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Text File | 1990-08-06 | 19.9 KB | 487 lines

DVAWARE TC++ Library Release 1.0 August, 1990 _______________________________________________________________ Copyright 1990 Mark Potter Purpose: A library to be used in TC++ v1.0 in order to write C or C++ programs which are DESQview aware. This library includes the ability of making the TC conio routines DESQview screen aware. File List: BUILDALL BAT 123 Used to (re)build all the library files. BUILDLIB BAT 1203 Used to (re)build one of the library files based on a given memory model letter. DVAWARE DOC 20363 This Documentation file. DVAWARE H 6450 Header file for DVAWARE Library. DVAWAREC LIB 2560 DVAWARE Libraries. Each for DVAWAREH LIB 2560 one of the six different DVAWAREL LIB 2560 memory model. DVAWAREM LIB 2560 DVAWARES LIB 2560 DVAWARET LIB 2560 DVA_TEST C 8093 A sample program in C. DVA_TEST CPP 7981 A sample program in C++. DVCONIO C 1949 Source files for the DVAWARE DVCRIT C 3139 Libraries. DVGETVER C 1861 DVGETVID C 3470 DVPAUSE C 1412 INDV C 1342 Description: Routines found in the DVAWARE library are found on the following pages. To use the libraries one should only have to include the DVAWARE.H file in your program, and the appropriate DVAWAREx.LIB file in the project or make file. One can then call the DVAWARE routines freely. Note: The inDV variable is set by dv_get_version() and only by dv_get_version(). Therefore if you wish to use the inDV variable in your program, make sure you call dv_get_version() near the beginning of the program. Inline: If you are using the DVAWARE library in a C++ program you may opt to have the DVAWARE routines inline. One might have the routines inline for possible speed and size advantages, depending on how the DVAWARE routines are call. To make the DVAWARE routine inline, simply define the macro DVAWARE_INLINE before you include the DVAWARE.H file. #define DVAWARE_INLINE #include "DVAWARE.H" This will make all the function in DVAWARE inline. This will also make the need for the DVAWAREx.LIB file unnecessary in the project file, except for the possible need of the inDV variable. This can be overcome by including the library anyway, or by defining the inDV variable in one of your own modules. One will need the inDV variable if the dv_get_version() function is called. dv_beginc ________________________________________________________________ Function: Begin critical Region. Syntax: #include "dvaware.h" void dv_beginc( void ); Prototype in: dvaware.h Remarks: The dv_beginc() call causes the current task to enter a critical region during which all multitasking is suspended. The calling task is allowed to continue execution until it calls dv_endc() or voluntarily gives up control. If it voluntarily gives up control (by waiting for keyboard input for instance) multitasking is allowed to resume until the task regains control, at which time multitasking is again suspended. This facility can be useful for executing time critical sections of code and for controlling access to common resources. It should be used sparingly to avoid degrading overall system performance. If another task is using DOS when the dv_beginc() call is made, the caller will be suspended until DOS is free. This means that you are free to call DOS from inside a critical region. (From Quarterdeck's DESQview API manual) Return value: None. Portability: dv_beginc is unique to the dvaware or similar libraries. See also: dv_endc, dv_pause Example: #include <conio.h> #include "dvaware.h" int main( void ) { long i=0; dv_conio(); dv_beginc(); while( !kbhit() ) i++; getch(); dv_endc(); cprintf( "%ul\r\n", i ); return 0; } dv_conio ________________________________________________________________ Function: Sets up the TC conio system to be DESQview screen aware. Syntax: #include "dvaware.h" void dv_conio( void ); Prototype in: dvaware.h Remarks: It has been noted that during the TC++ start up code a program identifies the screen type of screen it is running on, and places the segment address of the screen display in the word directly before the directvideo. Therefore, using this as the input to dv_get_video_buffer() and placing the return value in the same location this should make all the later conio calls use the DESQview video buffer. This function should be called as close to the begin of the program's executions as possible. It will no longer be required to set directvideo to 0 for the program to be DESQview screen nice. Return value: None. Portability: dv_conio is unique to the dvaware or similar libraries. See also: dv_get_video_buffer Example: #include <conio.h> #include "dvaware.h" int main( void ) { dv_conio(); cputs( "Hello World\r\n" ); return 0; } dv_endc ________________________________________________________________ Function: End critical region. Syntax: #include "dvaware.h" void dv_endc( void ); Prototype in: dvaware.h Remarks: The dv_endc() call defines the end of a critical region of code. Critical regions are entered via the dv_beginc() call. Calls to dv_beginc() and dv_endc() may be nested. Multitasking does not resume until an dv_endc() call has been executed for every dv_beginc() call that has been made. (From Quarterdeck's DESQview API manual) Return value: None. Portability: dv_endc is unique to the dvaware or similar libraries. See also: dv_beginc, dv_pause. Example: #include <conio.h> #include <stdlib.h> #include "dvaware.h" int main( void ) { long i=0; dv_conio(); dv_beginc(); while( !kbhit() ) i++; getch(); dv_endc(); cprintf( "%ul\r\n", i ); return 0; } dv_get_version ________________________________________________________________ Function: Get the version of DESQview that is running. Syntax: #include "dvaware.h" unsigned int dv_get_version( void ); Prototype in: dvaware.h Remarks: dv_get_version() can be used to test for the existence of DESQview such as in: if ( dv_get_version() ) ... dv_get_version() also sets the inDV flag, so that the version of DESQview running can be tested at a latter time. Return value: Returns the version of DESQview running, or 0 if DESQview is not running. The value returned is encoded as follows: The high byte of the return value is the major version number; The low byte is the minor. Portability: dv_get_version is unique to the dvaware or similar libraries. See also: inDV Example: #include <conio.h> #include "dvaware.h" int main( void ) { unsigned int ver = dv_get_version(); dv_conio(); if ( ver ) cprintf( "The version of DESQview running" " is %u.