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Text File | 1990-02-12 | 12.8 KB | 304 lines

GRASP 3.5 Readme File - February 12, 1990 This file contains three sections: New features in Grasp 3.5 Updating applications from Grasp 3.1 Additions to the manual There are two additional Readme files, for Inset and for the High-Level Language examples. Inset's Readme is in the INSET directory. The HLL Readme in is the HLL directory. -------------------------------------------------------------------------- New features in Grasp 3.5 Grasp now sports 102 commands, greatly improved performance, and many new features which give Grasp all the capabilities of other third-generation languages like C and Pascal. Here are some of the highlights: Grasp Video modes Grasp now supports most of the enhanced VGA modes, including 16-color 1024x768 and 256-color 800x600. As always, the modes available to you depend on your video card. Page 6-4 in the Grasp manual lists all of the modes. Differential animation The utility GDFF creates differential animation files which Grasp can play back. This technique saves the changes from one frame to another in a sequence of images, resulting in much smaller and faster animations. See page 2-13 for an introduction to the concept. DOS commands, CDs, and other devices Grasp now has full multimedia capability. The INT command calls interrupts, which allows Grasp programs to control CD players and other devices and to issue DOS commands such as Make Directory. See the files DOSIO.TXT and CDCMD.TXT for examples. Conditional execution Grasp now features conditional execution in If-Else-Endif constructs, which can be built around value comparisons, user keystrokes, mouse clicks, and other testable conditions. See pages 3-34 through 3-37. Variables, operators, and functions Grasp now allows variables and can perform string and math operations. See pages 3-28 and 3-29 for an introduction to variables, and pages 6-18 through 6-20 for lists of operators and functions. Subroutines You can now pass parameters to subroutines, including variables. See pages 3-37 through 3-41 for details. Typographic controls The Text command now wraps text within windows automatically, and you can choose left, center, or right alignment of text. Letter and word spacing can also be controlled. See page 4-88. Picture/clipping command use All Grasp commands can now work with clippings or pictures. To use a clipping with a command designed for pictures such as Pfade, preface the buffer number with a C. To use a picture with a clipping command such as Putup, preface the buffer number with a P. Pictor Quick keys The quick-key feature has been expanded to include more menu options and to allow you to select all of the drawing tools. See section six of the Pictor manual for a complete list. Also note that it's no longer necessary to use the Alt key with a letter key to select menu options or tools, unless you're using the Text tool. VGA color cycling In VGA modes you can cycle a range of colors on screen by pressing Tab. All colors from the left to the right mouse button color will begin shifting positions as they do in Grasp with the Cycle command. Tab again to speed up shifting; use Shift-Tab to slow it down and stop it. Press the Backspace key to reverse cycling direction. VGA color range adjustment The range of colors from the left to the right mouse button color can be adjusted in hue, brightness, and contrast, using the Ctrl key with the function keys. These are listed in section six of the Pictor manual. Press the Asterisk key to restore the original palette, or save the image to make the adjustments permanent. Note that until you save the image and reload it, any adjustments you make with this feature affect the underlying palette. Edit menu and Change Colors dialog box When the Change Colors dialog box is displayed, you can use the Edit menu functions Cut, Copy, Paste, and Invert Colors. They will operate on the selected range of colors (from left to right button color). Copy and Paste make it easy to move ranges of colors in 256-color mode. To use this feature, just click on Edit on the menu bar or press the quick key for the function you want (C for Copy, for example). Artools Artools is now bundled with Grasp. If you're familiar with the previous version of Artools, you'll notice two program changes: TXTCLP (for converting text-mode images to graphics modes) has been added, and TGAPIC/PICTGA are no longer included. The Artools program has also been eliminated: each of the programs now has its own interactive screen. -------------------------------------------------------------------------- Updating existing applications Applications written in Grasp 3.1 will run under version 3.5 with four exceptions. We're confident that Grasp's enhanced capabilities and performance will make converting your applications worthwhile. 1 The TOUCH command has been eliminated. Touchscreen users should rely on the software provided with their screens, which can be used to simulate keystrokes in response to touches. Grasp programs can then test for keystrokes instead. 2 The FLOAT command has been enhanced with ENDFLOAT. Float still leaves a clipping displayed at its last location, but now it saves the background under that clipping in a buffer. The next Float command restores the background from that buffer before starting its Float. This new feature allows you to put together a sequence of Floats to create complex movement. However, the Endfloat command must now be issued after the last Float in a series. Existing applications that use Float may need Endfloats to work correctly. 3 The new math operators include the dash (subtraction and negation). Unfortunately, this means that filenames in Grasp programs cannot use dashes unless they're enclosed in quotes. For example, PLOAD T-12,1 will cause an error, but PLOAD "T-12",1 will work. If you've used dashes in filenames, add quotes or rename the files. 