mirror of
https://github.com/elliotnunn/sys7.1-doc-wip.git
synced 2024-06-01 04:41:39 +00:00
345 lines
7.8 KiB
OpenEdge ABL
345 lines
7.8 KiB
OpenEdge ABL
{
|
|
File: ColorConvert.p
|
|
|
|
Copyright: © 1987-1991 by Apple Computer, Inc., all rights reserved.
|
|
|
|
Change History (most recent first):
|
|
|
|
<3> 5/21/91 gbm Stop using the "empty" units (MemTypes, etc...)
|
|
<2> 12/28/89 dba got rid of obsolete compile-time options (options are controlled
|
|
by the Makefile)
|
|
<1.1> 7/24/89 CSD FOR 6.0.4: Forcing submission to upgrade to the 32-Bit QuickDraw
|
|
Color Picker.
|
|
|
|
To Do:
|
|
}
|
|
|
|
UNIT ColorConvert;
|
|
|
|
INTERFACE
|
|
|
|
USES
|
|
Types, QuickDraw, ToolUtils, FixMath;
|
|
|
|
CONST
|
|
MaxSmallFract = $0000FFFF; {Maximum small fract value, as LONGINT}
|
|
|
|
TYPE
|
|
{A SmallFract value is just the fractional part of a Fixed number,
|
|
which is the low order word. SmallFracts are used to save room,
|
|
and to be compatible with Quickdraw's RGBColor. They can be
|
|
assigned directly to and from INTEGERs.}
|
|
|
|
SmallFract = INTEGER; {Unsigned fraction between 0 and 1}
|
|
|
|
{For developmental simplicity in switching between the HLS and HSV
|
|
models, HLS is reordered into HSL. Thus both models start with
|
|
hue and saturation values; value/lightness/brightness is last.}
|
|
|
|
HSVColor = RECORD
|
|
hue: SmallFract; {Fraction of circle, red at 0}
|
|
saturation: SmallFract; {0-1, 0 for gray, 1 for pure color}
|
|
value: SmallFract; {0-1, 0 for black, 1 for max intensity}
|
|
END;
|
|
HSLColor = RECORD
|
|
hue: SmallFract; {Fraction of circle, red at 0}
|
|
saturation: SmallFract; {0-1, 0 for gray, 1 for pure color}
|
|
lightness: SmallFract; {0-1, 0 for black, 1 for white}
|
|
END;
|
|
CMYColor = RECORD
|
|
cyan: SmallFract;
|
|
magenta: SmallFract;
|
|
yellow: SmallFract;
|
|
END;
|
|
|
|
FUNCTION Max(a, b: Fixed): Fixed;
|
|
FUNCTION Min(a, b: Fixed): Fixed;
|
|
FUNCTION Fix2SmallFract(f: Fixed): SmallFract;
|
|
FUNCTION SmallFract2Fix(s: SmallFract): Fixed;
|
|
PROCEDURE CMY2RGB(cColor: CMYColor; VAR rColor: RGBColor);
|
|
PROCEDURE RGB2CMY(rColor: RGBColor; VAR cColor: CMYColor);
|
|
PROCEDURE HSL2RGB(hColor: HSLColor; VAR rColor: RGBColor);
|
|
PROCEDURE RGB2HSL(rColor: RGBColor; VAR hColor: HSLColor);
|
|
PROCEDURE HSV2RGB(hColor: HSVColor; VAR rColor: RGBColor);
|
|
PROCEDURE RGB2HSV(rColor: RGBColor; VAR hColor: HSVColor);
|
|
|
|
IMPLEMENTATION
|
|
|
|
FUNCTION Max(a, b: Fixed): Fixed;
|
|
BEGIN
|
|
IF a > b
|
|
THEN Max := a
|
|
ELSE Max := b;
|
|
END;
|
|
|
|
FUNCTION Min(a, b: Fixed): Fixed;
|
|
BEGIN
|
|
IF a < b
|
|
THEN Min := a
|
|
ELSE Min := b;
|
|
END;
|
|
|
|
FUNCTION Fix2SmallFract(f: Fixed): SmallFract;
|
|
BEGIN
|
|
IF f > MaxSmallFract
|
|
THEN Fix2SmallFract := LoWrd(MaxSmallFract)
|
|
ELSE Fix2SmallFract := f;
|
|
END;
|
|
|
|
FUNCTION SmallFract2Fix(s: SmallFract): Fixed;
|
|
BEGIN
|
|
SmallFract2Fix := BAnd(s, MaxSmallFract);
|
|
END;
|
|
|
|
{---------------------------------------------------------------------------------
|
|
CMY Model (cyan, magenta, yellow)
|
|
}
|
|
|
|
FUNCTION Complement(inColor: INTEGER): INTEGER;
|
|
BEGIN
|
|
Complement := Fix2SmallFract(MaxSmallFract - SmallFract2Fix(inColor));
|
|
END;
|
|
|
|
PROCEDURE CMY2RGB(cColor: CMYColor; VAR rColor: RGBColor);
|
|
BEGIN
|
|
WITH cColor, rColor DO
|
|
BEGIN
|
|
red := Complement(cyan);
|
|
green := Complement(magenta);
|
|
blue := Complement(yellow);
|
|
END;
|
|
END;
|
|
|
|
PROCEDURE RGB2CMY(rColor: RGBColor; VAR cColor: CMYColor);
|
|
BEGIN
|
|
WITH cColor, rColor DO
|
|
BEGIN
|
|
cyan := Complement(red);
|
|
magenta := Complement(green);
|
|
yellow := Complement(blue);
|
|
END;
|
|
END;
|
|
|
|
{---------------------------------------------------------------------------------
|
|
HSL Model (hue, saturation, lightness)
|
|
}
|
|
|
|
PROCEDURE HSL2RGB(hColor: HSLColor; VAR rColor: RGBColor);
|
|
VAR
|
|
aThird: Fixed;
|
|
h: Fixed;
|
|
l, s, ls: Fixed;
|
|
m1, m2: Fixed;
|
|
|
|
FUNCTION Value(h: Fixed): SmallFract;
|
|
VAR
|
|
temp: Fixed;
|
|
BEGIN
|
|
IF h >= $00010000 THEN
|
|
h := h - $00010000
|
|
ELSE IF h < 0 THEN
|
|
h := h + $00010000;
|
|
|
|
h := h * 6;
|
|
CASE HiWrd(h) OF
|
|
0: temp := m1 + FixMul(m2 - m1, h);
|
|
1,2: temp := m2;
|
|
3: temp := m1 + FixMul(m2 - m1, $00040000 - h);
|
|
4,5: temp := m1;
|
|
END;
|
|
Value := Fix2SmallFract(temp);
|
|
END;
|
|
|
|
BEGIN
|
|
WITH hColor, rColor DO
|
|
BEGIN
|
|
l := SmallFract2Fix(lightness);
|
|
s := SmallFract2Fix(saturation);
|
|
ls := FixMul(l, s);
|
|
|
|
IF l <= $00008000 {0.5}
|
|
THEN m2 := l + ls
|
|
ELSE m2 := l + s - ls;
|
|
m1 := BSL(l, 1) - m2;
|
|
|
|
IF saturation = 0 THEN {achromatic case; no hue}
|
|
BEGIN
|
|
red := lightness;
|
|
green := lightness;
|
|
blue := lightness;
|
|
END
|
|
ELSE
|
|
BEGIN {chormatic case: there is hue}
|
|
aThird := FixRatio(1, 3);
|
|
h := SmallFract2Fix(hue);
|
|
red := Value(h + aThird);
|
|
green := Value(h);
|
|
blue := Value(h - aThird);
|
|
END;
|
|
END;
|
|
END;
|
|
|
|
PROCEDURE RGB2HSL(rColor: RGBColor; VAR hColor: HSLColor);
|
|
VAR
|
|
cr, cg, cb: Fixed;
|
|
r, g, b: Fixed;
|
|
h: Fixed;
|
|
maxRGB,
|
|
minRGB: Fixed;
|
|
mSum,
|
|
mDiff: Fixed;
|
|
BEGIN
|
|
WITH hColor, rColor DO
|
|
BEGIN
|
|
r := SmallFract2Fix(red);
|
|
g := SmallFract2Fix(green);
|
|
b := SmallFract2Fix(blue);
|
|
|
|
{Determine the lightness.}
|
|
maxRGB := Max(r, Max(g, b));
|
|
minRGB := Min(r, Min(g, b));
|
|
mSum := maxRGB + minRGB;
|
|
mDiff := maxRGB - minRGB;
|
|
|
|
{Average max and min to get lightness.}
|
|
lightness := Fix2SmallFract(BSR(mSum, 1));
|
|
|
|
{Determine the saturation.}
|
|
IF maxRGB = minRGB THEN
|
|
{achromatic case (hue is undefined)}
|
|
saturation := 0
|
|
ELSE
|
|
BEGIN {chromatic case}
|
|
IF SmallFract2Fix(lightness) > $00008000 THEN {0.5}
|
|
mSum := $00020000 - mSum;
|
|
