-- CGAISImageImpl.mesa
-- Last changed by Doug Wyatt, October 4, 1982 11:35 am
-- Last changed by Paul Rovner, August 10, 1983 11:34 am
DIRECTORY
Basics
USING [LongDiv, LongMult],
CGAIS
USING [
APH, Header, password, RasterPart,
UCA, UCACodingType],
CGArea
USING [Empty, Ref],
CGContext
USING [GenBox, Rep],
CGDevice
USING [Ref],
CGMatrix
USING [Assign, Concat, ConcatTransformation, Make, New, Ref, SetTrans],
CGPrivate
USING [Context],
CGSource
USING [Ref, Rep],
CGStorage
USING [qZone],
GraphicsOps
USING [],
-- exports only
GraphicsBasic
USING [black],
FS
USING [Open, OpenFile, Read],
PrincOps
USING [wordsPerPage],
Rope
USING [
ROPE],
VM
USING [Interval, Free, Allocate, AddressForPageNumber];
CGAISImageImpl:
CEDAR
MONITOR
IMPORTS Basics, CGArea, CGContext, CGMatrix, CGStorage, FS,
VM
EXPORTS CGPrivate, GraphicsOps, GraphicsBasic = {
OPEN
AIS:
CGAIS;
Context:
TYPE = CGPrivate.Context;
ContextData:
TYPE =
REF ContextDataRep;
ContextDataRep:
PUBLIC
TYPE = CGContext.Rep;
ImageObject:
PUBLIC
TYPE = DataRep;
-- export to GraphicsBasic
-- This is cheating!
-- A new representation-independent Image interface is neeeded.
-- But for now, this module exports NewAisImage and ImageBox
-- directly into GraphicsOps.
Data:
TYPE =
REF DataRep;
DataRep:
TYPE =
RECORD [
file: FS.OpenFile,
-- the AIS file
rasterBase: INT,
-- where the raster begins
rasterPages: INT,
-- number of pages in the raster
scanDirection:
CARDINAL,
-- scan direction code
scanCount:
CARDINAL,
-- number of scan lines in raster
scanLength:
CARDINAL,
-- pixels per scan line
wordsPerLine:
CARDINAL,
-- words per scan line
miv: CGMatrix.Ref,
-- image-to-virtual matrix
matrix: CGMatrix.Ref,
-- image-to-device matrix
src: CGSource.Ref
-- source info for image
];
dataZone:
ZONE = CGStorage.qZone;
srcZone:
ZONE = CGStorage.qZone;
repZone:
ZONE = CGStorage.qZone;
MalformedFile:
ERROR =
CODE;
NotImplemented:
ERROR =
CODE;
-- Monitored data: cache most recently mapped space
cachedFile:
FS.OpenFile ← [
NIL];
cachedSpace: VM.Interval ← [0, 0];
-- end monitored data
NewAisImage:
PUBLIC
PROC[name: Rope.
ROPE]
RETURNS[Data] = {
RETURN[NewAisImageFromCapability[FS.Open[name]]];
};
NewAisImageFromCapability:
PUBLIC
PROC[file: FS.OpenFile]
RETURNS[Data] =
TRUSTED {
lp:
LONG
POINTER;
header:
LONG
POINTER
TO
AIS.Header ←
NIL;
part:
LONG
POINTER
TO
AIS.
APH ←
NIL;
rp:
LONG
POINTER
TO
AIS.RasterPart ←
NIL;
up:
LONG
POINTER
TO
AIS.
UCA ←
NIL;
lines,pixels,wpl,bps:
CARDINAL;
rbase, apages, rpages:
CARDINAL;
rwords:
LONG
CARDINAL;
self: Data ←
NIL;
space: VM.Interval ← VM.Allocate[count: 4];
-- for reading header
{
ENABLE
UNWIND => VM.Free[space];
header ← lp ← VM.AddressForPageNumber[space.page];
FS.Read[file: file, from: 0, nPages: 4, to: lp];
IF header.password=
AIS.password
THEN
part ←
LOOPHOLE[header+
SIZE[
AIS.Header]]
ELSE
ERROR MalformedFile;
-- Wrong password
apages ← header.attributeLength/PrincOps.wordsPerPage;
rbase ← 1+apages;
IF part.type=raster
THEN {
rp ←
LOOPHOLE[part]; part ← part+part.length }
ELSE
ERROR MalformedFile;
-- Raster part missing
IF rp.samplesPerPixel=1
THEN
NULL
ELSE
ERROR NotImplemented;
-- Can't handle multiple samples per pixel
IF rp.codingType=
AIS.UCACodingType
THEN
up ←
LOOPHOLE[rp+
SIZE[
AIS.RasterPart]]
ELSE
ERROR NotImplemented;
-- Coding type not UCA
IF up.scanLinesPerBlock=
LAST[
CARDINAL]
THEN
NULL
ELSE
ERROR NotImplemented;
-- Can't handle blocked encoding yet
lines ← rp.scanCount;
pixels ← rp.scanLength;
wpl ← up.wordsPerScanLine;
bps ← up.bitsPerSample;
rwords ← Basics.LongMult[lines, wpl];
-- number of words in raster part
rpages ← Basics.LongDiv[rwords+(PrincOps.wordsPerPage-1), PrincOps.wordsPerPage];
-- number of pages needed
self ← dataZone.
