nanosvgrast.h

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// Update from https://github.com/texus/nanosvg
// Some modifications have been made to the original file:
// - All floats were replaced by doubles (to get rid of warnings about implicit conversions and promotions)
// - Some other c++ compiler warnings were fixed, mainly about usage of old-style casts
 
/*
 * Copyright (c) 2013-14 Mikko Mononen memon@inside.org
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * The polygon rasterization is heavily based on stb_truetype rasterizer
 * by Sean Barrett - http://nothings.org/
 *
 */
 
#ifndef NANOSVGRAST_H
#define NANOSVGRAST_H
 
#ifndef NANOSVGRAST_CPLUSPLUS
#ifdef __cplusplus
extern "C" {
#endif
#endif
 
typedef struct NSVGrasterizer NSVGrasterizer;
 
/* Example Usage:
  // Load SVG
  NSVGimage* image;
  image = nsvgParseFromFile("test.svg", "px", 96);
  // Create rasterizer (can be used to render multiple images).
  struct NSVGrasterizer* rast = nsvgCreateRasterizer();
  // Allocate memory for image
  unsigned char* img = malloc(w*h*4);
  // Rasterize
  nsvgRasterize(rast, image, 0,0,1, img, w, h, w*4);
*/
 
// Allocated rasterizer context.
NSVGrasterizer* nsvgCreateRasterizer();
 
// Rasterizes SVG image, returns RGBA image (non-premultiplied alpha)
//   r - pointer to rasterizer context
//   image - pointer to image to rasterize
//   tx,ty - image offset (applied after scaling)
//   scale - image scale
//   dst - pointer to destination image data, 4 bytes per pixel (RGBA)
//   w - width of the image to render
//   h - height of the image to render
//   stride - number of bytes per scaleline in the destination buffer
void nsvgRasterize(NSVGrasterizer* r,
           NSVGimage* image, double tx, double ty, double scale,
           unsigned char* dst, int w, int h, int stride);
 
void nsvgRasterizeFull(NSVGrasterizer* r, NSVGimage* image,
            double tx, double ty, double scalex, double scaley,
            unsigned char* dst, int w, int h, int stride, int bgr);
 
// Deletes rasterizer context.
void nsvgDeleteRasterizer(NSVGrasterizer*);
 
 
#ifndef NANOSVGRAST_CPLUSPLUS
#ifdef __cplusplus
}
#endif
#endif
 
#endif // NANOSVGRAST_H
 
#ifdef NANOSVGRAST_IMPLEMENTATION
 
#include <math.h>
 
#define NSVG__SUBSAMPLES  5
#define NSVG__FIXSHIFT    10
#define NSVG__FIX     (1 << NSVG__FIXSHIFT)
#define NSVG__FIXMASK   (NSVG__FIX-1)
#define NSVG__MEMPAGE_SIZE  1024
 
typedef struct NSVGedge {
  double x0,y0, x1,y1;
  int dir;
  struct NSVGedge* next;
} NSVGedge;
 
typedef struct NSVGpoint {
  double x, y;
  double dx, dy;
  double len;
  double dmx, dmy;
  unsigned char flags;
} NSVGpoint;
 
typedef struct NSVGactiveEdge {
  int x,dx;
  double ey;
  int dir;
  struct NSVGactiveEdge *next;
} NSVGactiveEdge;
 
typedef struct NSVGmemPage {
  unsigned char mem[NSVG__MEMPAGE_SIZE];
  int size;
  struct NSVGmemPage* next;
} NSVGmemPage;
 
typedef struct NSVGcachedPaint {
  char type;
  char spread;
  double xform[6];
  unsigned int colors[256];
} NSVGcachedPaint;
 
struct NSVGrasterizer
{
  double px, py;
 
  double tessTol;
  double distTol;
 
  NSVGedge* edges;
  int nedges;
  int cedges;
 
  NSVGpoint* points;
  int npoints;
  int cpoints;
 
  NSVGpoint* points2;
  int npoints2;
  int cpoints2;
 
  NSVGactiveEdge* freelist;
  NSVGmemPage* pages;
  NSVGmemPage* curpage;
 
  unsigned char* scanline;
  int cscanline;
 
  unsigned char* bitmap;
  int width, height, stride;
};
 
NSVGrasterizer* nsvgCreateRasterizer()
{
  NSVGrasterizer* r = static_cast<NSVGrasterizer*>(malloc(sizeof(NSVGrasterizer)));
  if (r == nullptr) goto error;
  memset(r, 0, sizeof(NSVGrasterizer));
 
  r->tessTol = 0.25;
  r->distTol = 0.01;
 
  return r;
 
error:
  nsvgDeleteRasterizer(r);
  return nullptr;
}
 
void nsvgDeleteRasterizer(NSVGrasterizer* r)
{
  NSVGmemPage* p;
 
  if (r == nullptr) return;
 
  p = r->pages;
  while (p != nullptr) {
    NSVGmemPage* next = p->next;
    free(p);
    p = next;
  }
 
  if (r->edges) free(r->edges);
  if (r->points) free(r->points);
  if (r->points2) free(r->points2);
  if (r->scanline) free(r->scanline);
 
  free(r);
}
 
static NSVGmemPage* nsvg__nextPage(NSVGrasterizer* r, NSVGmemPage* cur)
{
  NSVGmemPage *newp;
 
  // If using existing chain, return the next page in chain
  if (cur != nullptr && cur->next != nullptr) {
    return cur->next;
  }
 
  // Alloc new page
  newp = static_cast<NSVGmemPage*>(malloc(sizeof(NSVGmemPage)));
  if (newp == nullptr) return nullptr;
  memset(newp, 0, sizeof(NSVGmemPage));
 
  // Add to linked list
  if (cur != nullptr)
    cur->next = newp;
  else
    r->pages = newp;
 
  return newp;
}
 
static void nsvg__resetPool(NSVGrasterizer* r)
{
  NSVGmemPage* p = r->pages;
  while (p != nullptr) {
    p->size = 0;
    p = p->next;
  }
  r->curpage = r->pages;
}
 
static unsigned char* nsvg__alloc(NSVGrasterizer* r, int size)
{
  unsigned char* buf;
  if (size > NSVG__MEMPAGE_SIZE) return nullptr;
  if (r->curpage == nullptr || r->curpage->size+size > NSVG__MEMPAGE_SIZE) {
    r->curpage = nsvg__nextPage(r, r->curpage);
  }
  buf = &r->curpage->mem[r->curpage->size];
  r->curpage->size += size;
  return buf;
}
 
static int nsvg__ptEquals(double x1, double y1, double x2, double y2, double tol)
{
  double dx = x2 - x1;
  double dy = y2 - y1;
  return dx*dx + dy*dy < tol*tol;
}
 
