nanosvgrast.h
author Ryan C. Gordon <icculus@icculus.org>
Wed, 26 Sep 2018 15:19:34 -0400
changeset 587 32a18ca05935
parent 573 a07b331fd1aa
permissions -rw-r--r--
pnm: Don't get into infinite loops on truncated files.
     1 /*
     2  * Copyright (c) 2013-14 Mikko Mononen memon@inside.org
     3  *
     4  * This software is provided 'as-is', without any express or implied
     5  * warranty.  In no event will the authors be held liable for any damages
     6  * arising from the use of this software.
     7  *
     8  * Permission is granted to anyone to use this software for any purpose,
     9  * including commercial applications, and to alter it and redistribute it
    10  * freely, subject to the following restrictions:
    11  *
    12  * 1. The origin of this software must not be misrepresented; you must not
    13  * claim that you wrote the original software. If you use this software
    14  * in a product, an acknowledgment in the product documentation would be
    15  * appreciated but is not required.
    16  * 2. Altered source versions must be plainly marked as such, and must not be
    17  * misrepresented as being the original software.
    18  * 3. This notice may not be removed or altered from any source distribution.
    19  *
    20  * The polygon rasterization is heavily based on stb_truetype rasterizer
    21  * by Sean Barrett - http://nothings.org/
    22  *
    23  */
    24 
    25 #ifndef NANOSVGRAST_H
    26 #define NANOSVGRAST_H
    27 
    28 #ifdef __cplusplus
    29 extern "C" {
    30 #endif
    31 
    32 typedef struct NSVGrasterizer NSVGrasterizer;
    33 
    34 /* Example Usage:
    35 	// Load SVG
    36 	struct SNVGImage* image = nsvgParseFromFile("test.svg.");
    37 
    38 	// Create rasterizer (can be used to render multiple images).
    39 	struct NSVGrasterizer* rast = nsvgCreateRasterizer();
    40 	// Allocate memory for image
    41 	unsigned char* img = malloc(w*h*4);
    42 	// Rasterize
    43 	nsvgRasterize(rast, image, 0,0,1, img, w, h, w*4);
    44 */
    45 
    46 // Allocated rasterizer context.
    47 NSVGrasterizer* nsvgCreateRasterizer(void);
    48 
    49 // Rasterizes SVG image, returns RGBA image (non-premultiplied alpha)
    50 //   r - pointer to rasterizer context
    51 //   image - pointer to image to rasterize
    52 //   tx,ty - image offset (applied after scaling)
    53 //   scale - image scale
    54 //   dst - pointer to destination image data, 4 bytes per pixel (RGBA)
    55 //   w - width of the image to render
    56 //   h - height of the image to render
    57 //   stride - number of bytes per scaleline in the destination buffer
    58 void nsvgRasterize(NSVGrasterizer* r,
    59 				   NSVGimage* image, float tx, float ty, float scale,
    60 				   unsigned char* dst, int w, int h, int stride);
    61 
    62 // Deletes rasterizer context.