%02u.\r\n", ver >> 8, ver & 0xFF ); else cprintf( "DESQview is not running.\r\n" ); } dv_get_video_buffer ________________________________________________________________ Function: Get the video buffer segment. Syntax: #include "dvaware.h" char _seg* dv_get_video_buffer( char _seg* assumed ); Prototype in: dvaware.h Remarks: Return the address of the Logic Window buffer for the current task and begins "shadowing" changes to the buffer. Programs that have been written to place text directly into the display memory can be easily converted to run in a small window by making this call and writing into the Logical Window Buffer instead. DESQview checks periodically to see if the contents of the buffer have changed and, if so, updates the display accordingly. The assumed value on entry should contain the address of display memory that the program would write into if running outside DESQview. If this routine is called outside DESQview it does nothing but return with the assumed value. You can, therefore, make this call and trust the results either inside of outside DESQview. There is no need to synchronize with video retrace when writing into the Logical Window Buffer. (From Quarterdeck's DESQview API manual) Return value: Segment of the video display buffer. Portability: dv_get_video_buffer is unique to the dvaware or similar libraries. See also: dv_conio() Example: #include "dvaware.h" int main( void ) { char *msg = "This is a test"; char _seg* video = (char _seg*)0xB800; // B000 for mono unsigned offset = 0; video = dv_get_video_buffer( video ); while ( *msg ) { *(video+offset) = *msg; offset+=2; msg++; } return 0; } dv_pause ________________________________________________________________ Function: Give up the rest of time slice. Syntax: #include "dvaware.h" void dv_pause( void ); Prototype in: dvaware.h Remarks: The dv_pause call gives up control to the dispatcher so that other tasks can be run. The calling task will regain control when its normal turn occurs. Applications should make this call within all busy-wait loops, that is, loops that are doing nothing useful but looking for something to do. (From Quarterdeck's DESQview API manual) Return value: None. Portability: dv_pause is unique to the dvaware or similar libraries. See also: dv_beginc, dv_endc Example: #include <conio.h> #include "dvaware.h" int main( void ) { dv_conio(); cputs( "Press a key to continue..." ); while (!kbhit()) dv_pause(); getch(); return 0; } inDV ________________________________________________________________ Function: Holds the version of DESQview running, or 0 if not in DESQview. Syntax: extern unsigned int inDV; Declared in: dvaware.h Remarks: Set to 0 if DESQview is not running. Set to the version of the DV API active if DESQview is running. The high byte of inDV is the major version number, the low byte is the minor. The value of inDV is set by the dv_get_version function. Example: #include <conio.h> #include <stdlib.h> #include "dvaware.h" int main( void ) { long i=0; dv_get_version(); dv_conio(); if (inDV) dv_beginc(); while( !kbhit() ) i++; getch(); if (inDV) dv_endc(); cprintf( "%ul\r\n", i ); return 0; } Restrictions: Copyright 1987, Mark Potter. All rights reserved by the author, except for those specifically granted as follows. The author grants the right to copy and distribute this package providing no fee greater than $5.00 US (or equivalent) is charged for this package. This package may be placed on public or private computer systems for distribution, providing that the $5.00 fee is not exceeded and that no extra copyright is proclaimed on this work. Any other distribution of this package requires permission from the author. Programmers may use this library with there own code without any worry of royalty requirements. See shareware notice below. Users of this package may freely modify the program for personal use. Such modified libraries may be distributed to close associates but not to the general public. Such distributions must include the complete original package. Shareware: This library is not shareware, nor is it public domain, this is a copyrighted package. To call it freeware would be correct, it is a copyrighted package which I ask no monetary return for its use. However freeware is a trademarked term, so I can't actually call it that. I do ask that if you find this package of use, that you drop me a postcard saying so. That way I will know my work wasn't for not, and thus may come out with other libraries or programs. Thank you. Author: Suggestions and comments about this and other programs can be sent to: Mark Potter 1407 Hillcrest Dr. Blacksburg, VA 24060-5523 Or electronically on the following BBSs: MBT (703)552-8767 VTBBS (703)231-7498 Note that the Author is a presently a MS student in CS at Virginia Tech and due to finish soon. The electronic mail may have delayed response after this date. Physical mail should be forwarded for may years to come.