static void nsvg__addPathPoint(NSVGrasterizer* r, double x, double y, int flags)
{
  NSVGpoint* pt;
 
  if (r->npoints > 0) {
    pt = &r->points[r->npoints-1];
    if (nsvg__ptEquals(pt->x,pt->y, x,y, r->distTol)) {
      pt->flags = static_cast<unsigned char>(pt->flags | flags);
      return;
    }
  }
 
  if (r->npoints+1 > r->cpoints) {
    r->cpoints = r->cpoints > 0 ? r->cpoints * 2 : 64;
    r->points = static_cast<NSVGpoint*>(realloc(r->points, sizeof(NSVGpoint) * r->cpoints));
    if (r->points == nullptr) return;
  }
 
  pt = &r->points[r->npoints];
  pt->x = x;
  pt->y = y;
  pt->flags = static_cast<unsigned char>(flags);
  r->npoints++;
}
 
static void nsvg__appendPathPoint(NSVGrasterizer* r, NSVGpoint pt)
{
  if (r->npoints+1 > r->cpoints) {
    r->cpoints = r->cpoints > 0 ? r->cpoints * 2 : 64;
    r->points = static_cast<NSVGpoint*>(realloc(r->points, sizeof(NSVGpoint) * r->cpoints));
    if (r->points == nullptr) return;
  }
  r->points[r->npoints] = pt;
  r->npoints++;
}
 
static void nsvg__duplicatePoints(NSVGrasterizer* r)
{
  if (r->npoints > r->cpoints2) {
    r->cpoints2 = r->npoints;
    r->points2 = static_cast<NSVGpoint*>(realloc(r->points2, sizeof(NSVGpoint) * r->cpoints2));
    if (r->points2 == nullptr) return;
  }
 
  memcpy(r->points2, r->points, sizeof(NSVGpoint) * r->npoints);
  r->npoints2 = r->npoints;
}
 
static void nsvg__addEdge(NSVGrasterizer* r, double x0, double y0, double x1, double y1)
{
  NSVGedge* e;
 
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wfloat-equal"
  // Skip horizontal edges
  if (y0 == y1)
#pragma GCC diagnostic pop
    return;
 
  if (r->nedges+1 > r->cedges) {
    r->cedges = r->cedges > 0 ? r->cedges * 2 : 64;
    r->edges = static_cast<NSVGedge*>(realloc(r->edges, sizeof(NSVGedge) * r->cedges));
    if (r->edges == nullptr) return;
  }
 
  e = &r->edges[r->nedges];
  r->nedges++;
 
  if (y0 < y1) {
    e->x0 = x0;
    e->y0 = y0;
    e->x1 = x1;
    e->y1 = y1;
    e->dir = 1;
  } else {
    e->x0 = x1;
    e->y0 = y1;
    e->x1 = x0;
    e->y1 = y0;
    e->dir = -1;
  }
}
 
static double nsvg__normalize(double *x, double* y)
{
  double d = sqrt((*x)*(*x) + (*y)*(*y));
  if (d > 1e-6) {
    double id = 1.0 / d;
    *x *= id;
    *y *= id;
  }
  return d;
}
 
static double nsvg__absf(double x) { return x < 0 ? -x : x; }
 
static void nsvg__flattenCubicBez(NSVGrasterizer* r,
                  double x1, double y1, double x2, double y2,
                  double x3, double y3, double x4, double y4,
                  int level, int type)
{
  double x12,y12,x23,y23,x34,y34,x123,y123,x234,y234,x1234,y1234;
  double dx,dy,d2,d3;
 
  if (level > 10) return;
 
  x12 = (x1+x2)*0.5;
  y12 = (y1+y2)*0.5;
  x23 = (x2+x3)*0.5;
  y23 = (y2+y3)*0.5;
  x34 = (x3+x4)*0.5;
  y34 = (y3+y4)*0.5;
  x123 = (x12+x23)*0.5;
  y123 = (y12+y23)*0.5;
 
  dx = x4 - x1;
  dy = y4 - y1;
  d2 = nsvg__absf(((x2 - x4) * dy - (y2 - y4) * dx));
  d3 = nsvg__absf(((x3 - x4) * dy - (y3 - y4) * dx));
 
  if ((d2 + d3)*(d2 + d3) < r->tessTol * (dx*dx + dy*dy)) {
    nsvg__addPathPoint(r, x4, y4, type);
    return;
  }
 
  x234 = (x23+x34)*0.5;
  y234 = (y23+y34)*0.5;
  x1234 = (x123+x234)*0.5;
  y1234 = (y123+y234)*0.5;
 
  nsvg__flattenCubicBez(r, x1,y1, x12,y12, x123,y123, x1234,y1234, level+1, 0);
  nsvg__flattenCubicBez(r, x1234,y1234, x234,y234, x34,y34, x4,y4, level+1, type);
}
 
static void nsvg__flattenShape(NSVGrasterizer* r, NSVGshape* shape, double scalex, double scaley)
{
  int i, j;
  NSVGpath* path;
 
  for (path = shape->paths; path != nullptr; path = path->next) {
    r->npoints = 0;
    // Flatten path
    nsvg__addPathPoint(r, path->pts[0]*scalex, path->pts[1]*scaley, 0);
    for (i = 0; i < path->npts-1; i += 3) {
      double* p = &path->pts[i*2];
      nsvg__flattenCubicBez(r, p[0]*scalex,p[1]*scaley, p[2]*scalex,p[3]*scaley, p[4]*scalex,p[5]*scaley, p[6]*scalex,p[7]*scaley, 0, 0);
    }
    // Close path
    nsvg__addPathPoint(r, path->pts[0]*scalex, path->pts[1]*scaley, 0);
    // Build edges
    for (i = 0, j = r->npoints-1; i < r->npoints; j = i++)
      nsvg__addEdge(r, r->points[j].x, r->points[j].y, r->points[i].x, r->points[i].y);
  }
}
 
enum NSVGpointFlags
{
  NSVG_PT_CORNER = 0x01,
  NSVG_PT_BEVEL = 0x02,
  NSVG_PT_LEFT = 0x04
};
 
static void nsvg__initClosed(NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, double lineWidth)
{
  double w = lineWidth * 0.5;
  double dx = p1->x - p0->x;
  double dy = p1->y - p0->y;
  double len = nsvg__normalize(&dx, &dy);
  double px = p0->x + dx*len*0.5, py = p0->y + dy*len*0.5;
  double dlx = dy, dly = -dx;
  double lx = px - dlx*w, ly = py - dly*w;
  double rx = px + dlx*w, ry = py + dly*w;
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
static void nsvg__buttCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, double dx, double dy, double lineWidth, int connect)
{
  double w = lineWidth * 0.5;
  double px = p->x, py = p->y;
  double dlx = dy, dly = -dx;
  double lx = px - dlx*w, ly = py - dly*w;
  double rx = px + dlx*w, ry = py + dly*w;
 
