mizerline.c 11 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
/***********************************************************

Copyright 1987, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

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
OPEN GROUP 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 of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.

Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.

                        All Rights Reserved

29 30
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
31
provided that the above copyright notice appear in all copies and that
32
both that copyright notice and this permission notice appear in
33 34
supporting documentation, and that the name of Digital not be
used in advertising or publicity pertaining to distribution of the
35
software without specific, written prior permission.
36 37 38 39 40 41 42 43 44 45

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

******************************************************************/
46 47 48 49
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

50
#include <X11/X.h>
51

52
#include "misc.h"
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98
#include "scrnintstr.h"
#include "gcstruct.h"
#include "windowstr.h"
#include "pixmap.h"
#include "mi.h"
#include "miline.h"

/* Draw lineSolid, fillStyle-independent zero width lines.
 *
 * Must keep X and Y coordinates in "ints" at least until after they're
 * translated and clipped to accomodate CoordModePrevious lines with very
 * large coordinates.
 *
 * Draws the same pixels regardless of sign(dx) or sign(dy).
 *
 * Ken Whaley
 *
 */

/* largest positive value that can fit into a component of a point.
 * Assumes that the point structure is {type x, y;} where type is
 * a signed type.
 */
#define MAX_COORDINATE ((1 << (((sizeof(DDXPointRec) >> 1) << 3) - 1)) - 1)

#define MI_OUTPUT_POINT(xx, yy)\
{\
    if ( !new_span && yy == current_y)\
    {\
        if (xx < spans->x)\
	    spans->x = xx;\
	++*widths;\
    }\
    else\
    {\
        ++Nspans;\
	++spans;\
	++widths;\
	spans->x = xx;\
	spans->y = yy;\
	*widths = 1;\
	current_y = yy;\
        new_span = FALSE;\
    }\
}

99
void
100 101 102
miZeroLine(DrawablePtr pDraw, GCPtr pGC, int mode,      /* Origin or Previous */
           int npt,             /* number of points */
           DDXPointPtr pptInit)
103
{
104
    int Nspans, current_y = 0;
105
    DDXPointPtr ppt;
106 107 108 109
    DDXPointPtr pspanInit, spans;
    int *pwidthInit, *widths, list_len;
    int xleft, ytop, xright, ybottom;
    int new_x1, new_y1, new_x2, new_y2;
110
    int x = 0, y = 0, x1, y1, x2, y2, xstart, ystart;
111 112 113 114 115 116 117 118 119 120
    int oc1, oc2;
    int result;
    int pt1_clipped, pt2_clipped = 0;
    Bool new_span;
    int signdx, signdy;
    int clipdx, clipdy;
    int width, height;
    int adx, ady;
    int octant;
    unsigned int bias = miGetZeroLineBias(pDraw->pScreen);
121 122
    int e, e1, e2, e3;          /* Bresenham error terms */
    int length;                 /* length of lines == # of pixels on major axis */
123

124 125 126
    xleft = pDraw->x;
    ytop = pDraw->y;
    xright = pDraw->x + pDraw->width - 1;
127 128
    ybottom = pDraw->y + pDraw->height - 1;

129 130 131 132 133 134
    if (!pGC->miTranslate) {
        /* do everything in drawable-relative coordinates */
        xleft = 0;
        ytop = 0;
        xright -= pDraw->x;
        ybottom -= pDraw->y;
135 136 137 138 139 140 141
    }

    /* it doesn't matter whether we're in drawable or screen coordinates,
     * FillSpans simply cannot take starting coordinates outside of the
     * range of a DDXPointRec component.
     */
    if (xright > MAX_COORDINATE)
142
        xright = MAX_COORDINATE;
143
    if (ybottom > MAX_COORDINATE)
144
        ybottom = MAX_COORDINATE;
145 146 147 148 149 150 151 152

    /* since we're clipping to the drawable's boundaries & coordinate
     * space boundaries, we're guaranteed that the larger of width/height
     * is the longest span we'll need to output
     */
    width = xright - xleft + 1;
    height = ybottom - ytop + 1;
    list_len = (height >= width) ? height : width;
153 154
    pspanInit = xallocarray(list_len, sizeof(DDXPointRec));
    pwidthInit = xallocarray(list_len, sizeof(int));
155
    if (!pspanInit || !pwidthInit) {
156 157 158
        free(pspanInit);
        free(pwidthInit);
        return;
159
    }
160 161
    Nspans = 0;
    new_span = TRUE;
162
    spans = pspanInit - 1;
163 164 165 166 167
    widths = pwidthInit - 1;
    ppt = pptInit;

    xstart = ppt->x;
    ystart = ppt->y;
168 169 170
    if (pGC->miTranslate) {
        xstart += pDraw->x;
        ystart += pDraw->y;
171
    }
172

173 174 175 176 177 178 179 180
    /* x2, y2, oc2 copied to x1, y1, oc1 at top of loop to simplify
     * iteration logic
     */
    x2 = xstart;
    y2 = ystart;
    oc2 = 0;
    MIOUTCODES(oc2, x2, y2, xleft, ytop, xright, ybottom);

