xref: /xsrc/external/mit/xterm/dist/linedata.c

/* $XTermId: linedata.c,v 1.107 2024/12/01 20:27:00 tom Exp $ */

/*
 * Copyright 2009-2023,2024 by Thomas E. Dickey
 *
 *                         All Rights Reserved
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name(s) of the above copyright
 * holders shall not be used in advertising or otherwise to promote the
 * sale, use or other dealings in this Software without prior written
 * authorization.
 */

#include <xterm.h>
#include <data.h>

#include <assert.h>

/*
 * Given a row-number, find the corresponding data for the line in the VT100
 * widget.  Row numbers can be positive or negative.
 *
 * If the data comes from the scrollback, defer that to getScrollback().
 */
LineData *
getLineData(TScreen *screen, int row)
{
    LineData *result = NULL;
    ScrnBuf buffer;
    int max_row = LastRowNumber(screen);

    if (row >= 0) {
	buffer = screen->visbuf;
    } else {
	buffer = NULL;
	result = getScrollback(screen, row);
    }
    if (row >= 0 && row <= max_row) {
	result = (LineData *) scrnHeadAddr(screen, buffer, (unsigned) row);
    }

    return result;
}

/*
 * Copy line's data, e.g., from one screen buffer to another, given the preset
 * pointers for the destination.
 *
 * TODO: optionally prune unused combining character data from the result.
 */
void
copyLineData(LineData *dst, CLineData *src)
{
    if (dst == NULL || src == NULL || dst == src)
	return;

    dst->bufHead = src->bufHead;

#if OPT_WIDE_CHARS
    dst->combSize = src->combSize;
#endif

    /*
     * Usually we're copying the same-sized line; a memcpy is faster than
     * several loops.
     */
    if (dst->lineSize == src->lineSize) {
	size_t size = (sizeof(dst->attribs[0])
#if OPT_ISO_COLORS
		       + sizeof(dst->color[0])
#endif
		       + sizeof(dst->charData[0])
#if OPT_WIDE_CHARS
		       + sizeof(dst->combData[0][0]) * dst->combSize
#endif
#if OPT_DEC_RECTOPS
		       + sizeof(dst->charSeen[0])
		       + sizeof(dst->charSets[0])
#endif
	);

	memcpy(dst->attribs, src->attribs, size * dst->lineSize);
    } else {
	Dimension col;
	Dimension limit = ((dst->lineSize < src->lineSize)
			   ? dst->lineSize
			   : src->lineSize);
#if OPT_WIDE_CHARS
	Char comb;
#endif

	for (col = 0; col < limit; ++col) {
	    dst->attribs[col] = src->attribs[col];
#if OPT_ISO_COLORS
	    dst->color[col] = src->color[col];
#endif
	    dst->charData[col] = src->charData[col];
#if OPT_DEC_RECTOPS
	    dst->charSeen[col] = src->charSeen[col];
	    dst->charSets[col] = src->charSets[col];
#endif
#if OPT_WIDE_CHARS
	    for (comb = 0; comb < dst->combSize; ++comb) {
		dst->combData[comb][col] = src->combData[comb][col];
	    }
#endif
	}
	for (col = limit; col < dst->lineSize; ++col) {
	    dst->attribs[col] = 0;
#if OPT_ISO_COLORS
	    dst->color[col] = initCColor;
#endif
	    dst->charData[col] = 0;
#if OPT_DEC_RECTOPS
	    dst->charSeen[col] = 0;
	    dst->charSets[col] = 0;
#endif
#if OPT_WIDE_CHARS
	    for (comb = 0; comb < dst->combSize; ++comb) {
		dst->combData[comb][col] = 0;
	    }
#endif
	}
    }
}

#if OPT_WIDE_CHARS
#define initLineExtra(screen) \
    screen->lineExtra = ((size_t) (screen->max_combining) * sizeof(IChar *)); \
    screen->cellExtra = ((size_t) (screen->max_combining) * sizeof(IChar))
#else
#define initLineExtra(screen) \
    screen->lineExtra = 0; \
    screen->cellExtra = 0
#endif

/*
 * CellData size depends on the "combiningChars" resource.
 */
#define CellDataSize(screen) (SizeOfCellData + screen->cellExtra)

#define CellDataAddr(screen, data, cell) \
	( (CellData *)(void *) ((char *)data + (cell * CellDataSize(screen))) )
#define ConstCellDataAddr(screen, data, cell) \
	( (const CellData *)(const void *) ( \
	      (const char *)data + (cell * CellDataSize(screen))) )

void
initLineData(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    initLineExtra(screen);

#if OPT_WIDE_CHARS
    TRACE(("initLineData %lu (%d combining chars)\n",
	   (unsigned long) screen->lineExtra, screen->max_combining));
#else
    TRACE(("initLineData\n"));
#endif

