nanosvgrast.h

/*
 * 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, float tx, float ty, float scale,
                   unsigned char* dst, int w, int h, int stride);

// 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 {
    float x0,y0, x1,y1;
    int dir;
    struct NSVGedge* next;
} NSVGedge;

typedef struct NSVGpoint {
    float x, y;
    float dx, dy;
    float len;
    float dmx, dmy;
    unsigned char flags;
} NSVGpoint;

typedef struct NSVGactiveEdge {
    int x,dx;
    float 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;
    float xform[6];
    unsigned int colors[256];
} NSVGcachedPaint;

struct NSVGrasterizer
{
    float px, py;

    float tessTol;
    float 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 = (NSVGrasterizer*)malloc(sizeof(NSVGrasterizer));
    if (r == NULL) goto error;
    memset(r, 0, sizeof(NSVGrasterizer));

    r->tessTol = 0.25f;
    r->distTol = 0.01f;

    return r;

error:
    nsvgDeleteRasterizer(r);
    return NULL;
}

void nsvgDeleteRasterizer(NSVGrasterizer* r)
{
    NSVGmemPage* p;

    if (r == NULL) return;

    p = r->pages;
    while (p != NULL) {
        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 != NULL && cur->next != NULL) {
        return cur->next;
    }

    // Alloc new page
    newp = (NSVGmemPage*)malloc(sizeof(NSVGmemPage));
    if (newp == NULL) return NULL;
    memset(newp, 0, sizeof(NSVGmemPage));

    // Add to linked list
    if (cur != NULL)
        cur->next = newp;
    else
        r->pages = newp;

    return newp;
}

static void nsvg__resetPool(NSVGrasterizer* r)
{
    NSVGmemPage* p = r->pages;
    while (p != NULL) {
        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 NULL;
    if (r->curpage == NULL || 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(float x1, float y1, float x2, float y2, float tol)
{
    float dx = x2 - x1;
    float dy = y2 - y1;
    return dx*dx + dy*dy < tol*tol;
}

static void nsvg__addPathPoint(NSVGrasterizer* r, float x, float 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 = (unsigned char)(pt->flags | flags);
            return;
        }
    }

    if (r->npoints+1 > r->cpoints) {
        r->cpoints = r->cpoints > 0 ? r->cpoints * 2 : 64;
        r->points = (NSVGpoint*)realloc(r->points, sizeof(NSVGpoint) * r->cpoints);
        if (r->points == NULL) return;
    }

    pt = &r->points[r->npoints];
    pt->x = x;
    pt->y = y;
    pt->flags = (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 = (NSVGpoint*)realloc(r->points, sizeof(NSVGpoint) * r->cpoints);
        if (r->points == NULL) 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 = (NSVGpoint*)realloc(r->points2, sizeof(NSVGpoint) * r->cpoints2);
        if (r->points2 == NULL) return;
    }

    memcpy(r->points2, r->points, sizeof(NSVGpoint) * r->npoints);
    r->npoints2 = r->npoints;
}

static void nsvg__addEdge(NSVGrasterizer* r, float x0, float y0, float x1, float y1)
{
    NSVGedge* e;

    // Skip horizontal edges
    if (y0 == y1)
        return;

    if (r->nedges+1 > r->cedges) {
        r->cedges = r->cedges > 0 ? r->cedges * 2 : 64;
        r->edges = (NSVGedge*)realloc(r->edges, sizeof(NSVGedge) * r->cedges);
        if (r->edges == NULL) 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 float nsvg__normalize(float *x, float* y)
{
    float d = sqrtf((*x)*(*x) + (*y)*(*y));
    if (d > 1e-6f) {
        float id = 1.0f / d;
        *x *= id;
        *y *= id;
    }
    return d;
}

static float nsvg__absf(float x) { return x < 0 ? -x : x; }

static void nsvg__flattenCubicBez(NSVGrasterizer* r,
                                  float x1, float y1, float x2, float y2,
                                  float x3, float y3, float x4, float y4,
                                  int level, int type)
{
    float x12,y12,x23,y23,x34,y34,x123,y123,x234,y234,x1234,y1234;
    float dx,dy,d2,d3;

    if (level > 10) return;

    x12 = (x1+x2)*0.5f;
    y12 = (y1+y2)*0.5f;
    x23 = (x2+x3)*0.5f;
    y23 = (y2+y3)*0.5f;
    x34 = (x3+x4)*0.5f;
    y34 = (y3+y4)*0.5f;
    x123 = (x12+x23)*0.5f;
    y123 = (y12+y23)*0.5f;

    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)*0.5f;
    y234 = (y23+y34)*0.5f;
    x1234 = (x123+x234)*0.5f;
    y1234 = (y123+y234)*0.5f;

    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, float scale)
{
    int i, j;
    NSVGpath* path;

    for (path = shape->paths; path != NULL; path = path->next) {
        r->npoints = 0;
        // Flatten path
        nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, 0);
        for (i = 0; i < path->npts-1; i += 3) {
            float* p = &path->pts[i*2];
            nsvg__flattenCubicBez(r, p[0]*scale,p[1]*scale, p[2]*scale,p[3]*scale, p[4]*scale,p[5]*scale, p[6]*scale,p[7]*scale, 0, 0);
        }
        // Close path
        nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, 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, float lineWidth)
{
    float w = lineWidth * 0.5f;
    float dx = p1->x - p0->x;
    float dy = p1->y - p0->y;
    float len = nsvg__normalize(&dx, &dy);
    float px = p0->x + dx*len*0.5f, py = p0->y + dy*len*0.5f;
    float dlx = dy, dly = -dx;
    float lx = px - dlx*w, ly = py - dly*w;
    float 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, float dx, float dy, float lineWidth, int connect)
{
    float w = lineWidth * 0.5f;
    float px = p->x, py = p->y;
    float dlx = dy, dly = -dx;
    float lx = px - dlx*w, ly = py - dly*w;
    float 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, float dx, float dy, float lineWidth, int connect)
{
    float w = lineWidth * 0.5f;
    float px = p->x - dx*w, py = p->y - dy*w;
    float dlx = dy, dly = -dx;
    float lx = px - dlx*w, ly = py - dly*w;
    float 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 (3.14159265358979323846264338327f)
#endif

static void nsvg__roundCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, float dx, float dy, float lineWidth, int ncap, int connect)
{
    int i;
    float w = lineWidth * 0.5f;
    float px = p->x, py = p->y;
    float dlx = dy, dly = -dx;
    float lx = 0, ly = 0, rx = 0, ry = 0, prevx = 0, prevy = 0;

    for (i = 0; i < ncap; i++) {
        float a = (float)i/(float)(ncap-1)*NSVG_PI;
        float ax = cosf(a) * w, ay = sinf(a) * w;
        float x = px - dlx*ax - dx*ay;
        float 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, float lineWidth)
{
    float w = lineWidth * 0.5f;
    float dlx0 = p0->dy, dly0 = -p0->dx;
    float dlx1 = p1->dy, dly1 = -p1->dx;
    float lx0 = p1->x - (dlx0 * w), ly0 = p1->y - (dly0 * w);
    float rx0 = p1->x + (dlx0 * w), ry0 = p1->y + (dly0 * w);
    float lx1 = p1->x - (dlx1 * w), ly1 = p1->y - (dly1 * w);
    float 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, float lineWidth)
{
    float w = lineWidth * 0.5f;
    float dlx0 = p0->dy, dly0 = -p0->dx;
    float dlx1 = p1->dy, dly1 = -p1->dx;
    float lx0, rx0, lx1, rx1;
    float 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, float lineWidth, int ncap)
{
    int i, n;
    float w = lineWidth * 0.5f;
    float dlx0 = p0->dy, dly0 = -p0->dx;
    float dlx1 = p1->dy, dly1 = -p1->dx;
    float a0 = atan2f(dly0, dlx0);
    float a1 = atan2f(dly1, dlx1);
    float da = a1 - a0;
    float lx, ly, rx, ry;

    if (da < NSVG_PI) da += NSVG_PI*2;
    if (da > NSVG_PI) da -= NSVG_PI*2;

    n = (int)ceilf((nsvg__absf(da) / NSVG_PI) * (float)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++) {
        float u = (float)i/(float)(n-1);
        float a = a0 + u*da;
        float ax = cosf(a) * w, ay = sinf(a) * w;
        float lx1 = p1->x - ax, ly1 = p1->y - ay;
        float 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, float lineWidth)
{
    float w = lineWidth * 0.5f;
    float lx = p1->x - (p1->dmx * w), ly = p1->y - (p1->dmy * w);
    float 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(float r, float arc, float tol)
{
    float da = acosf(r / (r + tol)) * 2.0f;
    int divs = (int)ceilf(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, float lineWidth)
{
    int ncap = nsvg__curveDivs(lineWidth*0.5f, 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
        float dx = p1->x - p0->x;
        float 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
        float dx = p1->x - p0->x;
        float 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, float 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++) {
        float dlx0, dly0, dlx1, dly1, dmr2, cross;
        dlx0 = p0->dy;
        dly0 = -p0->dx;
        dlx1 = p1->dy;
        dly1 = -p1->dx;
        // Calculate extrusions
        p1->dmx = (dlx0 + dlx1) * 0.5f;
        p1->dmy = (dly0 + dly1) * 0.5f;
        dmr2 = p1->dmx*p1->dmx + p1->dmy*p1->dmy;
        if (dmr2 > 0.000001f) {
            float s2 = 1.0f / dmr2;
            if (s2 > 600.0f) {
                s2 = 600.0f;
            }
            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 > 0.0f)
            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) < 1.0f || lineJoin == NSVG_JOIN_BEVEL || lineJoin == NSVG_JOIN_ROUND) {
                p1->flags |= NSVG_PT_BEVEL;
            }
        }

        p0 = p1++;
    }
}

static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float scale)
{
    int i, j, closed;
    NSVGpath* path;
    NSVGpoint* p0, *p1;
    float miterLimit = shape->miterLimit;
    int lineJoin = shape->strokeLineJoin;
    int lineCap = shape->strokeLineCap;
    float lineWidth = shape->strokeWidth * scale;

    for (path = shape->paths; path != NULL; path = path->next) {
        // Flatten path
        r->npoints = 0;
        nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, NSVG_PT_CORNER);
        for (i = 0; i < path->npts-1; i += 3) {
            float* p = &path->pts[i*2];
            nsvg__flattenCubicBez(r, p[0]*scale,p[1]*scale, p[2]*scale,p[3]*scale, p[4]*scale,p[5]*scale, p[6]*scale,p[7]*scale, 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;
            float 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 *= 2.0f;
            // Find location inside pattern
            dashOffset = fmodf(shape->strokeDashOffset, allDashLen);
            if (dashOffset < 0.0f)
                dashOffset += allDashLen;

            while (dashOffset > shape->strokeDashArray[idash]) {
                dashOffset -= shape->strokeDashArray[idash];
                idash = (idash + 1) % shape->strokeDashCount;
            }
            dashLen = (shape->strokeDashArray[idash] - dashOffset) * scale;

            for (j = 1; j < r->npoints2; ) {
                float dx = r->points2[j].x - cur.x;
                float dy = r->points2[j].y - cur.y;
                float dist = sqrtf(dx*dx + dy*dy);

                if ((totalDist + dist) > dashLen) {
                    // Calculate intermediate point
                    float d = (dashLen - totalDist) / dist;
                    float x = cur.x + dx * d;
                    float 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] * scale;
                    // Restart
                    cur.x = x;
                    cur.y = y;
                    cur.flags = NSVG_PT_CORNER;
                    totalDist = 0.0f;
                    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 = (const NSVGedge*)p;
    const NSVGedge* b = (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, float startPoint)
{
     NSVGactiveEdge* z;

    if (r->freelist != NULL) {
        // Restore from freelist.
        z = r->freelist;
        r->freelist = z->next;
    } else {
        // Alloc new edge.
        z = (NSVGactiveEdge*)nsvg__alloc(r, sizeof(NSVGactiveEdge));
        if (z == NULL) return NULL;
    }

    float 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 = (int)(-floorf(NSVG__FIX * -dxdy));
    else
        z->dx = (int)floorf(NSVG__FIX * dxdy);
    z->x = (int)floorf(NSVG__FIX * (e->x0 + dxdy * (startPoint - e->y0)));
//  z->x -= off_x * FIX;
    z->ey = e->y1;
    z->next = 0;
    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] = (unsigned char)(scanline[i] + ((x1 - x0) * maxWeight >> NSVG__FIXSHIFT));
        } else {
            if (i >= 0) // add antialiasing for x0
                scanline[i] = (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] = (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] = (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 != NULL) {
            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 != NULL) {
            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 float nsvg__clampf(float a, float mn, float 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, float u)
{
    int iu = (int)(nsvg__clampf(u, 0.0f, 1.0f) * 256.0f);
    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((unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a);
}

static unsigned int nsvg__applyOpacity(unsigned int c, float u)
{
    int iu = (int)(nsvg__clampf(u, 0.0f, 1.0f) * 256.0f);
    int r = (c) & 0xff;
    int g = (c>>8) & 0xff;
    int b = (c>>16) & 0xff;
    int a = (((c>>24) & 0xff)*iu) >> 8;
    return nsvg__RGBA((unsigned char)r, (unsigned char)g, (unsigned char)b, (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,
                                float tx, float ty, float scale, 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((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 * (int)dst[0]);
            g += nsvg__div255(ia * (int)dst[1]);
            b += nsvg__div255(ia * (int)dst[2]);
            a += nsvg__div255(ia * (int)dst[3]);

            dst[0] = (unsigned char)r;
            dst[1] = (unsigned char)g;
            dst[2] = (unsigned char)b;
            dst[3] = (unsigned char)a;

            cover++;
            dst += 4;
        }
    } else if (cache->type == NSVG_PAINT_LINEAR_GRADIENT) {
        // TODO: spread modes.
        // TODO: plenty of opportunities to optimize.
        float fx, fy, dx, gy;
        float* t = cache->xform;
        int i, cr, cg, cb, ca;
        unsigned int c;

        fx = ((float)x - tx) / scale;
        fy = ((float)y - ty) / scale;
        dx = 1.0f / scale;

        for (i = 0; i < count; i++) {
            int r,g,b,a,ia;
            gy = fx*t[1] + fy*t[3] + t[5];
            c = cache->colors[(int)nsvg__clampf(gy*255.0f, 0, 255.0f)];
            cr = (c) & 0xff;
            cg = (c >> 8) & 0xff;
            cb = (c >> 16) & 0xff;
            ca = (c >> 24) & 0xff;

            a = nsvg__div255((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 * (int)dst[0]);
            g += nsvg__div255(ia * (int)dst[1]);
            b += nsvg__div255(ia * (int)dst[2]);
            a += nsvg__div255(ia * (int)dst[3]);

            dst[0] = (unsigned char)r;
            dst[1] = (unsigned char)g;
            dst[2] = (unsigned char)b;
            dst[3] = (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)
        float fx, fy, dx, gx, gy, gd;
        float* t = cache->xform;
        int i, cr, cg, cb, ca;
        unsigned int c;

        fx = ((float)x - tx) / scale;
        fy = ((float)y - ty) / scale;
        dx = 1.0f / scale;

        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 = sqrtf(gx*gx + gy*gy);
            c = cache->colors[(int)nsvg__clampf(gd*255.0f, 0, 255.0f)];
            cr = (c) & 0xff;
            cg = (c >> 8) & 0xff;
            cb = (c >> 16) & 0xff;
            ca = (c >> 24) & 0xff;

            a = nsvg__div255((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 * (int)dst[0]);
            g += nsvg__div255(ia * (int)dst[1]);
            b += nsvg__div255(ia * (int)dst[2]);
            a += nsvg__div255(ia * (int)dst[3]);

            dst[0] = (unsigned char)r;
            dst[1] = (unsigned char)g;
            dst[2] = (unsigned char)b;
            dst[3] = (unsigned char)a;

            cover++;
            dst += 4;
            fx += dx;
        }
    }
}

static void nsvg__rasterizeSortedEdges(NSVGrasterizer *r, float tx, float ty, float scale, NSVGcachedPaint* cache, char fillRule)
{
    NSVGactiveEdge *active = NULL;
    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
            float scany = (float)(y*NSVG__SUBSAMPLES + s) + 0.5f;
            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 == NULL) break;
                    // find insertion point
                    if (active == NULL) {
                        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 != NULL)
                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, scale, 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] = (unsigned char)(r*255/a);
                row[1] = (unsigned char)(g*255/a);
                row[2] = (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] = (unsigned char)(r/n);
                    row[1] = (unsigned char)(g/n);
                    row[2] = (unsigned char)(b/n);
                }
            }
            row += 4;
        }
    }
}


static void nsvg__initPaint(NSVGcachedPaint* cache, NSVGpaint* paint, float 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(float)*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;
        float 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 = (int)(ua * 255.0f);
        ib = (int)(ub * 255.0f);
        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 = (int)(ua * 255.0f);
            ib = (int)(ub * 255.0f);
            count = ib - ia;
            if (count <= 0) continue;
            u = 0;
            du = 1.0f / (float)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;
    }

}

/*
static void dumpEdges(NSVGrasterizer* r, const char* name)
{
    float xmin = 0, xmax = 0, ymin = 0, ymax = 0;
    NSVGedge *e = NULL;
    int i;
    if (r->nedges == 0) return;
    FILE* fp = fopen(name, "w");
    if (fp == NULL) return;

    xmin = xmax = r->edges[0].x0;
    ymin = ymax = r->edges[0].y0;
    for (i = 0; i < r->nedges; i++) {
        e = &r->edges[i];
        xmin = nsvg__minf(xmin, e->x0);
        xmin = nsvg__minf(xmin, e->x1);
        xmax = nsvg__maxf(xmax, e->x0);
        xmax = nsvg__maxf(xmax, e->x1);
        ymin = nsvg__minf(ymin, e->y0);
        ymin = nsvg__minf(ymin, e->y1);
        ymax = nsvg__maxf(ymax, e->y0);
        ymax = nsvg__maxf(ymax, e->y1);
    }

    fprintf(fp, "<svg viewBox=\"%f %f %f %f\" xmlns=\"http://www.w3.org/2000/svg\">", xmin, ymin, (xmax - xmin), (ymax - ymin));

    for (i = 0; i < r->nedges; i++) {
        e = &r->edges[i];
        fprintf(fp ,"<line x1=\"%f\" y1=\"%f\" x2=\"%f\" y2=\"%f\" style=\"stroke:#000;\" />", e->x0,e->y0, e->x1,e->y1);
    }

    for (i = 0; i < r->npoints; i++) {
        if (i+1 < r->npoints)
            fprintf(fp ,"<line x1=\"%f\" y1=\"%f\" x2=\"%f\" y2=\"%f\" style=\"stroke:#f00;\" />", r->points[i].x, r->points[i].y, r->points[i+1].x, r->points[i+1].y);
        fprintf(fp ,"<circle cx=\"%f\" cy=\"%f\" r=\"1\" style=\"fill:%s;\" />", r->points[i].x, r->points[i].y, r->points[i].flags == 0 ? "#f00" : "#0f0");
    }

    fprintf(fp, "</svg>");
    fclose(fp);
}
*/

void nsvgRasterize(NSVGrasterizer* r,
                   NSVGimage* image, float tx, float ty, float scale,
                   unsigned char* dst, int w, int h, int stride)
{
    NSVGshape *shape = NULL;
    NSVGedge *e = NULL;
    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 = (unsigned char*)realloc(r->scanline, w);
        if (r->scanline == NULL) return;
    }

    for (i = 0; i < h; i++)
        memset(&dst[i*stride], 0, w*4);

    for (shape = image->shapes; shape != NULL; shape = shape->next) {
        if (!(shape->flags & NSVG_FLAGS_VISIBLE))
            continue;

        if (shape->fill.type != NSVG_PAINT_NONE) {
            nsvg__resetPool(r);
            r->freelist = NULL;
            r->nedges = 0;

            nsvg__flattenShape(r, shape, scale);

            // 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,scale, &cache, shape->fillRule);
        }
        if (shape->stroke.type != NSVG_PAINT_NONE && (shape->strokeWidth * scale) > 0.01f) {
            nsvg__resetPool(r);
            r->freelist = NULL;
            r->nedges = 0;

            nsvg__flattenShapeStroke(r, shape, scale);

//          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,scale, &cache, NSVG_FILLRULE_NONZERO);
        }
    }

    nsvg__unpremultiplyAlpha(dst, w, h, stride);

    r->bitmap = NULL;
    r->width = 0;
    r->height = 0;
    r->stride = 0;
}

#endif