Announcement

**Andrew Collins** · 28 May 2001, 04:58 PM

Originally posted by Jose Antonio Esteva R:
How can I GET and PUT all the screen using 640x480x16colors?

How you would normally do it is....

DEFINT a-z
DIM huge image(76802)
SCREEN 12
LINE (0,0)-(639,479),15,b
GET (0,0)-(639,479),image
CLS
PUT (0,0),image
'below is to determine the size of the array needed
? (4+CEIL(640/8)*4*480)/2 '153604/2=76802

But it doesn't work with my version of PBDOS(3.5).
So in the source code section you will find a way to do it with ASM
It will only copy the entire screen.

------------------

**Davide Vecchi** · 29 May 2001, 12:19 AM

AFAIK the size of the needed array can' t exceed 64K; this should be the reason why your example doesn' t work.
I dthink it' s not possible to normally GET the whole screen 12.

------------------

**Lance Edmonds** · 29 May 2001, 05:58 AM

It looks like someone has kindly posted some code in the Source Code forum that may be of some use...

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Jose Antonio Esteva R** · 29 May 2001, 10:26 AM

The example at the Source Code is this:

'*******************************************************

%vga = &hA000

DIM screen1(-32000 TO 31999) AS BYTE

CopyBuffer = VARSEG(screen1(-32000))

SCREEN 12

LINE (0,0)-(639,479),15,b

flip %vga,CopyBuffer

CLS

Print "Press any key to restore": sleep 100

CLS

flip CopyBuffer,%vga

SUB flip (BYVAL source??, BYVAL dest??) PUBLIC ' Copy the entire screen at source to destination

! PUSH DS
! MOV AX, source??
! MOV DS, AX
! MOV AX, dest??
! MOV ES, AX
! XOR SI, SI
! XOR DI, DI
! CLD
! MOV CX, 32000
! REP MOVSW
! POP DS

END SUB

'*********************************************************

It seems be right, but when I draw shapes with other colors
the code not works.

------------------

**Tom Hanlin** · 29 May 2001, 10:57 AM

There's a key problem with the posted save/restore function in that it doesn't
save colors. The deal here is, SCREEN 12 is stored in a number of separate
planes (red, green, and blue, if I recall correctly). As far as the computer
is concerned, these planes occupy the same area of memory, so you can only read
or write all of them by swapping to each plane in succession. This is done with
OUT commands to the display controller. In the default mode, apparently, all you
get is a blend of on/off settings, so all of your colors turn white or black.

I don't have the details for plane manipulation at my fingertips, but this used
to be fairly common code. I'd start by looking in the Downloads section here and,
if that turns up no leads, try searching the old ABC records (All BASIC Code): try
PowerBASIC Archives

------------------
Tom Hanlin
PowerBASIC Staff

**Dave Stanton** · 29 May 2001, 03:35 PM

I've used these routines for the last few years without problems.

Here they are with a demo front end.

You have to keep the size of any dimention in the virtual
array <16k, or you get corruption.
I think it's due to frame size.
Thats why the each colour plane is split into 3 parts.

Hope it helps.

Dave.

Code:

        %Scrnmax=10
        %Scrnsize=12800

        DIM VIRTUAL G12Scr(1:%Scrnmax,1:12) AS STRING*%Scrnsize

        SCREEN 12
        CLS
        FOR Scrn?=1 TO %Scrnmax
            CLS SCREEN
            FOR Q?=1 TO 24
                LINE (RND(1,639),RND(1,479))-(RND(1,639),RND(1,479)),Q?,BF
            NEXT Q?
            LOCATE 30,30
            PRINT USING "Screen  ##";Scrn?;
            G12Scrarc Scrn?,0
        NEXT Scrn?

        FOR Scrn?=1 TO %Scrnmax
            IF INPUT$(1)=CHR$(27) THEN EXIT FOR
            MTIMER
            G12Scrdearc Scrn?,0
            T???=MTIMER
            LOCATE 30,1
            PRINT USING " ###### msec";T???/1000;
        NEXT Scrn?

