First commit - moving from LuaForge to SourceForge

1 files changed, 1000 insertions, 0 deletions

diff --git a/src/sim/sim_linepolyfill.c b/src/sim/sim_linepolyfill.c
new file mode 100644
index 0000000..1a20907
--- /dev/null
+++ b/src/sim/sim_linepolyfill.c
@@ -0,0 +1,1000 @@
+/** \file
+ * \brief Primitives of the Simulation Base Driver
+ *
+ * See Copyright Notice in cd.h
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <memory.h>
+#include <assert.h>
+
+#include "cd.h"
+#include "cd_private.h"
+#include "cd_truetype.h"
+#include "sim.h"
+
+
+/* para estilos de linha usando rotacao de bits */
+static const unsigned short int simLineStyleBitTable[5]=
+{ 
+  0xFFFF, /* CD_CONTINUOUS  */
+  0xFF00, /* CD_DASHED      */
+  0x1111, /* CD_DOTTED      */
+  0xFE10, /* CD_DASH_DOT    */
+  0xFF24, /* CD_DASH_DOT_DOT*/
+};
+int simLineStyleNoReset = 0;
+static unsigned short int simLineStyleLastBits = 0;
+
+#define simRotateLineStyle(_x) (((_x) & 0x8000)? ((_x) << 1)|(0x0001): ((_x) << 1))
+
+#define INTENSITYSHIFT 8  /* # of bits by which to shift ErrorAcc to get intensity level */
+
+
+/* Point in Polygon was obtained from:
+   www.geometryalgorithms.com/Archive/algorithm_0103/algorithm_0103.htm
+
+   Copyright 2001, softSurfer (www.softsurfer.com)
+   This code may be freely used and modified for any purpose
+   providing that this copyright notice is included with it.
+   SoftSurfer makes no warranty for this code, and cannot be held
+   liable for any real or imagined damage resulting from its use.
+*/
+
+#define isLeft( _P0, _P1, _x, _y )  ((_P1.x - _P0.x)*(_y - _P0.y) - (_x - _P0.x)*(_P1.y - _P0.y))
+
+int simIsPointInPolyWind(cdPoint* poly, int n, int x, int y)
+{
+  int i, i1, 
+      wn = 0;  /* the winding number counter  */
+
+  for (i = 0; i < n; i++) 
+  {   
+    i1 = (i+1)%n; /* next point(i+1), next of last(n-1) is first(0) */
+
+    if (poly[i].y <= y) 
+    {         
+      if (poly[i1].y > y)      /* an upward crossing */
+        if (isLeft(poly[i], poly[i1], x, y) > 0)  /* P left of edge */
+          ++wn;                /* have a valid up intersect */
+    }
+    else 
+    {                       
+      if (poly[i1].y <= y)     /* a downward crossing */
+        if (isLeft(poly[i], poly[i1], x, y) < 0)  /* P right of edge */
+          --wn;                /* have a valid down intersect */
+    }
+  }
+
+  return wn;
+}
+
+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)
+{
+  /* Make sure p2.y > p1.y */
+  if (y1 > y2) 
+  {
+    _cdSwapInt(y1, y2);
+    _cdSwapInt(x1, x2);
+  }
+
+  segment->x1 = x1;
+  segment->y1 = y1;
+  segment->x2 = x2;
+  segment->y2 = y2;
+
+  segment->x = x2;  /* initial value */
+  
+  segment->DeltaY = y2 - y1;
+  segment->DeltaX = x2 - x1;
+  if (segment->DeltaX >= 0)
+    segment->XDir = -1;  /* inverted from simLineThin since here is from p2 to p1 */
+  else 
+  {
+    segment->XDir = 1;
+    segment->DeltaX = -segment->DeltaX; /* make DeltaX positive */
+  }
+
+  segment->ErrorAcc = 0;  /* initialize the line error accumulator to 0 */
+
+  /* Is this an X-major or Y-major line? */
+  if (segment->DeltaY > segment->DeltaX) 
+  {
+    if (segment->DeltaY==0)  /* do not compute for horizontal segments */
+      return;
+
+    /* Y-major line; calculate 16-bit fixed-point fractional part of a
+    pixel that X advances each time Y advances 1 pixel, truncating the
+    result so that we won't overrun the endpoint along the X axis */
+    segment->ErrorInc = (unsigned short)(((unsigned long)segment->DeltaX << 16) / (unsigned long)segment->DeltaY);
+  }
+  else
+  {
+    if (segment->DeltaX==0)  /* do not compute for vertical segments */