181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
    while (--npt > 0) {
        x1 = x2;
        y1 = y2;
        oc1 = oc2;
        ++ppt;

        x2 = ppt->x;
        y2 = ppt->y;
        if (pGC->miTranslate && (mode != CoordModePrevious)) {
            x2 += pDraw->x;
            y2 += pDraw->y;
        }
        else if (mode == CoordModePrevious) {
            x2 += x1;
            y2 += y1;
        }

        oc2 = 0;
        MIOUTCODES(oc2, x2, y2, xleft, ytop, xright, ybottom);

        CalcLineDeltas(x1, y1, x2, y2, adx, ady, signdx, signdy, 1, 1, octant);

203 204 205 206 207 208 209 210
        if (ady + 1 > (list_len - Nspans)) {
            (*pGC->ops->FillSpans) (pDraw, pGC, Nspans, pspanInit,
                                    pwidthInit, FALSE);
            Nspans = 0;
            spans = pspanInit - 1;
            widths = pwidthInit - 1;
        }
        new_span = TRUE;
211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237
        if (adx > ady) {
            e1 = ady << 1;
            e2 = e1 - (adx << 1);
            e = e1 - adx;
            length = adx;       /* don't draw endpoint in main loop */

            FIXUP_ERROR(e, octant, bias);

            new_x1 = x1;
            new_y1 = y1;
            new_x2 = x2;
            new_y2 = y2;
            pt1_clipped = 0;
            pt2_clipped = 0;

            if ((oc1 | oc2) != 0) {
                result = miZeroClipLine(xleft, ytop, xright, ybottom,
                                        &new_x1, &new_y1, &new_x2, &new_y2,
                                        adx, ady,
                                        &pt1_clipped, &pt2_clipped,
                                        octant, bias, oc1, oc2);
                if (result == -1)
                    continue;

                length = abs(new_x2 - new_x1);

                /* if we've clipped the endpoint, always draw the full length
238
                 * of the segment, because then the capstyle doesn't matter
239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297
                 */
                if (pt2_clipped)
                    length++;

                if (pt1_clipped) {
                    /* must calculate new error terms */
                    clipdx = abs(new_x1 - x1);
                    clipdy = abs(new_y1 - y1);
                    e += (clipdy * e2) + ((clipdx - clipdy) * e1);
                }
            }

            /* draw the segment */

            x = new_x1;
            y = new_y1;

            e3 = e2 - e1;
            e = e - e1;

            while (length--) {
                MI_OUTPUT_POINT(x, y);
                e += e1;
                if (e >= 0) {
                    y += signdy;
                    e += e3;
                }
                x += signdx;
            }
        }
        else {                  /* Y major line */

            e1 = adx << 1;
            e2 = e1 - (ady << 1);
            e = e1 - ady;
            length = ady;       /* don't draw endpoint in main loop */

            SetYMajorOctant(octant);
            FIXUP_ERROR(e, octant, bias);

            new_x1 = x1;
            new_y1 = y1;
            new_x2 = x2;
            new_y2 = y2;
            pt1_clipped = 0;
            pt2_clipped = 0;

            if ((oc1 | oc2) != 0) {
                result = miZeroClipLine(xleft, ytop, xright, ybottom,
                                        &new_x1, &new_y1, &new_x2, &new_y2,
                                        adx, ady,
                                        &pt1_clipped, &pt2_clipped,
                                        octant, bias, oc1, oc2);
                if (result == -1)
                    continue;

                length = abs(new_y2 - new_y1);

                /* if we've clipped the endpoint, always draw the full length
298
                 * of the segment, because then the capstyle doesn't matter
299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
                 */
                if (pt2_clipped)
                    length++;

                if (pt1_clipped) {
                    /* must calculate new error terms */
                    clipdx = abs(new_x1 - x1);
                    clipdy = abs(new_y1 - y1);
                    e += (clipdx * e2) + ((clipdy - clipdx) * e1);
                }
            }

            /* draw the segment */

            x = new_x1;
            y = new_y1;

            e3 = e2 - e1;
            e = e - e1;

            while (length--) {
                MI_OUTPUT_POINT(x, y);
                e += e1;
                if (e >= 0) {
                    x += signdx;
                    e += e3;
                }
                y += signdy;
            }
        }
329 330 331 332 333 334 335
    }

    /* only do the capnotlast check on the last segment
     * and only if the endpoint wasn't clipped.  And then, if the last
     * point is the same as the first point, do not draw it, unless the
     * line is degenerate
     */
336 337 338 339
    if ((!pt2_clipped) && (pGC->capStyle != CapNotLast) &&
        (((xstart != x2) || (ystart != y2)) || (ppt == pptInit + 1))) {
        MI_OUTPUT_POINT(x, y);
    }
340 341

    if (Nspans > 0)
342 343
        (*pGC->ops->FillSpans) (pDraw, pGC, Nspans, pspanInit,
                                pwidthInit, FALSE);
344

345 346
    free(pwidthInit);
    free(pspanInit);
347 348
}

349
void
350 351 352
miZeroDashLine(DrawablePtr dst, GCPtr pgc, int mode, int nptInit,       /* number of points in polyline */
               DDXPointRec * pptInit    /* points in the polyline */
    )
353 354 355
{
    /* XXX kludge until real zero-width dash code is written */
    pgc->lineWidth = 1;
356
    miWideDash(dst, pgc, mode, nptInit, pptInit);
357 358
    pgc->lineWidth = 0;
}