From d96819756a30e82b52798487343a4fcbdec11a88 Mon Sep 17 00:00:00 2001 From: scuri Date: Fri, 27 Nov 2009 22:44:15 +0000 Subject: Fixed: polygon filling in the IMAGERGB driver when the segments contain horizontal lines. --- src/sim/sim_linepolyfill.c | 345 +++++++++++++++++++++++++++++++-------------- 1 file changed, 240 insertions(+), 105 deletions(-) (limited to 'src/sim/sim_linepolyfill.c') diff --git a/src/sim/sim_linepolyfill.c b/src/sim/sim_linepolyfill.c index 1a20907..74c98c1 100644 --- a/src/sim/sim_linepolyfill.c +++ b/src/sim/sim_linepolyfill.c @@ -76,8 +76,11 @@ static int compare_int(const int* xx1, const int* xx2) return *xx1 - *xx2; } -void simAddSegment(simLineSegment* segment, int x1, int y1, int x2, int y2, int *y_max, int *y_min) +int simAddSegment(simLineSegment* segment, int x1, int y1, int x2, int y2, int *y_max, int *y_min) { + if (x1==x2 && y1==y2) + return 0; + /* Make sure p2.y > p1.y */ if (y1 > y2) { @@ -108,7 +111,7 @@ void simAddSegment(simLineSegment* segment, int x1, int y1, int x2, int y2, int if (segment->DeltaY > segment->DeltaX) { if (segment->DeltaY==0) /* do not compute for horizontal segments */ - return; + return 1; /* Y-major line; calculate 16-bit fixed-point fractional part of a pixel that X advances each time Y advances 1 pixel, truncating the @@ -118,7 +121,7 @@ void simAddSegment(simLineSegment* segment, int x1, int y1, int x2, int y2, int else { if (segment->DeltaX==0) /* do not compute for vertical segments */ - return; + return 1; /* It's an X-major line; calculate 16-bit fixed-point fractional part of a pixel that Y advances each time X advances 1 pixel, truncating the @@ -131,9 +134,11 @@ void simAddSegment(simLineSegment* segment, int x1, int y1, int x2, int y2, int *y_max = y2; if (y1 < *y_min) *y_min = y1; + + return 1; } -int simSegmentInc(simLineSegment* segment, cdCanvas* canvas, int y) +int simSegmentInc(simLineSegment* segment) { unsigned short ErrorAccTemp, Weighting; @@ -248,7 +253,7 @@ static void simPolyAAPixels(cdCanvas *canvas, simIntervalList* line_int_list, in /* Line is not horizontal, diagonal, or vertical */ - /* start and end pixels are not necessary + /* highest and lowest pixels are not necessary since they are always drawn in the previous step. */ ErrorAcc = 0; /* initialize the line error accumulator to 0 */ @@ -357,142 +362,272 @@ static void simLineIntervallAdd(simIntervalList* line_int_list, int x1, int x2) line_int_list->n += 2; } -void simPolyFill(cdSimulation* simulation, cdPoint* poly, int n) +void simPolyMakeSegments(simLineSegment *segments, int *n_seg, cdPoint* poly, int n, int *max_hh, int *y_max, int *y_min) +{ + int i, i1; + *y_max = poly[0].y; + *y_min = poly[0].y; + *max_hh=0, *n_seg = n; + for(i = 0; i < n; i++) + { + i1 = (i+1)%n; /* next point(i+1), next of last(n-1) is first(0) */ + if (simAddSegment(segments, poly[i].x, poly[i].y, poly[i1].x, poly[i1].y, y_max, y_min)) + { + if (poly[i].y == poly[i1].y) + (*max_hh)++; /* increment the number of horizontal segments */ + + segments++; + } + else + (*n_seg)--; + } +} + +static void simAddHxx(int *hh, int *hh_count, int x1, int x2) +{ + /* It will add a closed interval in a list of closed intervals. + But if some intersect then they must be merged. */ + + int i, count = *hh_count; + + if (x1 > x2) + { + int t = x2; + x2 = x1; + x1 = t; + } + + for (i=0; i= h_begin AND x_begin <= h_end */ + if (x2 >= hh[i] && x1 <= hh[i+1]) + { + /* there is some intersection, merge interval and remove point */ + if (hh[i] < x1) + x1 = hh[i]; + if (hh[i+1] > x2) + x2 = hh[i+1]; + + memmove(hh+i, hh+i+2, (count-(i+2))*sizeof(int)); + count -= 2; + } + } + + /* no intersection, add both points at the end */ + hh[count] = x1; + hh[count+1] = x2; + *hh_count = count + 2; +} + +static void simMergeHxx(int *xx, int *xx_count, int *hh, int hh_count) +{ + int hh_i; + + if (*xx_count == 0) + { + memcpy(xx, hh, hh_count*sizeof(int)); + *xx_count = hh_count; + return; + } + + /* remember that xx and hh both have an even number of points, + and all pairs are intervals. + So infact this call will behave as simAddHxx for each pair of hh. */ + for (hh_i=0; hh_iy1 || y > seg_i->y2) + continue; + + /* if it is an horizontal line, then store the segment in a separate buffer. */ + if (seg_i->y1 == seg_i->y2) /* because of the previous test, also implies "==y" */ + { + int prev_y, next_y; + int i_next = (i==n_seg-1)? 