'===========================================================================
' Subject: SVGA 16 BIT MODE                  Date: 11-08-98 (18:49)       
' Author:  ATyler85@aol.com                  Code: QB, PDS                
' Origin:  ATyler85@aol.com                Packet: GRAPHICS.ABC
'===========================================================================
' This program is a SVGA 16 bit mode. It requires a VESA SVGA card. If you
' make any improvements on this program or have any questions send them to
' ATyler85@aol.com
DECLARE SUB InitBank ()
DECLARE SUB DEMO (num%)
DECLARE SUB DrawTextV (Text$, Row!, Column!, clr&, bclr&)
DECLARE SUB LoadText ()
DECLARE FUNCTION DetectVESA% ()
DECLARE FUNCTION SetMode% (mode%)
DECLARE SUB SetText ()
DECLARE SUB Pixel (X%, Y%, r%, g%, b%)
DEFINT A-Z
'$INCLUDE: 'qb.bi'
DIM SHARED RegsX AS RegTypeX, Regs AS RegType, BANK.asm$, pal(256, 3)
COMMON SHARED xRes, yRes, yOffset, curBank, winGranul, Segment, bpp
CLS
TYPE VGAInfoBlock
		    VESASignature AS STRING * 4
		    VESAVersion AS INTEGER
		    OEMStringPointer AS LONG
		    Capabilities AS LONG
		    VideoModePtr AS INTEGER
		    TotalMemory AS INTEGER
		    Reserved AS STRING * 236
END TYPE

TYPE ModeInfoBlock
		    ModeAttributes AS INTEGER
		    WinAAttributes AS STRING * 1
		    WinBAttributes AS STRING * 1
		    WinGranularity AS INTEGER
		    WinSize AS INTEGER
		    WinASegment AS INTEGER
		    WinBSegment AS INTEGER
		    WinFuncPointer AS LONG
		    BytesPerScanLine AS INTEGER
		    XResolution AS INTEGER
		    YResolution AS INTEGER
		    XCharSize AS STRING * 1
		    YCharSize AS STRING * 1
		    NumberOfPlanes AS STRING * 1
		    BitsPerPixel AS STRING * 1
		    NumberOfBanks AS STRING * 1
		    MemoryModel AS STRING * 1
		    BankSize AS STRING * 1
		    NumberOfImagePages AS STRING * 1
		    SizeOfBank AS STRING * 1
		    RedMaskSize AS STRING * 1
		    RedFieldPosition AS STRING * 1
		    GreenMaskSize AS STRING * 1
		    GreenFieldPosition AS STRING * 1
		    BlueMaskSize AS STRING * 1
		    BlueFieldPosition AS STRING * 1
		    RsvdMaskSize AS STRING * 1
		    RsvdFieldPosition AS STRING * 1
		    DirectColorModeInfo AS STRING * 1
		    Reserved AS STRING * 216
END TYPE
InitBank
IF DetectVESA = 0 THEN PRINT "No VESA driver is installed.": END
pages = SetMode(&H111)
DEMO
pleasetypeakey$ = INPUT$(1)
SetText

SUB DEMO
FOR Y = 0 TO yRes - 1                           'Fill the screen with pixels
   FOR X = 0 TO xRes - 1
	   Pixel X, Y, X \ 40 + Y \ 30, ABS(X - (xRes \ 2)) \ 10 + ABS(Y - (yRes - 1)) \ 15, ABS(X - (xRes - 1)) \ 40 + Y \ 30
	 NEXT X
NEXT Y
END IF

END SUB

FUNCTION DetectVESA
DIM VGAInfo AS VGAInfoBlock
RegsX.ax = &H4F00
RegsX.es = VARSEG(VGAInfo)
RegsX.di = VARPTR(VGAInfo)
CALL INTERRUPTX(&H10, RegsX, RegsX)
IF RegsX.ax = &H4F THEN
DetectVESA = 1
IF VGAInfo.VESASignature <> "VESA" THEN DetectVESA = 0
PRINT "VESA Version:"; RTRIM$(STR$(VGAInfo.VESAVersion \ 255)); ".";
PRINT LTRIM$(STR$(VGAInfo.VESAVersion AND 255))

