Power-Programmierung/CD1.mdf/assemblr/library/grafik/hgdemo/hgdemo.asm

Assembly Source File | 1993-07-12 | 26KB | 1,420 lines

    PAGE    60,132
    TITLE  HGDEMO   GRAPHICS PACKAGE FOR HERCULES CARD
    DOSSEG
    .MODEL  SMALL

;***********************************************************************
; HGDEMO       Title: HERCULES GRAPHICS PACKAGE DEMO                   *
;                                                                      *
; Programmer: Scott A. Armitage     (c) 1993                           *
;                                                                      *
; Purpose: Illustrate the use of HIGH resolution graphics              *
;          routines for HGA display.                                   *
;                                                                      *
;                                                                      *
; Special Requirements: Must use a HERCULES CARD                       *
;***********************************************************************


GLOBAL SCRN_ADR:WORD, PLOT_SUB:WORD

;  some equates....

;  HGA port address           used by _gmode, _tmode & setmd procs.
index equ 03b4h
cntrl equ 03b8h

;        control    codes
scrn_on           equ        8
grph               equ        2
text               equ        20h


SX_MIN   EQU  0      ; MIN/MAX X/Y VALUES FOR HGA HIGH RES...
SX_MAX   EQU  719
SY_MIN   EQU  0
SY_MAX   EQU  347

HGA_ADR  EQU  0B000H  ; HGA SCREEN ADR

FNT_LEN  EQU 8        ; SIZE OF CHARS IN TABLE - FOR DSPLY_MGS PROC...



.CODE

MAIN PROC FAR

    MOV  AX,@DATA
    MOV  DS,AX        ; GET ADDRESSABILITY TO OUR DATA SEGMENT

    CALL SET_MODE     ; SET TO GRAPHICS HIGH RESOLUTION MODE


    MOV  DX,3
    MOV  BX,9
    MOV  CX,4
    MOV  AX,7

    CALL G_FR_2


    LEA SI,HR_MESS
    CALL DSPLY_MSG

    LEA SI,SA_MESS
    CALL DSPLY_MSG
    CALL WOW_WHEE    ; display "wow" in 7 sizes.... font scaleing demo


    ; START OF MAIN LOOP, DRAW SCREENS UNTIL KEYHIT.....

LLLS:
    CALL CLR_FR    ; CLEAR SCREEN AND FRAME IT....

    CALL STEP_ADJ  ; ADJUST SOME COORDINATE VALUES....
    CALL CHK_KBD   ; CHECK KEYBOARD...
    JNZ MX_T0

    LEA SI,FRAME_DAT   ; SET UP FOR CALL TO SWEEP BOX...
    MOV  X1,359
    MOV  Y1,170
    MOV  X2,83
    MOV  Y2,23
    CALL SWEEP_BOX     ; DRAW BOX FULL OF SWEEPING LINES...

    CALL STEP_ADJ      ; ADJUST SOME COORDINATES AGAIN...

    CALL DELAY         ; WAIT A BIT AND DO MORE OF THE SAME....

    CALL CHK_KBD
    JNZ MX_T0

   LEA SI,FRAME_DAT
    MOV  X1,359
    MOV  Y1,170
    MOV  X2,283
    MOV  Y2,123
    CALL SWEEP_BOX

    CALL DELAY
    CALL STEP_ADJ

    CALL CHK_KBD
MX_T0:
    JNZ MX_TARG_0

    CALL STEP_ADJ

    LEA  SI,CIRCLE_DATA          ;SET UP FOR DRAWING 3 CIRCLES...
    MOV  WORD PTR [SI+4],140
    MOV  WORD PTR [SI+8],1100

REPEAT:

    CALL CHK_KBD
    JNZ  MX_TARG

    SUB  WORD PTR [SI],150
    CALL CIRCLE
    ADD  WORD PTR [SI],150
    CALL CIRCLE
    ADD  WORD PTR [SI],150
    CALL CIRCLE
    SUB  WORD PTR [SI],150
    SUB  WORD PTR [SI+4],AX
    JG   REPEAT

    CALL DELAY

    CALL CHK_KBD
MX_TARG_0:
    JNZ  MX_TARG

    CALL CLR_FR          ; CLEAR WHOLE SCREEN
    CALL STEP_ADJ


   LEA SI,FRAME_DAT
    MOV  X1,359
    MOV  Y1,170
    MOV  X2,122
    MOV  Y2,84
    CALL SWEEP_BOX

    CALL DELAY
    CALL STEP_ADJ




    LEA  SI,CIRCLE_DATA            ; DRAW SOME MORE CIRCLES....
    MOV  WORD PTR [SI+4],155
    MOV  WORD PTR [SI+8],1000

REPEAT1:

    CALL CHK_KBD
MX_TARG:
    JNZ  MX_TARGIT

    SUB  WORD PTR [SI],150
    CALL CIRCLE
    ADD  WORD PTR [SI],150
    CALL CIRCLE
    ADD  WORD PTR [SI],150
    CALL CIRCLE
    SUB  WORD PTR [SI],150
    SUB  WORD PTR [SI+4],AX

    JG   REPEAT1


    CALL DELAY
    CALL CLR_FR          ; CLEAR WHOLE SCREEN


    CALL STEP_ADJ

    LEA  SI,CIRCLE_DATA
    MOV  WORD PTR [SI+4],115
    MOV  WORD PTR [SI+8],600

REPEAT2:
    CALL CHK_KBD
    JNZ  MX_TARGIT
    SUB  WORD PTR [SI],175
    CALL CIRCLE
    ADD  WORD PTR [SI],175
    CALL CIRCLE
    ADD  WORD PTR [SI],175
    CALL CIRCLE
    SUB  WORD PTR [SI],175
    SUB  WORD PTR [SI+4],AX

    JG   REPEAT2

    CALL STEP_ADJ
    CALL CHK_KBD
MX_TARGIT:
    JNZ  M_EXIT

    CALL SWEEP_FRAME

    CALL STEP_ADJ

    LEA  SI,CIRCLE_DATA
    MOV  WORD PTR [SI+4],115
    MOV  WORD PTR [SI+8],1200

REPEAT3:
    CALL CHK_KBD
    JNZ  M_EXIT
    SUB  WORD PTR [SI],175
    CALL CIRCLE
    ADD  WORD PTR [SI],175
    CALL CIRCLE
    ADD  WORD PTR [SI],175
    CALL CIRCLE
    SUB  WORD PTR [SI],175
    SUB  WORD PTR [SI+4],AX
    JG   REPEAT3


    CALL CHK_KBD
    JNZ  M_EXIT
    CALL DELAY
    JMP  LLLS           ; GO DO THE WHOLE MESS AGAIN UNTIL KEYPRESS...

M_EXIT:

    MOV  AH,0
    INT  16H

    CALL RESTORE_MODE ; RESTORE hga text MODE

    MOV  AX,4C00H     ; SET FOR RETURN TO DOS WITH RETURN CODE 0
    INT  21H

MAIN ENDP

    SUBTTL  VARIOUS graphics ROUTINES
    PAGE    +


G_FRAME PROC NEAR   ; draws a box... set X1,X2,Y1,Y2  to opposite corner
                    ; coordinates.....
    PUSH AX
    PUSH BX
    PUSH CX
    PUSH DX
    PUSH SI

    LEA  SI,LINE1
    MOV  AX,X1
    MOV  BX,X2
    MOV  CX,Y1
    MOV  DX,Y2

    MOV  Y2,CX
    CALL PLOTLINE

    MOV  X2,AX
    MOV  Y2,DX
    CALL PLOTLINE

    MOV  X1,BX
    MOV  Y1,DX
    CALL PLOTLINE

    MOV  X2,BX
    MOV  Y1,CX
    CALL PLOTLINE

    MOV X1,AX
    MOV X2,BX
    MOV Y1,CX
    MOV Y2,DX
    POP SI
    POP DX
    POP CX
    POP BX
    POP AX
    RET
G_FRAME ENDP

G_FR_2 PROC NEAR   ; SETS UP LINE1 FOR G_FRAME CALLS
                   ; USES FRAME_PARMS STRUC AND FRAME_DAT DATA
                   ; draws box with NUMREPS lines spaced @
                   ; X_STEP/Y_STEP pixels apart...

FRAME_PARMS STRUC

X_MIN    DW ?
X_MAX    DW ?
Y_MIN    DW ?
Y_MAX    DW ?
X_STEP   DW ?
Y_STEP   DW ?
NUM_REPS DW ?

FRAME_PARMS ENDS

    PUSH AX
    PUSH BX
    PUSH CX
    PUSH SI
    LEA  SI,FRAME_DAT
    MOV  AX,[SI].X_MIN
    MOV  X1,AX
    MOV  AX,[SI].X_MAX
    MOV  X2,AX
    MOV  AX,[SI].Y_MIN
    MOV  Y1,AX
    MOV  AX,[SI].Y_MAX
    MOV  Y2,AX
    MOV  CX,[SI].NUM_REPS
    MOV  AX,[SI].X_STEP
    MOV  BX,[SI].Y_STEP

GFR_LOOP:
    CALL G_FRAME
    ADD X1,AX
    SUB X2,AX
    ADD Y1,BX
    SUB Y2,BX
    LOOP GFR_LOOP

    POP SI
    POP CX
    POP BX
    POP AX
    RET
G_FR_2 ENDP


SWEEP_BOX PROC NEAR  ; draws box of sweeping lines.....
    PUSH AX
    PUSH BX
    PUSH CX
    PUSH DX
    PUSH SI
    PUSH DI