0: i+1; + int i_prev = (i==0)? n_seg-1: i-1; + simLineSegment *seg_i_next = segments + i_next; + simLineSegment *seg_i_prev = segments + i_prev; + + simAddHxx(hh, &hh_count, seg_i->x1, seg_i->x2); + + /* save the previous y, not in the horizontal line */ + if (seg_i_prev->y1 == y) + prev_y = seg_i_prev->y2; + else + prev_y = seg_i_prev->y1; + + /* include horizontal segments that are in a sequence */ + while (seg_i_next->y1 == seg_i_next->y2 && i < n_seg) + { + simAddHxx(hh, &hh_count, seg_i_next->x1, seg_i_next->x2); + + i++; + i_next = (i==n_seg-1)? 0: i+1; + seg_i_next = segments + i_next; + } + + /* save the next y, not in the horizontal line */ + if (seg_i_next->y1 == y) + next_y = seg_i_next->y2; + else + next_y = seg_i_next->y1; + + /* if the horizontal line is part of a step |_ then compute a normal intersection in the middle */ + /* | */ + if ((next_y > y && prev_y < y) || + (next_y < y && prev_y > y)) + { + xx[xx_count++] = (seg_i->x1+seg_i->x2)/2; /* save the intersection point, any value inside the segment will be fine */ + } + } + else if (y == seg_i->y1) /* intersection at the lowest point (x1,y1) */ + { + int i_next = (i==n_seg-1)? 0: i+1; + int i_prev = (i==0)? n_seg-1: i-1; + simLineSegment *seg_i_next = segments + i_next; + simLineSegment *seg_i_prev = segments + i_prev; + + /* but add only if it does not belongs to an horizontal line */ + if (!((seg_i_next->y1 == y && seg_i_next->y2 == y) || /* next is an horizontal line */ + (seg_i_prev->y1 == y && seg_i_prev->y2 == y))) /* previous is an horizontal line */ + { + xx[xx_count++] = seg_i->x1; /* save the intersection point */ + } + } + else if (y == seg_i->y2) /* intersection at the highest point (x2,y2) */ + { + int i_next = (i==n_seg-1)? 0: i+1; + int i_prev = (i==0)? n_seg-1: i-1; + simLineSegment *seg_i_next = segments + i_next; + simLineSegment *seg_i_prev = segments + i_prev; + + /* Normally do nothing, because this point is duplicated in another segment, + i.e only save the intersection point for (y2) if not handled by (y1) of another segment. + The exception is the top-corner points (^). */ + if ((seg_i_next->y2 == y && seg_i_next->x2 == seg_i->x2 && seg_i_next->y1 != y) || + (seg_i_prev->y2 == y && seg_i_prev->x2 == seg_i->x2 && seg_i_prev->y1 != y)) + { + xx[xx_count++] = seg_i->x2; /* save the intersection point */ + } + } + else /* if ((y > seg_i->y1) && (y < seg_i->y2)) intersection inside the segment */ + { + xx[xx_count++] = simSegmentInc(seg_i); /* save the intersection point */ + } + } + + /* if outside the canvas, ignore the intervals and */ + /* continue since the segments where updated in simSegmentInc. */ + if (y > height-1) + return 0; + + /* sort the intervals */ + if (xx_count) + qsort(xx, xx_count, sizeof(int), (int (*)(const void*,const void*))compare_int); + + /* add the horizontal segments. */ + if (hh_count) + { + simMergeHxx(xx, &xx_count, hh, hh_count); + + /* sort again */ + if (xx_count) + qsort(xx, xx_count, sizeof(int), (int (*)(const void*,const void*))compare_int); + } + + return xx_count; +} + +void simPolyFill(cdSimulation* simulation, cdPoint* poly, int n) +{ + /***********IMPORTANT: this function is used as a reference for irgbClipPoly in "cdirgb.c", + if a change is made here, must be reflected there, and vice-versa */ simIntervalList* line_int_list, *line_il; int y_max, y_min, i, y, i1, fill_mode, num_lines, - inter_count, width, height, *xx; + xx_count, width, height, *xx, *hh, max_hh, n_seg; - simLineSegment *segment = (simLineSegment *)malloc(n*sizeof(simLineSegment)); + /* alloc