supermario/base/SuperMarioProj.1994-02-09/QuickDraw/PictUtilities/puMedian.c
2019-06-29 23:17:50 +08:00

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/*
File: puMedian.c
Contains: This is the median color finding algorithm for the picture utilities package.
Written by: Dave Good. Some ideas stolen from Konstantin Othmer and Bruce Leak. Algorithm by Keith McGreggor.
Copyright: © 1990 by Apple Computer, Inc., all rights reserved.
This file is used in these builds: BigBang
Change History (most recent first):
<11> 2/6/91 SMC DDG,#81681: Removed un-uncommented code in box splitting
routine, since it is never executed (or necessary).
<10> 2/4/91 SMC KON,#81681: Un-uncommented code in box splitting routine to
deal with a box filled with more than copy of the same color.
<9> 2/4/91 SMC KON,#81589: Fixed the median box splitting code. It didn't
seem to want to break a box on the blue axis.
<8> 12/17/90 KON <with DDG> Made the median color algorithm return better results
by splitting the box with the largest spread, instead of
splitting every box that we find.
<7> 9/21/90 DDG Made changes from code review. Fixed a possible stack overflow
problem, by allocating the boxInfo array as a buffer, instead of
a stack array. Minor changes to reflect the new interface to the
buffering routines.
<6> 8/16/90 DDG Cleaned up the comments.
<5> 8/5/90 DDG Added a parameter to the RecordMedianColors routine. This
routine should still never be called.
<4> 7/31/90 DDG Fixed a bug in the RecordMedianColors routine. Note that this
routine should never be called, but better safe than sorry.
<3> 7/30/90 DDG Added init, record, and kill routines to support the generic
colorPickMethod model. Also fixed a few bugs.
<2> 7/29/90 DDG Fixed header.
<1> 7/29/90 DDG First checked in using new structure.
To Do:
*/
/*----------------------------------------------------------------------------------------------------------*/
/*
| Includes
*/
#include "puPrivate.h"
/*----------------------------------------------------------------------------------------------------------*/
/*
| Private Defines
*/
#define noBoxToSplit -1
/*----------------------------------------------------------------------------------------------------------*/
/*
| Private Data Structures
*/
typedef struct BoxInfo
{
unsigned short count;
unsigned short minRed;
unsigned short maxRed;
unsigned short minGreen;
unsigned short maxGreen;
unsigned short minBlue;
unsigned short maxBlue;
unsigned long totalRed;
unsigned long totalGreen;
unsigned long totalBlue;
unsigned long padding1;
unsigned short padding2;
} BoxInfo;
typedef struct RangeInfo
{
unsigned short spread;
unsigned short start;
unsigned short end;
unsigned short step;
} RangeInfo;
/*----------------------------------------------------------------------------------------------------------*/
/*
| Private Function Declarations
*/
void SplitBox( BoxInfo *, short *, short, short );
void FillMedianTable( BoxInfo *, ColorSpec *, short );
/*----------------------------------------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------------------------------------*/
/************************************************************************************************************/
/**** Functions Follow ****/
/************************************************************************************************************/
/*----------------------------------------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------------------------------------*/
/*
| This routine is called to initialize the median method. It doesnt really do anything, except tell
| the main picture utilities package that it should store the colors in the ExactAnd555 format.
*/
pascal OSErr InitMedianMethod(
short colorsRequested,
long *dataHandlePtr,
short *colorBankTypePtr )
{
#pragma unused( colorsRequested )
*dataHandlePtr = nil;
*colorBankTypePtr = ColorBankIsExactAnd555;
return noErr;
}
/*----------------------------------------------------------------------------------------------------------*/
/*
| This routine is called to kill the median method. It doesnt do anything.
*/
pascal OSErr KillMedianMethod(
long dataHandle )
{
#pragma unused( dataHandle )
return noErr;
}
/*----------------------------------------------------------------------------------------------------------*/
/*
| This routine should never be called, so it returns an error.
*/
pascal OSErr RecordMedianColors(
long dataHandle,
RGBColor *colorPtr,
long colorCount,
long *uniqueColorsPtr )
{
#pragma unused( dataHandle, colorPtr, colorCount, uniqueColorsPtr )
return cantLoadPickMethodErr;
}
/*----------------------------------------------------------------------------------------------------------*/
/*
| This returns the colors that cover the widest range in the histogram.
*/
pascal OSErr CalcMedianTable(
long dataHandle,
short colorsRequested,
short *colorBankPtr,
ColorSpec *resultPtr )
{
#pragma unused( dataHandle )
register BoxInfo *boxInfoPtr;
register short *boxIDPtr;
register short index;
Buffer boxIDBuffer;
Buffer boxInfoBuffer;
short colorsToFill;
OSErr error;
/*
| Allocate two buffers, one to hold a box ID number for each color in the histogram and the second one to hold
| the actual box information (component range, etc). Then make “boxInfoPtr” a pointer to the first boxInfo in
| the boxInfo buffer. This variable wont get reset until after the main loop.