    LEA  DI,FRAME_DAT

    MOV AX,X1
    MOV BX,X2
    SUB AX,BX
    ADD AX,X1
    MOV [DI].X_MAX,AX
    MOV [DI].X_MIN,BX
    MOV AX,Y1
    MOV BX,Y2
    SUB AX,BX
    ADD AX,Y1
    MOV [DI].Y_MAX,AX
    MOV [DI].Y_MIN,BX

    MOV  AX,[DI].X_STEP
    MOV  BX,[DI].Y_STEP

    LEA  SI,LINE1
    MOV  CX,[DI].X_MAX
TOP_SIDE:

    CALL PLOTLINE
    ADD  X2,AX
    CMP  X2,CX
    JBE  TOP_SIDE
    SUB  X2,AX

    MOV  CX,[DI].Y_MAX
RIGHT_SIDE:

    CALL PLOTLINE
    ADD  Y2,BX
    CMP  Y2,CX
    JBE  RIGHT_SIDE
    SUB  Y2,BX

    MOV  CX,[DI].X_MIN
BOT_SIDE:

    CALL PLOTLINE
    SUB  X2,AX
    CMP  X2,CX
    JGE   BOT_SIDE
    ADD X2,AX

    MOV  CX,[DI].Y_MIN
LEFT_SIDE:

    CALL PLOTLINE
    SUB  Y2,BX
    CMP  Y2,CX
    JGE   LEFT_SIDE

    POP DI
    POP SI
    POP DX
    POP CX
    POP BX
    POP AX
    RET
SWEEP_BOX ENDP


SWEEP_FRAME PROC NEAR  ; draws frame where each edge is a swept box....?
    PUSH AX
    PUSH SI

    LEA  SI,SWFRAME_DAT


    MOV  AX,[SI].X_MAX
    SUB  AX,[SI].X_MIN
    SHR  AX,1
    ADD  AX,[SI].X_MIN

    MOV  X1,AX
    MOV  AX,[SI].Y_MIN
    ADD  AX,[SI].Y_STEP
    MOV  Y1,AX

    MOV  AX,[SI].X_MIN
    MOV  X2,AX
    MOV  AX,[SI].Y_MIN
    MOV  Y2,AX
    CALL SWEEP_BOX

    MOV  AX,[SI].X_MAX
    SUB  AX,[SI].X_MIN
    SHR  AX,1
    ADD  AX,[SI].X_MIN

    MOV  X1,AX
    MOV  AX,[SI].Y_MAX
    SUB  AX,[SI].Y_STEP
    MOV  Y1,AX

    MOV  AX,[SI].X_MIN
    MOV  X2,AX
    MOV  AX,[SI].Y_MAX
    SUB  AX,[SI].Y_STEP
    SUB  AX,[SI].Y_STEP
    MOV  Y2,AX
    CALL SWEEP_BOX

    MOV  AX,[SI].Y_MAX
    SUB  AX,[SI].Y_MIN
    SHR  AX,1
    ADD  AX,[SI].Y_MIN

    MOV  Y1,AX
    MOV  AX,[SI].X_MIN
    ADD  AX,[SI].X_STEP
    MOV  X1,AX

    MOV  AX,[SI].Y_MIN
    ADD  AX,[SI].Y_STEP
    ADD  AX,[SI].Y_STEP
    MOV  Y2,AX
    MOV  AX,[SI].X_MIN
    MOV  X2,AX
    CALL SWEEP_BOX

    MOV  AX,[SI].Y_MAX
    SUB  AX,[SI].Y_MIN
    SHR  AX,1
    ADD  AX,[SI].Y_MIN
    MOV  Y1,AX
    MOV  AX,[SI].X_MAX
    SUB  AX,[SI].X_STEP
    MOV  X1,AX

    MOV  AX,[SI].X_MAX
    SUB  AX,[SI].X_STEP
    SUB  AX,[SI].X_STEP
    MOV  X2,AX
    MOV  AX,[SI].Y_MIN
    ADD  AX,[SI].Y_STEP
    ADD  AX,[SI].Y_STEP
    MOV  Y2,AX
    CALL SWEEP_BOX


    POP  SI
    POP  AX
    RET
SWEEP_FRAME ENDP



; Routines to plot straight lines and circles
; Based on routines by Rollins - "8088 Macro Assembler Programming"

    INCLUDE HGD.INC  ; INCLUDE ROUTINES FOR PLOTLINE AND CIRCLE HERE
                     ; SOURCE CODE NOT PROVIDED....see doc file.