maximum number of segments */ + simLineSegment *segments = (simLineSegment *)malloc(n*sizeof(simLineSegment)); width = simulation->canvas->w; height = simulation->canvas->h; fill_mode = simulation->canvas->fill_mode; - y_max = poly[0].y; - y_min = poly[0].y; - for(i = 0; i < n; i++) - { - i1 = (i+1)%n; /* next point(i+1), next of last(n-1) is first(0) */ - simAddSegment(segment+i, poly[i].x, poly[i].y, poly[i1].x, poly[i1].y, &y_max, &y_min); - } + simPolyMakeSegments(segments, &n_seg, poly, n, &max_hh, &y_max, &y_min); if (y_min > height-1 || y_max < 0) { - free(segment); + free(segments); return; } if (y_min < 0) y_min = 0; + /* number of horizontal lines */ if (y_max > height-1) num_lines = height-y_min; else num_lines = y_max-y_min+1; + /* will store all horizontal intervals for each horizontal line, + will be used to draw the antialiased and incomplete pixels */ line_int_list = malloc(sizeof(simIntervalList)*num_lines); memset(line_int_list, 0, sizeof(simIntervalList)*num_lines); - xx = (int*)malloc((n+1)*sizeof(int)); + /* buffer to store the current horizontal intervals during the fill of an horizontal line */ + xx = (int*)malloc((n+1)*sizeof(int)); /* allocated to the maximum number of possible intervals in one line */ + hh = (int*)malloc((2*max_hh)*sizeof(int)); /* for all horizontal lines between y_max and y_min */ for(y = y_max; y >= y_min; y--) { - inter_count = 0; - - /* for all segments, calculates the intervals to be filled - from the intersection with the horizontal line y. */ - for(i = 0; i < n; i++) - { - seg_i = segment + i; - - /* if the minimum Y coordinate of the segment is greater than the current y, then ignore the segment. */ - /* if it is an horizontal line, then ignore the segment. */ - if (seg_i->y1 > y || - seg_i->y1 == seg_i->y2) - continue; - - if (y == seg_i->y1) /* intersection at the start point (x1,y1) */ - { - int i_next = (i==n-1)? 0: i+1; - int i_prev = (i==0)? n-1: i-1; - simLineSegment *seg_i_next = segment + i_next; - simLineSegment *seg_i_prev = segment + i_prev; - - /* always save at least one intersection point for (y1) */ - - xx[inter_count++] = seg_i->x1; /* save the intersection point */ - - /* check for missing bottom-corner points (|_|), must duplicate the intersection */ - if ((seg_i_next->y1 == y && seg_i_next->y2 == seg_i_next->y1) || /* next is an horizontal line */ - (seg_i_prev->y1 == y && seg_i_prev->y2 == seg_i_prev->y1)) /* previous is an horizontal line */ - { - xx[inter_count++] = seg_i->x1; /* save the intersection point */ - } - } - else if ((y > seg_i->y1) && (y < seg_i->y2)) /* intersection inside the segment, do not include y2 */ - { - xx[inter_count++] = simSegmentInc(seg_i, simulation->canvas, y); /* save the intersection point */ - } - else if (y == seg_i->y2) /* intersection at the end point (x2,y2) */ - { - int i_next = (i==n-1)? 0: i+1; - int i_prev = (i==0)? n-1: i-1; - simLineSegment *seg_i_next = segment + i_next; - simLineSegment *seg_i_prev = segment + i_prev; - - /* only save the intersection point for (y2) if not handled by (y1) of another segment */ - - /* check for missing top-corner points (^) or (|ŻŻ|) */ - if ((seg_i_next->y2 == y && seg_i_next->y2 == seg_i_next->y1) || /* next is an horizontal line */ - (seg_i_prev->y2 == y && seg_i_prev->y2 == seg_i_prev->y1) || /* previous is an horizontal line */ - (seg_i_next->y2 == y && seg_i_next->x2 == seg_i->x2 && seg_i_next->x1 != seg_i->x1) || - (seg_i_prev->y2 == y && seg_i_prev->x2 == seg_i->x2 && seg_i_prev->x1 != seg_i->x1)) - { - xx[inter_count++] = seg_i->x2; /* save the intersection point */ - } - } - } - - /* if outside the canvas, ignore the intervals and */ - /* continue since the segments where updated. */ - if (y > height-1 || inter_count == 0) + xx_count = simPolyFindHorizontalIntervals(segments, n_seg, xx, hh, y, height); + if (xx_count < 2) continue; - /* sort the intervals */ - qsort(xx, inter_count, sizeof(int), (int (*)(const void*,const