*/
if( error = NewBufferClear( &boxIDBuffer, HistogramTableSize, bufferFixedType ) )
return error;
if( error = NewBufferClear( &boxInfoBuffer, 256 * sizeof(BoxInfo), bufferFixedType ) )
return error;
boxInfoPtr = (BoxInfo *)(boxInfoBuffer.ptr);
/*
| Mark all the entries in the histogram as either being in box zero (if they have at least one color) or -1 if
| they had no colors. This will also give us the total number of colors in the histogram, which we must make
| sure to clip to the number of colors requested to get the number of colors to fill.
*/
{
register long histogramEnd;
short *histogramPtr;
boxIDPtr = (short *)(boxIDBuffer.ptr);
histogramPtr = colorBankPtr;
histogramEnd = (long)colorBankPtr + HistogramTableSize;
while( histogramPtr < (char *)histogramEnd )
{
if( *(histogramPtr++) > 0 )
{
*(boxIDPtr++) = 0;
boxInfoPtr->count++;
}
else
*(boxIDPtr++) = -1;
}
}
colorsToFill = (boxInfoPtr->count > colorsRequested) ? colorsRequested : boxInfoPtr->count;
/*
| Find the minimum and maximum range for each component of all the colors in box zero. Since all the colors are
| in box zero to start with, this finds the range for all the colors in the histogram. Note that we must
| initialize the minimum values for each box, but not the maximum ones. This is because we have cleared the
| boxInfo buffer, so that our maximum values are already initialized to zero for us. boxInfoPtr continues to
| point to the BoxInfo structure for block zero.
|
| Note that we declare a separate block to allow us to registerize the our component indexes.
*/
boxIDPtr = (short *)(boxIDBuffer.ptr);
{
register unsigned short red, green, blue;
boxInfoPtr->minRed = boxInfoPtr->minGreen = boxInfoPtr->minBlue = 0xFFFF;
for(red = 0; red < 32; red++)
{
for(green = 0; green < 32; green++)
{
for(blue = 0; blue < 32; blue++)
{
if( *(boxIDPtr++) == 0 )
{
if( red < boxInfoPtr->minRed ) boxInfoPtr->minRed = red;
if( green < boxInfoPtr->minGreen ) boxInfoPtr->minGreen = green;
if( blue < boxInfoPtr->minBlue ) boxInfoPtr->minBlue = blue;
if( red > boxInfoPtr->maxRed ) boxInfoPtr->maxRed = red;
if( green > boxInfoPtr->maxGreen ) boxInfoPtr->maxGreen = green;
if( blue > boxInfoPtr->maxBlue ) boxInfoPtr->maxBlue = blue;
}
}
}
}
}
/*
| We scan thru all the filled boxes multiple times, each time looking for the one that has the largest spread
| in either red, green or blue. Note that we only look at boxes that have more than one color, because we are
| going to split the box that we find into two sub-boxes. After we split the box, we loop back and scan thru
| all the filled boxes again (this time there is one more filled box than last time. We terminate both loops,
| when we have reached the number of colors to fill. Note that since we clipped colorsToFill to the total number
| of colors in the histogram, we will never be in a situation where we cant split a box, but we havent used
| all our colors yet.
|
| Note that we declare a separate block to allow us to registerize some other variables.
*/
{
register short availableBox;
register short filledBoxes;
filledBoxes = availableBox = 1;
while( true /* filledBoxes < 256 */ )
{
register short theSpread;
register short spreadMax;
short maxIndex;
if( availableBox >= colorsToFill )
goto exitMain;
spreadMax = maxIndex = 0;
for(index = 0; (index < filledBoxes) && (spreadMax != 0x1F); index++)
{
boxInfoPtr = (BoxInfo *)( boxInfoBuffer.ptr + (index * sizeof(BoxInfo)) );
if( boxInfoPtr->count > 1 )
{
theSpread = boxInfoPtr->maxRed - boxInfoPtr->minRed;
if( theSpread > spreadMax )
{
spreadMax = theSpread;
maxIndex = index;
}
theSpread = boxInfoPtr->maxGreen - boxInfoPtr->minGreen;
if( theSpread > spreadMax )
{
spreadMax = theSpread;
maxIndex = index;
}
theSpread = boxInfoPtr->maxBlue - boxInfoPtr->minBlue;
if( theSpread > spreadMax )
{
spreadMax = theSpread;
maxIndex = index;
}
}
}
SplitBox((BoxInfo *)(boxInfoBuffer.ptr), (short *)(boxIDBuffer.ptr), maxIndex, availableBox++);
filledBoxes = availableBox;
}
}
exitMain:
/*
| Calculate the totals for each color component for all colors contained in each of the boxes. We first loop
| thru each color checking to see which box it belongs to. We then get a pointer to the BoxInfo for that
| particular box and for each component, we add the color to the appropriate total.
|
| Note that we declare a separate block to allow us to registerize the our component indexes.