GET_RLET PROC NEAR  ; LOOKUP CHAR IN BL STASH VALS IN LETTER DB 8 DUP ?
                    ; GRABS FONT VALUE FROM ROM TABLE...
     PUSH AX
     PUSH CX
     PUSH SI
     PUSH DI

     MOV  CX,8
     MOV  AL,BL
     CBW
     SHL  AX,1
     SHL  AX,1
     SHL  AX,1
     ADD  AX,0FA6EH+7
     MOV  SI,AX
     MOV  DI,DS        ; SAVE  DS
     MOV  AX,0F000H
     MOV  DS,AX
     STD

G_RCH1:
     LODSB
     PUSH AX
     LOOP G_RCH1

     MOV  DS,DI        ; RESTORE DS...
     LEA  SI,LETTER
     MOV  CX,8

P_RCH1:
     POP  AX
     MOV  [SI],AL
     INC  SI
     LOOP P_RCH1

     POP  DI
     POP  SI
     POP  CX
     POP  AX
     RET

GET_RLET ENDP


    SUBTTL  C_DISPLAY  ROUTINE TO DISPLAY A CHARACTER
    PAGE    +

C_DISPLAY PROC     ; CALLED BY DSPLY_MSG PROCEDURE....

; C_DISPLAY shows a character in small format for HIGH resolution graphics
; uses LETTER_TBL for stroke sequences - assumes color 1 - pixel on...
; each letter uses 4 pixels by 8 pixels x X/Y scale values

; assumes DX = line number
;         CX = column number
;         BL = character to display
;         AH = SIZE OF CHARACTER... WIDTH  8xAH COLS...
;         BH = SIZE OF CHARACTER... LENGTH 8xBH ROWS...

    PUSH AX
    PUSH BX
    PUSH CX
    PUSH DX
    PUSH SI
    PUSH DI
    PUSH BP


; set SI to point to character definition array
     CALL GET_RLET
     LEA  SI,LETTER

; set length to display 8 lines of 1 byte

    MOV  BL,8       ; SET NUMBER OF BYTES TO MOVE
    PUSH AX
    MOV  AL,AH
    CBW
    MOV  BP,AX      ; BP NOW HAS S_XSIZE VALUE...
    POP  AX

DISPLAY_LOOP:

    MOV  AL,[SI]    ; GET NEXT BYTE TO SHOW

    PUSH CX

SCALE_LOOP:
; now display the lines that make the character

    MOV  AH,080H

T_PIX_L:
    TEST AL,AH    ; ANY PIXEL?
    JZ   D1         ; NO SO SKIP

    CALL CD_PLOT2

D1:
    ADD  CX,BP

    SHR  AH,1
    JNZ  T_PIX_L





    ADD  DL,BH
    ADC  DH,00H
    POP  CX

    INC  SI           ; POINT TO NEXT BYTE TO DISPLAY
    DEC  BL
    JNZ  DISPLAY_LOOP ; REPEAT FOR WHOLE LETTER


    POP  BP
    POP  DI
    POP  SI
    POP  DX
    POP  CX
    POP  BX
    POP  AX

    RET

C_DISPLAY ENDP

CD_PLOT2 PROC NEAR
    PUSH  AX
    PUSH  BX
    PUSH  CX
    PUSH  DX
    PUSH  BP

    MOV  AX,BP    ; HOLD X SCALE VALUE IN AX...
CD_PL:
    MOV  BP,AX    ; RESTORE X SCALE FOR EACH PASS
    PUSH CX       ; HOLD COL VAL ON STACK...
CD_PLX:
    CALL PLOT_SUB ; PLOT A DOT
    INC  CX       ; INC COLUMN
    DEC  BP       ; DO THE LOOP THING WITH BP...
    JNZ  CD_PLX

    POP  CX       ; RESTORE START COLUMN VALUE...
    INC  DX       ; DX = LINE#, BH = Y SCALE...
    DEC  BH       ; DO IT FOR ALL LINES NEEDED
    JNZ CD_PL

    POP  BP
    POP  DX
    POP  CX
    POP  BX
    POP  AX
    RET
CD_PLOT2 ENDP


    SUBTTL  DSPLY_MSG  ROUTINE TO DISPLAY ANY SIZED LETTER MESSAGE
    PAGE    +

DSPLY_MSG PROC

; Routine will display a message in ASCIIZ string format

; assumes  SI = address of scale_mess structure

SCALE_MESS STRUC

S_ROW   DW ?      ; ROW COORD
S_COL   DW ?      ; COLUMN COORD
S_XSIZE   DB ?    ; X SCALE
S_YSIZE   DB ?    ; Y SCALE
MESSAGE DW ?      ; ACTUALLY A ASCIIZ STRING....