END IF

END FUNCTION

SUB InitBank
BANK.asm$ = ""
BANK.asm$ = BANK.asm$ + CHR$(&H55)                                    'PUSH     BP
BANK.asm$ = BANK.asm$ + CHR$(&H89) + CHR$(&HE5)                       'MOV      BP,SP
BANK.asm$ = BANK.asm$ + CHR$(&HB8) + CHR$(&H5) + CHR$(&H4F)           'MOV      AX,4F05
BANK.asm$ = BANK.asm$ + CHR$(&HBB) + CHR$(&H0) + CHR$(&H0)            'MOV      BX,0000
BANK.asm$ = BANK.asm$ + CHR$(&H8B) + CHR$(&H56) + CHR$(&H6)           'MOV      DX,[BP+06]
BANK.asm$ = BANK.asm$ + CHR$(&HCD) + CHR$(&H10)                       'INT      10
BANK.asm$ = BANK.asm$ + CHR$(&H5D)                                    'POP      BP
BANK.asm$ = BANK.asm$ + CHR$(&HCB)                                    'RETF

END SUB

SUB Pixel (X, Y, r, g, b)
r = r AND 31: g = g AND 63: b = b AND 31

yA& = (Y + yOffset) * 2
offset& = yA& * xRes + (X * 2)
BANK = offset& \ &H10000
offset& = offset& - &H10000 * BANK
IF BANK <> curBank THEN
  curBank = BANK
  BANK% = curBank

'  Regs.ax = &H4F05
'  Regs.bx = 0
'  Regs.dx = curBank
'  CALL INTERRUPT(&H10, Regs, Regs)
 DEF SEG = VARSEG(BANK.asm$)
  CALL ABSOLUTE(BYVAL BANK%, SADD(BANK.asm$))
 DEF SEG
DEF SEG = Segment

END IF
hiClr = r * 8 + g \ 8: loClr = (g AND 7) * 32 + b
POKE offset&, loClr: POKE offset& + 1, hiClr

END SUB


FUNCTION SetMode (mode)

DIM ModeInfo AS ModeInfoBlock
RegsX.ax = &H4F01
RegsX.cx = mode
RegsX.es = VARSEG(ModeInfo)
RegsX.di = VARPTR(ModeInfo)
CALL INTERRUPTX(&H10, RegsX, RegsX)
IF ModeInfo.ModeAttributes AND 1 = 0 THEN PRINT "Cannot access mode"
winGranul = 64 \ ModeInfo.WinGranularity
xRes = ModeInfo.XResolution
yRes = ModeInfo.YResolution
IF ModeInfo.WinSize < 64 THEN
  PRINT "This program only works with those modes with more than 64k of window"
  SetMode = 0
  EXIT FUNCTION                                 'these routines.
END IF
IF ASC(ModeInfo.MemoryModel) <> 6 THEN
    PRINT "This Screen Mode is not available"
    SetMode = 0
    EXIT FUNCTION
END IF
Segment = ModeInfo.WinASegment
DEF SEG = Segment

Regs.ax = &H4F02                                'Set the mode.
Regs.bx = mode
CALL INTERRUPT(&H10, Regs, Regs)

IF Regs.ax <> &H4F THEN                         'Make sure it worked.
  PRINT "Screen mode could not be initialized"
  SetMode = 0
  EXIT FUNCTION
END IF

curBank = 0                                     'Initialize bank and page.
yOffset = 0
bpp = ASC(ModeInfo.BitsPerPixel)
SetMode = ASC(ModeInfo.NumberOfImagePages) + 1


END FUNCTION

SUB SetText
Regs.ax = &H3
CALL INTERRUPT(&H10, Regs, Regs)
END SUB