  nsvg__addEdge(r, lx, ly, rx, ry);
 
  if (connect) {
    nsvg__addEdge(r, left->x, left->y, lx, ly);
    nsvg__addEdge(r, rx, ry, right->x, right->y);
  }
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
static void nsvg__squareCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, double dx, double dy, double lineWidth, int connect)
{
  double w = lineWidth * 0.5;
  double px = p->x - dx*w, py = p->y - dy*w;
  double dlx = dy, dly = -dx;
  double lx = px - dlx*w, ly = py - dly*w;
  double rx = px + dlx*w, ry = py + dly*w;
 
  nsvg__addEdge(r, lx, ly, rx, ry);
 
  if (connect) {
    nsvg__addEdge(r, left->x, left->y, lx, ly);
    nsvg__addEdge(r, rx, ry, right->x, right->y);
  }
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
#ifndef NSVG_PI
#define NSVG_PI (3.14159265358979323846264338327)
#endif
 
static void nsvg__roundCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, double dx, double dy, double lineWidth, int ncap, int connect)
{
  int i;
  double w = lineWidth * 0.5;
  double px = p->x, py = p->y;
  double dlx = dy, dly = -dx;
  double lx = 0, ly = 0, rx = 0, ry = 0, prevx = 0, prevy = 0;
 
  for (i = 0; i < ncap; i++) {
    double a = static_cast<double>(i)/static_cast<double>(ncap-1)*NSVG_PI;
    double ax = cos(a) * w, ay = sin(a) * w;
    double x = px - dlx*ax - dx*ay;
    double y = py - dly*ax - dy*ay;
 
    if (i > 0)
      nsvg__addEdge(r, prevx, prevy, x, y);
 
    prevx = x;
    prevy = y;
 
    if (i == 0) {
      lx = x; ly = y;
    } else if (i == ncap-1) {
      rx = x; ry = y;
    }
  }
 
  if (connect) {
    nsvg__addEdge(r, left->x, left->y, lx, ly);
    nsvg__addEdge(r, rx, ry, right->x, right->y);
  }
 
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
static void nsvg__bevelJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, double lineWidth)
{
  double w = lineWidth * 0.5;
  double dlx0 = p0->dy, dly0 = -p0->dx;
  double dlx1 = p1->dy, dly1 = -p1->dx;
  double lx0 = p1->x - (dlx0 * w), ly0 = p1->y - (dly0 * w);
  double rx0 = p1->x + (dlx0 * w), ry0 = p1->y + (dly0 * w);
  double lx1 = p1->x - (dlx1 * w), ly1 = p1->y - (dly1 * w);
  double rx1 = p1->x + (dlx1 * w), ry1 = p1->y + (dly1 * w);
 
  nsvg__addEdge(r, lx0, ly0, left->x, left->y);
  nsvg__addEdge(r, lx1, ly1, lx0, ly0);
 
  nsvg__addEdge(r, right->x, right->y, rx0, ry0);
  nsvg__addEdge(r, rx0, ry0, rx1, ry1);
 
  left->x = lx1; left->y = ly1;
  right->x = rx1; right->y = ry1;
}
 
static void nsvg__miterJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, double lineWidth)
{
  double w = lineWidth * 0.5;
  double dlx0 = p0->dy, dly0 = -p0->dx;
  double dlx1 = p1->dy, dly1 = -p1->dx;
  double lx0, rx0, lx1, rx1;
  double ly0, ry0, ly1, ry1;
 
  if (p1->flags & NSVG_PT_LEFT) {
    lx0 = lx1 = p1->x - p1->dmx * w;
    ly0 = ly1 = p1->y - p1->dmy * w;
    nsvg__addEdge(r, lx1, ly1, left->x, left->y);
 
    rx0 = p1->x + (dlx0 * w);
    ry0 = p1->y + (dly0 * w);
    rx1 = p1->x + (dlx1 * w);
    ry1 = p1->y + (dly1 * w);
    nsvg__addEdge(r, right->x, right->y, rx0, ry0);
    nsvg__addEdge(r, rx0, ry0, rx1, ry1);
  } else {
    lx0 = p1->x - (dlx0 * w);
    ly0 = p1->y - (dly0 * w);
    lx1 = p1->x - (dlx1 * w);
    ly1 = p1->y - (dly1 * w);
    nsvg__addEdge(r, lx0, ly0, left->x, left->y);
    nsvg__addEdge(r, lx1, ly1, lx0, ly0);
 
    rx0 = rx1 = p1->x + p1->dmx * w;
    ry0 = ry1 = p1->y + p1->dmy * w;
    nsvg__addEdge(r, right->x, right->y, rx1, ry1);
  }
 
  left->x = lx1; left->y = ly1;
  right->x = rx1; right->y = ry1;
}
 
static void nsvg__roundJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, double lineWidth, int ncap)
{
  int i, n;
  double w = lineWidth * 0.5;
  double dlx0 = p0->dy, dly0 = -p0->dx;
  double dlx1 = p1->dy, dly1 = -p1->dx;
  double a0 = atan2(dly0, dlx0);
  double a1 = atan2(dly1, dlx1);
  double da = a1 - a0;
  double lx, ly, rx, ry;
 
  if (da < NSVG_PI) da += NSVG_PI*2;
  if (da > NSVG_PI) da -= NSVG_PI*2;
 
  n = static_cast<int>(ceil((nsvg__absf(da) / NSVG_PI) * static_cast<double>(ncap)));
  if (n < 2) n = 2;
  if (n > ncap) n = ncap;
 
  lx = left->x;
  ly = left->y;
  rx = right->x;
  ry = right->y;
 
  for (i = 0; i < n; i++) {
    double u = static_cast<double>(i)/static_cast<double>(n-1);
    double a = a0 + u*da;
    double ax = cos(a) * w, ay = sin(a) * w;
    double lx1 = p1->x - ax, ly1 = p1->y - ay;
    double rx1 = p1->x + ax, ry1 = p1->y + ay;
 
    nsvg__addEdge(r, lx1, ly1, lx, ly);
    nsvg__addEdge(r, rx, ry, rx1, ry1);
 
    lx = lx1; ly = ly1;
    rx = rx1; ry = ry1;
  }
 
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
static void nsvg__straightJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p1, double lineWidth)
{
  double w = lineWidth * 0.5;
  double lx = p1->x - (p1->dmx * w), ly = p1->y - (p1->dmy * w);
  double rx = p1->x + (p1->dmx * w), ry = p1->y + (p1->dmy * w);
 
  nsvg__addEdge(r, lx, ly, left->x, left->y);
  nsvg__addEdge(r, right->x, right->y, rx, ry);
 
  left->x = lx; left->y = ly;
  right->x = rx; right->y = ry;
}
 
static int nsvg__curveDivs(double r, double arc, double tol)
{
  double da = acos(r / (r + tol)) * 2.0;
  int divs = static_cast<int>(ceil(arc / da));
  if (divs < 2) divs = 2;
  return divs;
}
 
static void nsvg__expandStroke(NSVGrasterizer* r, NSVGpoint* points, int npoints, int closed, int lineJoin, int lineCap, double lineWidth)
{
  int ncap = nsvg__curveDivs(lineWidth*0.5, NSVG_PI, r->tessTol); // Calculate divisions per half circle.
  NSVGpoint left = {0,0,0,0,0,0,0,0}, right = {0,0,0,0,0,0,0,0}, firstLeft = {0,0,0,0,0,0,0,0}, firstRight = {0,0,0,0,0,0,0,0};
  NSVGpoint* p0, *p1;
  int j, s, e;
 
  // Build stroke edges
  if (closed) {
    // Looping
    p0 = &points[npoints-1];
    p1 = &points[0];
    s = 0;
    e = npoints;
  } else {
    // Add cap
    p0 = &points[0];
    p1 = &points[1];
    s = 1;
    e = npoints-1;
  }
 
  if (closed) {
    nsvg__initClosed(&left, &right, p0, p1, lineWidth);
    firstLeft = left;
    firstRight = right;
  } else {
    // Add cap
    double dx = p1->x - p0->x;
    double dy = p1->y - p0->y;
    nsvg__normalize(&dx, &dy);
    if (lineCap == NSVG_CAP_BUTT)
      nsvg__buttCap(r, &left, &right, p0, dx, dy, lineWidth, 0);
    else if (lineCap == NSVG_CAP_SQUARE)
      nsvg__squareCap(r, &left, &right, p0, dx, dy, lineWidth, 0);
    else if (lineCap == NSVG_CAP_ROUND)
      nsvg__roundCap(r, &left, &right, p0, dx, dy, lineWidth, ncap, 0);
  }
 
  for (j = s; j < e; ++j) {
    if (p1->flags & NSVG_PT_CORNER) {
      if (lineJoin == NSVG_JOIN_ROUND)
        nsvg__roundJoin(r, &left, &right, p0, p1, lineWidth, ncap);
      else if (lineJoin == NSVG_JOIN_BEVEL || (p1->flags & NSVG_PT_BEVEL))
        nsvg__bevelJoin(r, &left, &right, p0, p1, lineWidth);
      else
        nsvg__miterJoin(r, &left, &right, p0, p1, lineWidth);
    } else {
      nsvg__straightJoin(r, &left, &right, p1, lineWidth);
    }
    p0 = p1++;
  }
 
  if (closed) {
    // Loop it
    nsvg__addEdge(r, firstLeft.x, firstLeft.y, left.x, left.y);
    nsvg__addEdge(r, right.x, right.y, firstRight.x, firstRight.y);
  } else {
    // Add cap
    double dx = p1->x - p0->x;
    double dy = p1->y - p0->y;
    nsvg__normalize(&dx, &dy);
    if (lineCap == NSVG_CAP_BUTT)
      nsvg__buttCap(r, &right, &left, p1, -dx, -dy, lineWidth, 1);
    else if (lineCap == NSVG_CAP_SQUARE)
      nsvg__squareCap(r, &right, &left, p1, -dx, -dy, lineWidth, 1);
    else if (lineCap == NSVG_CAP_ROUND)
      nsvg__roundCap(r, &right, &left, p1, -dx, -dy, lineWidth, ncap, 1);
  }
}
 
static void nsvg__prepareStroke(NSVGrasterizer* r, double miterLimit, int lineJoin)
{
  int i, j;
  NSVGpoint* p0, *p1;
 
  p0 = &r->points[r->npoints-1];
  p1 = &r->points[0];
  for (i = 0; i < r->npoints; i++) {
    // Calculate segment direction and length
    p0->dx = p1->x - p0->x;
    p0->dy = p1->y - p0->y;
    p0->len = nsvg__normalize(&p0->dx, &p0->dy);
    // Advance
    p0 = p1++;
  }
 
  // calculate joins
  p0 = &r->points[r->npoints-1];
  p1 = &r->points[0];
  for (j = 0; j < r->npoints; j++) {
    double dlx0, dly0, dlx1, dly1, dmr2, cross;
    dlx0 = p0->dy;
    dly0 = -p0->dx;
    dlx1 = p1->dy;
    dly1 = -p1->dx;
    // Calculate extrusions
    p1->dmx = (dlx0 + dlx1) * 0.5;
    p1->dmy = (dly0 + dly1) * 0.5;
    dmr2 = p1->dmx*p1->dmx + p1->dmy*p1->dmy;
    if (dmr2 > 0.000001) {
      double s2 = 1.0 / dmr2;
      if (s2 > 600.0) {
        s2 = 600.0;
      }
      p1->dmx *= s2;
      p1->dmy *= s2;
    }
 
    // Clear flags, but keep the corner.
    p1->flags = (p1->flags & NSVG_PT_CORNER) ? NSVG_PT_CORNER : 0;
 
    // Keep track of left turns.
    cross = p1->dx * p0->dy - p0->dx * p1->dy;
    if (cross > 0.0)
      p1->flags |= NSVG_PT_LEFT;
 
    // Check to see if the corner needs to be beveled.
    if (p1->flags & NSVG_PT_CORNER) {
      if ((dmr2 * miterLimit*miterLimit) < 1.0 || lineJoin == NSVG_JOIN_BEVEL || lineJoin == NSVG_JOIN_ROUND) {
        p1->flags |= NSVG_PT_BEVEL;
      }
    }
 
    p0 = p1++;
  }
}
 
static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, double scalex, double scaley)
{
  int i, j, closed;
  NSVGpath* path;
  NSVGpoint* p0, *p1;
  double miterLimit = shape->miterLimit;
  int lineJoin = shape->strokeLineJoin;
  int lineCap = shape->strokeLineCap;
  double lineWidth = shape->strokeWidth * (scalex+scaley)*0.5;
 
  for (path = shape->paths; path != nullptr; path = path->next) {
    // Flatten path
    r->npoints = 0;
    nsvg__addPathPoint(r, path->pts[0]*scalex, path->pts[1]*scaley, NSVG_PT_CORNER);
    for (i = 0; i < path->npts-1; i += 3) {
      double* p = &path->pts[i*2];
      nsvg__flattenCubicBez(r, p[0]*scalex,p[1]*scaley, p[2]*scalex,p[3]*scaley, p[4]*scalex,p[5]*scaley, p[6]*scalex,p[7]*scaley, 0, NSVG_PT_CORNER);
    }
    if (r->npoints < 2)
      continue;
 
    closed = path->closed;
 
    // If the first and last points are the same, remove the last, mark as closed path.
    p0 = &r->points[r->npoints-1];
    p1 = &r->points[0];
    if (nsvg__ptEquals(p0->x,p0->y, p1->x,p1->y, r->distTol)) {
      r->npoints--;
      p0 = &r->points[r->npoints-1];
      closed = 1;
    }
 
    if (shape->strokeDashCount > 0) {
      int idash = 0, dashState = 1;
      double totalDist = 0, dashLen, allDashLen, dashOffset;
      NSVGpoint cur;
 
      if (closed)
        nsvg__appendPathPoint(r, r->points[0]);
 
      // Duplicate points -> points2.
      nsvg__duplicatePoints(r);
 
      r->npoints = 0;
      cur = r->points2[0];
      nsvg__appendPathPoint(r, cur);
 
      // Figure out dash offset.
      allDashLen = 0;
      for (j = 0; j < shape->strokeDashCount; j++)
        allDashLen += shape->strokeDashArray[j];
      if (shape->strokeDashCount & 1)
        allDashLen *= 2.0;
      // Find location inside pattern
      dashOffset = fmod(shape->strokeDashOffset, allDashLen);
      if (dashOffset < 0.0)
        dashOffset += allDashLen;
 
      while (dashOffset > shape->strokeDashArray[idash]) {
        dashOffset -= shape->strokeDashArray[idash];
        idash = (idash + 1) % shape->strokeDashCount;
      }
      dashLen = (shape->strokeDashArray[idash] - dashOffset) * (scalex+scaley)*0.5;
 
      for (j = 1; j < r->npoints2; ) {
        double dx = r->points2[j].x - cur.x;
        double dy = r->points2[j].y - cur.y;
        double dist = sqrt(dx*dx + dy*dy);
 
        if ((totalDist + dist) > dashLen) {
          // Calculate intermediate point
          double d = (dashLen - totalDist) / dist;
          double x = cur.x + dx * d;
          double y = cur.y + dy * d;
          nsvg__addPathPoint(r, x, y, NSVG_PT_CORNER);
 
          // Stroke
          if (r->npoints > 1 && dashState) {
            nsvg__prepareStroke(r, miterLimit, lineJoin);
            nsvg__expandStroke(r, r->points, r->npoints, 0, lineJoin, lineCap, lineWidth);
          }
          // Advance dash pattern
          dashState = !dashState;
          idash = (idash+1) % shape->strokeDashCount;
          dashLen = shape->strokeDashArray[idash] * (scalex+scaley)*0.5;
          // Restart
          cur.x = x;
          cur.y = y;
          cur.flags = NSVG_PT_CORNER;
          totalDist = 0.0;
          r->npoints = 0;
          nsvg__appendPathPoint(r, cur);
        } else {
          totalDist += dist;
          cur = r->points2[j];
          nsvg__appendPathPoint(r, cur);
          j++;
        }
      }
      // Stroke any leftover path
      if (r->npoints > 1 && dashState)
        nsvg__expandStroke(r, r->points, r->npoints, 0, lineJoin, lineCap, lineWidth);
    } else {
      nsvg__prepareStroke(r, miterLimit, lineJoin);
      nsvg__expandStroke(r, r->points, r->npoints, closed, lineJoin, lineCap, lineWidth);
    }
  }
}
 
static int nsvg__cmpEdge(const void *p, const void *q)
{
  const NSVGedge* a = static_cast<const NSVGedge*>(p);
  const NSVGedge* b = static_cast<const NSVGedge*>(q);
 
  if (a->y0 < b->y0) return -1;
  if (a->y0 > b->y0) return  1;
  return 0;
}
 
 
static NSVGactiveEdge* nsvg__addActive(NSVGrasterizer* r, NSVGedge* e, double startPoint)
{
   NSVGactiveEdge* z;
 
  if (r->freelist != nullptr) {
    // Restore from freelist.
    z = r->freelist;
    r->freelist = z->next;
  } else {
    // Alloc new edge.
    z = reinterpret_cast<NSVGactiveEdge*>(nsvg__alloc(r, sizeof(NSVGactiveEdge)));
    if (z == nullptr) return nullptr;
  }
 
  double dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
//  STBTT_assert(e->y0 <= start_point);
  // round dx down to avoid going too far
  if (dxdy < 0)
    z->dx = static_cast<int>(-floor(NSVG__FIX * -dxdy));
  else
    z->dx = static_cast<int>(floor(NSVG__FIX * dxdy));
  z->x = static_cast<int>(floor(NSVG__FIX * (e->x0 + dxdy * (startPoint - e->y0))));
//  z->x -= off_x * FIX;
  z->ey = e->y1;
  z->next = nullptr;
  z->dir = e->dir;
 
  return z;
}
 
static void nsvg__freeActive(NSVGrasterizer* r, NSVGactiveEdge* z)
{
  z->next = r->freelist;
  r->freelist = z;
}
 
static void nsvg__fillScanline(unsigned char* scanline, int len, int x0, int x1, int maxWeight, int* xmin, int* xmax)
{
  int i = x0 >> NSVG__FIXSHIFT;
  int j = x1 >> NSVG__FIXSHIFT;
  if (i < *xmin) *xmin = i;
  if (j > *xmax) *xmax = j;
  if (i < len && j >= 0) {
    if (i == j) {
      // x0,x1 are the same pixel, so compute combined coverage
      scanline[i] = static_cast<unsigned char>(scanline[i] + ((x1 - x0) * maxWeight >> NSVG__FIXSHIFT));
    } else {
      if (i >= 0) // add antialiasing for x0
        scanline[i] = static_cast<unsigned char>(scanline[i] + (((NSVG__FIX - (x0 & NSVG__FIXMASK)) * maxWeight) >> NSVG__FIXSHIFT));
      else
        i = -1; // clip
 
      if (j < len) // add antialiasing for x1
        scanline[j] = static_cast<unsigned char>(scanline[j] + (((x1 & NSVG__FIXMASK) * maxWeight) >> NSVG__FIXSHIFT));
      else
        j = len; // clip
 
      for (++i; i < j; ++i) // fill pixels between x0 and x1
        scanline[i] = static_cast<unsigned char>(scanline[i] + maxWeight);
    }
  }
}
 
// note: this routine clips fills that extend off the edges... ideally this
// wouldn't happen, but it could happen if the truetype glyph bounding boxes
// are wrong, or if the user supplies a too-small bitmap
static void nsvg__fillActiveEdges(unsigned char* scanline, int len, NSVGactiveEdge* e, int maxWeight, int* xmin, int* xmax, char fillRule)
{
  // non-zero winding fill
  int x0 = 0, w = 0;
 
  if (fillRule == NSVG_FILLRULE_NONZERO) {
    // Non-zero
    while (e != nullptr) {
      if (w == 0) {
        // if we're currently at zero, we need to record the edge start point
        x0 = e->x; w += e->dir;
      } else {
        int x1 = e->x; w += e->dir;
        // if we went to zero, we need to draw
        if (w == 0)
          nsvg__fillScanline(scanline, len, x0, x1, maxWeight, xmin, xmax);
      }
      e = e->next;
    }
  } else if (fillRule == NSVG_FILLRULE_EVENODD) {
    // Even-odd
    while (e != nullptr) {
      if (w == 0) {
        // if we're currently at zero, we need to record the edge start point
        x0 = e->x; w = 1;
      } else {
        int x1 = e->x; w = 0;
        nsvg__fillScanline(scanline, len, x0, x1, maxWeight, xmin, xmax);
      }
      e = e->next;
    }
  }
}
 
static double nsvg__clampf(double a, double mn, double mx) { return a < mn ? mn : (a > mx ? mx : a); }
 
static unsigned int nsvg__RGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
  return (r) | (g << 8) | (b << 16) | (a << 24);
}
 
static unsigned int nsvg__lerpRGBA(unsigned int c0, unsigned int c1, double u)
{
  int iu = static_cast<int>(nsvg__clampf(u, 0.0, 1.0) * 256.0);
  int r = (((c0) & 0xff)*(256-iu) + (((c1) & 0xff)*iu)) >> 8;
  int g = (((c0>>8) & 0xff)*(256-iu) + (((c1>>8) & 0xff)*iu)) >> 8;
  int b = (((c0>>16) & 0xff)*(256-iu) + (((c1>>16) & 0xff)*iu)) >> 8;
  int a = (((c0>>24) & 0xff)*(256-iu) + (((c1>>24) & 0xff)*iu)) >> 8;
  return nsvg__RGBA(static_cast<unsigned char>(r), static_cast<unsigned char>(g), static_cast<unsigned char>(b), static_cast<unsigned char>(a));
}
 
static unsigned int nsvg__applyOpacity(unsigned int c, double u)
{
  int iu = static_cast<int>(nsvg__clampf(u, 0.0, 1.0) * 256.0);
  int r = (c) & 0xff;
  int g = (c>>8) & 0xff;
  int b = (c>>16) & 0xff;
  int a = (((c>>24) & 0xff)*iu) >> 8;
  return nsvg__RGBA(static_cast<unsigned char>(r), static_cast<unsigned char>(g), static_cast<unsigned char>(b), static_cast<unsigned char>(a));
}
 
static inline int nsvg__div255(int x)
{
    return ((x+1) * 257) >> 16;
}
 
static void nsvg__scanlineSolid(unsigned char* dst, int count, unsigned char* cover, int x, int y,
                double tx, double ty, double scalex, double scaley, NSVGcachedPaint* cache)
{
 
  if (cache->type == NSVG_PAINT_COLOR) {
    int i, cr, cg, cb, ca;
    cr = cache->colors[0] & 0xff;
    cg = (cache->colors[0] >> 8) & 0xff;
    cb = (cache->colors[0] >> 16) & 0xff;
    ca = (cache->colors[0] >> 24) & 0xff;
 
    for (i = 0; i < count; i++) {
      int r,g,b;
      int a = nsvg__div255(static_cast<int>(cover[0]) * ca);
      int ia = 255 - a;
      // Premultiply
      r = nsvg__div255(cr * a);
      g = nsvg__div255(cg * a);
      b = nsvg__div255(cb * a);
 
      // Blend over
      r += nsvg__div255(ia * static_cast<int>(dst[0]));
      g += nsvg__div255(ia * static_cast<int>(dst[1]));
      b += nsvg__div255(ia * static_cast<int>(dst[2]));
      a += nsvg__div255(ia * static_cast<int>(dst[3]));
 
      dst[0] = static_cast<unsigned char>(r);
      dst[1] = static_cast<unsigned char>(g);
      dst[2] = static_cast<unsigned char>(b);
      dst[3] = static_cast<unsigned char>(a);
 
      cover++;
      dst += 4;
    }
  } else if (cache->type == NSVG_PAINT_LINEAR_GRADIENT) {
    // TODO: spread modes.
    // TODO: plenty of opportunities to optimize.
    double fx, fy, dx, gy;
    double* t = cache->xform;
    int i, cr, cg, cb, ca;
    unsigned int c;
 
    fx = (static_cast<double>(x) - tx) / scalex;
    fy = (static_cast<double>(y) - ty) / scaley;
    dx = 1.0 / scalex;
 
    for (i = 0; i < count; i++) {
      int r,g,b,a,ia;
      gy = fx*t[1] + fy*t[3] + t[5];
      c = cache->colors[static_cast<int>(nsvg__clampf(gy*255.0, 0, 255.0))];
      cr = (c) & 0xff;
      cg = (c >> 8) & 0xff;
      cb = (c >> 16) & 0xff;
      ca = (c >> 24) & 0xff;
 
      a = nsvg__div255(static_cast<int>(cover[0]) * ca);
      ia = 255 - a;
 
      // Premultiply
      r = nsvg__div255(cr * a);
      g = nsvg__div255(cg * a);
      b = nsvg__div255(cb * a);
 
      // Blend over
      r += nsvg__div255(ia * static_cast<int>(dst[0]));
      g += nsvg__div255(ia * static_cast<int>(dst[1]));
      b += nsvg__div255(ia * static_cast<int>(dst[2]));
      a += nsvg__div255(ia * static_cast<int>(dst[3]));
 
      dst[0] = static_cast<unsigned char>(r);
      dst[1] = static_cast<unsigned char>(g);
      dst[2] = static_cast<unsigned char>(b);
      dst[3] = static_cast<unsigned char>(a);
 
      cover++;
      dst += 4;
      fx += dx;
    }
  } else if (cache->type == NSVG_PAINT_RADIAL_GRADIENT) {
    // TODO: spread modes.
    // TODO: plenty of opportunities to optimize.
    // TODO: focus (fx,fy)
    double fx, fy, dx, gx, gy, gd;
    double* t = cache->xform;
    int i, cr, cg, cb, ca;
    unsigned int c;
 
    fx = (static_cast<double>(x) - tx) / scalex;
    fy = (static_cast<double>(y) - ty) / scaley;
    dx = 1.0 / scalex;
 
    for (i = 0; i < count; i++) {
      int r,g,b,a,ia;
      gx = fx*t[0] + fy*t[2] + t[4];
      gy = fx*t[1] + fy*t[3] + t[5];
      gd = sqrt(gx*gx + gy*gy);
      c = cache->colors[static_cast<int>(nsvg__clampf(gd*255.0, 0, 255.0))];
      cr = (c) & 0xff;
      cg = (c >> 8) & 0xff;
      cb = (c >> 16) & 0xff;
      ca = (c >> 24) & 0xff;
 
      a = nsvg__div255(static_cast<int>(cover[0]) * ca);
      ia = 255 - a;
 
