411 REFERENCE · Wikibooks
Oberon/ETH Oberon/2.3.7/DisplayVGA4.Mod
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
(* ETH Oberon, Copyright 1990-2003 Computer Systems Institute, ETH Zurich, CH-8092 Zurich.
Refer to the license.txt file provided with this distribution. *)
MODULE DisplayVGA4; (* pjm *)
(*
16-color VGA display driver for Native Oberon with virtual truecolor.
Config strings:
Display="Displays."
DDriver="DisplayVGA4"
Init="b81200cd10"
*)
IMPORT SYSTEM, Kernel, CLUTs, Displays;
CONST
Width = 640; Height = 480;
VAR
d: Display;
base: LONGINT;
clut: POINTER TO CLUTs.CLUT;
pal: ARRAY 16 OF LONGINT;
shadow: POINTER TO ARRAY OF CHAR;
pelmask: LONGINT; (* trace *)
TYPE
Display* = OBJECT (Displays.Display)
PROCEDURE Transfer*(VAR buf: ARRAY OF CHAR; ofs, stride, x, y, w, h, op: LONGINT);
VAR bufadr, buflow, bufhigh, dispadr, scradr: LONGINT;
BEGIN
IF w > 0 THEN
bufadr := SYSTEM.ADR(buf[ofs]);
IF op = Displays.set THEN
buflow := SYSTEM.ADR(shadow[0]); bufhigh := buflow + LEN(shadow^);
dispadr := SYSTEM.ADR(shadow[0]) + ((y*Width)+x);
scradr := base + (x DIV 8 + y*(Width DIV 8)) MOD 10000H;
WHILE h > 0 DO
ASSERT((dispadr >= buflow) & (dispadr+w <= bufhigh)); (* index check *)
SYSTEM.MOVE(bufadr, dispadr, w);
CopyLineTo(bufadr, scradr, x, w);
INC(bufadr, stride); INC(dispadr, Width); INC(scradr, Width DIV 8);
DEC(h)
END
ELSIF op = Displays.get THEN
buflow := SYSTEM.ADR(buf[0]); bufhigh := buflow + LEN(buf);
dispadr := SYSTEM.ADR(shadow[0]) + ((y*Width)+x);
WHILE h > 0 DO
ASSERT((bufadr >= buflow) & (bufadr+w <= bufhigh)); (* index check *)
SYSTEM.MOVE(dispadr, bufadr, w);
INC(bufadr, stride); INC(dispadr, Width);
DEC(h)
END
ELSE (* skip *)
END
END
END Transfer;
(*
PROCEDURE Dot*(col, x, y: LONGINT);
VAR ch: CHAR;
BEGIN
y := base + (x + y*Width) DIV 8 MOD 10000H;
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 8 + ASH(100H, 7-x MOD 8)));
IF ASH(col, 1) >= 0 THEN (* replace *)
SYSTEM.GET(y, ch);
SYSTEM.PUT(y, CHR(CLUTs.Match(clut^, col)))
ELSE (* invert *)
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 1803H));
SYSTEM.GET(y, ch);
SYSTEM.PUT(y, CHR(CLUTs.Match(clut^, col)));
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 0003H))
END
END Dot;
*)
PROCEDURE ColorToIndex*(col: LONGINT): LONGINT;
BEGIN
RETURN CLUTs.Match(clut^, col)
END ColorToIndex;
PROCEDURE IndexToColor*(index: LONGINT): LONGINT;
BEGIN
RETURN pal[index MOD 16]
END IndexToColor;
END Display;
(* Copy a line of pixels to the display. *)
PROCEDURE CopyLineTo(src, dst, x, w: LONGINT);
CODE {SYSTEM.i386}
MOV ESI, src[EBP]
MOV EDI, dst[EBP]
MOV EBX, x[EBP]
MOV EDX, 3CEH
MOV AL, 8
new:
MOV CH, [ESI] ; CH = current pixel color
MOV AH, 80H ; AH = mask for current pixels (at left of byte)
MOV CL, BL
AND CL, 7 ; CL = offset to shift mask right
JMP loop
same:
SAR AH, 1