SCALE_MESS ENDS

    PUSH AX
    PUSH BX
    PUSH CX
    PUSH SI

    MOV  AL,00H
    MOV  AH,[SI].S_XSIZE
C_XSL:
    ADD  AL,8
    DEC  AH
    JNZ  C_XSL

    MOV  BH,[SI].S_YSIZE
    MOV  AH,[SI].S_XSIZE
    MOV  DX,[SI].S_ROW
    MOV  CX,[SI].S_COL
    LEA  SI,[SI].MESSAGE

DSPLY_LOOP:

    MOV  BL,[SI]    ; FETCH CHARACTER TO DISPLAY
    CMP  BL,0       ; ARE WE DONE?
    JE   DSPLY_DONE ; YES, SO LEAVE
    CALL C_DISPLAY    ; SHOW ONE CHARACTER



    INC  SI         ; POINT TO NEXT CHARACTER TO DISPLAY
    ADD  CL,AL      ; POINT TO NEXT BYTE ON LINE
    ADC  CH,00H     ; + ANY CARRY...

    JMP  DSPLY_LOOP ; REPEAT FOR ENTIRE MESSAGE

DSPLY_DONE:

    POP  SI
    POP  CX
    POP  BX
    POP  AX
    RET

DSPLY_MSG ENDP

CLR_FR PROC NEAR
    PUSH CX
    PUSH SI

    CALL CLS           ; CLEAR THE SCREEN
    CALL G_FR_2        ; DRAW A DOUBLE FRAME

    MOV  SI,PLOT_ADR
    MOV  PLOT_SUB,SI

    LEA SI,HR_MESS    ; POINT AT HI-RES MESSAGE DATA
    CALL DSPLY_MSG    ; DISPLAY IT....
    LEA SI,PX_MESS    ; POINT AT PRESS ANY KEY MESSAGE DATA
    CALL DSPLY_MSG    ; DISPLAY IT


    POP  CX
    POP  SI
    RET
CLR_FR ENDP

WOW_WHEE PROC NEAR
    PUSH CX

    MOV  CX,3     ; CALL ROUTINE WOW 3 TIMES...

WOW_LOOP:
    CALL WOW
    LOOP WOW_LOOP

    POP  CX
    RET
WOW_WHEE ENDP


WOW PROC NEAR    ; DISPLAY 'WOW' MESSAGE AND SCALE IT UP AND DOWN ON THE FLY
     PUSH CX
     PUSH SI

    MOV  SI,XPLOT_ADR    ; USE XPLOT FOR EASY WIPE OUT OF PREVIOUS MESSAGE...
    MOV  PLOT_SUB,SI
    LEA  SI,TST_MESS

    MOV  CX,7            ; SHOW 7 INCREASEING SIZES....
WL_1:
    CALL DSPLY_MSG
    ; NO CALL DELAY
    CALL DSPLY_MSG

    SUB WORD PTR [SI],4     ; ADJUST ROW COORDINATE TO KEEP MESSAGE CENTERED
    SUB WORD PTR [SI+2],12  ;  "  "  COLUMN  "    "          "          "
    INC BYTE PTR [SI+4]     ; INCREASE SCALE..
    INC BYTE PTR [SI+5]
    LOOP WL_1

    MOV  CX,7            ; SHOW 7 DECREASING SIZES....
WL_2:
    LEA  SI,TST_MESS
    CALL DSPLY_MSG

    LEA  SI,TST_MESS
    CALL DSPLY_MSG
    ADD WORD PTR [SI],4
    ADD WORD PTR [SI+2],12
    DEC BYTE PTR [SI+4]
    DEC BYTE PTR [SI+5]
    LOOP WL_2

    ; COORDINATES FOR TST_MESS DATA NOW AT ORIGINAL VALUES....

    POP  SI
    POP  CX
    RET
WOW ENDP



STEP_ADJ PROC NEAR  ; ROUTINE MODIFIES COORDINATES, NUMBER
                    ; OF REPETITIONS AND PLOT ROUTINE USED
                    ; IN AN ATTEMPT TO CREATE MANY VARIATIONS
                    ; OF THE GRAPHICS SCREENS....

   PUSH SI
   DEC  AX
   DEC  BX
   INC  CX
   INC  DX
   CMP  AX,0
   JA  SA_1
   MOV  AX,5
SA_1:
   CMP  BX,0
   JA  SA_2
   MOV  BX,12
SA_2:
   CMP  DX,17
   JB  SA_3
   MOV  DX,2
SA_3:
   CMP  CX,14
   JB  SA_X
   MOV  CX,2

SA_X:
   TEST CX,1
   JNZ NPDT
   CALL PD_TOG

NPDT:
   LEA  SI,SWFRAME_DAT
   MOV  [SI].NUM_REPS,DX
   MOV [SI].X_MIN,0
   MOV [SI].X_MAX,719
   MOV [SI].Y_MIN,0
   MOV [SI].Y_MAX,347
   ADD [SI].X_STEP,CX
   ADD [SI].Y_STEP,DX
   CMP [SI].X_STEP,100
   JB  NFXS
   MOV [SI].X_STEP,CX
   SHL [SI].X_STEP,1