+      return;
+
+    /* 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
+    result to avoid overrunning the endpoint along the X axis */
+    segment->ErrorInc = (unsigned short)(((unsigned long)segment->DeltaY << 16) / (unsigned long)segment->DeltaX);
+  }
+
+  /* also calculates y_max and y_min of the polygon */
+  if (y2 > *y_max)
+    *y_max = y2;
+  if (y1 < *y_min)
+    *y_min = y1;
+}
+
+int simSegmentInc(simLineSegment* segment, cdCanvas* canvas, int y)
+{
+  unsigned short ErrorAccTemp, Weighting;
+
+  if (segment->DeltaY == 0) 
+  {
+    /* Horizontal line */
+    while (segment->DeltaX-- != 0) 
+      segment->x += segment->XDir;
+    return segment->x;
+  }
+
+  if (segment->DeltaX == 0) 
+  {
+    /* Vertical line */
+    segment->DeltaY--;
+    return segment->x;
+  }
+
+  if (segment->DeltaX == segment->DeltaY) 
+  {
+    /* Perfect Diagonal line */
+    segment->x += segment->XDir;
+    segment->DeltaY--;
+    return segment->x;
+  }
+
+  /* Is this an X-major or Y-major line? */
+  if (segment->DeltaY > segment->DeltaX) 
+  {
+    /* Increment pixels other than the first and last */
+    ErrorAccTemp = segment->ErrorAcc;   /* remember currrent accumulated error */
+    segment->ErrorAcc += segment->ErrorInc;      /* calculate error for next pixel */
+    if (segment->ErrorAcc <= ErrorAccTemp) 
+    {
+      /* The error accumulator turned over, so advance the X coord */
+      segment->x += segment->XDir;
+    }
+
+    Weighting = segment->ErrorAcc >> INTENSITYSHIFT;
+
+    if (Weighting < 128)
+      return segment->x;
+    else
+      return segment->x + segment->XDir;
+  }
+  else
+  {
+    /* Increment all pixels other than the first and last */
+    int hline_end = 0;
+    while (!hline_end)
+    {
+      ErrorAccTemp = segment->ErrorAcc;   /* remember currrent accumulated error */
+      segment->ErrorAcc += segment->ErrorInc;      /* calculate error for next pixel */
+      if (segment->ErrorAcc <= ErrorAccTemp) 
+      {
+        /* The error accumulator turned over, so advance the Y coord */
+        hline_end = 1;
+      }
+
+      segment->x += segment->XDir; /* X-major, so always advance X */
+    }
+
+    return segment->x;
+  }
+}
+
+typedef struct _simIntervalList
+{
+  int* xx;
+  int n, count;
+} simIntervalList;
+
+static int simFillCheckAAPixel(simIntervalList* line_int_list, int x)
+{
+  int i, *xx = line_int_list->xx;
+  for (i = 0; i < line_int_list->n; i+=2)
+  {
+    if (xx[i] <= x && x <= xx[i+1])
+      return 0; /* inside, already drawn, do not draw */
+  }
+  return 1;
+}
+
+static void simPolyAAPixels(cdCanvas *canvas, simIntervalList* line_int_list, int y_min, int y_max, int x1, int y1, int x2, int y2)
+{
+  unsigned short ErrorInc, ErrorAcc;
+  unsigned short ErrorAccTemp, Weighting;
+  int DeltaX, DeltaY, XDir;
+  int no_antialias = !(canvas->simulation->antialias);
+
+  /* Make sure p2.y > p1.y */
+  if (y1 > y2) 
+  {
+    _cdSwapInt(y1, y2);
+    _cdSwapInt(x1, x2);
+  }
+
+  DeltaX = x2 - x1;
+  if (DeltaX >= 0)
+    XDir = 1;
+  else 
+  {
+    XDir = -1;
+    DeltaX = -DeltaX; /* make DeltaX positive */
+  }
+
+  /* Special-case horizontal, vertical, and diagonal lines, which
+  require no weighting because they go right through the center of
+  every pixel */
+  DeltaY = y2 - y1;
+  if (DeltaY == 0 || DeltaX == 0 || DeltaX == DeltaY) return;
+
+  /* Line is not horizontal, diagonal, or vertical */
+
+  /* start and end pixels are not necessary 
+     since they are always drawn in the previous step. */
+
+  ErrorAcc = 0;  /* initialize the line error accumulator to 0 */
+
+  /* Is this an X-major or Y-major line? */
+  if (DeltaY > DeltaX) 
