/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- cmpIntersect
- getBBoxAA
- getSpanBounds
- test
- testSpan
- getNextSpan
- computeIntersections
- renderAALine
- clipAALine
//========================================================================
//
// SplashXPathScanner.cc
//
//========================================================================
#include <aconf.h>
#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif
#include <stdlib.h>
#include <string.h>
#include "gmem.h"
#include "SplashMath.h"
#include "SplashXPath.h"
#include "SplashBitmap.h"
#include "SplashXPathScanner.h"
//------------------------------------------------------------------------
struct SplashIntersect {
int x0, x1; // intersection of segment with [y, y+1)
int count; // EO/NZWN counter increment
};
static int cmpIntersect(const void *p0, const void *p1) {
return ((SplashIntersect *)p0)->x0 - ((SplashIntersect *)p1)->x0;
}
//------------------------------------------------------------------------
// SplashXPathScanner
//------------------------------------------------------------------------
SplashXPathScanner::SplashXPathScanner(SplashXPath *xPathA, GBool eoA) {
SplashXPathSeg *seg;
SplashCoord xMinFP, yMinFP, xMaxFP, yMaxFP;
int i;
xPath = xPathA;
eo = eoA;
// compute the bbox
if (xPath->length == 0) {
xMin = yMin = 1;
xMax = yMax = 0;
} else {
seg = &xPath->segs[0];
if (seg->x0 <= seg->x1) {
xMinFP = seg->x0;
xMaxFP = seg->x1;
} else {
xMinFP = seg->x1;
xMaxFP = seg->x0;
}
if (seg->flags & splashXPathFlip) {
yMinFP = seg->y1;
yMaxFP = seg->y0;
} else {
yMinFP = seg->y0;
yMaxFP = seg->y1;
}
for (i = 1; i < xPath->length; ++i) {
seg = &xPath->segs[i];
if (seg->x0 < xMinFP) {
xMinFP = seg->x0;
} else if (seg->x0 > xMaxFP) {
xMaxFP = seg->x0;
}
if (seg->x1 < xMinFP) {
xMinFP = seg->x1;
} else if (seg->x1 > xMaxFP) {
xMaxFP = seg->x1;
}
if (seg->flags & splashXPathFlip) {
if (seg->y0 > yMaxFP) {
yMaxFP = seg->y0;
}
} else {
if (seg->y1 > yMaxFP) {
yMaxFP = seg->y1;
}
}
}
xMin = splashFloor(xMinFP);
xMax = splashFloor(xMaxFP);
yMin = splashFloor(yMinFP);
yMax = splashFloor(yMaxFP);
}
interY = yMin - 1;
xPathIdx = 0;
inter = NULL;
interLen = interSize = 0;
}
SplashXPathScanner::~SplashXPathScanner() {
gfree(inter);
}
void SplashXPathScanner::getBBoxAA(int *xMinA, int *yMinA,
int *xMaxA, int *yMaxA) {
*xMinA = xMin / splashAASize;
*yMinA = yMin / splashAASize;
*xMaxA = xMax / splashAASize;
*yMaxA = yMax / splashAASize;
}
void SplashXPathScanner::getSpanBounds(int y, int *spanXMin, int *spanXMax) {
if (interY != y) {
computeIntersections(y);
}
if (interLen > 0) {
*spanXMin = inter[0].x0;
*spanXMax = inter[interLen - 1].x1;
} else {
*spanXMin = xMax + 1;
*spanXMax = xMax;
}
}
GBool SplashXPathScanner::test(int x, int y) {
int count, i;
if (interY != y) {
computeIntersections(y);
}
count = 0;
for (i = 0; i < interLen && inter[i].x0 <= x; ++i) {
if (x <= inter[i].x1) {
return gTrue;
}
count += inter[i].count;
}