NEW[DataRep ← [file: file, rasterBase: rbase, rasterPages: rpages,
scanDirection: rp.scanDirection, scanCount: lines, scanLength: pixels, wordsPerLine: wpl,
miv:
NIL, matrix:
NIL, src:
NIL]];
SELECT self.scanDirection
FROM
2 => self.miv ← CGMatrix.Make[[1,0,0,1,0,0]];
3 => self.miv ← CGMatrix.Make[[1,0,0,-1,0,lines]];
8 => self.miv ← CGMatrix.Make[[0,1,1,0,0,0]];
ENDCASE =>
ERROR;
-- unexpected scanDirection
self.matrix ← CGMatrix.New[];
-- placeholder for image-to-device mapping
self.src ← srcZone.
NEW[CGSource.Rep ← [type: array, mode: opaque,
fat:
FALSE, bps: bps, color: GraphicsBasic.black, xbase:
NIL, xrast: wpl, Get:
NIL]];
};
VM.Free[space];
RETURN[self];
};
DrawImage:
PUBLIC
PROC[self: Context, image: Data, raw:
BOOLEAN] = {
ctx: ContextData ←
NARROW[self.data];
data: Data ← image;
T: CGMatrix.Ref ← ctx.matrix;
-- virtual to destination mapping
M: CGMatrix.Ref ← data.matrix;
-- image to destination mapping
src: CGSource.Ref ← data.src;
wpl:
CARDINAL ← data.wordsPerLine;
device: CGDevice.Ref ← ctx.device;
DrawImageEntry:
ENTRY
PROC =
TRUSTED {
ENABLE
UNWIND => cachedFile ← [
NIL];
-- and release lock
file: FS.OpenFile ← data.file;
base:
INT ← data.rasterBase;
pages:
INT ← data.rasterPages;
space: VM.Interval ← cachedSpace;
area: CGArea.Ref;
IF cachedFile#file
THEN { create:
BOOLEAN ←
FALSE;
-- first ensure a large enough space
IF space=[0, 0]
THEN create ←
TRUE
ELSE
IF space.count<pages
THEN {
VM.Free[space]; cachedSpace ← [0, 0]; create ←
TRUE;
};
IF create
THEN space ← VM.Allocate[count: pages];
-- now map the space onto the new file
FS.Read[
file: file, from: base, nPages: space.count, to: VM.AddressForPageNumber[space.page]];
cachedFile ← file; cachedSpace ← space;
};
src.xbase ← VM.AddressForPageNumber[space.page];
area ← CGContext.GenBox[ctx,
[xmin: 1, ymin: 1, xmax: data.scanLength-1, ymax: data.scanCount-1],
M];
IF
NOT CGArea.Empty[area]
THEN device.Show[device, area, src,
M ];
};
CGMatrix.Assign[
M,
T];
CGMatrix.SetTrans[
M,ctx.cp];
-- translate to current position
IF
NOT ctx.yUp
THEN CGMatrix.Concat[
M,1,0,0,-1];
CGMatrix.ConcatTransformation[
M, data.miv.m];
-- M ← miv * T
src.color ← ctx.src.color; src.mode ← ctx.src.mode; src.raw ← raw;
DrawImageEntry[];
};
ImageBox:
PUBLIC
PROC[image: Data]
RETURNS[xmin,ymin,xmax,ymax:
REAL] = {
w:
REAL ← image.scanLength;
h:
REAL ← image.scanCount;
SELECT image.scanDirection
FROM
2,3 =>
RETURN[0,0,w,h];
8 =>
RETURN[0,0,h,w];
ENDCASE =>
ERROR;
-- Unexpected scanDirection;
};
}.