NFXS:
   CMP [SI].Y_STEP,100
   JB  NFYS
   MOV [SI].Y_STEP,DX
   SHL [SI].Y_STEP,1

NFYS:

   LEA  SI,FRAME_DAT
   MOV  [SI].NUM_REPS,CX
   MOV [SI].X_MIN,0
   MOV [SI].X_MAX,719
   MOV [SI].Y_MIN,0
   MOV [SI].Y_MAX,347
   MOV [SI].X_STEP,BX
   MOV [SI].Y_STEP,DX
   INC [SI].NUM_REPS
   SHL [SI].NUM_REPS,1


   POP SI
   RET
STEP_ADJ ENDP



CHK_KBD PROC NEAR   ; CALL BIOS FOR KEYCHECK.....
    PUSH AX

    MOV  AH,1
    INT  16H
    POP AX
    RET
CHK_KBD ENDP

PD_TOG PROC NEAR    ; TOGGLE CURRENT PLOT ROUTINE ADDRESS....
   PUSH SI
   MOV  SI,PLOT_ADR
   CMP  SI,PLOT_SUB
   JNE  SET_PLD
   MOV  SI,XPLOT_ADR
   MOV  PLOT_SUB,SI
   JMP  HR_CONT
SET_PLD:
   MOV  SI,PLOT_ADR
   MOV  PLOT_SUB,SI

HR_CONT:
   POP SI
   RET
PD_TOG ENDP




PLOT_HGA PROC NEAR

; assumes DX = line offset number 0 to 347
;         CX = column offset from 0 to 719

; routine plots the pixel dot


    PUSH AX
    PUSH BX
    PUSH DI
    PUSH ES

; determine mask by table look up

    MOV  DI,CX
    AND  DI,7
    SHL  DI,1       ; AND MULTIPLY BY 2

    MOV  BX,GMASK_TBL [DI] ; BL = OFF MASK, BH = ON MASK
    PUSH BX
; get the address of the pixel byte

    MOV  DI,DX      ; GET LINE NUMBER
    AND  DI,0FFFEH  ; ELIMINATE EVEN ODD BIT
    SHR  DI,1
    SHR  DI,1

    SHL  DI,1       ; AND MULTIPLY BY SUCCESSIVE POWERS OF 2
    MOV  BX,DI      ; save val*2...
    SHL  DI,1
    SHL  DI,1
    ADD  BX,DI      ; add val*2...

    SHL  DI,1       ; DI IS NOW MULTIPLIED BY 16
    MOV  AX,DI      ; SAVE PARTIAL PRODUCT
    SHL  DI,1
    SHL  DI,1       ; DI IS NOW MULTIPLIED BY 64
    ADD  DI,AX      ; DI IS NOW * 80
    ADD  DI,BX      ; DI IS NOW * 90
    POP  BX

    TEST DX,3       ; IS LINE N3?
    JZ   N_N1       ; NO BITS SET, GO ON
    ADD  DI,2000H   ; ODD, SO ADD 2000H TO GET TO 2ND SECTION
    TEST DX,2
    JZ   N_N1
    ADD  DI,2000H
    TEST DX,1
    JZ   N_N1
    ADD  DI,2000H
N_N1:

    MOV  AX,CX      ; GET COLUMN NUMBER
    SHR  AX,1
    SHR  AX,1       ; AND DIVIDE BY 4 FOR OFFSET FROM START OF LINE
    SHR  AX,1

    ADD  DI,AX      ; AND ADD TO FINAL ADDRESS

    MOV  AX,0B000H  ; POINT TO DMA
    MOV  ES,AX      ; ES = DMA

; now set the pixel

    AND  ES:[DI],BL ; BLANK OUT PIXEL
    OR   ES:[DI],BH ; INSERT NEW PIXEL

    POP  ES
    POP  DI
    POP  BX
    POP  AX

    RET

PLOT_HGA ENDP

    SUBTTL  XPLOTDOT  PLOTS ONE PIXEL DOT USING XOR
    PAGE    +

XPLOT_HGA PROC NEAR

; assumes DX = line offset number 0 to 347
;         CX = column offset from 0 to 719

; routine plots the pixel dot by XOR





    PUSH AX
    PUSH BX
    PUSH DI
    PUSH ES

; determine mask and color bits by table look up
; table index = ( (pixel number * 4) + color ) * 2

    MOV  DI,CX
    AND  DI,7
    SHL  DI,1       ; AND MULTIPLY BY 2

    MOV  BX,GMASK_TBL [DI] ; BL = OFF MASK, BH = ON MASK
    PUSH BX
; get the address of the pixel byte

