ImagerStd24BitDisplayImpl.mesa
Copyright © 1984 by Xerox Corporation. All rights reserved.
Frank Crow, July 30, 1984 5:50:05 pm PDT
DIRECTORY
Imager USING [Error, Context],
ImagerBasic USING [DeviceRectangle, Color, ColorRep],
ImagerDisplay USING [DisplayClass, DisplayClassRep, DisplayData, CreateImagerClass],
ImagerStdColorDisplay USING [SetUpMapProc, CachedColorProc, Create, ApplyMask,
PinPixelMap, ReleasePixelMap, LoadColorMap, DoUnderLock,
ColorMapData, LoadColorProc],
ImagerManhattan USING [Polygon],
ImagerMasks USING [Mask],
ImagerPrivate USING [Class, RegisterDevice],
ImagerPixelMapsExtras USING[MergeMaps],
ColorModels USING [Calibration],
ConstantColors USING [ColorToRGB],
Terminal USING [ColorMode, Current, SetRedMap, SetGreenMap, SetBlueMap, Virtual],
Atom USING [GetPropFromList],
Real USING [FixC],
RealFns USING [Power];
ImagerStd24BitDisplayImpl:
CEDAR
MONITOR
IMPORTS Imager, ImagerDisplay, ImagerPrivate, ConstantColors, Terminal, Real, RealFns, Atom,
ImagerStdColorDisplay, ImagerPixelMapsExtras
~ BEGIN
This implements an 24-bit-per-pixel color display with no antialiasing.
DisplayClass: TYPE ~ ImagerDisplay.DisplayClass;
DisplayClassRep: TYPE ~ ImagerDisplay.DisplayClassRep;
DisplayData: TYPE ~ ImagerDisplay.DisplayData;
Color:
TYPE ~ ImagerBasic.Color;
ColorRep: TYPE ~ ImagerBasic.ColorRep;
ConstantColor: TYPE = REF ColorRep.constant;
Mask:
TYPE ~ ImagerMasks.Mask;
on: BOOLEAN ~ TRUE;
off: BOOLEAN ~ FALSE;
bitsPerPixel: NAT ~ 24; -- truncated value, ImagerStdColorDisplayImpl expects this
vt: Terminal.Virtual;
mode: Terminal.ColorMode ~ [full: TRUE, bitsPerPixelChannelA: 8, bitsPerPixelChannelB: 8];
std24BitDisplayClass: ImagerDisplay.DisplayClass ~
NEW[ImagerDisplay.DisplayClassRep ← [
displayType: $Std24bpp,
viewUnitsPerPixel: 1,
Create: Create,
ApplyMask: ApplyMask,
DoUnderLock: ImagerStdColorDisplay.DoUnderLock
]];
ColorDisplayError: PUBLIC ERROR [reason: ATOM] ~ CODE;
Create:
PROC [displayClass: DisplayClass, creationData:
REF]
RETURNS [displayData: DisplayData] ~ {
displayData ← ImagerStdColorDisplay.Create[
vt, mode, displayClass, creationData, bitsPerPixel, SetUpColorMap];
};
ApplyMask: PROC [displayData: DisplayData, color: Color, mask: Mask,
sTranslate, fTranslate:
INTEGER] ~ {
ImagerStdColorDisplay.ApplyMask[displayData, color, mask, sTranslate, fTranslate, CacheColor];
};
SpecialOp:
PROC[context: Imager.Context, op:
ATOM, data:
REF]
RETURNS[
REF] ~ {
SELECT op
FROM
$DisplayContext => {
-- Pin a pixel map to the color display, replace what was there before.
ImagerStdColorDisplay.PinPixelMap[vt, NARROW[context.data, ImagerDisplay.DisplayData],
mode ];
};
$UnDisplayContext => ImagerStdColorDisplay.ReleasePixelMap[vt,
NARROW[context.data, ImagerDisplay.DisplayData]];
$LoadColorMap => ImagerStdColorDisplay.LoadColorMap[vt, data,
NARROW[context.data, ImagerDisplay.DisplayData],
LoadColor ];
$MergeRGMaps => MergeRGMaps[NARROW[context.data, ImagerDisplay.DisplayData]];
ENDCASE => Imager.Error[$UnimplementedSpecialOp];
RETURN[ NIL ];
};
MergeRGMaps:
PROC[displayData: ImagerDisplay.DisplayData] ~ {
ImagerPixelMapsExtras.MergeMaps[displayData[0], displayData[1], 8, 8];
};
LoadColor: ImagerStdColorDisplay.LoadColorProc ~ {
PROC [ color: ConstantColor, colorCalibration: ColorModels.Calibration, mapEntry: [0..1024) ]
r, g, b: REAL;
mr, mg, mb: [0..256);
IF mapEntry < 256
THEN {
[r, g, b] ← ConstantColors.ColorToRGB[color, colorCalibration];
r ← MIN[1.0, MAX[0.0, r]]; g ← MIN[1.0, MAX[0.0, g]]; b ← MIN[1.0, MAX[0.0, b]];
mr ← Real.FixC[255.0 * RealFns.Power[r, .43]];
mg ← Real.FixC[255.0 * RealFns.Power[g, .43]];
mb ← Real.FixC[255.0 * RealFns.Power[b, .43]];
vt.SetRedMap[mapEntry, mr];
vt.SetGreenMap[mapEntry, mg];
vt.SetBlueMap[mapEntry, mb];
};
};
SetUpColorMap: ImagerStdColorDisplay.SetUpMapProc ~ {
PROC[displayData: DisplayData]
IF Atom.GetPropFromList[displayData.props, $PixelMapStatus] = $Displayed
THEN
FOR i:
NAT
IN [0..256)
DO
j: NAT ← Real.FixC[RealFns.Power[i/256.0, .43] * 256.0]; -- Linearize power law display
vt.SetRedMap[i, j];
vt.SetGreenMap[i, j];
vt.SetBlueMap[i, j];
ENDLOOP;
};
CacheColor: ImagerStdColorDisplay.CachedColorProc ~ {
PROC [displayData: DisplayData, color: Color]
Convert color to RGB and cache merged RG value plus blue for subsequent writes
colorData: REF ImagerStdColorDisplay.ColorMapData ← NARROW[displayData.cachedColorData];
WITH color
SELECT
FROM
constantColor: ConstantColor => {
r, g, b: REAL;
nr, ng, nb: CARDINAL;
[r, g, b] ← ConstantColors.ColorToRGB[constantColor, colorData.colorCalibration];
r ← MIN[1.0, MAX[0.0, r]]; g ← MIN[1.0, MAX[0.0, g]]; b ← MIN[1.0, MAX[0.0, b]];
nr ← Real.FixC[255.0 * r]; ng ← Real.FixC[255.0 * g]; nb ← Real.FixC[255.0 * b];
displayData.cachedColor ← color;
colorData.pixelValueList ← LIST[ nr * 256 + ng, nb];
};
ENDCASE => Imager.Error[$UnsupportedColorType];
};
Init:
PROC[] ~ {
std24BitImagerClass: ImagerPrivate.Class ~ ImagerDisplay.CreateImagerClass[std24BitDisplayClass]; -- pick up Imager class record
std24BitImagerClass.SpecialOp ← SpecialOp; -- modify procedure bindings
ImagerPrivate.RegisterDevice[std24BitImagerClass]; -- register device class
vt ← Terminal.Current[];
};
END.