        END

        SUB G12Scrarc(BYVAL Q?,BYVAL Page?)
            DIM G12Scr(MIN,2) AS SHARED STRING*%Scrnsize
            IF Page? THEN
               DEF SEG=&HA800
            ELSE
               DEF SEG=&HA000
            END IF
            OUT &H3CE, 4: OUT &H3CF,0
            G12Scr(Q?,1)=PEEK$(0,%Scrnsize)          'Blue
            G12Scr(Q?,2)=PEEK$(%Scrnsize,%Scrnsize)  'Blue
            G12Scr(Q?,3)=PEEK$(2*%Scrnsize,%Scrnsize)  'Blue
            OUT &H3CE, 4: OUT &H3CF,1
            G12Scr(Q?,4)=PEEK$(0,%Scrnsize)          'Green
            G12Scr(Q?,5)=PEEK$(%Scrnsize,%Scrnsize)  'Green
            G12Scr(Q?,6)=PEEK$(2*%Scrnsize,%Scrnsize)  'Green
            OUT &H3CE, 4: OUT &H3CF,2
            G12Scr(Q?,7)=PEEK$(0,%Scrnsize)          'Red
            G12Scr(Q?,8)=PEEK$(%Scrnsize,%Scrnsize)  'Red
            G12Scr(Q?,9)=PEEK$(2*%Scrnsize,%Scrnsize)  'Red
            OUT &H3CE, 4: OUT &H3CF,3
            G12Scr(Q?,10)=PEEK$(0,%Scrnsize)          'Intensity
            G12Scr(Q?,11)=PEEK$(%Scrnsize,%Scrnsize)  'Intensity
            G12Scr(Q?,12)=PEEK$(2*%Scrnsize,%Scrnsize)  'Intensity


            OUT &H3CE, 4: OUT &H3C5,&H0
            DEF SEG
        END SUB

        SUB G12Scrdearc(BYVAL Q?,BYVAL Page?)
            DIM G12Scr(MIN,2) AS SHARED STRING*%Scrnsize
            IF Page? THEN
               DEF SEG=&HA800
            ELSE
               DEF SEG=&HA000
            END IF
            OUT &H3C4, 2: OUT &H3C5, 1
            POKE$ 0,G12Scr(Q?,1)                 'Blue
            POKE$ %Scrnsize,G12Scr(Q?,2)         'Blue
            POKE$ 2*%Scrnsize,G12Scr(Q?,3)         'Blue
            OUT &H3C4, 2: OUT &H3C5, 2
            POKE$ 0,G12Scr(Q?,4)                 'Green
            POKE$ %Scrnsize,G12Scr(Q?,5)         'Green
            POKE$ 2*%Scrnsize,G12Scr(Q?,6)         'Green
            OUT &H3C4, 2: OUT &H3C5, 4
            POKE$ 0,G12Scr(Q?,7)                 'Red
            POKE$ %Scrnsize,G12Scr(Q?,8)         'Red
            POKE$ 2*%Scrnsize,G12Scr(Q?,9)         'Red
            OUT &H3C4, 2: OUT &H3C5, 8
            POKE$ 0,G12Scr(Q?,10)                 'Intensity
            POKE$ %Scrnsize,G12Scr(Q?,11)         'Intensity
            POKE$ 2*%Scrnsize,G12Scr(Q?,12)         'Intensity
            OUT &H3C4, 2: OUT &H3C5,&HF
            DEF SEG
        END SUB

------------------

**Sebastian Groeneveld** · 30 May 2001, 03:37 AM

The 'flip' routine of Andrew confuses me once again, it start like this:
! PUSH DS
! MOV AX, source??
! MOV DS, AX
! MOV AX, dest??
! MOV ES, AX

Am I correct in saying that it's a matter of luck whether this will work or not?
Because the variable dest?? is accessed after DS has been altered. And am I also
correct that Powerbasic allows direct modification of DS and ES unlike plain
assembler? So IMO the routine would be better if it started like this:
! PUSH DS
! MOV ES, dest??
! MOV DS, source??

