diff options
Diffstat (limited to 'xorg-server/hw/xfree86/xf4bpp/mfbline.c')
-rw-r--r-- | xorg-server/hw/xfree86/xf4bpp/mfbline.c | 976 |
1 files changed, 976 insertions, 0 deletions
diff --git a/xorg-server/hw/xfree86/xf4bpp/mfbline.c b/xorg-server/hw/xfree86/xf4bpp/mfbline.c new file mode 100644 index 000000000..d2d4e0b0e --- /dev/null +++ b/xorg-server/hw/xfree86/xf4bpp/mfbline.c @@ -0,0 +1,976 @@ +/*********************************************************** + +Copyright (c) 1987 X Consortium + +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 +X CONSORTIUM 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 X Consortium 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 X Consortium. + + +Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts. + + All Rights Reserved + +Permission to use, copy, modify, and distribute this software and its +documentation for any purpose and without fee is hereby granted, +provided that the above copyright notice appear in all copies and that +both that copyright notice and this permission notice appear in +supporting documentation, and that the name of Digital not be +used in advertising or publicity pertaining to distribution of the +software without specific, written prior permission. + +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. + +******************************************************************/ +/* GJA -- modified this file for vga16 */ + +#ifdef HAVE_XORG_CONFIG_H +#include <xorg-config.h> +#endif + +#include <stdlib.h> + +#include "xf4bpp.h" +#include "OScompiler.h" +#include "mfbmap.h" +#include "mfb.h" +#include "maskbits.h" +#include "mi.h" +#include "miline.h" +#include "vgaVideo.h" +#include "wm3.h" + +#include "xf86str.h" /* for pScrn->vtSema */ +extern ScrnInfoPtr *xf86Screens; + +/* single-pixel lines on a color frame buffer + + NON-SLOPED LINES + horizontal lines are always drawn left to right; we have to +move the endpoints right by one after they're swapped. + horizontal lines will be confined to a single band of a +region. the code finds that band (giving up if the lower +bound of the band is above the line we're drawing); then it +finds the first box in that band that contains part of the +line. we clip the line to subsequent boxes in that band. + vertical lines are always drawn top to bottom (y-increasing.) +this requires adding one to the y-coordinate of each endpoint +after swapping. + + SLOPED LINES + when clipping a sloped line, we bring the second point inside +the clipping box, rather than one beyond it, and then add 1 to +the length of the line before drawing it. this lets us use +the same box for finding the outcodes for both endpoints. since +the equation for clipping the second endpoint to an edge gives us +1 beyond the edge, we then have to move the point towards the +first point by one step on the major axis. + eventually, there will be a diagram here to explain what's going +on. the