'===========================================================================
' Subject: 3D SINE GRAPH FOR BASEC           Date: 06-24-99 (10:00)       
' Author:  The ABC Programmer                Code: BEC, QB, QBasic        
' Origin:  voxel@edmc.net                  Packet: BASEC.ABC
'===========================================================================
' Converted to BASEC v0.20 by William Yu
' Yes, it does crash, but you get the idea.
'===========================================================================
' Subject: SINE GRAPH                        Date: 03-11-92 (10:20:00)    
'  Author: Rick Pedley                       Code: QB, QBasic             
'    Keys: SINE,GRAPH                      Packet: EGAVGA.ABC
'===========================================================================
DIM SineRow(1 TO 240) AS SINGLE
DIM SineCol(1 TO 350) AS SINGLE
DIM X AS INTEGER
DIM CF AS INTEGER
DIM MAXVERTRES AS INTEGER
DIM MAXHORZRES AS INTEGER
DIM R AS INTEGER
DIM P AS INTEGER
DIM H AS INTEGER
DIM C AS INTEGER
DIM A AS INTEGER
DIM Z AS INTEGER
DIM UNDER AS INTEGER
DIM T AS INTEGER
DIM L AS INTEGER
DIM K AS INTEGER
DIM D AS INTEGER
DIM G AS INTEGER

FOR x = 1 TO 240
   SineRow(x) = SIN(x / 10) * 30
NEXT x

FOR x = 1 TO 350
   SineCol(x) = SIN(x / 20) * 30
NEXT x
                                                                 
SCREEN 12
CF = 1
MaxVertRes = 480
MaxHorzRes = 640
R = 0: P = 0: H = 0
C = 0: A = 0: Z = 0
Under = -1  'Change to 0 for no under side.
T = 1: L = 1: K = MaxVertRes: D = 0: G = 0
Start:                                                          
   P = K
   FOR C = T + D TO 1 STEP -1
      A = T + L: R = A - C: IF R > 240 THEN GOTO SkipSurface
      Z = (SineRow(R) + SineCol(C)) + 150
      H = K - Z - R
      IF H >= P OR H < 0 THEN GOTO Underside
      P = H: PSET (A - 1, P), 9  '<-Try 10,12,13,etc.           
Underside:                                                      
      IF Under THEN
         IF R = L OR R = L + 1 THEN G = H + 5: GOTO SkipUnder
         IF H <= G THEN GOTO SkipUnder
         G = H: IF G > MaxVertRes THEN GOTO SkipUnder
         PSET (A - 1, G), 1 '<-Try 2,4,12, etc.                 
      END IF
SkipUnder:                                                      
   NEXT C
                                                                 
SkipSurface:                                                    
   IF A = MaxHorzRes THEN GOTO Done
   T = T + 1
   IF T > 350 THEN
      T = 350
      L = L + 1: D = D + 1
      IF D = CF THEN D = 0
   END IF
   GOTO Start
Done:                                                           
DO
LOOP UNTIL INKEY$<>""

END