pjs/gfx/src/nsColor.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "plstr.h"
#include "nsColor.h"
#include "nsColorNames.h"
#include "nsString.h"
#include "nscore.h"
#include "nsCoord.h"
#include "nsUnitConversion.h"
#include "nsCOMPtr.h"
#include "nsIServiceManager.h"
#include "nsIScreen.h"
#include "nsIScreenManager.h"
#include <math.h>
#include "prprf.h"
static int ComponentValue(const char* aColorSpec, int aLen, int color, int dpc)
{
int component = 0;
int index = (color * dpc);
if (2 < dpc) {
dpc = 2;
}
while (--dpc >= 0) {
char ch = ((index < aLen) ? aColorSpec[index++] : '0');
if (('0' <= ch) && (ch <= '9')) {
component = (component * 16) + (ch - '0');
} else if ((('a' <= ch) && (ch <= 'f')) ||
(('A' <= ch) && (ch <= 'F'))) {
// "ch&7" handles lower and uppercase hex alphabetics
component = (component * 16) + (ch & 7) + 9;
}
else { // not a hex digit, treat it like 0
component = (component * 16);
}
}
return component;
}
extern "C" NS_GFX_(PRBool) NS_HexToRGB(const nsString& aColorSpec,
nscolor* aResult)
{
// XXXldb nsStackString<10>
NS_LossyConvertUCS2toASCII bufferStr(aColorSpec);
return NS_ASCIIHexToRGB(bufferStr, aResult);
}
extern "C" NS_GFX_(PRBool) NS_ASCIIHexToRGB(const nsCString& aColorSpec,
nscolor* aResult)
{
const char* buffer = aColorSpec.get();
int nameLen = aColorSpec.Length();
if ((nameLen == 3) || (nameLen == 6)) {
// Make sure the digits are legal
for (int i = 0; i < nameLen; i++) {
char ch = buffer[i];
if (((ch >= '0') && (ch <= '9')) ||
((ch >= 'a') && (ch <= 'f')) ||
((ch >= 'A') && (ch <= 'F'))) {
// Legal character
continue;
}
// Whoops. Illegal character.
return PR_FALSE;
}
// Convert the ascii to binary
int dpc = ((3 == nameLen) ? 1 : 2);
// Translate components from hex to binary
int r = ComponentValue(buffer, nameLen, 0, dpc);
int g = ComponentValue(buffer, nameLen, 1, dpc);
int b = ComponentValue(buffer, nameLen, 2, dpc);
if (dpc == 1) {
// Scale single digit component to an 8 bit value. Replicate the
// single digit to compute the new value.
r = (r << 4) | r;
g = (g << 4) | g;
b = (b << 4) | b;
}
NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
if (nsnull != aResult) {
*aResult = NS_RGB(r, g, b);
}
return PR_TRUE;
}
// Improperly formatted color value
return PR_FALSE;
}
// compatible with legacy Nav behavior
extern "C" NS_GFX_(PRBool) NS_LooseHexToRGB(const nsString& aColorSpec, nscolor* aResult)
{
// XXXldb nsStackString<30>
NS_LossyConvertUCS2toASCII buffer(aColorSpec);
int nameLen = buffer.Length();
const char* colorSpec = buffer.get();
if ('#' == colorSpec[0]) {
++colorSpec;
--nameLen;
}
if (3 < nameLen) {
// Convert the ascii to binary
int dpc = (nameLen / 3) + (((nameLen % 3) != 0) ? 1 : 0);
if (4 < dpc) {
dpc = 4;
}
// Translate components from hex to binary
int r = ComponentValue(colorSpec, nameLen, 0, dpc);
int g = ComponentValue(colorSpec, nameLen, 1, dpc);
int b = ComponentValue(colorSpec, nameLen, 2, dpc);
NS_ASSERTION((r >= 0) && (r <= 255), "bad r");
NS_ASSERTION((g >= 0) && (g <= 255), "bad g");
NS_ASSERTION((b >= 0) && (b <= 255), "bad b");
if (nsnull != aResult) {
*aResult = NS_RGB(r, g, b);
}
}
else {
if (nsnull != aResult) {
*aResult = NS_RGB(0, 0, 0);
}
}
return PR_TRUE;
}
extern "C" NS_GFX_(void) NS_RGBToHex(nscolor aColor, nsAString& aResult)
{
char buf[10];
PR_snprintf(buf, sizeof(buf), "#%02x%02x%02x",
NS_GET_R(aColor), NS_GET_G(aColor), NS_GET_B(aColor));
CopyASCIItoUTF16(buf, aResult);