The program below is just a merge of Andrew's code and Dave's code...

Code:

$LIB VGA ON, GRAPH ON
DEFINT A-Z

%vga = &HA000

  'Reserve 64000 bytes for each plane
DIM Plane1(0 TO 32000) AS WORD
DIM Plane2(0 TO 32000) AS WORD
DIM Plane3(0 TO 32000) AS WORD
DIM Plane4(0 TO 32000) AS WORD

DIM PlaneAddress(0 TO 3) AS SHARED WORD

  'Store the segment of each reserved block
PlaneAddress(0) = VARSEG( Plane1(0) )
PlaneAddress(1) = VARSEG( Plane2(0) )
PlaneAddress(2) = VARSEG( Plane3(0) )
PlaneAddress(3) = VARSEG( Plane4(0) )

SCREEN 12

  'Fill the screen with colored boxes
FOR i = 0 TO 100
    LINE (i * 2, i * 2)-(639 - i * 2, 479 - i * 2), i MOD 16, B
NEXT i
LOCATE 15, 31
PRINT "Screen 12 save/restore"

WHILE INKEY$ = "": WEND

SaveVGA

CLS
PRINT "Press any key to restore"

WHILE INKEY$ = "": WEND

LoadVGA

WHILE INKEY$ = "": WEND

SCREEN 0,0,0

SUB SaveVGA

    FOR planenr?? = 0 TO 3
          'Select plane to read from
        OUT &H3CE, 4
        OUT &H3CF, planenr??

          'And save video memory
        CopySegment %vga, PlaneAddress(planenr??)

    NEXT planenr??

     'Reset read plane select
   OUT &H3CE, 4
   OUT &H3CF, 0

END SUB


SUB LoadVGA

    DIM PlaneMask AS LOCAL BYTE

      'We need a bit mask to select the planes we want to write to
      'This allows us to write to multiple planes at once (default)
    PlaneMask = &B0001

    FOR planenr?? = 0 TO 3

          'Select plane to write to
        OUT &H3C4, 2
        OUT &H3C5, PlaneMask

          'Load video memory
        CopySegment PlaneAddress(planenr??), %vga

          'Move to next plane
        SHIFT LEFT PlaneMask, 1

    NEXT planenr??

      'Reset write plane select (all)
    OUT &H3C4, 2
    OUT &H3C5, &B1111

END SUB


SUB CopySegment (BYVAL source??, BYVAL dest??) PUBLIC

   ! push  ds
   ! mov   es, dest??
   ! mov   ds, source??
   ! xor   si, si
   ! xor   di, di
   ! cld
   ! mov   cx, 32000
   ! rep   movsw
   ! pop   ds

END SUB

Kind regards

------------------
Sebastian Groeneveld
mailto:[email protected][email protected]</A>

[This message has been edited by Sebastian Groeneveld (edited May 30, 2001).]

**Andrew Collins** · 30 May 2001, 05:11 AM

several points.

Mr Hanlin is correct the code I posted will only save the color white(15)
I only tested it on white so there's egg on my face.

Second I tested the get and put code by dividing the 640X480 screen
into 4 sections and it still didn't work. It would get the first section
but would crash on getting the other ones.So I don't know if it is a bug in the compiler
or something else.

Anyway I apologize for my oversight.

Andrew

------------------

**Tom Hanlin** · 30 May 2001, 07:29 AM

The 'flip' routine of Andrew confuses me once again, it start like this:
! PUSH DS
! MOV AX, source??
! MOV DS, AX
! MOV AX, dest??
! MOV ES, AX

Am I correct in saying that it's a matter of luck whether this will work or not?
Because the variable dest?? is accessed after DS has been altered. And am I also
correct that Powerbasic allows direct modification of DS and ES unlike plain
assembler? So IMO the routine would be better if it started like this:
! PUSH DS
! MOV ES, dest??
! MOV DS, source??

Good point. Yes, ES does need to be loaded first. Loading segment registers from
memory should be possible with any assembler, not just PowerBASIC.

Announcement

Question about SCREEN 12

Question about SCREEN 12

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment