poppler-24.05.0/splash/SplashClip.cc

//========================================================================
//
// SplashClip.cc
//
//========================================================================

//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2010, 2021 Albert Astals Cid <[email protected]>
// Copyright (C) 2013, 2021 Thomas Freitag <[email protected]>
// Copyright (C) 2019 Stefan Brüns <[email protected]>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================

#include <config.h>

#include <cstdlib>
#include <cstring>
#include "goo/gmem.h"
#include "SplashErrorCodes.h"
#include "SplashMath.h"
#include "SplashPath.h"
#include "SplashXPath.h"
#include "SplashXPathScanner.h"
#include "SplashBitmap.h"
#include "SplashClip.h"

//------------------------------------------------------------------------
// SplashClip.flags
//------------------------------------------------------------------------

#define splashClipEO 0x01 // use even-odd rule

//------------------------------------------------------------------------
// SplashClip
//------------------------------------------------------------------------

SplashClip::SplashClip(SplashCoord x0, SplashCoord y0, SplashCoord x1, SplashCoord y1, bool antialiasA)
{
    antialias = antialiasA;
    if (x0 < x1) {
        xMin = x0;
        xMax = x1;
    } else {
        xMin = x1;
        xMax = x0;
    }
    if (y0 < y1) {
        yMin = y0;
        yMax = y1;
    } else {
        yMin = y1;
        yMax = y0;
    }
    xMinI = splashFloor(xMin);
    yMinI = splashFloor(yMin);
    xMaxI = splashCeil(xMax) - 1;
    yMaxI = splashCeil(yMax) - 1;
    flags = nullptr;
    length = size = 0;
}

SplashClip::SplashClip(const SplashClip *clip)
{
    int i;

    antialias = clip->antialias;
    xMin = clip->xMin;
    yMin = clip->yMin;
    xMax = clip->xMax;
    yMax = clip->yMax;
    xMinI = clip->xMinI;
    yMinI = clip->yMinI;
    xMaxI = clip->xMaxI;
    yMaxI = clip->yMaxI;
    length = clip->length;
    size = clip->size;
    flags = (unsigned char *)gmallocn(size, sizeof(unsigned char));
    scanners = clip->scanners;
    for (i = 0; i < length; ++i) {
        flags[i] = clip->flags[i];
    }
}

SplashClip::~SplashClip()
{
    gfree(flags);
}

void SplashClip::grow(int nPaths)
{
    if (length + nPaths > size) {
        if (size == 0) {
            size = 32;
        }
        while (size < length + nPaths) {
            size *= 2;
        }
        flags = (unsigned char *)greallocn(flags, size, sizeof(unsigned char));
    }
}

void SplashClip::resetToRect(SplashCoord x0, SplashCoord y0, SplashCoord x1, SplashCoord y1)
{
    gfree(flags);
    flags = nullptr;
    scanners = {};
    length = size = 0;

    if (x0 < x1) {
        xMin = x0;
        xMax = x1;
    } else {
        xMin = x1;
        xMax = x0;
    }
    if (y0 < y1) {
        yMin = y0;
        yMax = y1;
    } else {
        yMin = y1;
        yMax = y0;
    }
    xMinI = splashFloor(xMin);
    yMinI = splashFloor(yMin);
    xMaxI = splashCeil(xMax) - 1;
    yMaxI = splashCeil(yMax) - 1;
}

SplashError SplashClip::clipToRect(SplashCoord x0, SplashCoord y0, SplashCoord x1, SplashCoord y1)
{
    if (x0 < x1) {
        if (x0 > xMin) {
            xMin = x0;
            xMinI = splashFloor(xMin);
        }
        if (x1 < xMax) {
            xMax = x1;
            xMaxI = splashCeil(xMax) - 1;
        }
    } else {
        if (x1 > xMin) {
            xMin = x1;
            xMinI = splashFloor(xMin);
        }
        if (x0 < xMax) {
            xMax = x0;
            xMaxI = splashCeil(xMax) - 1;
        }
    }
    if (y0 < y1) {
        if (y0 > yMin) {
            yMin = y0;
            yMinI = splashFloor(yMin);
        }
        if (y1 < yMax) {
            yMax = y1;
            yMaxI = splashCeil(yMax) - 1;
        }
    } else {
        if (y1 > yMin) {
            yMin = y1;
            yMinI = splashFloor(yMin);
        }
        if (y0 < yMax) {
            yMax = y0;
            yMaxI = splashCeil(yMax) - 1;
        }
    }
    return splashOk;
}

