Color Utilities for app_server and general use added to build

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2491 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/ColorUtils.cc

@@ -0,0 +1,210 @@
+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		ColorUtils.cc
+//	Author:			DarkWyrm <bpmagic@columbus.rr.com>
+//	Description:	Miscellaneous useful functions for working with colors
+//					
+//  
+//------------------------------------------------------------------------------
+#include "ColorUtils.h"
+#include <stdlib.h>
+
+/*!
+	\brief An approximation of 31/255, which is needed for converting from 32-bit
+		colors to 16-bit.
+*/
+#define RATIO_32_TO_16_BIT .121568627451
+
+/*!
+	\brief An approximation of 255/31, which is needed for converting from 16-bit
+		colors to 32-bit.
+*/
+#define RATIO_16_TO_32_BIT 8.225806451613
+
+/*!
+	\brief Function for easy assignment of values to rgb_color objects
+	\param Pointer to an rgb_color
+	\param red value
+	\param green value
+	\param blue value
+	\param alpha value, defaults to 255
+	
+	This function will do nothing if given a NULL color pointer.
+*/
+void SetRGBColor(rgb_color *col,uint8 r, uint8 g, uint8 b, uint8 a)
+{
+	if(col)
+	{
+		col->red=r;
+		col->green=g;
+		col->blue=b;
+		col->alpha=a;
+	}
+}
+
+/*!
+	\brief Function for easy conversion of 16-bit colors to 32-bit
+	\param Pointer to an rgb_color.
+	\param RGBA16 color
+	
+	This function will do nothing if passed a NULL 32-bit color.
+*/
+void SetRGBColor(rgb_color *col,uint16 color)
+{
+	if(!col)
+		return;
+	
+	uint16 r16,g16,b16;
+	
+	// alpha's the easy part
+	col->alpha=(color & 0x8000)?255:0;
+
+	r16= (color >> 15) & 31;
+	g16= (color >> 10) & 31;
+	b16= color & 31;
+
+	col->red=uint8(r16 * RATIO_16_TO_32_BIT);
+	col->green=uint8(g16 * RATIO_16_TO_32_BIT);
+	col->blue=uint8(b16 * RATIO_16_TO_32_BIT);
+}
+
+/*!
+	\brief Finds the index of the closest matching color in a rgb_color palette array
+	\param Array of 256 rgb_color objects
+	\param Color to match
+	\return Index of the closest matching color
+	
+	Note that passing a NULL palette will always return 0 and passing an array of less
+	than 256 rgb_colors will cause a crash.
+*/
+uint8 FindClosestColor(rgb_color *palette, rgb_color color)
+{
+	if(!palette)
+		return 0;
+	
+	uint16 cindex=0,cdelta=765,delta=765;
+	rgb_color *c;
+	
+	for(uint16 i=0;i<256;i++)
+	{
+		c=&(palette[i]);
+		delta=abs(c->red-color.red)+abs(c->green-color.green)+
+			abs(c->blue-color.blue);
+
+		if(delta==0)
+		{
+			cindex=i;
+			break;
+		}
+
+		if(delta<cdelta)
+		{
+			cindex=i;
+			cdelta=delta;
+		}
+	}
+
+	return (uint8)cindex;
+}
+
+/*!
+	\brief Constructs a RGBA15 color which best matches a given 32-bit color
+	\param Color to match
+	\return The closest matching color's value
+	
+	Format is ARGB, 1:5:5:5
+*/
+uint16 FindClosestColor16(rgb_color color)
+{
+	uint16 r16,g16,b16;
+	uint16 color16;
+	
+	r16=uint16(color.red * RATIO_32_TO_16_BIT);
+	g16=uint16(color.green * RATIO_32_TO_16_BIT);
+	b16=uint16(color.blue * RATIO_32_TO_16_BIT);
+
+	// start with alpha value
+	color16=(color.alpha>127)?0x8000:0;
+
+	color16 |= r16 << 15;
+	color16 |= g16 << 10;
+	color16 |= b16;
+
+	return color16;
+}
+
+// Function which could be used to . Position is
+//  Any number outside
+// this range will cause the function to fail and return the color (0,0,0,0)
+// Alpha components are included in the calculations. 0 yields color #1
+// and 1 yields color #2.
+
+/*!
+	\brief Function mostly for calculating gradient colors
+	\param Start color
+	\param End color
+	\param A floating point number such that 0.0 <= position <= 1.0. 0.0 results in the
+		start color and 1.0 results in the end color.
+	\return The blended color. If an invalid position was given, {0,0,0,0} is returned.
+*/
+rgb_color MakeBlendColor(rgb_color col, rgb_color col2, float position)
+{
+	rgb_color newcol={0,0,0,0};
+	float mod=0;
+	int16 delta;
+	if(position<0 || position>1)
+		return newcol;
+
+	delta=int16(col2.red)-int16(col.red);
+	mod=col.red + (position * delta);
+	newcol.red=uint8(mod);
+	if(mod>255 )
+		newcol.red=255;
+	if(mod<0 )
+		newcol.red=0;
+
+	delta=int16(col2.green)-int16(col.green);
+	mod=col.green + (position * delta);
+	newcol.green=uint8(mod);
+	if(mod>255 )
+		newcol.green=255;
+	if(mod<0 )
+		newcol.green=0;
+
+	delta=int16(col2.blue)-int16(col.blue);
+	mod=col.blue + (position * delta);
+	newcol.blue=uint8(mod);
+	if(mod>255 )
+		newcol.blue=255;
+	if(mod<0 )
+		newcol.blue=0;
+
+	delta=int8(col2.alpha)-int8(col.alpha);
+	mod=col.alpha + (position * delta);
+	newcol.alpha=uint8(mod);
+	if(mod>255 )
+		newcol.alpha=255;
+	if(mod<0 )
+		newcol.alpha=0;
+
+	return newcol;
+}

src/kits/interface/interface.src

@@ -4,6 +4,7 @@ INTERFACE_KIT_SOURCE =
 	Box.cpp
 	Button.cpp
 	CheckBox.cpp
+	ColorUtils.cc
 	Control.cpp
 	Deskbar.cpp
 	Font.cpp