loop:
DEC w[EBP]
JZ done
INC EBX
INC ESI
TEST BL, 7
JZ edge
CMP CH, [ESI]
JE same
diff:
SHR AH, CL
OUT DX, AX
MOV CL, [EDI]
MOV [EDI], CH
JMP new
edge:
SHR AH, CL ; adjust mask
OUT DX, AX ; set mask
MOV CL, [EDI] ; latch
MOV [EDI], CH ; output color
INC EDI
JMP new
done:
SHR AH, CL
OUT DX, AX
MOV CL, [EDI]
MOV [EDI], CH
end:
END CopyLineTo;
PROCEDURE Install*;
BEGIN
IF d # NIL THEN Displays.main := d END
END Install;
PROCEDURE InitPalette;
VAR i, col: LONGINT; ch: CHAR;
BEGIN
(* standard Oberon colours *)
pal[0] := 0; pal[1] := 0FF0000H; pal[2] := 000FF00H;
pal[3] := 00000FFH; pal[4] := 0FF00FFH; pal[5] := 0FFFF00H;
pal[6] := 000FFFFH; pal[7] := 0AA0000H; pal[9] := 000009AH;
pal[10] := 0A6CBF3H; pal[11] := 0008282H; pal[12] := 08A8A8AH;
pal[13] := 0BEBEBEH; pal[14] := 0DFDFDFH; pal[15] := 0FFFFFFH;
(* set attribute controller registers *)
SYSTEM.PORTIN(3DAH, ch); (* clear flip/flop *)
FOR i := 0 TO 0FH DO
SYSTEM.PORTOUT(3C0H, CHR(i)); (* EGA palette register i *)
SYSTEM.PORTOUT(3C0H, CHR(i)) (* maps to VGA palette i *)
END;
SYSTEM.PORTOUT(3C0H, 11X); (* overscan color *)
SYSTEM.PORTOUT(3C0H, 0X); (* black/EGA palette 0/VGA palette 0 *)
SYSTEM.PORTOUT(3C0H, 12X); (* color plane enable *)
SYSTEM.PORTOUT(3C0H, 0FX); (* enable all planes *)
SYSTEM.PORTOUT(3C0H, 14X); (* color select *)
SYSTEM.PORTOUT(3C0H, 0X); (* use first 16 colors in VGA palette *)
SYSTEM.PORTOUT(3C0H, 20X); (* enable display to use palette again *)
(* set up VGA palette and reverse lookup table *)
NEW(clut);
SYSTEM.PORTOUT(3C8H, 0X); (* select index 0 *)
FOR i := 0 TO 15 DO
col := pal[i]; CLUTs.Set(clut^, i, col);
SYSTEM.PORTOUT(3C9H, CHR(col DIV 10000H MOD 100H DIV 4));
SYSTEM.PORTOUT(3C9H, CHR(col DIV 100H MOD 100H DIV 4));
SYSTEM.PORTOUT(3C9H, CHR(col MOD 100H DIV 4))
END;
FOR i := 16 TO 255 DO
SYSTEM.PORTOUT(3C9H, 0X);
SYSTEM.PORTOUT(3C9H, 0X);
SYSTEM.PORTOUT(3C9H, 0X)
END;
CLUTs.Init(clut^, 16, 3);
SYSTEM.PORTIN(3C6H, ch); pelmask := ORD(ch)
END InitPalette;
(*
IF i = 6 THEN j := 14H
ELSIF i > 7 THEN j := i+30H
ELSE j := i
END;
*)
PROCEDURE Init;
BEGIN
NEW(d);
d.width := Width; d.height := Height; d.offscreen := 0;
d.format := Displays.index8; d.unit := 10000;
Kernel.MapPhysical(0A0000H, 10000H, base);
NEW(shadow, Width*Height);
(* data rotate 0 *)
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 0003H));
(* write mode 2 *)
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 0205H));
(* set/reset disabled *)
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 0001H));
(* no set/reset *)
SYSTEM.PORTOUT(3CEH, SYSTEM.VAL(INTEGER, 0000H));
(* map mask enable all planes *)
SYSTEM.PORTOUT(3C4H, SYSTEM.VAL(INTEGER, 0F02H));
InitPalette
END Init;
BEGIN
Init; Install
END DisplayVGA4.
(*
to do:
1 fix for Mach64
1 remove shadow (read from real display)
1 offscreen
*)