}
extern "C" NS_GFX_(void) NS_RGBToASCIIHex(nscolor aColor,
nsAFlatCString& aResult)
{
aResult.SetLength(7);
char *buf = aResult.BeginWriting();
PR_snprintf(buf, 8, "#%02x%02x%02x",
NS_GET_R(aColor), NS_GET_G(aColor), NS_GET_B(aColor));
}
extern "C" NS_GFX_(PRBool) NS_ColorNameToRGB(const nsAString& aColorName, nscolor* aResult)
{
nsColorName id = nsColorNames::LookupName(aColorName);
if (eColorName_UNKNOWN < id) {
NS_ASSERTION(id < eColorName_COUNT, "LookupName mess up");
if (nsnull != aResult) {
*aResult = nsColorNames::kColors[id];
}
return PR_TRUE;
}
return PR_FALSE;
}
extern "C" NS_GFX_(nscolor) NS_BrightenColor(nscolor inColor)
{
PRIntn r, g, b, max, over;
r = NS_GET_R(inColor);
g = NS_GET_G(inColor);
b = NS_GET_B(inColor);
//10% of max color increase across the board
r += 25;
g += 25;
b += 25;
//figure out which color is largest
if (r > g)
{
if (b > r)
max = b;
else
max = r;
}
else
{
if (b > g)
max = b;
else
max = g;
}
//if we overflowed on this max color, increase
//other components by the overflow amount
if (max > 255)
{
over = max - 255;
if (max == r)
{
g += over;
b += over;
}
else if (max == g)
{
r += over;
b += over;
}
else
{
r += over;
g += over;
}
}
//clamp
if (r > 255)
r = 255;
if (g > 255)
g = 255;
if (b > 255)
b = 255;
return NS_RGBA(r, g, b, NS_GET_A(inColor));
}
extern "C" NS_GFX_(nscolor) NS_DarkenColor(nscolor inColor)
{
PRIntn r, g, b, max;
r = NS_GET_R(inColor);
g = NS_GET_G(inColor);
b = NS_GET_B(inColor);
//10% of max color decrease across the board
r -= 25;
g -= 25;
b -= 25;
//figure out which color is largest
if (r > g)
{
if (b > r)
max = b;
else
max = r;
}
else
{
if (b > g)
max = b;
else
max = g;
}
//if we underflowed on this max color, decrease
//other components by the underflow amount
if (max < 0)
{
if (max == r)
{
g += max;
b += max;
}
else if (max == g)
{
r += max;
b += max;
}
else
{
r += max;
g += max;
}
}
//clamp
if (r < 0)
r = 0;
if (g < 0)
g = 0;
if (b < 0)
b = 0;
return NS_RGBA(r, g, b, NS_GET_A(inColor));
}
extern "C" NS_GFX_(nscolor)
NS_ComposeColors(nscolor aBG, nscolor aFG)
{
PRIntn bgAlpha = NS_GET_A(aBG);
PRIntn r, g, b, a;
// First compute what we get drawing aBG onto RGBA(0,0,0,0)
MOZ_BLEND(r, 0, NS_GET_R(aBG), bgAlpha);
MOZ_BLEND(g, 0, NS_GET_G(aBG), bgAlpha);
MOZ_BLEND(b, 0, NS_GET_B(aBG), bgAlpha);
a = bgAlpha;
// Now draw aFG on top of that
PRIntn fgAlpha = NS_GET_A(aFG);
MOZ_BLEND(r, r, NS_GET_R(aFG), fgAlpha);
MOZ_BLEND(g, g, NS_GET_G(aFG), fgAlpha);
MOZ_BLEND(b, b, NS_GET_B(aFG), fgAlpha);
MOZ_BLEND(a, a, 255, fgAlpha);
return NS_RGBA(r, g, b, a);
}
// Functions to convert from HSL color space to RGB color space.
// This is the algorithm described in the CSS3 specification
// helper
static float
HSL_HueToRGB(float m1, float m2, float h)
{
if (h < 0.0f)
h += 1.0f;
if (h > 1.0f)
h -= 1.0f;
if (h < (float)(1.0/6.0))
return m1 + (m2 - m1)*h*6.0f;
if (h < (float)(1.0/2.0))
return m2;
if (h < (float)(2.0/3.0))
return m1 + (m2 - m1)*((float)(2.0/3.0) - h)*6.0f;
return m1;
}
// The float parameters are all expected to be in the range 0-1
extern "C" NS_GFX_(nscolor)
NS_HSL2RGB(float h, float s, float l)
{
PRUint8 r, g, b;
float m1, m2;
if (l <= 0.5f) {
m2 = l*(s+1);
} else {
m2 = l + s - l*s;
}
m1 = l*2 - m2;
r = PRUint8(255 * HSL_HueToRGB(m1, m2, h + 1.0f/3.0f));
g = PRUint8(255 * HSL_HueToRGB(m1, m2, h));
b = PRUint8(255 * HSL_HueToRGB(m1, m2, h - 1.0f/3.0f));
return NS_RGB(r, g, b);
}