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Tweak to FindClosestColor

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git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8853 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
DarkWyrm 2004-09-05 00:46:37 +00:00
parent d5a48f5dcf
commit 3713534518
2 changed files with 39 additions and 16 deletions
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2
headers/os/interface/ColorUtils.h
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@ -35,7 +35,7 @@ void SetRGBColor15(rgb_color *col,uint16 color);
void SetRGBColor16(rgb_color *col,uint16 color);
void SetRGBColor(rgb_color *col,uint32 color);
uint8 FindClosestColor(rgb_color *palette, rgb_color color);
uint8 FindClosestColor(const rgb_color *palette, rgb_color color);
uint16 FindClosestColor15(rgb_color color);
uint16 FindClosestColor16(rgb_color color);

53
src/kits/interface/ColorUtils.cc
View File

@ -26,6 +26,30 @@
#include "ColorUtils.h"
#include <stdlib.h>
/*!
\brief An approximation of 31/255, which is needed for converting from 32-bit
colors to 16-bit and 15-bit.
*/
#define RATIO_8_TO_5_BIT .121568627451
/*!
\brief An approximation of 63/255, which is needed for converting from 32-bit
colors to 16-bit.
*/
#define RATIO_8_TO_6_BIT .247058823529
/*!
\brief An approximation of 255/31, which is needed for converting from 16-bit
and 15-bit colors to 32-bit.
*/
#define RATIO_5_TO_8_BIT 8.22580645161
/*!
\brief An approximation of 255/63, which is needed for converting from 16-bit
colors to 32-bit.
*/
#define RATIO_6_TO_8_BIT 4.04761904762
/*!
\brief Function for easy assignment of values to rgb_color objects
\param col Pointer to an rgb_color
@ -68,9 +92,9 @@ void SetRGBColor15(rgb_color *col,uint16 color)
g16= (color >> 5) & 31;
b16= color & 31;
col->red=uint8(r16 << 3);
col->green=uint8(g16 << 3);
col->blue=uint8(b16 << 3);
col->red=uint8(r16 * RATIO_5_TO_8_BIT);
col->green=uint8(g16 * RATIO_5_TO_8_BIT);
col->blue=uint8(b16 * RATIO_5_TO_8_BIT);
}
/*!
@ -94,9 +118,9 @@ void SetRGBColor16(rgb_color *col,uint16 color)
g16= (color >> 5) & 63;
b16= color & 31;
col->red=uint8(r16 << 3);
col->green=uint8(g16 << 2);
col->blue=uint8(b16 << 3);
col->red=uint8(r16 * RATIO_5_TO_8_BIT);
col->green=uint8(g16 * RATIO_6_TO_8_BIT);
col->blue=uint8(b16 * RATIO_5_TO_8_BIT);
}
/*!
@ -127,17 +151,16 @@ void SetRGBColor(rgb_color *col,uint32 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)
uint8 FindClosestColor(const 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]);
const rgb_color *c=&(palette[i]);
delta=abs(c->red-color.red)+abs(c->green-color.green)+
abs(c->blue-color.blue);
@ -169,9 +192,9 @@ uint16 FindClosestColor15(rgb_color color)
uint16 r16,g16,b16;
uint16 color16=0;
r16=uint16(color.red >> 3);
g16=uint16(color.green >> 3);
b16=uint16(color.blue >> 3);
r16=uint16(color.red * RATIO_8_TO_5_BIT);
g16=uint16(color.green * RATIO_8_TO_5_BIT);
b16=uint16(color.blue * RATIO_8_TO_5_BIT);
// start with alpha value
color16=(color.alpha>127)?0x8000:0;
@ -195,9 +218,9 @@ uint16 FindClosestColor16(rgb_color color)
uint16 r16,g16,b16;
uint16 color16=0;
r16=uint16(color.red >> 3);
g16=uint16(color.green >> 2);
b16=uint16(color.blue >> 3);
r16=uint16(color.red * RATIO_8_TO_5_BIT);
g16=uint16(color.green * RATIO_8_TO_6_BIT);
b16=uint16(color.blue * RATIO_8_TO_5_BIT);
color16 |= r16 << 11;
color16 |= g16 << 5;