4 Since text can now span multiple lines, it's imperative that all quotes be balanced. This was not true in version 3.1: you could leave off the closing quote from a Text command without causing an error. In version 3.5 the interpreter will scan lines, treating them as text, until it finds the next quote. -------------------------------------------------------------------------- Omissions from the manual (new features that didn't make it to press). String function The function STRING(LENGTH,CHAR) returns a string of the specified length filled with the specified character (or filled with the first character of CHAR if it's longer than one character). For example, this command displays a line of dashes: TEXT STRING(80,"-") CD control The disk file CDCMD.TXT (in your Grasp directory) contains Grasp routines to play audio CD's in a CD-ROM drive. The file contains an example of their use, which is a revision of the example on page 3-41. DOS functions and text file manipulation The disk file DOSIO.TXT (in your Grasp directory) contains Grasp routines that execute DOS commands such as Make Directory. It also contains routines to read and write to disk files, and a simple example of their use. Return variable The return variable @0, which is discussed on page 3-40, is also set when a subroutine is called. It's set equal to the subroutine's name, which makes it easy to trace program flow when debugging or reporting errors. The DOS routine DOSERR, in DOSIO.TXT, uses this feature. Exclusive OR The caret (^) is the exclusive-OR operator. Comparison is bit-by-bit. Address function The function ADR(variable) returns a 32-bit address in hex, containing both the segment and offset. For example, ADR("myname") might return the string "0x287B3E58". In addition, the PEEK functions and POKE commands (PEEK, PEEKL, PEEKW, POKE, POKEL, POKEW) can use one 32-bit address parameter instead of two 16-bit ones. This approach, however, limits you to Poking one value rather than multiple ones. Here's an example: SET POINTER ADR("SHARY") ; put address of string "SHARY" in STRPOINTER POKE @POINTER+4 ASC("I") ; write "I" to memory at fifth byte position TEXT @@POINTER ; display "SHARI" WAITKEY Memory and variables The previous example illustrates a peculiarity of memory addressing in Grasp. You can't use the obvious method to directly alter variables: SET X "SHARY" ; put string "SHARY" into variable X SET POINTER ADR(@X) ; put address of X into variable POINTER POKE @POINTER+4 ASC("I") ; write "I" to memory at fifth byte position TEXT @X ; still displays "SHARY" WAITKEY You have to create a variable which is the address of a string, and refer to the string itself by double indirection. Here's a correct example: SET XPOINTER "SHARY" ; create pointer variable to point to "SHARY" POKE @XPOINTER+4 ASC("I"); write "I" to memory at fifth byte position TEXT @@XPOINTER ; display "SHARI" WAITKEY This limitation is imposed by Grasp's own memory management routines, which are designed to maximize available memory for image buffers. Direct memory reference As illustrated in the manual, the indirection function @ looks at the contents of what follows. For example, @X refers to the contents of X instead of the string "X". However, if @ is used with a number greater than 255, Grasp will interpret it as a reference to the contents of memory at the given location, and will return the string at that address up to the first null (ASCII 0) character. For example, @0x287B3E58 refers to the string at hex address 287B3E58. New system function: Abort There is one additional system function called Abort that can be turned on and off with the SET (System Control) command. With Abort ON (it's on by default when Grasp starts), keystrokes will cancel a Waitkey or other timed pause. If you set Abort OFF, all timed events will take the allotted time--for instance, WAITKEY 100 will always wait one second. Set Abort off to preserve timing in applications where it's critical. See page 4-78 for details of the SET command. Editing Keys When editing programs in the Grasp editor, the following Wordstar key combinations can be used in addition to those listed on page 6-8 of the manual. Ctrl-F Next word Ctrl-A Previous word Ctrl-R Page up Ctrl-C Page down Ctrl-D Next character Ctrl-S Previous character Ctrl-X Next line Ctrl-E Previous line Ctrl-W Scroll down one line Ctrl-Z Scroll up one line Ctrl-Q C Go to end of file Ctrl-Q R Go to beginning of file Ctrl-Q D Go to end of line Ctrl-Q S Go to beginning of line Ctrl-Q B Go to start of block Ctrl-Q K Go to end of block Ctrl-K B Mark start of block Ctrl-K K Mark end of block Ctrl-K C Copy block Ctrl-K V Move block Ctrl-K R Read in a file Ctrl-K W Write block to disk Ctrl-K Y Delete block Ctrl-K H Turn off block Ctrl-K D Save changes & exit Ctrl-K Q Abandon changes & exit Ctrl-K S Save file & continue Ctrl-K X Exit to main menu Ctrl-N Insert new line Ctrl-Y Delete line Ctrl-G Delete character Ctrl-Q Y Delete to end of line Ctrl-P Insert next character typed even if it's a control character. Ctrl-V Toggle insert on and off When command A WHEN command that calls a subroutine has to use the word GOSUB before the subroutine's name. This is the only instance where using a subroutine's name alone will not work. Glib Ther's a new command option in Glib called Move (/M). Like Update (/U), it inserts the named files into the library file. Unlike Update, it also deletes the files from the directory. For example, the command GLIB /M MYAPP *.* would copy all files in the current directory into MYAPP.GL, then delete them, leaving only MYAPP.GL. -------------------------------------------------------------------------- --- end of file ---