu (Click 'menu' over a graph window)
- ==============
-
- Save Leads to the 'Save menu', from here you can save either a
- Euclid file or a sprite file of the graph. You need to have enabled
- 'sprite mode' and the sprite must be drawn before you can save the
- sprite (the sprite option will be faded until this is so).
- Style Leads to the 'Style' menu. From here you can select the style of the
- picture. See the section at the end on 'ray tracing' if you wish to
- use that option.
- Sprite Clicking here toggles 'sprite mode'. In sprite mode the euclid picture
- is drawn into a sprite (if there is enough memory). This makes
- redrawing the picture very fast. Try dragging another window across
- the graph when it is in sprite mode and when it isn't.
- This option has a sub-menu that determines various features of the
- sprite and the way it is drawn (see 'Sprite Menu' below).
- If there isn't enough memory when you enable sprite mode then
- 'Sprite' will still be ticked but the window will be redrawn
- in the usual way. However, if memory becomes available later
- the window will grab it and start using a sprite.
- Rotate Causes the graph to start/stop rotating around the vertical axis
-
-
- The sprite menu
- ===============
-
- Multitask Leads to a 'multitask' menu.
- Euclid pictures take time to draw and usually hold the computer
- up while they are being generated. However, there are three
- 'multitask' modes available that split the drawing process into
- sections when 'sprite mode' is enabled.
- 'Slow' draws very small sections at a time.
- 'Fast' draws fairly large sections at a time.
- 'VFast' draws very large sections at a time.
- The 'None' option disables multitasking.
- You can only see the effect of multitasking when the sprite is
- being drawn. This can be forced to happen by changing the
- mode of the sprite (see the next option) or by closing and then
- reopening the graph.
- Mode Leads to the 'mode' menu.
- This simply defines the mode of the sprite. Type in the mode
- that you want into the writable icon at the bottom of the menu.
- There are two special options :
- 'Current' simply selects the current mode.
- 'Dynamic' makes the picture keep track with the current mode.
- This means that if you start in mode 12 and select
- 'dynamic' (with sprite mode enabled) you will get a mode
- 12 sprite. If you then change to mode 15 the sprite will
- be redrawn as a mode 15 sprite.
-
- Ray tracing
- ===========
-
- The ray tracing style is only active under the following circumstances :
- i) Sprite mode is enabled (and the window is actually using a sprite).
- ii) The sprite's mode is not 'dynamic'
- iii) Multitasking is enabled
- iv) The graph is not rotating
-
- These restrictions are only there to protect you and the multitasking sprite.
- You should also choose a 256-colour to ray trace in, pictures in less colours
- come out rather poorly.
-
- Notice that once the raytracing style is selected the mode 'Dynamic'
- and the multitasking 'None' options will be shaded as well as 'Rotate'.
-
- Usually when you close the window the sprite is removed and redrawn when the
- window is opened. However, raytraced sprites remain attached to the window
- and drawing continues even though the window is closed.
-
-
-
-
- If you have any comments or queries contact :
-
- Paul Field
- 3, Little Heath
- Chadwell Heath
- Romford
- Essex
- RM6 4XX
-
- email: paulf@dcs.qmw.ac.uk (Until the end of 1994)
-