/* Copyright 2014 Adobe Systems Incorporated (http://www.adobe.com/). All Rights Reserved.
   This software is licensed as OpenSource, under the Apache License, Version 2.0. This license is available at: http://opensource.org/licenses/Apache-2.0. */
/***********************************************************************/

/*
 *  Horizontal metrics table.
 */

#include "hmtx.h"

/* ---------------------------- Table Definition --------------------------- */
typedef struct {
    uFWord advanceWidth;
    FWord lsb;
} LongHorMetrics;

typedef struct {
    dnaDCL(LongHorMetrics, hMetrics);
    dnaDCL(FWord, leftSideBearing);
} hmtxTbl;

/* --------------------------- Context Definition -------------------------- */
struct hmtxCtx_ {
    unsigned short nLongHorMetrics;
    unsigned short nLeftSideBearings;
    hmtxTbl tbl; /* Table data */
    hotCtx g;    /* Package context */
};

/* --------------------------- Standard Functions -------------------------- */

void hmtxNew(hotCtx g) {
    hmtxCtx h = MEM_NEW(g, sizeof(struct hmtxCtx_));

    dnaINIT(g->DnaCTX, h->tbl.hMetrics, 315, 14000);
    dnaINIT(g->DnaCTX, h->tbl.leftSideBearing, 315, 14000);

    /* Link contexts */
    h->g = g;
    g->ctx.hmtx = h;
}

int hmtxFill(hotCtx g) {
    hmtxCtx h = g->ctx.hmtx;
    int i;
    int j;
    FWord width;

    /* Fill table */
    dnaSET_CNT(h->tbl.hMetrics, g->font.glyphs.cnt);
    for (i = 0; i < h->tbl.hMetrics.cnt; i++) {
        LongHorMetrics *metric = &h->tbl.hMetrics.array[i];
        hotGlyphInfo *glyph = &g->font.glyphs.array[i];
        metric->advanceWidth = glyph->hAdv;
        metric->lsb = glyph->bbox.left;
    }

    /* Optimize metrics */
    width = h->tbl.hMetrics.array[h->tbl.hMetrics.cnt - 1].advanceWidth;
    for (i = h->tbl.hMetrics.cnt - 2; i >= 0; i--) {
        if (h->tbl.hMetrics.array[i].advanceWidth != width) {
            break;
        }
    }

    /* Construct left side-bearing array */
    dnaSET_CNT(h->tbl.leftSideBearing, h->tbl.hMetrics.cnt - i - 2);
    j = 0;
    for (i += 2; i < h->tbl.hMetrics.cnt; i++) {
        h->tbl.leftSideBearing.array[j++] = h->tbl.hMetrics.array[i].lsb;
    }
    h->tbl.hMetrics.cnt -= h->tbl.leftSideBearing.cnt;

    return 1;
}

void hmtxWrite(hotCtx g) {
    long i;
    hmtxCtx h = g->ctx.hmtx;

    /* Write horizontal metrics */
    for (i = 0; i < h->tbl.hMetrics.cnt; i++) {
        LongHorMetrics *metric = &h->tbl.hMetrics.array[i];
        OUT2(metric->advanceWidth);
        OUT2(metric->lsb);
    }

    /* Write left side-bearings */
    for (i = 0; i < h->tbl.leftSideBearing.cnt; i++) {
        OUT2(h->tbl.leftSideBearing.array[i]);
    }
}

void hmtxReuse(hotCtx g) {
}

void hmtxFree(hotCtx g) {
    hmtxCtx h = g->ctx.hmtx;
    dnaFREE(h->tbl.hMetrics);
    dnaFREE(h->tbl.leftSideBearing);
    MEM_FREE(g, g->ctx.hmtx);
}

/* ------------------------ Supplementary Functions ------------------------ */

int hmtxGetNLongHorMetrics(hotCtx g) {
    hmtxCtx h = g->ctx.hmtx;
    return h->tbl.hMetrics.cnt;
}