SplashError SplashClip::clipToPath(SplashPath *path, SplashCoord *matrix, SplashCoord flatness, bool eo)
{
    int yMinAA, yMaxAA;

    SplashXPath xPath(path, matrix, flatness, true);

    // check for an empty path
    if (xPath.length == 0) {
        xMax = xMin - 1;
        yMax = yMin - 1;
        xMaxI = splashCeil(xMax) - 1;
        yMaxI = splashCeil(yMax) - 1;

        // check for a rectangle
    } else if (xPath.length == 4
               && ((xPath.segs[0].x0 == xPath.segs[0].x1 && xPath.segs[0].x0 == xPath.segs[1].x0 && xPath.segs[0].x0 == xPath.segs[3].x1 && xPath.segs[2].x0 == xPath.segs[2].x1 && xPath.segs[2].x0 == xPath.segs[1].x1
                    && xPath.segs[2].x0 == xPath.segs[3].x0 && xPath.segs[1].y0 == xPath.segs[1].y1 && xPath.segs[1].y0 == xPath.segs[0].y1 && xPath.segs[1].y0 == xPath.segs[2].y0 && xPath.segs[3].y0 == xPath.segs[3].y1
                    && xPath.segs[3].y0 == xPath.segs[0].y0 && xPath.segs[3].y0 == xPath.segs[2].y1)
                   || (xPath.segs[0].y0 == xPath.segs[0].y1 && xPath.segs[0].y0 == xPath.segs[1].y0 && xPath.segs[0].y0 == xPath.segs[3].y1 && xPath.segs[2].y0 == xPath.segs[2].y1 && xPath.segs[2].y0 == xPath.segs[1].y1
                       && xPath.segs[2].y0 == xPath.segs[3].y0 && xPath.segs[1].x0 == xPath.segs[1].x1 && xPath.segs[1].x0 == xPath.segs[0].x1 && xPath.segs[1].x0 == xPath.segs[2].x0 && xPath.segs[3].x0 == xPath.segs[3].x1
                       && xPath.segs[3].x0 == xPath.segs[0].x0 && xPath.segs[3].x0 == xPath.segs[2].x1))) {
        clipToRect(xPath.segs[0].x0, xPath.segs[0].y0, xPath.segs[2].x0, xPath.segs[2].y0);

    } else {
        grow(1);
        if (antialias) {
            xPath.aaScale();
        }
        xPath.sort();
        flags[length] = eo ? splashClipEO : 0;
        if (antialias) {
            yMinAA = yMinI * splashAASize;
            yMaxAA = (yMaxI + 1) * splashAASize - 1;
        } else {
            yMinAA = yMinI;
            yMaxAA = yMaxI;
        }
        scanners.emplace_back(std::make_shared<SplashXPathScanner>(xPath, eo, yMinAA, yMaxAA));
        ++length;
    }

    return splashOk;
}

SplashClipResult SplashClip::testRect(int rectXMin, int rectYMin, int rectXMax, int rectYMax)
{
    // This tests the rectangle:
    //     x = [rectXMin, rectXMax + 1)    (note: rect coords are ints)
    //     y = [rectYMin, rectYMax + 1)
    // against the clipping region:
    //     x = [xMin, xMax)                (note: clipping coords are fp)
    //     y = [yMin, yMax)
    if ((SplashCoord)(rectXMax + 1) <= xMin || (SplashCoord)rectXMin >= xMax || (SplashCoord)(rectYMax + 1) <= yMin || (SplashCoord)rectYMin >= yMax) {
        return splashClipAllOutside;
    }
    if ((SplashCoord)rectXMin >= xMin && (SplashCoord)(rectXMax + 1) <= xMax && (SplashCoord)rectYMin >= yMin && (SplashCoord)(rectYMax + 1) <= yMax && length == 0) {
        return splashClipAllInside;
    }
    return splashClipPartial;
}