return eo ? (count & 1) : (count != 0);
}
GBool SplashXPathScanner::testSpan(int x0, int x1, int y) {
int count, xx1, i;
if (interY != y) {
computeIntersections(y);
}
count = 0;
for (i = 0; i < interLen && inter[i].x1 < x0; ++i) {
count += inter[i].count;
}
// invariant: the subspan [x0,xx1] is inside the path
xx1 = x0 - 1;
while (xx1 < x1) {
if (i >= interLen) {
return gFalse;
}
if (inter[i].x0 > xx1 + 1 &&
!(eo ? (count & 1) : (count != 0))) {
return gFalse;
}
if (inter[i].x1 > xx1) {
xx1 = inter[i].x1;
}
count += inter[i].count;
++i;
}
return gTrue;
}
GBool SplashXPathScanner::getNextSpan(int y, int *x0, int *x1) {
int xx0, xx1;
if (interY != y) {
computeIntersections(y);
}
if (interIdx >= interLen) {
return gFalse;
}
xx0 = inter[interIdx].x0;
xx1 = inter[interIdx].x1;
interCount += inter[interIdx].count;
++interIdx;
while (interIdx < interLen &&
(inter[interIdx].x0 <= xx1 ||
(eo ? (interCount & 1) : (interCount != 0)))) {
if (inter[interIdx].x1 > xx1) {
xx1 = inter[interIdx].x1;
}
interCount += inter[interIdx].count;
++interIdx;
}
*x0 = xx0;
*x1 = xx1;
return gTrue;
}
void SplashXPathScanner::computeIntersections(int y) {
SplashCoord xSegMin, xSegMax, ySegMin, ySegMax, xx0, xx1;
SplashXPathSeg *seg;
int i, j;
// find the first segment that intersects [y, y+1)
i = (y >= interY) ? xPathIdx : 0;
while (i < xPath->length &&
xPath->segs[i].y0 < y && xPath->segs[i].y1 < y) {
++i;
}
xPathIdx = i;
// find all of the segments that intersect [y, y+1) and create an
// Intersect element for each one
interLen = 0;
for (j = i; j < xPath->length; ++j) {
seg = &xPath->segs[j];
if (seg->flags & splashXPathFlip) {
ySegMin = seg->y1;
ySegMax = seg->y0;
} else {
ySegMin = seg->y0;
ySegMax = seg->y1;
}
// ensure that: ySegMin < y+1
// y <= ySegMax
if (ySegMin >= y + 1) {
break;
}
if (ySegMax < y) {
continue;
}
if (interLen == interSize) {
if (interSize == 0) {
interSize = 16;
} else {
interSize *= 2;
}
inter = (SplashIntersect *)greallocn(inter, interSize,
sizeof(SplashIntersect));
}
if (seg->flags & splashXPathHoriz) {
xx0 = seg->x0;
xx1 = seg->x1;
} else if (seg->flags & splashXPathVert) {
xx0 = xx1 = seg->x0;
} else {
if (seg->x0 < seg->x1) {
xSegMin = seg->x0;
xSegMax = seg->x1;
} else {
xSegMin = seg->x1;
xSegMax = seg->x0;
}
// intersection with top edge
xx0 = seg->x0 + ((SplashCoord)y - seg->y0) * seg->dxdy;
// intersection with bottom edge
xx1 = seg->x0 + ((SplashCoord)y + 1 - seg->y0) * seg->dxdy;
// the segment may not actually extend to the top and/or bottom edges
if (xx0 < xSegMin) {
xx0 = xSegMin;
} else if (xx0 > xSegMax) {
xx0 = xSegMax;
}
if (xx1 < xSegMin) {
xx1 = xSegMin;
} else if (xx1 > xSegMax) {
xx1 = xSegMax;
}
}
if (xx0 < xx1) {
inter[interLen].x0 = splashFloor(xx0);
inter[interLen].x1 = splashFloor(xx1);
} else {
inter[interLen].x0 = splashFloor(xx1);
inter[interLen].x1 = splashFloor(xx0);
}
if (ySegMin <= y &&
(SplashCoord)y < ySegMax &&
!(seg->flags & splashXPathHoriz)) {
inter[interLen].count = eo ? 1