    MOV  DI,DX      ; GET LINE NUMBER
    AND  DI,0FFFEH  ; ELIMINATE EVEN ODD BIT
    SHR  DI,1
    SHR  DI,1
    SHL  DI,1       ; AND MULTIPLY BY SUCCESSIVE POWERS OF 2
    MOV  BX,DI
    SHL  DI,1
    SHL  DI,1
    ADD  BX,DI

    SHL  DI,1       ; DI IS NOW MULTIPLIED BY 16
    MOV  AX,DI      ; SAVE PARTIAL PRODUCT
    SHL  DI,1
    SHL  DI,1       ; DI IS NOW MULTIPLIED BY 64
    ADD  DI,AX      ; DI IS NOW * 80
    ADD  DI,BX      ;  "    "   * 90
    POP  BX

    TEST DX,3       ; IS LINE N3?
    JZ   XN_N1      ; NO,
    ADD  DI,2000H   ; ODD, SO ADD 2000H TO GET TO 2ND SECTION
    TEST DX,2
    JZ   XN_N1
    ADD  DI,2000H
    TEST DX,1
    JZ   XN_N1
    ADD  DI,2000H
XN_N1:

    MOV  AX,CX      ; GET COLUMN NUMBER
    SHR  AX,1
    SHR  AX,1
    SHR  AX,1       ; AND DIVIDE BY 8 FOR OFFSET FROM START OF LINE

    ADD  DI,AX      ; AND ADD TO FINAL ADDRESS

    MOV  AX,0B000H  ; POINT TO DMA
    MOV  ES,AX      ; ES = DMA

; now set the pixel

    XOR  ES:[DI],BH ; XOR IN NEW COLOR

    POP  ES
    POP  DI
    POP  BX
    POP  AX

    RET

XPLOT_HGA ENDP




DELAY PROC NEAR
      PUSH AX
      PUSH BX
      PUSH CX
      PUSH ES

      MOV AX,0040H
      MOV ES,AX
      MOV CX,D_VAL        ; OR DELAY VAL  # OF CLOCKS....
      CMP CX,00H
      JE D2_L_EX

D2_L_2:
      MOV AX,ES:[006CH]
D2_L_1:
      MOV BX,ES:[006CH]
      CMP AX,BX
      JE  D2_L_1
      LOOP D2_L_2
D2_L_EX:
      POP ES
      POP CX
      POP BX
      POP AX
      RET
DELAY ENDP



    SUBTTL  SET_MODE  AND RESTORE GRAPHICS MODE ROUTINES
    PAGE    +

SET_MODE PROC

; routine to set high resolution mode and plot routine addresses...


    PUSH AX
    PUSH BX



    LEA  SI,PLOT_HGA
    MOV  PLOT_ADR,SI
    MOV  PLOT_SUB,SI

    LEA  SI,XPLOT_HGA
    MOV  XPLOT_ADR,SI
    MOV  SCRN_ADR,HGA_ADR

    CALL _GMODE     ; SET HERC TO 720 x 348 GRAPHICS MODE ??

    POP  BX
    POP  AX
    RET

SET_MODE ENDP



; routine to restore HGA text video mode

RESTORE_MODE PROC

    PUSH AX

    CALL _TMODE

    POP  AX
    RET

RESTORE_MODE ENDP



;*********************************************************************
;GRAPHICS MODE - Programs the 6845 CRT controller for the 720 x 348 graphics
;mode. The active page for both writing and display is set to the default value
;of page 0.
;ON ENTRY - no parameters.
;   source unknown ??   c-serve ?
;*********************************************************************

_gmode  proc near

    push    si
    push    di

    mov    al,1
    mov    dx, 3bfh
    out    dx, al
    mov    al,grph
    lea    si,gtable
    mov    bx,0
    mov    cx,4000h
    call    setmd

    pop    di
    pop    si

    ret

_gmode    endp

;**********************************************************************
;TEXT MODE - Programs the 6845 and control register to produce text mode.
;
;ON ENTRY - no parameters.
;***********************************************************************

_tmode proc near

    push    si
    push    di

    mov    al,text
    lea    si,ttable
    mov    bx,720h
    mov    cx,2000
    call    setmd

    pop    di
    pop    si

    ret

_tmode    endp

setmd    proc    near

;     sets mode to graphics or text
;     depending on al
;     si = parameter table
;     cx = number of words to be cleared
;     bx = blank value
    push    ds
    push    es
    push    ax
    push    bx
    push    cx