      // Premultiply
      r = nsvg__div255(cr * a);
      g = nsvg__div255(cg * a);
      b = nsvg__div255(cb * a);
 
      // Blend over
      r += nsvg__div255(ia * static_cast<int>(dst[0]));
      g += nsvg__div255(ia * static_cast<int>(dst[1]));
      b += nsvg__div255(ia * static_cast<int>(dst[2]));
      a += nsvg__div255(ia * static_cast<int>(dst[3]));
 
      dst[0] = static_cast<unsigned char>(r);
      dst[1] = static_cast<unsigned char>(g);
      dst[2] = static_cast<unsigned char>(b);
      dst[3] = static_cast<unsigned char>(a);
 
      cover++;
      dst += 4;
      fx += dx;
    }
  }
}
 
static void nsvg__rasterizeSortedEdges(NSVGrasterizer *r, double tx, double ty, double scalex, double scaley, NSVGcachedPaint* cache, char fillRule)
{
  NSVGactiveEdge *active = nullptr;
  int y, s;
  int e = 0;
  int maxWeight = (255 / NSVG__SUBSAMPLES);  // weight per vertical scanline
  int xmin, xmax;
 
  for (y = 0; y < r->height; y++) {
    memset(r->scanline, 0, r->width);
    xmin = r->width;
    xmax = 0;
    for (s = 0; s < NSVG__SUBSAMPLES; ++s) {
      // find center of pixel for this scanline
      double scany = static_cast<double>(y*NSVG__SUBSAMPLES + s) + 0.5;
      NSVGactiveEdge **step = &active;
 
      // update all active edges;
      // remove all active edges that terminate before the center of this scanline
      while (*step) {
        NSVGactiveEdge *z = *step;
        if (z->ey <= scany) {
          *step = z->next; // delete from list
//          NSVG__assert(z->valid);
          nsvg__freeActive(r, z);
        } else {
          z->x += z->dx; // advance to position for current scanline
          step = &((*step)->next); // advance through list
        }
      }
 
      // resort the list if needed
      for (;;) {
        int changed = 0;
        step = &active;
        while (*step && (*step)->next) {
          if ((*step)->x > (*step)->next->x) {
            NSVGactiveEdge* t = *step;
            NSVGactiveEdge* q = t->next;
            t->next = q->next;
            q->next = t;
            *step = q;
            changed = 1;
          }
          step = &(*step)->next;
        }
        if (!changed) break;
      }
 
      // insert all edges that start before the center of this scanline -- omit ones that also end on this scanline
      while (e < r->nedges && r->edges[e].y0 <= scany) {
        if (r->edges[e].y1 > scany) {
          NSVGactiveEdge* z = nsvg__addActive(r, &r->edges[e], scany);
          if (z == nullptr) break;
          // find insertion point
          if (active == nullptr) {
            active = z;
          } else if (z->x < active->x) {
            // insert at front
            z->next = active;
            active = z;
          } else {
            // find thing to insert AFTER
            NSVGactiveEdge* p = active;
            while (p->next && p->next->x < z->x)
              p = p->next;
            // at this point, p->next->x is NOT < z->x
            z->next = p->next;
            p->next = z;
          }
        }
        e++;
      }
 
      // now process all active edges in non-zero fashion
      if (active != nullptr)
        nsvg__fillActiveEdges(r->scanline, r->width, active, maxWeight, &xmin, &xmax, fillRule);
    }
    // Blit
    if (xmin < 0) xmin = 0;
    if (xmax > r->width-1) xmax = r->width-1;
    if (xmin <= xmax) {
      nsvg__scanlineSolid(&r->bitmap[y * r->stride] + xmin*4, xmax-xmin+1, &r->scanline[xmin], xmin, y, tx,ty, scalex, scaley, cache);
    }
  }
 
}
 
static void nsvg__unpremultiplyAlpha(unsigned char* image, int w, int h, int stride)
{
  int x,y;
 
  // Unpremultiply
  for (y = 0; y < h; y++) {
    unsigned char *row = &image[y*stride];
    for (x = 0; x < w; x++) {
      int r = row[0], g = row[1], b = row[2], a = row[3];
      if (a != 0) {
        row[0] = static_cast<unsigned char>(r*255/a);
        row[1] = static_cast<unsigned char>(g*255/a);
        row[2] = static_cast<unsigned char>(b*255/a);
      }
      row += 4;
    }
  }
 
  // Defringe
  for (y = 0; y < h; y++) {
    unsigned char *row = &image[y*stride];
    for (x = 0; x < w; x++) {
      int r = 0, g = 0, b = 0, a = row[3], n = 0;
      if (a == 0) {
        if (x-1 > 0 && row[-1] != 0) {
          r += row[-4];
          g += row[-3];
          b += row[-2];
          n++;
        }
        if (x+1 < w && row[7] != 0) {
          r += row[4];
          g += row[5];
          b += row[6];
          n++;
        }
        if (y-1 > 0 && row[-stride+3] != 0) {
          r += row[-stride];
          g += row[-stride+1];
          b += row[-stride+2];
          n++;
        }
        if (y+1 < h && row[stride+3] != 0) {
          r += row[stride];
          g += row[stride+1];
          b += row[stride+2];
          n++;
        }
        if (n > 0) {
          row[0] = static_cast<unsigned char>(r/n);
          row[1] = static_cast<unsigned char>(g/n);
          row[2] = static_cast<unsigned char>(b/n);
        }
      }
      row += 4;
    }
  }
}
 
 
static void nsvg__unpremultiplyBGRAlpha(unsigned char* image, int w, int h, int stride)
{
  int x,y;
 
  // Unpremultiply
  for (y = 0; y < h; y++) {
    unsigned char *row = &image[y*stride];
    for (x = 0; x < w; x++) {
      int b = row[0], g = row[1], r = row[2], a = row[3];
      if (a != 0) {
        row[0] = static_cast<unsigned char>(r*255/a);
        row[1] = static_cast<unsigned char>(g*255/a);
        row[2] = static_cast<unsigned char>(b*255/a);
      }
      row += 4;
    }
  }
 