*/
boxIDPtr = (short *)(boxIDBuffer.ptr);
{
register unsigned short red, green, blue;
for(red = 0; red < 32; red++)
{
for(green = 0; green < 32; green++)
{
for(blue = 0; blue < 32; blue++)
{
if( (index = *(boxIDPtr++)) >= 0 )
{
boxInfoPtr = (BoxInfo *)( boxInfoBuffer.ptr + (index * sizeof(BoxInfo)) );
boxInfoPtr->totalRed += red;
boxInfoPtr->totalGreen += green;
boxInfoPtr->totalBlue += blue;
}
}
}
}
}
/*
| Here is where we actually fill the color table that we are returning. We scan thru all the boxes in the
| boxInfo buffer, checking to see if their count is greater than zero. If it is, then we have a color to return,
| so for each component, we divide the total by the number of colors in this box to get the average component,
| then we smear the component out to fill a full 16-bit range for the color table. If the count for a particular
| color is zero, then we return black for that entry in the color table. Note that this will never happen until
| we have reached the end of the filled boxes, so at that point all we really want to do is fill the rest of the
| returned color table with black.
*/
FillMedianTable( (BoxInfo *)(boxInfoBuffer.ptr), resultPtr, colorsRequested );
/*
| Kill the buffers for the boxes and the boxIDs
*/
KillBuffer( &boxInfoBuffer );
KillBuffer( &boxIDBuffer );
return noErr;
}
/*----------------------------------------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------------------------------------*/
/************************************************************************************************************/
/**** Internal Functions Follow ****/
/************************************************************************************************************/
/*----------------------------------------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------------------------------------*/
static void SplitBox(
BoxInfo *boxInfoPtr,
short *mainBoxIDPtr,
short srcBox,
short dstBox )
{
RangeInfo first, second, third;
BoxInfo *slowSrcPtr, *slowDstPtr;
register unsigned short oneHalfCount;
/*
| Make pointers to the two boxes; the source box that we are taking colors from and the dest box
| that we are adding the taken colors to. These pointers are stored in non register locals, so
| that we can reload fast register pointers quickly.
*/
slowSrcPtr = boxInfoPtr + srcBox;
slowDstPtr = boxInfoPtr + dstBox;
/*
| The second box has a count that is equal to one half of the source box. Note that we subtract
| the number of colors we removed from the source boxs count to ensure that even if the count is
| odd, we will not lose a color.
|
| We use a separate block in order to get register variables for our two box pointers (srcBoxPtr
| and dstBoxPtr).
*/
{
register BoxInfo *srcBoxPtr = slowSrcPtr;
register BoxInfo *dstBoxPtr = slowDstPtr;
dstBoxPtr->count = oneHalfCount = srcBoxPtr->count >> 1;
srcBoxPtr->count -= oneHalfCount;
/*
| Here we setup the three range blocks. This is some very tricky code that allows us to sort the
| component range blocks in order of the spread between the minimum and maximum values of the
| components. The variables that we need for each of the range blocks are the spread between the
| values of the components, the starting index (the minimum component value shifted over by the
| proper amount), the ending index (the maximum component value shifted over by the proper amount),
| and the step (the amount to increment the component index by each time thru the loop.
*/
first.spread = srcBoxPtr->maxRed - srcBoxPtr->minRed;
first.start = (srcBoxPtr->minRed) << 10;
first.end = (srcBoxPtr->maxRed) << 10;
first.step = 1024;
second.spread = srcBoxPtr->maxGreen - srcBoxPtr->minGreen;
second.start = (srcBoxPtr->minGreen) << 5;
second.end = (srcBoxPtr->maxGreen) << 5;
second.step = 32;
third.spread = srcBoxPtr->maxBlue - srcBoxPtr->minBlue;
third.start = srcBoxPtr->minBlue;
third.end = srcBoxPtr->maxBlue;
third.step = 1;
}
/*
| Here is where we sort the range blocks in order of the spread between the components. Notice that
| since we have a RangeInfo structure for each, we only need to swap pointers to swap two elements
| in this structure. Also notice that we dont have to actually swap the pointers, since we know
| the value of at least one of them at all times.
|
| We need a separate code block again so that we can registerize the pointers to each of our range
| info structures. We also registerize some other frequently used variables.