+  {
+    ErrorInc = (unsigned short)(((unsigned long)DeltaX << 16) / (unsigned long)DeltaY);
+
+    /* Draw all pixels other than the first and last */
+    while (--DeltaY) 
+    {
+      ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */
+      ErrorAcc += ErrorInc;      /* calculate error for next pixel */
+      if (ErrorAcc <= ErrorAccTemp) 
+        x1 += XDir;
+
+      y1++; /* Y-major, so always advance Y */
+
+      Weighting = ErrorAcc >> INTENSITYSHIFT;
+
+      if (y1 < y_min || y1 > y_max) continue;
+
+      if (no_antialias)
+      {
+        if (Weighting < 128)
+        {
+          if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1))
+            simFillDrawAAPixel(canvas, x1, y1, 255);
+        }
+        else
+        {
+          if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1 + XDir))
+            simFillDrawAAPixel(canvas, x1 + XDir, y1, 255);
+        }
+      }
+      else
+      {
+        if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1))
+          simFillDrawAAPixel(canvas, x1, y1, 255-Weighting);
+
+        if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1 + XDir))
+          simFillDrawAAPixel(canvas, x1 + XDir, y1, Weighting);
+      }
+    }
+  }
+  else
+  {
+    ErrorInc = (unsigned short)(((unsigned long)DeltaY << 16) / (unsigned long)DeltaX);
+
+    /* Draw all pixels other than the first and last */
+    while (--DeltaX) 
+    {
+      ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */
+      ErrorAcc += ErrorInc;      /* calculate error for next pixel */
+      if (ErrorAcc <= ErrorAccTemp) 
+        y1++;
+
+      x1 += XDir; /* X-major, so always advance X */
+
+      Weighting = ErrorAcc >> INTENSITYSHIFT;
+
+      if (y1 < y_min || y1 > y_max) continue;
+
+      if (no_antialias)
+      {
+        if (Weighting < 128)
+        {
+          if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1))
+            simFillDrawAAPixel(canvas, x1, y1, 255);
+        }
+        else
+        {
+          if (y1+1 < y_min || y1+1 > y_max) continue;
+
+          if (simFillCheckAAPixel(line_int_list+(y1+1-y_min), x1))
+            simFillDrawAAPixel(canvas, x1, y1+1, 255);
+        }
+      }
+      else
+      {
+        if (simFillCheckAAPixel(line_int_list+(y1-y_min), x1))
+          simFillDrawAAPixel(canvas, x1, y1, 255-Weighting);
+
+        if (y1+1 < y_min || y1+1 > y_max) continue;
+
+        if (simFillCheckAAPixel(line_int_list+(y1+1-y_min), x1))
+          simFillDrawAAPixel(canvas, x1, y1+1, Weighting);
+      }
+    }
+  }
+}
+
+static void simLineIntervallInit(simIntervalList* line_int_list, int count)
+{
+  line_int_list->xx = malloc(sizeof(int)*count);
+  line_int_list->n = 0;
+  line_int_list->count = count;
+}
+
+static void simLineIntervallAdd(simIntervalList* line_int_list, int x1, int x2)
+{
+  int i = line_int_list->n;
+  line_int_list->xx[i] = x1;
+  line_int_list->xx[i+1] = x2;
+  line_int_list->n += 2;
+}
+
+void simPolyFill(cdSimulation* simulation, cdPoint* poly, int n) 
+{
+  simLineSegment *seg_i;
+  simIntervalList* line_int_list, *line_il;
+  int y_max, y_min, i, y, i1, fill_mode, num_lines,
+      inter_count, width, height, *xx;
+
+  simLineSegment *segment = (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);
+  }
+  
+  if (y_min > height-1 || y_max < 0)
+  {
+    free(segment);
+    return;
+  }
+
+  if (y_min < 0) 
+    y_min = 0;
+
+  if (y_max > height-1)
+    num_lines = height-y_min;
+  else
+    num_lines = y_max-y_min+1;
+
+  line_int_list = malloc(sizeof(simIntervalList)*num_lines);
+  memset(line_int_list, 0, sizeof(simIntervalList)*num_lines);
+