    63 void nsvgDeleteRasterizer(NSVGrasterizer*);
    64 
    65 
    66 #ifdef __cplusplus
    67 }
    68 #endif
    69 
    70 #endif // NANOSVGRAST_H
    71 
    72 #ifdef NANOSVGRAST_IMPLEMENTATION
    73 
    74 /*
    75 #include <math.h>
    76 */
    77 
    78 #define NSVG__SUBSAMPLES	5
    79 #define NSVG__FIXSHIFT		10
    80 #define NSVG__FIX			(1 << NSVG__FIXSHIFT)
    81 #define NSVG__FIXMASK		(NSVG__FIX-1)
    82 #define NSVG__MEMPAGE_SIZE	1024
    83 
    84 typedef struct NSVGedge {
    85 	float x0,y0, x1,y1;
    86 	int dir;
    87 	struct NSVGedge* next;
    88 } NSVGedge;
    89 
    90 typedef struct NSVGpoint {
    91 	float x, y;
    92 	float dx, dy;
    93 	float len;
    94 	float dmx, dmy;
    95 	unsigned char flags;
    96 } NSVGpoint;
    97 
    98 typedef struct NSVGactiveEdge {
    99 	int x,dx;
   100 	float ey;
   101 	int dir;
   102 	struct NSVGactiveEdge *next;
   103 } NSVGactiveEdge;
   104 
   105 typedef struct NSVGmemPage {
   106 	unsigned char mem[NSVG__MEMPAGE_SIZE];
   107 	int size;
   108 	struct NSVGmemPage* next;
   109 } NSVGmemPage;
   110 
   111 typedef struct NSVGcachedPaint {
   112 	char type;
   113 	char spread;
   114 	float xform[6];
   115 	unsigned int colors[256];
   116 } NSVGcachedPaint;
   117 
   118 struct NSVGrasterizer
   119 {
   120 	float px, py;
   121 
   122 	float tessTol;
   123 	float distTol;
   124 
   125 	NSVGedge* edges;
   126 	int nedges;
   127 	int cedges;
   128 
   129 	NSVGpoint* points;
   130 	int npoints;
   131 	int cpoints;
   132 
   133 	NSVGpoint* points2;
   134 	int npoints2;
   135 	int cpoints2;
   136 
   137 	NSVGactiveEdge* freelist;
   138 	NSVGmemPage* pages;
   139 	NSVGmemPage* curpage;
   140 
   141 	unsigned char* scanline;
   142 	int cscanline;
   143 
   144 	unsigned char* bitmap;
   145 	int width, height, stride;
   146 };
   147 
   148 NSVGrasterizer* nsvgCreateRasterizer()
   149 {
   150 	NSVGrasterizer* r = (NSVGrasterizer*)malloc(sizeof(NSVGrasterizer));
   151 	if (r == NULL) goto error;
   152 	memset(r, 0, sizeof(NSVGrasterizer));
   153 
   154 	r->tessTol = 0.25f;
   155 	r->distTol = 0.01f;
   156 
   157 	return r;
   158 
   159 error:
   160 	nsvgDeleteRasterizer(r);
   161 	return NULL;
   162 }
   163 
   164 void nsvgDeleteRasterizer(NSVGrasterizer* r)
   165 {
   166 	NSVGmemPage* p;
   167 
   168 	if (r == NULL) return;
   169 
   170 	p = r->pages;
   171 	while (p != NULL) {
   172 		NSVGmemPage* next = p->next;
   173 		free(p);
   174 		p = next;
   175 	}
   176 
   177 	if (r->edges) free(r->edges);
   178 	if (r->points) free(r->points);
   179 	if (r->points2) free(r->points2);
   180 	if (r->scanline) free(r->scanline);
   181 
   182 	free(r);
   183 }
   184 
   185 static NSVGmemPage* nsvg__nextPage(NSVGrasterizer* r, NSVGmemPage* cur)
   186 {
   187 	NSVGmemPage *newp;
   188 
   189 	// If using existing chain, return the next page in chain
   190 	if (cur != NULL && cur->next != NULL) {
   191 		return cur->next;
   192 	}
   193 
   194 	// Alloc new page
   195 	newp = (NSVGmemPage*)malloc(sizeof(NSVGmemPage));
   196 	if (newp == NULL) return NULL;
   197 	memset(newp, 0, sizeof(NSVGmemPage));
   198 
   199 	// Add to linked list
   200 	if (cur != NULL)
   201 		cur->next = newp;
   202 	else
   203 		r->pages = newp;
   204 
   205 	return newp;
   206 }
   207 
   208 static void nsvg__resetPool(NSVGrasterizer* r)
   209 {
   210 	NSVGmemPage* p = r->pages;
   211 	while (p != NULL) {
   212 		p->size = 0;
   213 		p = p->next;
   214 	}
   215 	r->curpage = r->pages;
   216 }
   217 
   218 static unsigned char* nsvg__alloc(NSVGrasterizer* r, int size)
   219 {
   220 	unsigned char* buf;
   221 	if (size > NSVG__MEMPAGE_SIZE) return NULL;
   222 	if (r->curpage == NULL || r->curpage->size+size > NSVG__MEMPAGE_SIZE) {
   223 		r->curpage = nsvg__nextPage(r, r->curpage);
   224 	}
   225 	buf = &r->curpage->mem[r->curpage->size];
   226 	r->curpage->size += size;
   227 	return buf;
   228 }
   229 
   230 static int nsvg__ptEquals(float x1, float y1, float x2, float y2, float tol)
   231 {
   232 	float dx = x2 - x1;
   233 	float dy = y2 - y1;
   234 	return dx*dx + dy*dy < tol*tol;
   235 }
   236 
   237 static void nsvg__addPathPoint(NSVGrasterizer* r, float x, float y, int flags)
   238 {
   239 	NSVGpoint* pt;
   240 
   241 	if (r->npoints > 0) {
   242 		pt = &r->points[r->npoints-1];
   243 		if (nsvg__ptEquals(pt->x,pt->y, x,y, r->distTol)) {
   244 			pt->flags = (unsigned char)(pt->flags | flags);
   245 			return;
   246 		}
   247 	}
   248 
   249 	if (r->npoints+1 > r->cpoints) {
   250 		r->cpoints = r->cpoints > 0 ? r->cpoints * 2 : 64;
   251 		r->points = (NSVGpoint*)realloc(r->points, sizeof(NSVGpoint) * r->cpoints);
   252 		if (r->points == NULL) return;
   253 	}
   254 
   255 	pt = &r->points[r->npoints];
   256 	pt->x = x;
   257 	pt->y = y;
   258 	pt->flags = (unsigned char)flags;
   259 	r->npoints++;
   260 }
   261 
   262 static void nsvg__appendPathPoint(NSVGrasterizer* r, NSVGpoint pt)
   263 {
   264 	if (r->npoints+1 > r->cpoints) {
   265 		r->cpoints = r->cpoints > 0 ? r->cpoints * 2 : 64;
   266 		r->points = (NSVGpoint*)realloc(r->points, sizeof(NSVGpoint) * r->cpoints);
   267 		if (r->points == NULL) return;
   268 	}
   269 	r->points[r->npoints] = pt;
   270 	r->npoints++;
   271 }
   272 
   273 static void nsvg__duplicatePoints(NSVGrasterizer* r)
   274 {
   275 	if (r->npoints > r->cpoints2) {
   276 		r->cpoints2 = r->npoints;
   277 		r->points2 = (NSVGpoint*)realloc(r->points2, sizeof(NSVGpoint) * r->cpoints2);
   278 		if (r->points2 == NULL) return;
   279 	}
   280 
   281 	memcpy(r->points2, r->points, sizeof(NSVGpoint) * r->npoints);
   282 	r->npoints2 = r->npoints;
   283 }
   284 
   285 static void nsvg__addEdge(NSVGrasterizer* r, float x0, float y0, float x1, float y1)
   286 {
   287 	NSVGedge* e;
   288 
   289 	// Skip horizontal edges
   290 	if (y0 == y1)
   291 		return;
   292 
   293 	if (r->nedges+1 > r->cedges) {
   294 		r->cedges = r->cedges > 0 ? r->cedges * 2 : 64;
   295 		r->edges = (NSVGedge*)realloc(r->edges, sizeof(NSVGedge) * r->cedges);
   296 		if (r->edges == NULL) return;
   297 	}
   298 
   299 	e = &r->edges[r->nedges];
   300 	r->nedges++;
   301 
   302 	if (y0 < y1) {
   303 		e->x0 = x0;
   304 		e->y0 = y0;
   305 		e->x1 = x1;
   306 		e->y1 = y1;
   307 		e->dir = 1;
   308 	} else {
   309 		e->x0 = x1;
   310 		e->y0 = y1;
   311 		e->x1 = x0;
   312 		e->y1 = y0;
   313 		e->dir = -1;
   314 	}
   315 }
   316 
   317 static float nsvg__normalize(float *x, float* y)
   318 {
   319 	float d = sqrtf((*x)*(*x) + (*y)*(*y));
   320 	if (d > 1e-6f) {
   321 		float id = 1.0f / d;
   322 		*x *= id;
   323 		*y *= id;
   324 	}
   325 	return d;
   326 }
   327 
   328 static float nsvg__absf(float x) { return x < 0 ? -x : x; }
   329 
   330 static void nsvg__flattenCubicBez(NSVGrasterizer* r,
   331 								  float x1, float y1, float x2, float y2,
   332 								  float x3, float y3, float x4, float y4,
   333 								  int level, int type)
   334 {
   335 	float x12,y12,x23,y23,x34,y34,x123,y123,x234,y234,x1234,y1234;
   336 	float dx,dy,d2,d3;
   337 
   338 	if (level > 10) return;
   339 
   340 	x12 = (x1+x2)*0.5f;
   341 	y12 = (y1+y2)*0.5f;
   342 	x23 = (x2+x3)*0.5f;
   343 	y23 = (y2+y3)*0.5f;
   344 	x34 = (x3+x4)*0.5f;
   345 	y34 = (y3+y4)*0.5f;
   346 	x123 = (x12+x23)*0.5f;
   347 	y123 = (y12+y23)*0.5f;
   348 
   349 	dx = x4 - x1;
   350 	dy = y4 - y1;
   351 	d2 = nsvg__absf(((x2 - x4) * dy - (y2 - y4) * dx));
   352 	d3 = nsvg__absf(((x3 - x4) * dy - (y3 - y4) * dx));
   353 
   354 	if ((d2 + d3)*(d2 + d3) < r->tessTol * (dx*dx + dy*dy)) {
   355 		nsvg__addPathPoint(r, x4, y4, type);
   356 		return;
   357 	}
   358 
   359 	x234 = (x23+x34)*0.5f;
   360 	y234 = (y23+y34)*0.5f;
   361 	x1234 = (x123+x234)*0.5f;
   362 	y1234 = (y123+y234)*0.5f;
   363 
   364 	nsvg__flattenCubicBez(r, x1,y1, x12,y12, x123,y123, x1234,y1234, level+1, 0);
   365 	nsvg__flattenCubicBez(r, x1234,y1234, x234,y234, x34,y34, x4,y4, level+1, type);
   366 }
   367 
   368 static void nsvg__flattenShape(NSVGrasterizer* r, NSVGshape* shape, float scale)
   369 {
   370 	int i, j;
   371 	NSVGpath* path;
   372 
   373 	for (path = shape->paths; path != NULL; path = path->next) {
   374 		r->npoints = 0;
   375 		// Flatten path
   376 		nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, 0);
   377 		for (i = 0; i < path->npts-1; i += 3) {
   378 			float* p = &path->pts[i*2];
   379 			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);
   380 		}
   381 		// Close path
   382 		nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, 0);
   383 		// Build edges
   384 		for (i = 0, j = r->npoints-1; i < r->npoints; j = i++)
   385 			nsvg__addEdge(r, r->points[j].x, r->points[j].y, r->points[i].x, r->points[i].y);
   386 	}
   387 }
   388 
   389 enum NSVGpointFlags
   390 {
   391 	NSVG_PT_CORNER = 0x01,
   392 	NSVG_PT_BEVEL = 0x02,
   393 	NSVG_PT_LEFT = 0x04
   394 };
   395 
   396 static void nsvg__initClosed(NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, float lineWidth)
   397 {
   398 	float w = lineWidth * 0.5f;
   399 	float dx = p1->x - p0->x;
   400 	float dy = p1->y - p0->y;
   401 	float len = nsvg__normalize(&dx, &dy);
   402 	float px = p0->x + dx*len*0.5f, py = p0->y + dy*len*0.5f;
   403 	float dlx = dy, dly = -dx;
   404 	float lx = px - dlx*w, ly = py - dly*w;
   405 	float rx = px + dlx*w, ry = py + dly*w;
   406 	left->x = lx; left->y = ly;
   407 	right->x = rx; right->y = ry;
   408 }
   409 
   410 static void nsvg__buttCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, float dx, float dy, float lineWidth, int connect)
   411 {
   412 	float w = lineWidth * 0.5f;
   413 	float px = p->x, py = p->y;
   414 	float dlx = dy, dly = -dx;
   415 	float lx = px - dlx*w, ly = py - dly*w;
   416 	float rx = px + dlx*w, ry = py + dly*w;
   417 
   418 	nsvg__addEdge(r, lx, ly, rx, ry);
   419 
   420 	if (connect) {
   421 		nsvg__addEdge(r, left->x, left->y, lx, ly);
   422 		nsvg__addEdge(r, rx, ry, right->x, right->y);
   423 	}
   424 	left->x = lx; left->y = ly;
   425 	right->x = rx; right->y = ry;
   426 }
   427 
   428 static void nsvg__squareCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, float dx, float dy, float lineWidth, int connect)
   429 {
   430 	float w = lineWidth * 0.5f;
   431 	float px = p->x - dx*w, py = p->y - dy*w;
   432 	float dlx = dy, dly = -dx;
   433 	float lx = px - dlx*w, ly = py - dly*w;
   434 	float rx = px + dlx*w, ry = py + dly*w;
   435 
   436 	nsvg__addEdge(r, lx, ly, rx, ry);
   437 
   438 	if (connect) {
   439 		nsvg__addEdge(r, left->x, left->y, lx, ly);
   440 		nsvg__addEdge(r, rx, ry, right->x, right->y);
   441 	}
   442 	left->x = lx; left->y = ly;
   443 	right->x = rx; right->y = ry;
   444 }
   445 
   446 #ifndef NSVG_PI
   447 #define NSVG_PI (3.14159265358979323846264338327f)
   448 #endif
   449 
   450 static void nsvg__roundCap(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p, float dx, float dy, float lineWidth, int ncap, int connect)
   451 {
   452 	int i;
   453 	float w = lineWidth * 0.5f;
   454 	float px = p->x, py = p->y;
   455 	float dlx = dy, dly = -dx;
   456 	float lx = 0, ly = 0, rx = 0, ry = 0, prevx = 0, prevy = 0;
   457 
   458 	for (i = 0; i < ncap; i++) {
   459 		float a = (float)i/(float)(ncap-1)*NSVG_PI;
   460 		float ax = cosf(a) * w, ay = sinf(a) * w;
   461 		float x = px - dlx*ax - dx*ay;
   462 		float y = py - dly*ax - dy*ay;
   463 
   464 		if (i > 0)
   465 			nsvg__addEdge(r, prevx, prevy, x, y);
   466 
   467 		prevx = x;
   468 		prevy = y;
   469 
   470 		if (i == 0) {
   471 			lx = x; ly = y;
   472 		} else if (i == ncap-1) {
   473 			rx = x; ry = y;
   474 		}
   475 	}
   476 
   477 	if (connect) {
   478 		nsvg__addEdge(r, left->x, left->y, lx, ly);
   479 		nsvg__addEdge(r, rx, ry, right->x, right->y);
   480 	}
   481 
   482 	left->x = lx; left->y = ly;
   483 	right->x = rx; right->y = ry;
   484 }
   485 
   486 static void nsvg__bevelJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, float lineWidth)
   487 {
   488 	float w = lineWidth * 0.5f;
   489 	float dlx0 = p0->dy, dly0 = -p0->dx;
   490 	float dlx1 = p1->dy, dly1 = -p1->dx;
   491 	float lx0 = p1->x - (dlx0 * w), ly0 = p1->y - (dly0 * w);
   492 	float rx0 = p1->x + (dlx0 * w), ry0 = p1->y + (dly0 * w);
   493 	float lx1 = p1->x - (dlx1 * w), ly1 = p1->y - (dly1 * w);
   494 	float rx1 = p1->x + (dlx1 * w), ry1 = p1->y + (dly1 * w);
   495 
   496 	nsvg__addEdge(r, lx0, ly0, left->x, left->y);
   497 	nsvg__addEdge(r, lx1, ly1, lx0, ly0);
   498 
   499 	nsvg__addEdge(r, right->x, right->y, rx0, ry0);
   500 	nsvg__addEdge(r, rx0, ry0, rx1, ry1);
   501 
   502 	left->x = lx1; left->y = ly1;
   503 	right->x = rx1; right->y = ry1;
   504 }
   505 
   506 static void nsvg__miterJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, float lineWidth)
   507 {
   508 	float w = lineWidth * 0.5f;
   509 	float dlx0 = p0->dy, dly0 = -p0->dx;
   510 	float dlx1 = p1->dy, dly1 = -p1->dx;
   511 	float lx0, rx0, lx1, rx1;
   512 	float ly0, ry0, ly1, ry1;
   513 
   514 	if (p1->flags & NSVG_PT_LEFT) {
   515 		lx0 = lx1 = p1->x - p1->dmx * w;
   516 		ly0 = ly1 = p1->y - p1->dmy * w;
   517 		nsvg__addEdge(r, lx1, ly1, left->x, left->y);
   518 
   519 		rx0 = p1->x + (dlx0 * w);
   520 		ry0 = p1->y + (dly0 * w);
   521 		rx1 = p1->x + (dlx1 * w);
   522 		ry1 = p1->y + (dly1 * w);
   523 		nsvg__addEdge(r, right->x, right->y, rx0, ry0);
   524 		nsvg__addEdge(r, rx0, ry0, rx1, ry1);
   525 	} else {
   526 		lx0 = p1->x - (dlx0 * w);
   527 		ly0 = p1->y - (dly0 * w);
   528 		lx1 = p1->x - (dlx1 * w);
   529 		ly1 = p1->y - (dly1 * w);
   530 		nsvg__addEdge(r, lx0, ly0, left->x, left->y);
   531 		nsvg__addEdge(r, lx1, ly1, lx0, ly0);
   532 
   533 		rx0 = rx1 = p1->x + p1->dmx * w;
   534 		ry0 = ry1 = p1->y + p1->dmy * w;
   535 		nsvg__addEdge(r, right->x, right->y, rx1, ry1);
   536 	}
   537 
   538 	left->x = lx1; left->y = ly1;
   539 	right->x = rx1; right->y = ry1;
   540 }
   541 
   542 static void nsvg__roundJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p0, NSVGpoint* p1, float lineWidth, int ncap)
   543 {
   544 	int i, n;
   545 	float w = lineWidth * 0.5f;
   546 	float dlx0 = p0->dy, dly0 = -p0->dx;
   547 	float dlx1 = p1->dy, dly1 = -p1->dx;
   548 	float a0 = atan2f(dly0, dlx0);
   549 	float a1 = atan2f(dly1, dlx1);
   550 	float da = a1 - a0;
   551 	float lx, ly, rx, ry;
   552 
   553 	if (da < NSVG_PI) da += NSVG_PI*2;
   554 	if (da > NSVG_PI) da -= NSVG_PI*2;
   555 
   556 	n = (int)ceilf((nsvg__absf(da) / NSVG_PI) * (float)ncap);
   557 	if (n < 2) n = 2;
   558 	if (n > ncap) n = ncap;
   559 
   560 	lx = left->x;
   561 	ly = left->y;
   562 	rx = right->x;
   563 	ry = right->y;
   564 
   565 	for (i = 0; i < n; i++) {
   566 		float u = (float)i/(float)(n-1);
   567 		float a = a0 + u*da;
   568 		float ax = cosf(a) * w, ay = sinf(a) * w;
   569 		float lx1 = p1->x - ax, ly1 = p1->y - ay;
   570 		float rx1 = p1->x + ax, ry1 = p1->y + ay;
   571 
   572 		nsvg__addEdge(r, lx1, ly1, lx, ly);
   573 		nsvg__addEdge(r, rx, ry, rx1, ry1);