void*))compare_int); - line_il = line_int_list+(y-y_min); - simLineIntervallInit(line_il, inter_count*2); + simLineIntervallInit(line_il, xx_count*2); /* for all intervals, fill the interval */ - for(i = 0; i < inter_count; i += 2) /* process only pairs */ + for(i = 0; i < xx_count; i += 2) /* process only pairs */ { - if (fill_mode == CD_EVENODD) - { - /* since it fills only pairs of intervals, */ - /* it is the EVENODD fill rule. */ - simFillHorizLine(simulation, xx[i], y, xx[i+1]); - simLineIntervallAdd(line_il, xx[i], xx[i+1]); - } - else + /* fills only pairs of intervals, */ + simFillHorizLine(simulation, xx[i], y, xx[i+1]); + simLineIntervallAdd(line_il, xx[i], xx[i+1]); + + if ((fill_mode == CD_WINDING) && /* NOT EVENODD */ + ((i+2 < xx_count) && (xx[i+1] < xx[i+2])) && /* avoid point intervals */ + simIsPointInPolyWind(poly, n, (xx[i+1]+xx[i+2])/2, y)) /* the next interval is inside the polygon */ { - simFillHorizLine(simulation, xx[i], y, xx[i+1]); - simLineIntervallAdd(line_il, xx[i], xx[i+1]); - if ((i+2 < inter_count) && (xx[i+1] < xx[i+2])) /* avoid point intervals */ - if (simIsPointInPolyWind(poly, n, (xx[i+1]+xx[i+2])/2, y)) /* if the next interval is inside the polygon then fill it */ - { - simFillHorizLine(simulation, xx[i+1], y, xx[i+2]); - simLineIntervallAdd(line_il, xx[i+1], xx[i+2]); - } + simFillHorizLine(simulation, xx[i+1], y, xx[i+2]); + simLineIntervallAdd(line_il, xx[i+1], xx[i+2]); } } } free(xx); - free(segment); + free(hh); + free(segments); /* Once the polygon has been filled, now let's draw the * antialiased and incomplete pixels at the edges */ @@ -500,7 +635,7 @@ void simPolyFill(cdSimulation* simulation, cdPoint* poly, int n) if (y_max > height-1) y_max = height-1; - /* Go through all line segments of the poly */ + /* Go through all line segments of the polygon */ for(i = 0; i < n; i++) { i1 = (i+1)%n; @@ -709,7 +844,7 @@ void simLineThin(cdCanvas* canvas, int x1, int y1, int x2, int y2) weighting for the paired pixel. Combine the Weighting with the existing alpha, When Weighting is zero alpha must be fully preserved. */ - aa_alpha = ((255-Weighting) * alpha) / 255; + aa_alpha = (unsigned char)(((255-Weighting) * alpha) / 255); aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha); _cdLineDrawPixel(canvas, x1, y1, ls, aa_fgcolor, bgcolor); @@ -760,7 +895,7 @@ void simLineThin(cdCanvas* canvas, int x1, int y1, int x2, int y2) weighting for the paired pixel. Combine the Weighting with the existing alpha, When Weighting is zero alpha must be fully preserved. */ - aa_alpha = ((255-Weighting) * alpha) / 255; + aa_alpha = (unsigned char)(((255-Weighting) * alpha) / 255); aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha); _cdLineDrawPixel(canvas, x1, y1, ls, aa_fgcolor, bgcolor); @@ -824,7 +959,7 @@ void simfLineThin(cdCanvas* canvas, double x1, double y1, double x2, double y2, int y1i = _cdRound(y1), y2i = _cdRound(y2); int yi_first = y1i; - int yi_last = y2i, xi_last; + int yi_last = y2i, xi_last = 0; if (y1i > y2i) _cdSwapInt(y1i, y2i); @@ -845,7 +980,7 @@ void simfLineThin(cdCanvas* canvas, double x1, double y1, double x2, double y2, /* Combine the Weighting with the existing alpha, When Weighting is zero alpha must be fully preserved. */ - aa_alpha = (int)((1.0-(x - xi)) * alpha); + aa_alpha = (unsigned char)((1.0-(x - xi)) * alpha); if (no_antialias) { @@ -915,7 +1050,7 @@ void simfLineThin(cdCanvas* canvas, double x1, double y1, double x2, double y2, int x1i = _cdRound(x1), x2i = _cdRound(x2); int xi_first = x1i; - int xi_last = x2i, yi_last; + int xi_last = x2i, yi_last = 0; if (x1i > x2i) _cdSwapInt(x1i, x2i); @@ -931,7 +1066,7 @@ void simfLineThin(cdCanvas* canvas, double x1, double y1, double x2, double y2, /* Combine the Weighting with the existing alpha, When Weighting is zero alpha must be fully preserved. */ - aa_alpha = (int)((1.0-(y - yi)) * alpha); + aa_alpha = (unsigned char)((1.0-(y - yi)) * alpha); if (no_antialias) { -- cgit v1.2.3