+  xx = (int*)malloc((n+1)*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)
+      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);
+
+    /* for all intervals, fill the interval */
+    for(i = 0; i < inter_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
+      {
+        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]);
+          }
+      }
+    }
+  }
+
+  free(xx);
+  free(segment);
+
+  /* Once the polygon has been filled, now let's draw the
+   * antialiased and incomplete pixels at the edges */
+
+  if (y_max > height-1)
+    y_max = height-1;
+
+  /* Go through all line segments of the poly */
+  for(i = 0; i < n; i++)
+  {
+    i1 = (i+1)%n;
+    simPolyAAPixels(simulation->canvas, line_int_list, y_min, y_max, poly[i].x, poly[i].y, poly[i1].x, poly[i1].y);
+  }
+
+  for (i = 0; i < num_lines; i++)
+  {
+    if (line_int_list[i].xx) 
+      free(line_int_list[i].xx);
+  }
+  free(line_int_list);
+}
+
+/*************************************************************************************/
+/*************************************************************************************/
+
+#define _cdLineDrawPixel(_canvas, _x1, _y1, _ls, _fgcolor, _bgcolor) \
+{                                                                    \
+  if (_ls & 1)                                                       \
+    _canvas->cxPixel(_canvas->ctxcanvas, _x1, _y1, _fgcolor);        \
+  else if (canvas->back_opacity == CD_OPAQUE)                        \
+    _canvas->cxPixel(_canvas->ctxcanvas, _x1, _y1, _bgcolor);        \
+}
+
+void simLineThick(cdCanvas* canvas, int x1, int y1, int x2, int y2)
+{
+  const int interior = canvas->interior_style;
+  const int width = canvas->line_width;
+  const int style = canvas->line_style;
+
+  const int dx = x2-x1;
+  const int dy = y2-y1;
+
+  const double len = hypot(dx,dy);
+
+  const double dnx = dx/len;
+  const double dny = dy/len;
+
+  const int w1 = (int)width/2;
+  const int w2 = width-w1;
+
+  const int n1x = cdRound( w1*dny);
+  const int n1y = cdRound(-w1*dnx);
+
+  const int n2x = cdRound(-w2*dny);
+  const int n2y = cdRound( w2*dnx);
+
+  const int p1x = x1 + n1x;
+  const int p1y = y1 + n1y;
+  const int p2x = x1 + n2x;
+  const int p2y = y1 + n2y;
+  const int p3x = p2x + dx;
+  const int p3y = p2y + dy;
+  const int p4x = p1x + dx;
+  const int p4y = p1y + dy;
+
+  cdPoint poly[4];
+
+  cdCanvasLineWidth(canvas, 1);
+  cdCanvasInteriorStyle(canvas, CD_SOLID);
+  cdCanvasLineStyle(canvas, CD_CONTINUOUS);
+
+  poly[0].x = p1x;
+  poly[0].y = p1y;
+  poly[1].x = p2x;
+  poly[1].y = p2y;
+  poly[2].x = p3x;
+  poly[2].y = p3y;
+  poly[3].x = p4x;
+  poly[3].y = p4y;
+
+  simPolyFill(canvas->simulation, poly, 4);
+
+  cdCanvasLineWidth(canvas, width);
+  cdCanvasInteriorStyle(canvas, interior);
+  cdCanvasLineStyle(canvas, style);
+}
+
+void simLineThin(cdCanvas* canvas, int x1, int y1, int x2, int y2)
+{
+  unsigned short ErrorInc, ErrorAcc;
+  unsigned short ErrorAccTemp, Weighting;
+  int DeltaX, DeltaY, XDir;
+  long aa_fgcolor;
+  unsigned char alpha = cdAlpha(canvas->foreground), aa_alpha;
+  int no_antialias = !(canvas->simulation->antialias);
+  unsigned short int ls;
+  long fgcolor = canvas->foreground;
+  long bgcolor = canvas->background;
+
+  if (simLineStyleNoReset == 2)
+    ls = simLineStyleLastBits;
+  else
+  {
+    ls = simLineStyleBitTable[canvas->line_style];
+
+    if (simLineStyleNoReset == 1)
+      simLineStyleNoReset = 2;
+  }
+
+  /* Make sure p2.y > p1.y */
+  if (y1 > y2) 
+  {
+    _cdSwapInt(y1, y2);
+    _cdSwapInt(x1, x2);
+  }
+
+  /* Draw the initial pixel, which is always exactly intersected by
+      the line and so needs no weighting */