method uses Cohen-Sutherland outcodes to determine +outsideness, and a method similar to Pike's layers for doing the +actual clipping. + +*/ +#ifdef POLYSEGMENT +static void DoV16SegmentSS( + DrawablePtr, GCPtr, int, xSegment* +); + +void +xf4bppSegmentSS (pDrawable, pGC, nseg, pSeg) + DrawablePtr pDrawable; + GCPtr pGC; + int nseg; + register xSegment *pSeg; +{ + if ( ! xf86Screens[pDrawable->pScreen->myNum]->vtSema ) { + miPolySegment(pDrawable, pGC, nseg, pSeg); + } else { + DO_WM3(pGC,DoV16SegmentSS (pDrawable, pGC, nseg, pSeg)); + } +} + +#else +static void DoV16LineSS( + DrawablePtr, GCPtr, int, int, DDXPointPtr +); + +void +xf4bppLineSS (pDrawable, pGC, mode, npt, pptInit) + DrawablePtr pDrawable; + GCPtr pGC; + int mode; /* Origin or Previous */ + int npt; /* number of points */ + DDXPointPtr pptInit; +{ + if ( ! xf86Screens[pDrawable->pScreen->myNum]->vtSema ) { + miZeroLine(pDrawable, pGC, mode, npt, pptInit); + } else { + DO_WM3(pGC,DoV16LineSS (pDrawable, pGC, mode, npt, pptInit)); + } +} +#endif + +static void +#ifdef POLYSEGMENT +DoV16SegmentSS (pDrawable, pGC, nseg, pSeg) + DrawablePtr pDrawable; + GCPtr pGC; + int nseg; + register xSegment *pSeg; +#else +DoV16LineSS (pDrawable, pGC, mode, npt, pptInit) + DrawablePtr pDrawable; + GCPtr pGC; + int mode; /* Origin or Previous */ + int npt; /* number of points */ + DDXPointPtr pptInit; +#endif +{ + int nboxInit; + register int nbox; + BoxPtr pboxInit; + register BoxPtr pbox; +#ifndef POLYSEGMENT + register DDXPointPtr ppt; /* pointer to list of translated points */ +#endif + + unsigned int oc1; /* outcode of point 1 */ + unsigned int oc2; /* outcode of point 2 */ + + PixelType *addrlBase; /* pointer to start of drawable */ +#ifndef POLYSEGMENT + PixelType *addrl; /* address of destination pixmap */ +#endif + int nlwidth; /* width in longwords of destination pixmap */ + int xorg, yorg; /* origin of window */ + + int adx; /* abs values of dx and dy */ + int ady; + int signdx; /* sign of dx and dy */ + int signdy; + int e, e1, e2; /* bresenham error and increments */ + int len; /* length of segment */ + int axis; /* major axis */ + int octant; + unsigned int bias = miGetZeroLineBias(pDrawable->pScreen); + + /* a bunch of temporaries */ + register int y1, y2; + register int x1, x2; + RegionPtr cclip; +#ifndef POLYSEGMENT + int alu = pGC->alu; /* GJA */ +#endif + + if (!(pGC->planemask & 0x0F)) + return; + + cclip = pGC->pCompositeClip; + pboxInit = REGION_RECTS(cclip); + nboxInit = REGION_NUM_RECTS(cclip); + + nlwidth = BYTES_PER_LINE(pDrawable) >> 2; /* GJA */ + addrlBase = (PixelType *)VIDBASE(pDrawable); /* GJA */ + + xorg = pDrawable->x; + yorg = pDrawable->y; +#ifdef POLYSEGMENT + while (nseg--) +#else + ppt = pptInit; + x2 = ppt->x + xorg; + y2 = ppt->y + yorg; + while(--npt) +#endif + { + nbox = nboxInit; + pbox = pboxInit; + +#ifdef POLYSEGMENT + x1 = pSeg->x1 + xorg; + y1 = pSeg->y1 + yorg; + x2 = pSeg->x2 + xorg; + y2 = pSeg->y2 + yorg; + pSeg++; +#else + x1 = x2; + y1 = y2; + ++ppt; + if (mode == CoordModePrevious) + { + xorg = x1; + yorg = y1; + } + x2 = ppt->x + xorg; + y2 = ppt->y + yorg; +#endif + + if (x1 == x2) /* vertical line */ + { + /* make the line go top to bottom of screen, keeping + endpoint semantics + */ + if (y1 > y2) + { + register int tmp; + + tmp = y2; + y2 = y1 + 1; + y1 = tmp + 1; +#ifdef POLYSEGMENT + if (pGC->capStyle != CapNotLast) + y1--; +#endif + } +#ifdef POLYSEGMENT + else if (pGC->capStyle != CapNotLast) + y2++; +#endif + /* get to first band that might contain part of line */ + while ((nbox) && (pbox->y2 <= y1)) + { + pbox++; + nbox--; + } + + if (nbox) + { + /* stop when lower edge of box is beyond end of line */ + while((nbox) && (y2 >= pbox->y1)) + { + if ((x1 >= pbox->x1) && (x1 < pbox->x2)) + { + int y1t, y2t; + /* this box has part of the line in it */ + y1t = max(y1, pbox->y1); + y2t = min(y2, pbox->y2); + if (y1t != y2t) + { + xf4bppVertS (addrlBase, nlwidth, + x1, y1t, y2t-y1t); + } + } + nbox--; + pbox++; + } + } +#ifndef POLYSEGMENT + y2 = ppt->y + yorg; +#endif + } + else if (y1 == y2) /* horizontal line */ + { + /* force line from left to right, keeping + endpoint semantics + */ + if (x1 > x2) + { + register int tmp; + + tmp = x2; + x2 = x1 + 1; + x1 = tmp + 1; +#ifdef POLYSEGMENT + if (pGC->capStyle != CapNotLast) + x1--; +#endif + } +#ifdef POLYSEGMENT + else if (pGC->capStyle != CapNotLast) + x2++; +#endif + + /* find the correct band */ + while( (nbox) && (pbox->y2 <= y1)) + { + pbox++; + nbox--; + } + + /* try to draw the line, if we haven't gone beyond it */ + if ((nbox) && (pbox->y1 <= y1)) + { + int tmp; + + /* when we leave this band, we're done */ + tmp = pbox->y1; + while((nbox) && (pbox->y1 == tmp)) + { + int x1t, x2t; + + if (pbox->x2 <= x1) + { + /* skip boxes until one might contain start point */ + nbox--; + pbox++; + continue; + } + + /* stop if left of box is beyond right of line */ + if (pbox->x1 >= x2) + { + nbox = 0; + break; + } + + x1t = max(x1, pbox->x1); + x2t = min(x2, pbox->x2); + if (x1t != x2t) + { + xf4bppHorzS (addrlBase, nlwidth, + x1t, y1, x2t-x1t); + } + nbox--; + pbox++; + } + } +#ifndef POLYSEGMENT + x2 = ppt->x + xorg; +#endif + } + else /* sloped line */ + { + CalcLineDeltas(x1, y1, x2, y2, adx, ady, signdx, signdy, + 1, 1, octant); + + if (adx > ady) + { + axis = X_AXIS; + e1 = ady << 1; + e2 = e1 - (adx << 1); + e = e1 - adx; + } + else + { + axis = Y_AXIS; + e1 = adx << 1; + e2 = e1 - (ady << 1); + e = e1 - ady; + SetYMajorOctant(octant); + } + + FIXUP_ERROR(e, octant, bias); + + /* we have bresenham parameters and two points. + all we have to do now is clip and draw. + */ + + while(nbox--) + { + oc1 = 0; + oc2 = 0; + OUTCODES(oc1, x1, y1, pbox); + OUTCODES(oc2, x2, y2, pbox); + if ((oc1 | oc2) == 0) + { + if (axis == X_AXIS) + len = adx; + else + len = ady; +#ifdef POLYSEGMENT + if (pGC->capStyle != CapNotLast) + len++; +#endif + xf4bppBresS (addrlBase, nlwidth, + signdx, signdy, axis, x1, y1, + e, e1, e2, len); + break; + } + else if (oc1 & oc2) + { + pbox++; + } + else + { + int new_x1 = x1, new_y1 = y1, new_x2 = x2, new_y2 = y2; + int clip1 = 0, clip2 = 0; + int clipdx, clipdy; + int err; + + if (miZeroClipLine(pbox->x1, pbox->y1, pbox->x2-1, + pbox->y2-1, + &new_x1, &new_y1, &new_x2, &new_y2, + adx, ady, &clip1, &clip2, + octant, bias, oc1, oc2) == -1) + { + pbox++; + continue; + } + + if (axis == X_AXIS) + len = abs(new_x2 - new_x1); + else + len = abs(new_y2 - new_y1); +#ifdef POLYSEGMENT + if (clip2 != 0 || pGC->capStyle != CapNotLast) + len++; +#else + len += (clip2 != 0); +#endif + if (len) + { + /* unwind bresenham error term to first point */ + if (clip1) + { + clipdx = abs(new_x1 - x1); + clipdy = abs(new_y1 - y1); + if (axis == X_AXIS) + err = e+((clipdy*e2) + ((clipdx-clipdy)*e1)); + else + err = e+((clipdx*e2) + ((clipdy-clipdx)*e1)); + } + else + err = e; + xf4bppBresS (addrlBase, nlwidth, + signdx, signdy, axis, new_x1, new_y1, + err, e1, e2, len); + } + pbox++; + } + } /* while (nbox--) */ + } /* sloped line */ + } /* while (nline--) */ + +#ifndef POLYSEGMENT + + /* paint the last point if the end style isn't CapNotLast. + (Assume that a projecting, butt, or round cap that is one + pixel wide is the same as the single pixel of the endpoint.) + */ + + if ((pGC->capStyle != CapNotLast) && + ((ppt->x + xorg != pptInit->x + pDrawable->x) || + (ppt->y + yorg != pptInit->y + pDrawable->y) || + (ppt == pptInit + 1))) + { + PixelType _mask; + + if (alu == RROP_BLACK) + _mask = mfbGetrmask(x2 & PIM); + else + _mask = mfbGetmask(x2 & PIM); + + nbox = nboxInit; + pbox = pboxInit; + while (nbox--) + { + if ((x2 >= pbox->x1) && + (y2 >= pbox->y1) && + (x2 < pbox->x2) && + (y2 < pbox->y2)) + { + addrl = mfbScanline(addrlBase, x2, y2, nlwidth); + UPDRW(addrl,_mask); + break; + } + else + pbox++; + } + } +#endif +} + +/* + * Draw dashed 1-pixel lines. + */ + +#ifdef POLYSEGMENT +static void DoV16SegmentSD( + DrawablePtr, GCPtr, int, xSegment* +); + +void +xf4bppSegmentSD (pDrawable, pGC, nseg, pSeg) + DrawablePtr pDrawable; + GCPtr pGC; + int nseg; + register xSegment *pSeg; +{ + if ( ! xf86Screens[pDrawable->pScreen->myNum]->vtSema ) { + miPolySegment(pDrawable, pGC, nseg, pSeg); + } else { + DO_WM3(pGC,DoV16SegmentSD (pDrawable, pGC, nseg, pSeg)); + } +} + +#else +static void DoV16LineSD( + DrawablePtr, GCPtr, int, int, DDXPointPtr +); + +void +xf4bppLineSD (pDrawable, pGC, mode, npt, pptInit) + DrawablePtr pDrawable; + GCPtr pGC; + int mode; /* Origin or Previous */ + int npt; /* number of points */ + DDXPointPtr pptInit; +{ + if ( ! xf86Screens[pDrawable->pScreen->myNum]->vtSema ) { + miZeroDashLine(pDrawable, pGC, mode, npt, pptInit); + } else { + DO_WM3(pGC,DoV16LineSD (pDrawable, pGC, mode, npt, pptInit)); + } +} +#endif + +static void +#ifdef POLYSEGMENT +DoV16SegmentSD (pDrawable, pGC, nseg, pSeg) + DrawablePtr pDrawable; + register GCPtr pGC; + int nseg; + register xSegment *pSeg; +#else +DoV16LineSD( pDrawable, pGC, mode, npt, pptInit) + DrawablePtr pDrawable; + register GCPtr pGC; + int mode; /* Origin or Previous */ + int npt; /* number of points */ + DDXPointPtr pptInit; +#endif +{ + int nboxInit; + register int nbox; + BoxPtr pboxInit; + register BoxPtr pbox; +#ifndef POLYSEGMENT + register DDXPointPtr ppt; /* pointer to list of translated points */ +#endif + + register unsigned int oc1; /* outcode of point 1 */ + register unsigned int oc2; /* outcode of point 2 */ + + PixelType *addrl; /* address of destination pixmap */ + int nlwidth; /* width in longwords of destination pixmap */ + int xorg, yorg; /* origin of window */ + + int adx; /* abs values of dx and dy */ + int ady; + int signdx; /* sign of dx and dy */ + int signdy; + int e, e1, e2; /* bresenham error and increments */ + int len; /* length of segment */ + int axis; /* major axis */ + int octant; + unsigned int bias = miGetZeroLineBias(pDrawable->pScreen); + int x1, x2, y1, y2; + RegionPtr cclip; + int fgink, bgink; /* GJA */ + unsigned char *pDash; + int dashOffset; + int numInDashList; + int dashIndex; + int isDoubleDash; + int dashIndexTmp, dashOffsetTmp; + int unclippedlen; + + if (!(pGC->planemask & 0x0F)) + return; + + cclip = pGC->pCompositeClip; + fgink = bgink = pGC->fgPixel; /* GJA */ + pboxInit = REGION_RECTS(cclip); + nboxInit = REGION_NUM_RECTS(cclip); + + nlwidth = BYTES_PER_LINE(pDrawable) >> 2; /* GJA */ + addrl = (PixelType *)VIDBASE(pDrawable); /* GJA */ + + /* compute initial dash values */ + + pDash = (unsigned char *) pGC->dash; + numInDashList = pGC->numInDashList; + isDoubleDash = (pGC->lineStyle == LineDoubleDash); + dashIndex = 0; + dashOffset = 0; + miStepDash ((int)pGC->dashOffset, &dashIndex, pDash, + numInDashList, &dashOffset); + + if (isDoubleDash) + bgink = pGC->bgPixel; /* GJA */ + + xorg = pDrawable->x; + yorg = pDrawable->y; +#ifdef POLYSEGMENT + while (nseg--) +#else + ppt = pptInit; + x2 = ppt->x + xorg; + y2 = ppt->y + yorg; + while(--npt) +#endif + { + nbox = nboxInit; + pbox = pboxInit; + +#ifdef POLYSEGMENT + x1 = pSeg->x1 + xorg; + y1 = pSeg->y1 + yorg; + x2 = pSeg->x2 + xorg; + y2 = pSeg->y2 + yorg; + pSeg++; +#else + x1 = x2; + y1 = y2; + ++ppt; + if (mode == CoordModePrevious) + { + xorg = x1; + yorg = y1; + } + x2 = ppt->x + xorg; + y2 = ppt->y + yorg; +#endif + + CalcLineDeltas(x1, y1, x2, y2, adx, ady, signdx, signdy, 1, 1, octant); + + if (adx > ady) + { + axis = X_AXIS; + e1 = ady << 1; + e2 = e1 - (adx << 1); + e = e1 - adx; + unclippedlen = adx; + } + else + { + axis = Y_AXIS; + e1 = adx << 1; + e2 = e1 - (ady << 1); + e = e1 - ady; + unclippedlen = ady; + SetYMajorOctant(octant); + } + + FIXUP_ERROR(e, octant, bias); + + /* we have bresenham parameters and two points. + all we have to do now is clip and draw. + */ + + while(nbox--) + { + oc1 = 0; + oc2 = 0; + OUTCODES(oc1, x1, y1, pbox); + OUTCODES(oc2, x2, y2, pbox); + if ((oc1 | oc2) == 0) + { +#ifdef POLYSEGMENT + if (pGC->capStyle != CapNotLast) + unclippedlen++; + dashIndexTmp = dashIndex; + dashOffsetTmp = dashOffset; + xf4bppBresD (pDrawable, fgink, bgink, + &dashIndexTmp, pDash, numInDashList, + &dashOffsetTmp, isDoubleDash, + addrl, nlwidth, + signdx, signdy, axis, x1, y1, + e, e1, e2, unclippedlen); + break; +#else + xf4bppBresD (pDrawable, fgink, bgink, + &dashIndex, pDash, numInDashList, + &dashOffset, isDoubleDash, + addrl, nlwidth, + signdx, signdy, axis, x1, y1, + e, e1, e2, unclippedlen); + goto dontStep; +#endif + } + else if (oc1 & oc2) + { + pbox++; + } + else /* have to clip */ + { + int new_x1 = x1, new_y1 = y1, new_x2 = x2, new_y2 = y2; + int clip1 = 0, clip2 = 0; + int clipdx, clipdy; + int err; + + if (miZeroClipLine(pbox->x1, pbox->y1, pbox->x2-1, pbox->y2-1, + &new_x1, &new_y1, &new_x2, &new_y2, + adx, ady, &clip1, &clip2, + octant, bias, oc1, oc2) == -1) + { + pbox++; + continue; + } + dashIndexTmp = dashIndex; + dashOffsetTmp = dashOffset; + if (clip1) + { + int dlen; + + if (axis == X_AXIS) + dlen = abs(new_x1 - x1); + else + dlen = abs(new_y1 - y1); + miStepDash (dlen, &dashIndexTmp, pDash, + numInDashList, &dashOffsetTmp); + } + if (axis == X_AXIS) + len = abs(new_x2 - new_x1); + else + len = abs(new_y2 - new_y1); +#ifdef POLYSEGMENT + if (clip2 != 0 || pGC->capStyle != CapNotLast) + len++; +#else + len += (clip2 != 0); +#endif + if (len) + { + /* unwind bresenham error term to first point */ + if (clip1) + { + clipdx = abs(new_x1 - x1); + clipdy = abs(new_y1 - y1); + if (axis == X_AXIS) + err = e+((clipdy*e2) + ((clipdx-clipdy)*e1)); + else + err = e+((clipdx*e2) + ((clipdy-clipdx)*e1)); + } + else + err = e; + xf4bppBresD (pDrawable, fgink, bgink, + &dashIndexTmp, pDash, numInDashList, + &dashOffsetTmp, isDoubleDash, + addrl, nlwidth, + signdx, signdy, axis, new_x1, new_y1, + err, e1, e2, len); + } + pbox++; + } + } /* while (nbox--) */ +#ifndef POLYSEGMENT + /* + * walk the dash list around to the next line + */ + miStepDash (unclippedlen, &dashIndex, pDash, + numInDashList, &dashOffset); +dontStep: ; +#endif + } /* while (nline--) */ + +#ifndef POLYSEGMENT + /* paint the last point if the end style isn't CapNotLast. + (Assume that a projecting, butt, or round cap that is one + pixel wide is the same as the single pixel of the endpoint.) + */ + + if ((pGC->capStyle != CapNotLast) && + ((dashIndex & 1) == 0 || isDoubleDash) && + ((ppt->x + xorg != pptInit->x + pDrawable->x) || + (ppt->y + yorg != pptInit->y + pDrawable->y) || + (ppt == pptInit + 1))) + { + nbox = nboxInit; + pbox = pboxInit; + while (nbox--) + { + if ((x2 >= pbox->x1) && + (y2 >= pbox->y1) && + (x2 < pbox->x2) && + (y2 < pbox->y2)) + { + unsigned long _mask; + + _mask = mfbGetmask(x2 & PIM); + addrl = mfbScanline(addrl, x2, y2, nlwidth); + UPDRW(addrl,_mask); + break; + } + else + pbox++; + } + } +#endif +} + + +#if 0 +#ifndef POLYSEGMENT +/* + the clipping code could be cleaned up some; most of its +mess derives from originally being inline in the line code, +then pulled out to make clipping dashes easier. +*/ + +int +mfbClipLine(pbox, box, + ppt1Orig, ppt1, ppt2, + adx, ady, signdx, signdy, axis, + pclip1, pclip2) +BoxPtr pbox; /* box to clip to */ +BoxRec box; /* box to do calculations with */ +DDXPointPtr ppt1Orig, ppt1, ppt2; +int adx, ady; +int signdx, signdy; +register int axis; +int *pclip1, *pclip2; +{ + DDXPointRec pt1Orig, pt1, pt2; + register int swapped = 0; + int clipDone = 0; + register unsigned int utmp; + register int oc1, oc2; + int clip1, clip2; + + pt1Orig = *ppt1Orig; + pt1 = *ppt1; + pt2 = *ppt2; + clip1 = 0; + clip2 = 0; + + do + { + oc1 = 0; + oc2 = 0; + OUTCODES(oc1, pt1.x, pt1.y, pbox); + OUTCODES(oc2, pt2.x, pt2.y, pbox); + + if (oc1 & oc2) + clipDone = -1; + else if ((oc1 | oc2) == 0) + { + clipDone = 1; + if (swapped) + { + SWAPPT(pt1, pt2); + SWAPINT(oc1, oc2); + SWAPINT(clip1, clip2); + } + } + else /* have to clip */ + { + /* only clip one point at a time */ + if (!oc1) + { + SWAPPT(pt1, pt2); + SWAPINT(oc1, oc2); + SWAPINT(clip1, clip2); + swapped = !swapped; + } + + clip1 |= oc1; + if (oc1 & OUT_LEFT) + { + pt1.x = box.x1; + utmp = abs(box.x1 - pt1Orig.x); + utmp *= ady; + if(axis==X_AXIS) + { + pt1.y = pt1Orig.y + SignTimes(signdy, round(utmp, adx)); + } + else + { + utmp <<= 1; + if (swapped) + utmp += ady; + else + utmp -= ady; + pt1.y = pt1Orig.y + SignTimes(signdy, ceiling(utmp, 2*adx)); + if (swapped) + pt1.y -= signdy; + } + } + else if (oc1 & OUT_ABOVE) + { + pt1.y = box.y1; + utmp = abs(box.y1 - pt1Orig.y); + utmp *= adx; + if (axis == Y_AXIS) + { + pt1.x = pt1Orig.x + SignTimes(signdx, round(utmp, ady)); + } + else + { + utmp <<= 1; + if (swapped) + utmp += adx; + else + utmp -= adx; + pt1.x = pt1Orig.x + SignTimes(signdx, ceiling(utmp, 2*ady)); + if (swapped) + pt1.x -= signdx; + } + } + else if (oc1 & OUT_RIGHT) + { + pt1.x = box.x2; + utmp = abs(pt1Orig.x - box.x2); + utmp *= ady; + if (axis == X_AXIS) + { + pt1.y = pt1Orig.y + SignTimes(signdy, round(utmp, adx)); + } + else + { + utmp <<= 1; + if (swapped) + utmp += ady; + else + utmp -= ady; + pt1.y = pt1Orig.y + SignTimes(signdy, ceiling(utmp, 2*adx)); + if (swapped) + pt1.y -= signdy; + } + } + else if (oc1 & OUT_BELOW) + { + pt1.y = box.y2; + utmp = abs(pt1Orig.y - box.y2); + utmp *= adx; + if (axis == Y_AXIS) + { + pt1.x = pt1Orig.x + SignTimes(signdx, round(utmp, ady)); + } + else + { + utmp <<= 1; + if (swapped) + utmp += adx; + else + utmp -= adx; + pt1.x = pt1Orig.x + SignTimes(signdx, ceiling(utmp, 2*ady)); + if (swapped) + pt1.x -= signdx; + } + } + } /* else have to clip */ + } while(!clipDone); + *ppt1 = pt1; + *ppt2 = pt2; + *pclip1 = clip1; + *pclip2 = clip2; + + return clipDone; +} +#endif +#endif |