    /*
     * Per-line size/offsets.
     */
    TRACE(("** sizeof(LineData)  %lu\n", (unsigned long) sizeof(LineData)));
    TRACE(("   offset(lineSize)  %lu\n", (unsigned long) offsetof(LineData, lineSize)));
    TRACE(("   offset(bufHead)   %lu\n", (unsigned long) offsetof(LineData, bufHead)));
#if OPT_WIDE_CHARS
    TRACE(("   offset(combSize)  %lu\n", (unsigned long) offsetof(LineData, combSize)));
#endif
#if OPT_DEC_RECTOPS
    TRACE(("   offset(*charSeen) %lu\n", (unsigned long) offsetof(LineData, charSeen)));
    TRACE(("   offset(*charSets) %lu\n", (unsigned long) offsetof(LineData, charSets)));
#endif
    TRACE(("   offset(*attribs)  %lu\n", (unsigned long) offsetof(LineData, attribs)));
#if OPT_ISO_COLORS
    TRACE(("   offset(*color)    %lu\n", (unsigned long) offsetof(LineData, color)));
#endif
    TRACE(("   offset(*charData) %lu\n", (unsigned long) offsetof(LineData, charData)));
    TRACE(("   offset(*combData) %lu\n", (unsigned long) offsetof(LineData, combData)));

    /*
     * Per-cell size/offsets.
     */
    TRACE(("** sizeof(CellData)  %lu\n", (unsigned long) CellDataSize(screen)));
    TRACE(("   offset(attribs)   %lu\n", (unsigned long) offsetof(CellData, attribs)));
#if OPT_WIDE_CHARS
    TRACE(("   offset(combSize)  %lu\n", (unsigned long) offsetof(CellData, combSize)));
#endif
#if OPT_DEC_RECTOPS
    TRACE(("   offset(charSeen)  %lu\n", (unsigned long) offsetof(CellData, charSeen)));
    TRACE(("   offset(charSets)  %lu\n", (unsigned long) offsetof(CellData, charSets)));
#endif
#if OPT_ISO_COLORS
    TRACE(("   offset(color)     %lu\n", (unsigned long) offsetof(CellData, color)));
#endif
    TRACE(("   offset(charData)  %lu\n", (unsigned long) offsetof(CellData, charData)));
    TRACE(("   offset(combData)  %lu\n", (unsigned long) offsetof(CellData, combData)));

    /*
     * Data-type sizes.
     */
#if OPT_ISO_COLORS
    TRACE(("** sizeof(CellColor) %lu\n", (unsigned long) sizeof(CellColor)));
#endif
    TRACE(("** sizeof(IAttr)     %lu\n", (unsigned long) sizeof(IAttr)));
    TRACE(("** sizeof(IChar)     %lu\n", (unsigned long) sizeof(IChar)));
    TRACE(("** sizeof(RowData)   %lu\n", (unsigned long) sizeof(RowData)));
}

CellData *
newCellData(XtermWidget xw, Cardinal count)
{
    CellData *result;
    TScreen *screen = TScreenOf(xw);

    initLineExtra(screen);
    result = (CellData *) calloc((size_t) count, (size_t) CellDataSize(screen));
    return result;
}

void
saveCellData(TScreen *screen,
	     CellData *data,
	     Cardinal cell,
	     CLineData *ld,
	     XTermRect *limits,
	     int column)
{
    CellData *item = CellDataAddr(screen, data, cell);

    (void) limits;
    if (column < MaxCols(screen)) {
	item->attribs = ld->attribs[column];
	if_OPT_ISO_COLORS(screen, {
	    item->color = ld->color[column];
	});
	if_OPT_DEC_RECTOPS({
	    item->charSeen = ld->charSeen[column];
	    item->charData = ld->charData[column];
	});
	if_OPT_WIDE_CHARS(screen, {
	    size_t off;
	    Bool blank = (((item->charData == HIDDEN_CHAR)
			   && (limits == NULL
			       || (column + 1) == limits->left))
			  || (item->charData != HIDDEN_CHAR
			      && WideCells(item->charData) > 1
			      && (limits == NULL
				  || (column + 1) >= limits->right)));
	    if (blank) {
		if_OPT_DEC_RECTOPS(item->charSeen = ' ');
		item->charData = (CharData) ' ';
	    }
	    item->combSize = blank ? 0 : ld->combSize;
	    if_OPT_DEC_RECTOPS(item->charSets = (blank
						 ? 0
						 : ld->charSets[column]));
	    for_each_combData(off, item) {
		item->combData[off] = ld->combData[off][column];
	    }
	});
	TRACE2(("SAVED::%s\n", visibleIChars(&(item->charData), 1)));
    }
}

void
restoreCellData(TScreen *screen,
		const CellData *data,
		Cardinal cell,
		LineData *ld,
		XTermRect *limits,
		int column)
{
    const CellData *item = ConstCellDataAddr(screen, data, cell);

    (void) limits;
    if (column < MaxCols(screen)) {
	ld->attribs[column] = item->attribs;
	TRACE2(("BEFORE:%2d:%s\n", column + 1, visibleIChars(ld->charData, ld->lineSize)));
	if_OPT_ISO_COLORS(screen, {
	    ld->color[column] = item->color;
	});
	if_OPT_DEC_RECTOPS({
	    ld->charSeen[column] = item->charSeen;
	    ld->charSets[column] = item->charSets;
	});
	ld->charData[column] = item->charData;
	if_OPT_WIDE_CHARS(screen, {
	    size_t off;
	    ld->combSize = item->combSize;
	    if_OPT_DEC_RECTOPS(ld->charSets[column] = item->charSets);
	    for_each_combData(off, ld) {
		ld->combData[off][column] = item->combData[off];
	    }
	});
	TRACE2(("AFTER::%2d:%s\n", column + 1, visibleIChars(ld->charData, ld->lineSize)));
    }
}