saturation := Fix2SmallFract(FixDiv(mDiff, mSum));
|
|
|
|
{Determine the hue.}
|
|
cr := FixDiv(maxRGB - r, mDiff);
|
|
cg := FixDiv(maxRGB - g, mDiff);
|
|
cb := FixDiv(maxRGB - b, mDiff);
|
|
|
|
IF r = maxRGB THEN
|
|
{between yellow and magenta}
|
|
h := cb - cg
|
|
ELSE IF g = maxRGB THEN
|
|
{between cyan and yellow}
|
|
h := $00020000 + cr - cb
|
|
ELSE
|
|
{between magenta and cyan}
|
|
h := $00040000 + cg - cr;
|
|
|
|
h := h DIV 6;
|
|
IF h < 0 THEN
|
|
h := h + $00010000;
|
|
hue := Fix2SmallFract(h);
|
|
END;
|
|
END;
|
|
END;
|
|
|
|
{---------------------------------------------------------------------------------
|
|
HSV Model (hue, saturation, value)
|
|
}
|
|
|
|
PROCEDURE HSV2RGB(hColor: HSVColor; VAR rColor: RGBColor);
|
|
VAR
|
|
kn, m: INTEGER;
|
|
segment: INTEGER;
|
|
subSeg: Fixed;
|
|
v, vs, vsf: Fixed;
|
|
BEGIN
|
|
WITH hColor, rColor DO
|
|
IF saturation = 0 THEN
|
|
BEGIN {achromatic case: no hue}
|
|
red := value;
|
|
green := value;
|
|
blue := value;
|
|
END
|
|
ELSE
|
|
BEGIN {chromatic case}
|
|
subSeg := SmallFract2Fix(hue) * 6;
|
|
{Get the integer part in segment, and fraction in subSeg.}
|
|
segment := HiWrd(subSeg);
|
|
subSeg := BAnd(subSeg, $0000FFFF);
|
|
|
|
{Compute out Smith's K/N and M as integers.}
|
|
v := SmallFract2Fix(value);
|
|
vs := FixMul(v, SmallFract2Fix(saturation));
|
|
vsf := FixMul(vs, subSeg);
|
|
IF ODD(segment)
|
|
THEN kn := Fix2SmallFract(v - vsf)
|
|
ELSE kn := Fix2SmallFract(v - vs + vsf);
|
|
m := Fix2SmallFract(v - vs);
|
|
|
|
{We have the RGB values, now figure out which is which.}
|
|
CASE segment OF
|
|
0,5: red := value;
|
|
1,4: red := kn;
|
|
2,3: red := m;
|
|
END;
|
|
CASE segment OF
|
|
1,2: green := value;
|
|
0,3: green := kn;
|
|
4,5: green := m;
|
|
END;
|
|
CASE segment OF
|
|
3,4: blue := value;
|
|
2,5: blue := kn;
|
|
0,1: blue := m;
|
|
END;
|
|
END; {end of chromatic case}
|
|
END;
|
|
|
|
PROCEDURE RGB2HSV(rColor: RGBColor; VAR hColor: HSVColor);
|
|
VAR
|
|
cr, cg, cb: Fixed;
|
|
r, g, b: Fixed;
|
|
h: Fixed;
|
|
temp: Fixed;
|
|
v, vt: Fixed;
|
|
BEGIN
|
|
WITH hColor, rColor DO
|
|
BEGIN
|
|
r := SmallFract2Fix(red);
|
|
g := SmallFract2Fix(green);
|
|
b := SmallFract2Fix(blue);
|
|
|
|
v := Max(r, Max(g, b));
|
|
temp := Min(r, Min(g, b));
|
|
vt := v - temp;
|
|
value := Fix2SmallFract(v);
|
|
|
|
IF v = 0
|
|
THEN saturation := 0
|
|
ELSE saturation := Fix2SmallFract(FixDiv(vt, v));
|
|
|
|
{Determine the hue.}
|
|
IF saturation = 0 THEN
|
|
hue := 0
|
|
ELSE
|
|
BEGIN
|
|
cr := FixDiv(v - r, vt);
|
|
cg := FixDiv(v - g, vt);
|
|
cb := FixDiv(v - b, vt);
|
|
|
|
IF r = v THEN
|
|
{between yellow and magenta}
|
|
h := cb - cg
|
|
ELSE IF g = v THEN
|
|
{between cyan and yellow}
|
|
h := $00020000 + cr - cb
|
|
ELSE
|
|
{between magenta and cyan}
|
|
h := $00040000 + cg - cr;
|
|
|
|
h := h DIV 6;
|
|
IF h < 0 THEN
|
|
h := h + $00010000;
|
|
hue := Fix2SmallFract(h);
|
|
END;
|
|
END;
|
|
END;
|
|
|
|
END.
|
|
|