//========================================================================
//
// SplashFont.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) 2007-2008, 2010, 2014, 2019 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2018 Oliver Sander <oliver.sander@tu-dresden.de>
//
// 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 <climits>
#include <cstring>
#include "goo/gmem.h"
#include "SplashMath.h"
#include "SplashGlyphBitmap.h"
#include "SplashFontFile.h"
#include "SplashFont.h"

//------------------------------------------------------------------------

struct SplashFontCacheTag
{
    int c;
    short xFrac, yFrac; // x and y fractions
    int mru; // valid bit (0x80000000) and MRU index
    int x, y, w, h; // offset and size of glyph
};

//------------------------------------------------------------------------
// SplashFont
//------------------------------------------------------------------------

SplashFont::SplashFont(SplashFontFile *fontFileA, const SplashCoord *matA, const SplashCoord *textMatA, bool aaA)
{
    fontFile = fontFileA;
    fontFile->incRefCnt();
    mat[0] = matA[0];
    mat[1] = matA[1];
    mat[2] = matA[2];
    mat[3] = matA[3];
    textMat[0] = textMatA[0];
    textMat[1] = textMatA[1];
    textMat[2] = textMatA[2];
    textMat[3] = textMatA[3];
    aa = aaA;

    cache = nullptr;
    cacheTags = nullptr;

    xMin = yMin = xMax = yMax = 0;
}

void SplashFont::initCache()
{
    int i;

    // this should be (max - min + 1), but we add some padding to
    // deal with rounding errors
    glyphW = xMax - xMin + 3;
    glyphH = yMax - yMin + 3;
    if (glyphW > INT_MAX / glyphH) {
        glyphSize = -1;
    } else {
        if (aa) {
            glyphSize = glyphW * glyphH;
        } else {
            glyphSize = ((glyphW + 7) >> 3) * glyphH;
        }
    }

    // set up the glyph pixmap cache
    cacheAssoc = 8;
    if (glyphSize <= 64) {
        cacheSets = 32;
    } else if (glyphSize <= 128) {
        cacheSets = 16;
    } else if (glyphSize <= 256) {
        cacheSets = 8;
    } else if (glyphSize <= 512) {
        cacheSets = 4;
    } else if (glyphSize <= 1024) {
        cacheSets = 2;
    } else {
        cacheSets = 1;
    }
    cache = (unsigned char *)gmallocn_checkoverflow(cacheSets * cacheAssoc, glyphSize);
    if (cache != nullptr) {
        cacheTags = (SplashFontCacheTag *)gmallocn(cacheSets * cacheAssoc, sizeof(SplashFontCacheTag));
        for (i = 0; i < cacheSets * cacheAssoc; ++i) {
            cacheTags[i].mru = i & (cacheAssoc - 1);
        }
    } else {
        cacheAssoc = 0;
    }
}

SplashFont::~SplashFont()
{
    fontFile->decRefCnt();
    if (cache) {
        gfree(cache);
    }
    if (cacheTags) {
        gfree(cacheTags);
    }
}

bool SplashFont::getGlyph(int c, int xFrac, int yFrac, SplashGlyphBitmap *bitmap, int x0, int y0, SplashClip *clip, SplashClipResult *clipRes)
{
    SplashGlyphBitmap bitmap2;
    int size;
    unsigned char *p;
    int i, j, k;

    // no fractional coordinates for large glyphs or non-anti-aliased
    // glyphs
    if (!aa || glyphH > 50) {
        xFrac = yFrac = 0;
    }

    // check the cache
    i = (c & (cacheSets - 1)) * cacheAssoc;
    for (j = 0; j < cacheAssoc; ++j) {
        if ((cacheTags[i + j].mru & 0x80000000) && cacheTags[i + j].c == c && (int)cacheTags[i + j].xFrac == xFrac && (int)cacheTags[i + j].yFrac == yFrac) {
            bitmap->x = cacheTags[i + j].x;
            bitmap->y = cacheTags[i + j].y;
            bitmap->w = cacheTags[i + j].w;
            bitmap->h = cacheTags[i + j].h;
            for (k = 0; k < cacheAssoc; ++k) {
                if (k != j && (cacheTags[i + k].mru & 0x7fffffff) < (cacheTags[i + j].mru & 0x7fffffff)) {
                    ++cacheTags[i + k].mru;
                }
            }
            cacheTags[i + j].mru = 0x80000000;
            bitmap->aa = aa;
            bitmap->data = cache + (i + j) * glyphSize;
            bitmap->freeData = false;

            *clipRes = clip->testRect(x0 - bitmap->x, y0 - bitmap->y, x0 - bitmap->x + bitmap->w - 1, y0 - bitmap->y + bitmap->h - 1);

            return true;
        }
    }

    // generate the glyph bitmap
    if (!makeGlyph(c, xFrac, yFrac, &bitmap2, x0, y0, clip, clipRes)) {
        return false;
    }

    if (*clipRes == splashClipAllOutside) {
        bitmap->freeData = false;
        if (bitmap2.freeData)
            gfree(bitmap2.data);
        return true;
    }

    // if the glyph doesn't fit in the bounding box, return a temporary
    // uncached bitmap
    if (bitmap2.w > glyphW || bitmap2.h > glyphH) {
        *bitmap = bitmap2;
        return true;
    }

    // insert glyph pixmap in cache
    if (aa) {
        size = bitmap2.w * bitmap2.h;
    } else {
        size = ((bitmap2.w + 7) >> 3) * bitmap2.h;
    }
    p = nullptr; // make gcc happy
    if (cacheAssoc == 0) {
        // we had problems on the malloc of the cache, so ignore it
        *bitmap = bitmap2;
    } else {
        for (j = 0; j < cacheAssoc; ++j) {
            if ((cacheTags[i + j].mru & 0x7fffffff) == cacheAssoc - 1) {
                cacheTags[i + j].mru = 0x80000000;
                cacheTags[i + j].c = c;
                cacheTags[i + j].xFrac = (short)xFrac;
                cacheTags[i + j].yFrac = (short)yFrac;
                cacheTags[i + j].x = bitmap2.x;
                cacheTags[i + j].y = bitmap2.y;
                cacheTags[i + j].w = bitmap2.w;
                cacheTags[i + j].h = bitmap2.h;
                p = cache + (i + j) * glyphSize;
                memcpy(p, bitmap2.data, size);
            } else {
                ++cacheTags[i + j].mru;
            }
        }
        *bitmap = bitmap2;
        bitmap->data = p;
        bitmap->freeData = false;
        if (bitmap2.freeData) {
            gfree(bitmap2.data);
        }
    }
    return true;
}