+  _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor);
+  ls = simRotateLineStyle(ls);
+
+  DeltaX = x2 - x1;
+  if (DeltaX >= 0)
+    XDir = 1;
+  else 
+  {
+    XDir = -1;
+    DeltaX = -DeltaX; /* make DeltaX positive */
+  }
+
+  /* Special-case horizontal, vertical, and diagonal lines, which
+  require no weighting because they go right through the center of
+  every pixel */
+  DeltaY = y2 - y1;
+  if (DeltaY == 0) 
+  {
+    /* Horizontal line */
+    while (DeltaX-- != 0) 
+    {
+      x1 += XDir;
+      _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor);
+      ls = simRotateLineStyle(ls);
+    }
+    simLineStyleLastBits = ls;
+    return;
+  }
+
+  if (DeltaX == 0) 
+  {
+    /* Vertical line */
+    do 
+    {
+      y1++;
+      _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor);
+      ls = simRotateLineStyle(ls);
+    } while (--DeltaY != 0);
+    simLineStyleLastBits = ls;
+    return;
+  }
+
+  if (DeltaX == DeltaY) 
+  {
+    /* Perfect Diagonal line */
+    do 
+    {
+      x1 += XDir;
+      y1++;
+      _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor);
+      ls = simRotateLineStyle(ls);
+    } while (--DeltaY != 0);
+    simLineStyleLastBits = ls;
+    return;
+  }
+
+  /* Line is not horizontal, diagonal, or vertical */
+
+  ErrorAcc = 0;  /* initialize the line error accumulator to 0 */
+
+  /* Is this an X-major or Y-major line? */
+  if (DeltaY > DeltaX) 
+  {
+    /* Y-major line; calculate 16-bit fixed-point fractional part of a
+    pixel that X advances each time Y advances 1 pixel, truncating the
+    result so that we won't overrun the endpoint along the X axis */
+    ErrorInc = (unsigned short)(((unsigned long)DeltaX << 16) / (unsigned long)DeltaY);
+
+    /* Draw all pixels other than the first and last */
+    while (--DeltaY) 
+    {
+      ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */
+      ErrorAcc += ErrorInc;      /* calculate error for next pixel */
+      if (ErrorAcc <= ErrorAccTemp) 
+      {
+        /* The error accumulator turned over, so advance the X coord */
+        x1 += XDir;
+      }
+
+      y1++; /* Y-major, so always advance Y */
+
+      Weighting = ErrorAcc >> INTENSITYSHIFT;
+
+      if (no_antialias)
+      {
+        if (Weighting < 128)
+          _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor)
+        else
+          _cdLineDrawPixel(canvas, x1 + XDir, y1, ls, fgcolor, bgcolor)
+        ls = simRotateLineStyle(ls);
+      }
+      else
+      {
+        /* The IntensityBits most significant bits of ErrorAcc give us the
+        intensity weighting for this pixel, and the complement of the
+        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_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+        _cdLineDrawPixel(canvas, x1, y1, ls, aa_fgcolor, bgcolor);
+        aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+        _cdLineDrawPixel(canvas, x1 + XDir, y1, ls, aa_fgcolor, bgcolor);
+        ls = simRotateLineStyle(ls);
+      }
+    }
+    /* Draw the final pixel, which is always exactly intersected by the line
+    and so needs no weighting */
+    _cdLineDrawPixel(canvas, x2, y2, ls, fgcolor, bgcolor);
+    ls = simRotateLineStyle(ls);
+  }
+  else
+  {
+    /* 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
+    result to avoid overrunning the endpoint along the X axis */
+    ErrorInc = (unsigned short)(((unsigned long)DeltaY << 16) / (unsigned long)DeltaX);
+
+    /* Draw all pixels other than the first and last */
+    while (--DeltaX) 
+    {
+      ErrorAccTemp = ErrorAcc;   /* remember currrent accumulated error */
+      ErrorAcc += ErrorInc;      /* calculate error for next pixel */
+      if (ErrorAcc <= ErrorAccTemp) 
+      {
+        /* The error accumulator turned over, so advance the Y coord */
+        y1++;
+      }
+
+      x1 += XDir; /* X-major, so always advance X */
+
+      Weighting = ErrorAcc >> INTENSITYSHIFT;
+
+      if (no_antialias)
+      {
+        if (Weighting < 128)
+          _cdLineDrawPixel(canvas, x1, y1, ls, fgcolor, bgcolor)
+        else
+          _cdLineDrawPixel(canvas, x1, y1+1, ls, fgcolor, bgcolor)
+        ls = simRotateLineStyle(ls);
+      }
+      else
+      {
+        /* The IntensityBits most significant bits of ErrorAcc give us the
+        intensity weighting for this pixel, and the complement of the
+        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_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+        _cdLineDrawPixel(canvas, x1, y1, ls, aa_fgcolor, bgcolor);
+        aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+        _cdLineDrawPixel(canvas, x1, y1+1, ls, aa_fgcolor, bgcolor);
+        ls = simRotateLineStyle(ls);
+      }
+    }
+
+    /* Draw the final pixel, which is always exactly intersected by the line
+    and so needs no weighting */
+    _cdLineDrawPixel(canvas, x2, y2, ls, fgcolor, bgcolor);
+    ls = simRotateLineStyle(ls);
+  }
+
+  simLineStyleLastBits = ls;
+}
+
+void simfLineThin(cdCanvas* canvas, double x1, double y1, double x2, double y2, int *last_xi_a, int *last_yi_a, int *last_xi_b, int *last_yi_b)
+{
+  double DeltaX, DeltaY, a, b;
+  long aa_fgcolor;
+  unsigned char alpha = cdAlpha(canvas->foreground), aa_alpha;
+  int no_antialias = !(canvas->simulation->antialias);
+  int yi, xi, update_a = 1, update_b = 1;
+  unsigned short int ls;
+  long fgcolor = canvas->foreground;
+  long bgcolor = canvas->background;
+
+  if (simLineStyleNoReset == 2)
+    ls = simLineStyleLastBits;
+  else
+  {
+    ls = simLineStyleBitTable[canvas->line_style];
+
+    if (simLineStyleNoReset == 1)
+      simLineStyleNoReset = 2;
+  }
+
+  DeltaX = fabs(x2 - x1);
+  DeltaY = fabs(y2 - y1);
+
+  if (DeltaX > 0.0001)
+  {
+    a = (y1-y2)/(x1-x2);
+    b = y1 - a*x1;
+  }
+  else
+  {
+    a = 0;
+    b = x1;
+  }
+
+  /* NOTICE: all the complexity of this function 
+  is related to check and update the previous point */
+
+  /* Is this an X-major or Y-major line? */
+  if (DeltaY > DeltaX) 
+  {
+    /* Increment in Y */
+    int y1i = _cdRound(y1), 
+        y2i = _cdRound(y2);
+    int yi_first = y1i;
+    int yi_last = y2i, xi_last;
+
+    if (y1i > y2i)
+      _cdSwapInt(y1i, y2i);
+
+    for (yi = y1i; yi <= y2i; yi++)
+    {
+      double x;
+      if (a)
+        x = (yi - b)/a;
+      else
+        x = b;
+
+      xi = (int)floor(x);
+
+      /* if at the last pixel, store the return value */
+      if (yi == yi_last)
+        xi_last = xi;
+
+      /* Combine the Weighting with the existing alpha,
+      When Weighting is zero alpha must be fully preserved. */
+      aa_alpha = (int)((1.0-(x - xi)) * alpha);
+
+      if (no_antialias)
+      {
+        if (aa_alpha > 128)
+          _cdLineDrawPixel(canvas, xi, yi, ls, fgcolor, bgcolor)
+        else
+          _cdLineDrawPixel(canvas, xi+1, yi, ls, fgcolor, bgcolor)
+      }
+      else
+      {
+        if (yi == yi_first)
+        {
+          if (yi == yi_last)  /* one pixel only */
+          {
+            update_a = 0;
+            update_b = 0;
+          }
+
+          /* if at first, compare with the last two previously drawn */
+          /* if the new is equal to the previous, do NOT draw */
+          if ((xi != *last_xi_a || yi != *last_yi_a) &&