*/
{
register RangeInfo *firstPtr, *secondPtr, *thirdPtr;
RangeInfo *swapPtr; /*<9>*/
register unsigned short firstIndex, secondIndex, index;
firstPtr = &first;
secondPtr = &second;
thirdPtr = &third;
if( secondPtr->spread > firstPtr->spread )
{
secondPtr = firstPtr;
firstPtr = &second;
}
if( thirdPtr->spread > secondPtr->spread )
{
thirdPtr = secondPtr;
secondPtr = &third;
if( secondPtr->spread > firstPtr->spread )
{
swapPtr = firstPtr; /*<9>*/
firstPtr = secondPtr; /*<9>*/
secondPtr = swapPtr; /*<9>*/
}
}
/*
| This is where we actually use these range blocks that we set up and sorted . We look through
| all the colors that are within this defined range and we set half of them to be in the dest
| box instead of the src box. Note that mainBoxIDPtr is not a register; it would be nice if
| it was, but it is actually less important than the other variables.
*/
firstIndex = firstPtr->start;
while( firstIndex <= firstPtr->end )
{
secondIndex = secondPtr->start;
while( secondIndex <= secondPtr->end )
{
index = firstIndex + secondIndex + thirdPtr->start;
while( index <= (firstIndex + secondIndex + thirdPtr->end) )
{
if( mainBoxIDPtr[index] == srcBox )
{
mainBoxIDPtr[index] = dstBox;
if( --oneHalfCount == 0 )
goto exitLoop;
}
index += thirdPtr->step;
}
secondIndex += secondPtr->step;
}
firstIndex += firstPtr->step;
}
}
exitLoop:
/*
| We have now divided the original box into two parts. Now all we need to do is find the range of
| each of the components for both the original source box and the new destination box.
|
| Again, we have a new code block so that we can declare a completely different set of register
| variables. This time the src and dst box pointers are very important. The indexes for our loops
| are also important.
*/
{
BoxInfo initialBox;
register BoxInfo *srcBoxPtr = slowSrcPtr;
register BoxInfo *dstBoxPtr = slowDstPtr;
register short *boxIDPtr;
register unsigned short red, green, blue; /*<9>*/
register short boxIndex;
/*
| Copy the initial box structure (particularly the range information) into our local structure.
| This is because we need the initial values in the source box structure for our loop ending
| conditions, but we want to be able to fill the new source box structure directly in the loop.
*/
initialBox = *srcBoxPtr;
/*
| Initialize the minimum and maximum fields of the src and dst box structures.
*/
srcBoxPtr->minRed = srcBoxPtr->minGreen = srcBoxPtr->minBlue = 0xFFFF;
dstBoxPtr->minRed = dstBoxPtr->minGreen = dstBoxPtr->minBlue = 0xFFFF;
srcBoxPtr->maxRed = srcBoxPtr->maxGreen = srcBoxPtr->maxBlue = 0x0000;
dstBoxPtr->maxRed = dstBoxPtr->maxGreen = dstBoxPtr->maxBlue = 0x0000;
/*
| This is where we loop thru all the colors in the old range, checking them against either the
| source or destination box structures minimums and maximums. Note that boxIDPtr is a pointer
| into the boxID buffer that tells which box each color belongs to. We can increment it by one
| as we move thru the blue component, but before each blue loop, we need to set it up properly.
*/
for( red = initialBox.minRed; red <= initialBox.maxRed; red++ )
{
for( green = initialBox.minGreen; green <= initialBox.maxGreen; green++ )
{
boxIDPtr = mainBoxIDPtr + (red << 10) + (green << 5) + initialBox.minBlue;
for( blue = initialBox.minBlue; blue <= initialBox.maxBlue; blue++ )
{
boxIndex = *(boxIDPtr++);
if( boxIndex == srcBox )
{
if( red < srcBoxPtr->minRed ) srcBoxPtr->minRed = red;
if( green < srcBoxPtr->minGreen ) srcBoxPtr->minGreen = green;
if( blue < srcBoxPtr->minBlue ) srcBoxPtr->minBlue = blue;
if( red > srcBoxPtr->maxRed ) srcBoxPtr->maxRed = red;
if( green > srcBoxPtr->maxGreen ) srcBoxPtr->maxGreen = green;
if( blue > srcBoxPtr->maxBlue ) srcBoxPtr->maxBlue = blue;
}
else if( boxIndex == dstBox )
{
if( red < dstBoxPtr->minRed ) dstBoxPtr->minRed = red;
if( green < dstBoxPtr->minGreen ) dstBoxPtr->minGreen = green;
if( blue < dstBoxPtr->minBlue ) dstBoxPtr->minBlue = blue;
if( red > dstBoxPtr->maxRed ) dstBoxPtr->maxRed = red;
if( green > dstBoxPtr->maxGreen ) dstBoxPtr->maxGreen = green;
if( blue > dstBoxPtr->maxBlue ) dstBoxPtr->maxBlue = blue;
}
}
}
}
}
}
/*----------------------------------------------------------------------------------------------------------*/