SplashClipResult SplashClip::testSpan(int spanXMin, int spanXMax, int spanY)
{
    int i;

    // This tests the rectangle:
    //     x = [spanXMin, spanXMax + 1)    (note: span coords are ints)
    //     y = [spanY, spanY + 1)
    // against the clipping region:
    //     x = [xMin, xMax)                (note: clipping coords are fp)
    //     y = [yMin, yMax)
    if ((SplashCoord)(spanXMax + 1) <= xMin || (SplashCoord)spanXMin >= xMax || (SplashCoord)(spanY + 1) <= yMin || (SplashCoord)spanY >= yMax) {
        return splashClipAllOutside;
    }
    if (!((SplashCoord)spanXMin >= xMin && (SplashCoord)(spanXMax + 1) <= xMax && (SplashCoord)spanY >= yMin && (SplashCoord)(spanY + 1) <= yMax)) {
        return splashClipPartial;
    }
    if (antialias) {
        for (i = 0; i < length; ++i) {
            if (!scanners[i]->testSpan(spanXMin * splashAASize, spanXMax * splashAASize + (splashAASize - 1), spanY * splashAASize)) {
                return splashClipPartial;
            }
        }
    } else {
        for (i = 0; i < length; ++i) {
            if (!scanners[i]->testSpan(spanXMin, spanXMax, spanY)) {
                return splashClipPartial;
            }
        }
    }
    return splashClipAllInside;
}

void SplashClip::clipAALine(SplashBitmap *aaBuf, int *x0, int *x1, int y, bool adjustVertLine)
{
    int xx0, xx1, xx, yy, i;
    SplashColorPtr p;

    // zero out pixels with x < xMin
    xx0 = *x0 * splashAASize;
    xx1 = splashFloor(xMin * splashAASize);
    if (xx1 > aaBuf->getWidth()) {
        xx1 = aaBuf->getWidth();
    }
    if (xx0 < xx1) {
        xx0 &= ~7;
        for (yy = 0; yy < splashAASize; ++yy) {
            p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx0 >> 3);
            for (xx = xx0; xx + 7 < xx1; xx += 8) {
                *p++ = 0;
            }
            if (xx < xx1 && !adjustVertLine) {
                *p &= 0xff >> (xx1 & 7);
            }
        }
        *x0 = splashFloor(xMin);
    }

    // zero out pixels with x > xMax
    xx0 = splashFloor(xMax * splashAASize) + 1;
    if (xx0 < 0) {
        xx0 = 0;
    }
    xx1 = (*x1 + 1) * splashAASize;
    if (xx0 < xx1 && !adjustVertLine) {
        for (yy = 0; yy < splashAASize; ++yy) {
            p = aaBuf->getDataPtr() + yy * aaBuf->getRowSize() + (xx0 >> 3);
            xx = xx0;
            if (xx & 7) {
                *p &= 0xff00 >> (xx & 7);
                xx = (xx & ~7) + 8;
                ++p;
            }
            for (; xx < xx1; xx += 8) {
                *p++ = 0;
            }
        }
        *x1 = splashFloor(xMax);
    }

    // check the paths
    for (i = 0; i < length; ++i) {
        scanners[i]->clipAALine(aaBuf, x0, x1, y);
    }
    if (*x0 > *x1) {
        *x0 = *x1;
    }
    if (*x0 < 0) {
        *x0 = 0;
    }
    if ((*x0 >> 1) >= aaBuf->getRowSize()) {
        xx0 = *x0;
        *x0 = (aaBuf->getRowSize() - 1) << 1;
        if (xx0 & 1) {
            *x0 = *x0 + 1;
        }
    }
    if (*x1 < *x0) {
        *x1 = *x0;
    }
    if ((*x1 >> 1) >= aaBuf->getRowSize()) {
        xx0 = *x1;
        *x1 = (aaBuf->getRowSize() - 1) << 1;
        if (xx0 & 1) {
            *x1 = *x1 + 1;
        }
    }
}

bool SplashClip::testClipPaths(int x, int y)
{
    if (antialias) {
        x *= splashAASize;
        y *= splashAASize;
    }

    for (int i = 0; i < length; ++i) {
        if (!scanners[i]->test(x, y)) {
            return false;
        }
    }

    return true;
}