+              (xi != *last_xi_b || yi != *last_yi_b))
+          {
+            aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+            _cdLineDrawPixel(canvas, xi, yi, ls, aa_fgcolor, bgcolor);
+
+            if (yi == yi_last)  /* one pixel only */
+              update_a = 1;
+          }
+
+          if ((xi+1 != *last_xi_a || yi != *last_yi_a) &&
+              (xi+1 != *last_xi_b || yi != *last_yi_b))
+          {
+            aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+            _cdLineDrawPixel(canvas, xi+1, yi, ls, aa_fgcolor, bgcolor);
+
+            if (yi == yi_last)  /* one pixel only */
+              update_b = 1;
+          }
+        }
+        else
+        {
+          aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+          _cdLineDrawPixel(canvas, xi, yi, ls, aa_fgcolor, bgcolor);
+          aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+          _cdLineDrawPixel(canvas, xi+1, yi, ls, aa_fgcolor, bgcolor);
+        }
+      }
+
+      ls = simRotateLineStyle(ls);
+    }
+
+    if (update_a)
+    {
+      *last_xi_a = xi_last;
+      *last_yi_a = yi_last;
+    }
+    if (update_b)
+    {
+      *last_xi_b = xi_last+1;
+      *last_yi_b = yi_last;
+    }
+  }
+  else
+  {
+    /* Increment in X */
+    int x1i = _cdRound(x1), 
+        x2i = _cdRound(x2);
+    int xi_first = x1i;
+    int xi_last = x2i, yi_last;
+
+    if (x1i > x2i)
+      _cdSwapInt(x1i, x2i);
+
+    for (xi = x1i; xi <= x2i; xi++)
+    {
+      double y = a*xi + b;
+      yi = (int)floor(y);
+
+      /* if at the last pixel, store the return value */
+      if (xi == xi_last)
+        yi_last = yi;
+
+      /* Combine the Weighting with the existing alpha,
+      When Weighting is zero alpha must be fully preserved. */
+      aa_alpha = (int)((1.0-(y - yi)) * alpha);
+
+      if (no_antialias)
+      {
+        if (aa_alpha > 128)
+          _cdLineDrawPixel(canvas, xi, yi, ls, fgcolor, bgcolor)
+        else
+          _cdLineDrawPixel(canvas, xi, yi+1, ls, fgcolor, bgcolor)
+      }
+      else
+      {
+        if (xi == xi_first)
+        {
+          if (xi == xi_last)  /* one pixel only */
+          {
+            update_a = 0;
+            update_b = 0;
+          }
+
+          /* if at first, compare with the last to draw */
+          /* if new is equal to the previous, do NOT draw */
+          if ((xi != *last_xi_a || yi != *last_yi_a) &&
+              (xi != *last_xi_b || yi != *last_yi_b))
+          {
+            aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+            _cdLineDrawPixel(canvas, xi, yi, ls, aa_fgcolor, bgcolor);
+
+            if (xi == xi_last) /* one pixel only */
+              update_a = 1;
+          }
+
+          if ((xi != *last_xi_a || yi+1 != *last_yi_a) &&
+              (xi != *last_xi_b || yi+1 != *last_yi_b))
+          {
+            aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+            _cdLineDrawPixel(canvas, xi, yi+1, ls, aa_fgcolor, bgcolor);
+
+            if (xi == xi_last) /* one pixel only */
+              update_b = 1;
+          }
+        }
+        else
+        {
+          aa_fgcolor = cdEncodeAlpha(fgcolor, aa_alpha);
+          _cdLineDrawPixel(canvas, xi, yi, ls, aa_fgcolor, bgcolor);
+          aa_fgcolor = cdEncodeAlpha(fgcolor, 255-aa_alpha);
+          _cdLineDrawPixel(canvas, xi, yi+1, ls, aa_fgcolor, bgcolor);
+        }
+      }
+
+      ls = simRotateLineStyle(ls);
+    }
+
+    if (update_a)
+    {
+      *last_xi_a = xi_last;
+      *last_yi_a = yi_last;
+    }
+    if (update_b)
+    {
+      *last_xi_b = xi_last;
+      *last_yi_b = yi_last+1;
+    }
+  }
+
+  simLineStyleLastBits = ls;
+}