/*
* AlphaLigne.cpp
* nlivarot
*
* Created by fred on Fri Jul 25 2003.
* public domain
*
*/
#include "AlphaLigne.h"
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
AlphaLigne::AlphaLigne(int iMin,int iMax)
{
min=iMin;
max=iMax;
if ( max < min+1 ) max=min+1;
steps=NULL;
nbStep=maxStep=0;
before.x=min-1;
before.delta=0;
after.x=max+1;
after.delta=0;
}
AlphaLigne::~AlphaLigne(void)
{
g_free(steps);
steps=NULL;
nbStep=maxStep=0;
}
void AlphaLigne::Affiche(void)
{
printf("%i steps\n",nbStep);
for (int i=0;i<nbStep;i++) {
printf("(%i %f) ",steps[i].x,steps[i].delta); // localization ok
}
printf("\n");
}
void AlphaLigne::Reset(void)
{
// reset to empty line
// doesn't deallocate the steps array, to minimize memory operations
curMin=max;
curMax=min;
nbStep=0;
before.x=min-1;
before.delta=0;
after.x=max+1;
after.delta=0;
}
int AlphaLigne::AddBord(float spos,float sval,float epos,float eval,float tPente)
{
// printf("%f %f -> %f %f / %f\n",spos,sval,epos,eval,tPente);
if ( sval == eval ) return 0;
// compute the footprint of [spos,epos] on the line of pixels
float curStF=floor(spos);
float curEnF=floor(epos);
int curSt=(int)curStF;
int curEn=(int)curEnF;
// update curMin and curMax
if ( curSt > max ) {
// we're on the right of the visible portion of the line: bail out!
if ( eval < sval ) curMax=max;
return 0;
}
if ( curSt < curMin ) curMin=curSt;
if ( ceil(epos) > curMax ) curMax=(int)ceil(epos);
// clamp the changed portion to [min,max], no need for bigger
if ( curMax > max ) curMax=max;
if ( curMin < min ) curMin=min;
// total amount of change in pixel coverage from before the right to after the run
float needed=eval-sval;
float needC=/*(int)ldexpf(*/needed/*,24)*/;
if ( curEn < min ) {
// the added portion is entirely on the left, so we only have to change the initial coverage for the line
before.delta+=needC;
return 0;
}
// add the steps
// the pixels from [curSt..curEn] (included) intersect with [spos;epos]
// since we're dealing with delta in the coverage, there is also a curEn+1 delta, since the curEn pixel intersect
// with [spos;epos] and thus has some delta with respect to its next pixel
// lots of different cases... ugly
if ( curSt == curEn ) {
if ( curSt+1 < min ) {
before.delta+=needC;
} else {
if ( nbStep+2 >= maxStep ) {
maxStep=2*nbStep+2;
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
float stC=/*(int)ldexpf(*/(eval-sval)*(0.5*(epos-spos)+curStF+1-epos)/*,24)*/;
steps[nbStep].x=curSt;
steps[nbStep].delta=stC;
nbStep++;
steps[nbStep].x=curSt+1;
steps[nbStep].delta=needC-stC; // au final, on a toujours le bon delta, meme avec une arete completement verticale
nbStep++;
}
} else if ( curEn == curSt+1 ) {
if ( curSt+2 < min ) {
before.delta+=needC;
} else {
if ( nbStep+3 >= maxStep ) {
maxStep=2*nbStep+3;
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
float stC=/*(int)ldexpf(*/0.5*tPente*(curEnF-spos)*(curEnF-spos)/*,24)*/;
float enC=/*(int)ldexpf(*/tPente-0.5*tPente*((spos-curStF)*(spos-curStF)+(curEnF+1.0-epos)*(curEnF+1.0-epos))/*,24)*/;
steps[nbStep].x=curSt;
steps[nbStep].delta=stC;
nbStep++;
steps[nbStep].x=curEn;
steps[nbStep].delta=enC;
nbStep++;
steps[nbStep].x=curEn+1;
steps[nbStep].delta=needC-stC-enC;
nbStep++;
}
} else {
float stC=/*(int)ldexpf(*/0.5*tPente*(curStF+1-spos)*(curStF+1-spos)/*,24)*/;
float stFC=/*(int)ldexpf(*/tPente-0.5*tPente*(spos-curStF)*(spos-curStF)/*,24)*/;
float enC=/*(int)ldexpf(*/tPente-0.5*tPente*(curEnF+1.0-epos)*(curEnF+1.0-epos)/*,24)*/;
float miC=/*(int)ldexpf(*/tPente/*,24)*/;
if ( curSt < min ) {
if ( curEn > max ) {
if ( nbStep+(max-min) >= maxStep ) {
maxStep=2*nbStep+(max-min);
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
float bfd=min-curSt-1;
bfd*=miC;
before.delta+=stC+bfd;
for (int i=min;i<max;i++) {
steps[nbStep].x=i;
steps[nbStep].delta=miC;
nbStep++;
}
} else {
if ( nbStep+(curEn-min)+2 >= maxStep ) {
maxStep=2*nbStep+(curEn-min)+2;
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
float bfd=min-curSt-1;
bfd*=miC;