;     change mode but without scrn_on
    mov    dx,cntrl
    out    dx,al

;     intialize the 6845

    mov    dx,index
    mov    cx,12        ;12 parameters to
                ;be output
    xor    ah,ah        ;starting from
                ;reg. 0
parms:    mov    al,ah
    out    dx,al        ;output register
                ;number
    cld

    inc    dx
    lodsb
    out    dx,al        ;output data

    inc    ah        ;next value
    dec    dx
    loop    parms

    pop    cx        ;clear the buffer
    mov    ax,0b000h

    mov    es,ax
    xor    di,di
    pop    ax
    rep    stosw

;     scrn_on, page 0

    mov    dx,cntrl
    pop    ax
    add    al,scrn_on
    out    dx,al

    pop    es
    pop    ds

    ret

setmd    endp



    SUBTTL  CLS  CLEAR THE GRAPHICS SCREEN
    PAGE    +

CLS PROC

; clears a graphics screen using color palette choice COLOR_CLS


    PUSH AX
    PUSH CX
    PUSH DI
    PUSH ES


    MOV  AX,0B000H    ; POINT TO DMA
    MOV  ES,AX        ; ES = DMA ADDRESS
    MOV  DI,0         ; POINT TO START OF SCREEN

    MOV  CX,4000H     ; WORD COUNT OF WHOLE SCREEN
    MOV  AX,COLOR_CLS ; SET PIXEL PATTERN FOR WHOLE SCREEN
    CLD               ; SET FOR FORWARD DIRECTION

    REP  STOSW        ; CLEAR WHOLE SCREEN

    POP  ES
    POP  DI
    POP  CX
    POP  AX

    RET


CLS ENDP


    SUBTTL  DATA AREA
    PAGE    +

.DATA


; used by CLS

COLOR_CLS DW  0000H ; SET CLEAR SCREEN COLOR TO 00


; used by SET_MODE and RESTORE_MODE routines

ST_MODE  DB  ?   ; OLD VIDEO MODE
SCRN_ADR DW  ?
PLOT_SUB DW  ?

PLOT_ADR DW ?
XPLOT_ADR DW ?




; used by PLOTDOT and XPLOTDOT routines

GMASK_TBL LABEL WORD

    DB  01111111B, 10000000B  ; LEFT PIXEL
    DB  10111111B, 01000000B  ;
    DB  11011111B, 00100000B  ;
    DB  11101111B, 00010000B  ;
    DB  11110111B, 00001000B  ; RIGHT PIXEL
    DB  11111011B, 00000100B  ;
    DB  11111101B, 00000010B  ;
    DB  11111110B, 00000001B  ;



; used by PLOTLINE routine

SHORT_STEP  DW  ?
LONG_STEP   DW  ?
LINE_START  DW  ?
LINE_STOP   DW  ?





LINE1 LABEL WORD
X1 DW 0
Y1 DW 0
X2 DW 719
Y2 DW 347
CO DB 1
LN DW 0
SK DW 0

FRAME_DAT LABEL WORD
        DW 0         ; X_MIN
        DW 719       ; X_MAX
        DW 0         ; Y_MIN
        DW 347       ; Y_MAX
        DW 8         ; X_STEP
        DW 3         ; Y_STEP
        DW 2         ; NUM_REPS

SWFRAME_DAT LABEL WORD
        DW 0         ; X_MIN
        DW 719       ; X_MAX
        DW 0         ; Y_MIN
        DW 347       ; Y_MAX
        DW 8         ; X_STEP
        DW 3         ; Y_STEP
        DW 2         ; NUM_REPS



; used by CIRCLE routine

CIRCLE_DATA DW 359, 172, 90, 1, 5000/8


gtable    db    35h,2dh,2eh,07h
        db    5bh,02h,57h,57h
        db    02h,03h,00h,00h

ttable    db    61h,50h,52h,0fh
        db    19h,06h,19h,19h
        db    02h,0dh,0bh,0ch


LETTER  DB FNT_LEN DUP (?)

HR_MESS LABEL WORD
     DW  5         ; LINE #
     DW  275       ; COLUMN #
     DB  1         ; X SCALE
     DB  2         ; Y SCALE
     DB  'Hi-Res graphics demo !?!',00H

SA_MESS LABEL WORD
     DW  275         ; LINE #
     DW  200       ; COLUMN #
     DB  2         ; X SCALE
     DB  1         ; Y SCALE
     DB  '(c) 1993 Scott Armitage',00H

PX_MESS LABEL WORD
     DW  320      ; LINE #
     DW  175      ; COLUMN #
     DB  2        ; X SCALE
     DB  3        ; Y SCALE
     DB 'Press any key to QUIT...',00H

TST_MESS LABEL WORD
     DW  162      ; LINE #
     DW  336      ; COLUMN #
     DB  2        ; X SCALE
     DB  2        ; Y SCALE
     DB 'WoW',00H

; USE FOR # OF CLOCKS TO DELAY IN DELAY ROUTINE...

D_VAL  DW 10H


.STACK

     DW  50 DUP (?)

    END MAIN