: (seg->flags & splashXPathFlip) ? 1 : -1;
} else {
inter[interLen].count = 0;
}
++interLen;
}
qsort(inter, interLen, sizeof(SplashIntersect), &cmpIntersect);
interY = y;
interIdx = 0;
interCount = 0;
}
void SplashXPathScanner::renderAALine(SplashBitmap *aaBuf,
int *x0, int *x1, int y) {
int xx0, xx1, xx, xxMin, xxMax, yy;
Guchar mask;
SplashColorPtr p;
memset(aaBuf->getDataPtr(), 0, aaBuf->getRowSize() * aaBuf->getHeight());
xxMin = aaBuf->getWidth();
xxMax = -1;
for (yy = 0; yy < splashAASize; ++yy) {
computeIntersections(splashAASize * y + yy);
while (interIdx < interLen) {
xx0 = inter[interIdx].x0;
xx1 = inter[interIdx].x1;
interCount += inter[interIdx].count;
++interIdx;
while (interIdx < interLen &&
(inter[interIdx].x0 <= xx1 ||
(eo ? (interCount & 1) : (interCount != 0)))) {
if (inter[interIdx].x1 > xx1) {
xx1 = inter[interIdx].x1;
}
interCount += inter[interIdx].count;
++interIdx;
}
if (xx0 < 0) {
xx0 = 0;
}
++xx1;
if (xx1 > aaBuf->getWidth()) {
xx1 = aaBuf->getWidth();
}
// set [xx0, xx1) to 1
if (xx0 < xx1) {
xx = xx0;
p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx >> 3);
if (xx & 7) {
mask = 0xff >> (xx & 7);
if ((xx & ~7) == (xx1 & ~7)) {
mask &= (Guchar)(0xff00 >> (xx1 & 7));
}
*p++ |= mask;
xx = (xx & ~7) + 8;
}
for (; xx + 7 < xx1; xx += 8) {
*p++ |= 0xff;
}
if (xx < xx1) {
*p |= (Guchar)(0xff00 >> (xx1 & 7));
}
}
if (xx0 < xxMin) {
xxMin = xx0;
}
if (xx1 > xxMax) {
xxMax = xx1;
}
}
}
*x0 = xxMin / splashAASize;
*x1 = (xxMax - 1) / splashAASize;
}
void SplashXPathScanner::clipAALine(SplashBitmap *aaBuf,
int *x0, int *x1, int y) {
int xx0, xx1, xx, yy;
Guchar mask;
SplashColorPtr p;
for (yy = 0; yy < splashAASize; ++yy) {
xx = *x0 * splashAASize;
computeIntersections(splashAASize * y + yy);
while (interIdx < interLen && xx < (*x1 + 1) * splashAASize) {
xx0 = inter[interIdx].x0;
xx1 = inter[interIdx].x1;
interCount += inter[interIdx].count;
++interIdx;
while (interIdx < interLen &&
(inter[interIdx].x0 <= xx1 ||
(eo ? (interCount & 1) : (interCount != 0)))) {
if (inter[interIdx].x1 > xx1) {
xx1 = inter[interIdx].x1;
}
interCount += inter[interIdx].count;
++interIdx;
}
if (xx0 > aaBuf->getWidth()) {
xx0 = aaBuf->getWidth();
}
// set [xx, xx0) to 0
if (xx < xx0) {
p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx >> 3);
if (xx & 7) {
mask = (Guchar)(0xff00 >> (xx & 7));
if ((xx & ~7) == (xx0 & ~7)) {
mask |= 0xff >> (xx0 & 7);
}
*p++ &= mask;
xx = (xx & ~7) + 8;
}
for (; xx + 7 < xx0; xx += 8) {
*p++ = 0x00;
}
if (xx < xx0) {
*p &= 0xff >> (xx0 & 7);
}
}
if (xx1 >= xx) {
xx = xx1 + 1;
}
}
xx0 = (*x1 + 1) * splashAASize;
// set [xx, xx0) to 0
if (xx < xx0) {
p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx >> 3);
if (xx & 7) {
mask = (Guchar)(0xff00 >> (xx & 7));
if ((xx & ~7) == (xx0 & ~7)) {
mask &= 0xff >> (xx0 & 7);
}
*p++ &= mask;
xx = (xx & ~7) + 8;
}
for (; xx + 7 < xx0; xx += 8) {
*p++ = 0x00;
}
if (xx < xx0) {
*p &= 0xff >> (xx0 & 7);
}
}
}
}