before.delta+=stC+bfd;
for (int i=min;i<curEn;i++) {
steps[nbStep].x=i;
steps[nbStep].delta=miC;
nbStep++;
}
steps[nbStep].x=curEn;
steps[nbStep].delta=enC;
nbStep++;
steps[nbStep].x=curEn+1;
steps[nbStep].delta=needC-stC-stFC-enC-(curEn-curSt-2)*miC;
nbStep++;
}
} else {
if ( curEn > max ) {
if ( nbStep+3+(max-curSt) >= maxStep ) {
maxStep=2*nbStep+3+(curEn-curSt);
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
steps[nbStep].x=curSt;
steps[nbStep].delta=stC;
nbStep++;
steps[nbStep].x=curSt+1;
steps[nbStep].delta=stFC;
nbStep++;
for (int i=curSt+2;i<max;i++) {
steps[nbStep].x=i;
steps[nbStep].delta=miC;
nbStep++;
}
} else {
if ( nbStep+3+(curEn-curSt) >= maxStep ) {
maxStep=2*nbStep+3+(curEn-curSt);
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
steps[nbStep].x=curSt;
steps[nbStep].delta=stC;
nbStep++;
steps[nbStep].x=curSt+1;
steps[nbStep].delta=stFC;
nbStep++;
for (int i=curSt+2;i<curEn;i++) {
steps[nbStep].x=i;
steps[nbStep].delta=miC;
nbStep++;
}
steps[nbStep].x=curEn;
steps[nbStep].delta=enC;
nbStep++;
steps[nbStep].x=curEn+1;
steps[nbStep].delta=needC-stC-stFC-enC-(curEn-curSt-2)*miC;
nbStep++;
}
}
}
return 0;
}
int AlphaLigne::AddBord(float spos,float sval,float epos,float eval)
{
// pas de pente dans ce cas; on ajoute le delta au premier pixel
float tPente=(eval-sval);
float curStF=floor(spos);
float curEnF=floor(epos);
int curSt=(int)curStF;
int curEn=(int)curEnF;
if ( curSt > max ) {
if ( eval < sval ) curMax=max;
return 0; // en dehors des limites (attention a ne pas faire ca avec curEn)
}
if ( curEn < min ) {
before.delta+=eval-sval;
return 0; // en dehors des limites (attention a ne pas faire ca avec curEn)
}
if ( curSt < curMin ) curMin=curSt;
// int curEn=(int)curEnF;
if ( ceil(epos) > curMax-1 ) curMax=1+(int)ceil(epos);
if ( curSt < min ) {
before.delta+=eval-sval;
} else {
AddRun(curSt,/*(int)ldexpf(*/(((float)(curSt+1))-spos)*tPente/*,24)*/);
AddRun(curSt+1,/*(int)ldexpf(*/(spos-((float)(curSt)))*tPente/*,24)*/);
}
return 0;
}
void AlphaLigne::Flatten(void)
{
// just sort
if ( nbStep > 0 ) qsort(steps,nbStep,sizeof(alpha_step),CmpStep);
}
void AlphaLigne::AddRun(int st,float pente)
{
if ( nbStep >= maxStep ) {
maxStep=2*nbStep+1;
steps=(alpha_step*)g_realloc(steps,maxStep*sizeof(alpha_step));
}
int nStep=nbStep++;
steps[nStep].x=st;
steps[nStep].delta=pente;
}
void AlphaLigne::Raster(raster_info &dest,void* color,RasterInRunFunc worker)
{
// start by checking if there are actually pixels in need of rasterization
if ( curMax <= curMin ) return;
if ( dest.endPix <= curMin || dest.startPix >= curMax ) return;
int nMin=curMin,nMax=curMax;
float alpSum=before.delta; // alpSum will be the pixel coverage value, so we start at before.delta
int curStep=0;
// first add all the deltas up to the first pixel in need of rasterization
while ( curStep < nbStep && steps[curStep].x < nMin ) {
alpSum+=steps[curStep].delta;
curStep++;
}
// just in case, if the line bounds are greater than the buffer bounds.
if ( nMin < dest.startPix ) {
for (;( curStep < nbStep && steps[curStep].x < dest.startPix) ;curStep++) alpSum+=steps[curStep].delta;
nMin=dest.startPix;
}
if ( nMax > dest.endPix ) nMax=dest.endPix;
// raster!
int curPos=dest.startPix;
for (;curStep<nbStep;curStep++) {
if ( alpSum > 0 && steps[curStep].x > curPos ) {
// we're going to change the pixel position curPos, and alpSum is > 0: rasterization needed from
// the last position (curPos) up to the pixel we're moving to (steps[curStep].x)
int nst=curPos,nen=steps[curStep].x;
//Buffer::RasterRun(dest,color,nst,alpSum,nen,alpSum);
(worker)(dest,color,nst,alpSum,nen,alpSum);
}
// add coverage deltas
alpSum+=steps[curStep].delta;
curPos=steps[curStep].x;
if ( curPos >= nMax ) break;
}
// if we ended the line with alpSum > 0, we need to raster from curPos to the right edge
if ( alpSum > 0 && curPos < nMax ) {
int nst=curPos,nen=max;
(worker)(dest,color,nst,alpSum,nen,alpSum);
//Buffer::RasterRun(dest,color,nst,alpSum,nen,alpSum);
}
}