  // Defringe
  for (y = 0; y < h; y++) {
    unsigned char *row = &image[y*stride];
    for (x = 0; x < w; x++) {
      int r = 0, g = 0, b = 0, a = row[3], n = 0;
      if (a == 0) {
        if (x-1 > 0 && row[-1] != 0) {
          b += row[-4];
          g += row[-3];
          r += row[-2];
          n++;
        }
        if (x+1 < w && row[7] != 0) {
          b += row[4];
          g += row[5];
          r += row[6];
          n++;
        }
        if (y-1 > 0 && row[-stride+3] != 0) {
          b += row[-stride];
          g += row[-stride+1];
          r += row[-stride+2];
          n++;
        }
        if (y+1 < h && row[stride+3] != 0) {
          b += row[stride];
          g += row[stride+1];
          r += row[stride+2];
          n++;
        }
        if (n > 0) {
          row[0] = static_cast<unsigned char>(b/n);
          row[1] = static_cast<unsigned char>(g/n);
          row[2] = static_cast<unsigned char>(r/n);
        }
      }
      row += 4;
    }
  }
}
 
 
static void nsvg__initPaint(NSVGcachedPaint* cache, NSVGpaint* paint, double opacity)
{
  int i, j;
  NSVGgradient* grad;
 
  cache->type = paint->type;
 
  if (paint->type == NSVG_PAINT_COLOR) {
    cache->colors[0] = nsvg__applyOpacity(paint->color, opacity);
    return;
  }
 
  grad = paint->gradient;
 
  cache->spread = grad->spread;
  memcpy(cache->xform, grad->xform, sizeof(double)*6);
 
  if (grad->nstops == 0) {
    for (i = 0; i < 256; i++)
      cache->colors[i] = 0;
  } if (grad->nstops == 1) {
    for (i = 0; i < 256; i++)
      cache->colors[i] = nsvg__applyOpacity(grad->stops[i].color, opacity);
  } else {
    unsigned int ca, cb = 0;
    double ua, ub, du, u;
    int ia, ib, count;
 
    ca = nsvg__applyOpacity(grad->stops[0].color, opacity);
    ua = nsvg__clampf(grad->stops[0].offset, 0, 1);
    ub = nsvg__clampf(grad->stops[grad->nstops-1].offset, ua, 1);
    ia = static_cast<int>(ua * 255.0);
    ib = static_cast<int>(ub * 255.0);
    for (i = 0; i < ia; i++) {
      cache->colors[i] = ca;
    }
 
    for (i = 0; i < grad->nstops-1; i++) {
      ca = nsvg__applyOpacity(grad->stops[i].color, opacity);
      cb = nsvg__applyOpacity(grad->stops[i+1].color, opacity);
      ua = nsvg__clampf(grad->stops[i].offset, 0, 1);
      ub = nsvg__clampf(grad->stops[i+1].offset, 0, 1);
      ia = static_cast<int>(ua * 255.0);
      ib = static_cast<int>(ub * 255.0);
      count = ib - ia;
      if (count <= 0) continue;
      u = 0;
      du = 1.0 / static_cast<double>(count);
      for (j = 0; j < count; j++) {
        cache->colors[ia+j] = nsvg__lerpRGBA(ca,cb,u);
        u += du;
      }
    }
 
    for (i = ib; i < 256; i++)
      cache->colors[i] = cb;
  }
 
}
 
 
void nsvgRasterizeFull(NSVGrasterizer* r,
           NSVGimage* image, double tx, double ty, double scalex, double scaley,
           unsigned char* dst, int w, int h, int stride, int bgr)
{
  NSVGshape *shape = nullptr;
  NSVGedge *e = nullptr;
  NSVGcachedPaint cache;
  int i;
 
  r->bitmap = dst;
  r->width = w;
  r->height = h;
  r->stride = stride;
 
  if (w > r->cscanline) {
    r->cscanline = w;
    r->scanline = static_cast<unsigned char*>(realloc(r->scanline, w));
    if (r->scanline == nullptr) return;
  }
 
  for (i = 0; i < h; i++)
    memset(&dst[i*stride], 0, w*4);
 
  for (shape = image->shapes; shape != nullptr; shape = shape->next) {
    if (!(shape->flags & NSVG_FLAGS_VISIBLE))
      continue;
 
    if (shape->fill.type != NSVG_PAINT_NONE) {
      nsvg__resetPool(r);
      r->freelist = nullptr;
      r->nedges = 0;
 
      nsvg__flattenShape(r, shape, scalex, scaley);
 
      // Scale and translate edges
      for (i = 0; i < r->nedges; i++) {
        e = &r->edges[i];
        e->x0 = tx + e->x0;
        e->y0 = (ty + e->y0) * NSVG__SUBSAMPLES;
        e->x1 = tx + e->x1;
        e->y1 = (ty + e->y1) * NSVG__SUBSAMPLES;
      }
 
      // Rasterize edges
      qsort(r->edges, r->nedges, sizeof(NSVGedge), nsvg__cmpEdge);
 
      // now, traverse the scanlines and find the intersections on each scanline, use non-zero rule
      nsvg__initPaint(&cache, &shape->fill, shape->opacity);
 
      nsvg__rasterizeSortedEdges(r, tx,ty, scalex, scaley, &cache, shape->fillRule);
    }
    if (shape->stroke.type != NSVG_PAINT_NONE && (shape->strokeWidth * (scalex+scaley)*0.5) > 0.01) {
      nsvg__resetPool(r);
      r->freelist = nullptr;
      r->nedges = 0;
 
      nsvg__flattenShapeStroke(r, shape, scalex, scaley);
 
//      dumpEdges(r, "edge.svg");
 
      // Scale and translate edges
      for (i = 0; i < r->nedges; i++) {
        e = &r->edges[i];
        e->x0 = tx + e->x0;
        e->y0 = (ty + e->y0) * NSVG__SUBSAMPLES;
        e->x1 = tx + e->x1;
        e->y1 = (ty + e->y1) * NSVG__SUBSAMPLES;
      }
 
      // Rasterize edges
      qsort(r->edges, r->nedges, sizeof(NSVGedge), nsvg__cmpEdge);
 
      // now, traverse the scanlines and find the intersections on each scanline, use non-zero rule
      nsvg__initPaint(&cache, &shape->stroke, shape->opacity);
 
      nsvg__rasterizeSortedEdges(r, tx,ty, scalex, scaley, &cache, NSVG_FILLRULE_NONZERO);
    }
  }
 
  if (bgr)
    nsvg__unpremultiplyBGRAlpha(dst, w, h, stride);
  else
    nsvg__unpremultiplyAlpha(dst, w, h, stride);
 
  r->bitmap = nullptr;
  r->width = 0;
  r->height = 0;
  r->stride = 0;
}
 
void nsvgRasterize(NSVGrasterizer* r,
          NSVGimage* image, double tx, double ty, double scale,
          unsigned char* dst, int w, int h, int stride)
{
  return nsvgRasterizeFull(r, image, tx, ty, scale, scale, dst, w, h, stride, 0);
}
 
#endif