   574 
   575 		lx = lx1; ly = ly1;
   576 		rx = rx1; ry = ry1;
   577 	}
   578 
   579 	left->x = lx; left->y = ly;
   580 	right->x = rx; right->y = ry;
   581 }
   582 
   583 static void nsvg__straightJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right, NSVGpoint* p1, float lineWidth)
   584 {
   585 	float w = lineWidth * 0.5f;
   586 	float lx = p1->x - (p1->dmx * w), ly = p1->y - (p1->dmy * w);
   587 	float rx = p1->x + (p1->dmx * w), ry = p1->y + (p1->dmy * w);
   588 
   589 	nsvg__addEdge(r, lx, ly, left->x, left->y);
   590 	nsvg__addEdge(r, right->x, right->y, rx, ry);
   591 
   592 	left->x = lx; left->y = ly;
   593 	right->x = rx; right->y = ry;
   594 }
   595 
   596 static int nsvg__curveDivs(float r, float arc, float tol)
   597 {
   598 	float da = acosf(r / (r + tol)) * 2.0f;
   599 	int divs = (int)ceilf(arc / da);
   600 	if (divs < 2) divs = 2;
   601 	return divs;
   602 }
   603 
   604 static void nsvg__expandStroke(NSVGrasterizer* r, NSVGpoint* points, int npoints, int closed, int lineJoin, int lineCap, float lineWidth)
   605 {
   606 	int ncap = nsvg__curveDivs(lineWidth*0.5f, NSVG_PI, r->tessTol);	// Calculate divisions per half circle.
   607 	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};
   608 	NSVGpoint* p0, *p1;
   609 	int j, s, e;
   610 
   611 	// Build stroke edges
   612 	if (closed) {
   613 		// Looping
   614 		p0 = &points[npoints-1];
   615 		p1 = &points[0];
   616 		s = 0;
   617 		e = npoints;
   618 	} else {
   619 		// Add cap
   620 		p0 = &points[0];
   621 		p1 = &points[1];
   622 		s = 1;
   623 		e = npoints-1;
   624 	}
   625 
   626 	if (closed) {
   627 		nsvg__initClosed(&left, &right, p0, p1, lineWidth);
   628 		firstLeft = left;
   629 		firstRight = right;
   630 	} else {
   631 		// Add cap
   632 		float dx = p1->x - p0->x;
   633 		float dy = p1->y - p0->y;
   634 		nsvg__normalize(&dx, &dy);
   635 		if (lineCap == NSVG_CAP_BUTT)
   636 			nsvg__buttCap(r, &left, &right, p0, dx, dy, lineWidth, 0);
   637 		else if (lineCap == NSVG_CAP_SQUARE)
   638 			nsvg__squareCap(r, &left, &right, p0, dx, dy, lineWidth, 0);
   639 		else if (lineCap == NSVG_CAP_ROUND)
   640 			nsvg__roundCap(r, &left, &right, p0, dx, dy, lineWidth, ncap, 0);
   641 	}
   642 
   643 	for (j = s; j < e; ++j) {
   644 		if (p1->flags & NSVG_PT_CORNER) {
   645 			if (lineJoin == NSVG_JOIN_ROUND)
   646 				nsvg__roundJoin(r, &left, &right, p0, p1, lineWidth, ncap);
   647 			else if (lineJoin == NSVG_JOIN_BEVEL || (p1->flags & NSVG_PT_BEVEL))
   648 				nsvg__bevelJoin(r, &left, &right, p0, p1, lineWidth);
   649 			else
   650 				nsvg__miterJoin(r, &left, &right, p0, p1, lineWidth);
   651 		} else {
   652 			nsvg__straightJoin(r, &left, &right, p1, lineWidth);
   653 		}
   654 		p0 = p1++;
   655 	}
   656 
   657 	if (closed) {
   658 		// Loop it
   659 		nsvg__addEdge(r, firstLeft.x, firstLeft.y, left.x, left.y);
   660 		nsvg__addEdge(r, right.x, right.y, firstRight.x, firstRight.y);
   661 	} else {
   662 		// Add cap
   663 		float dx = p1->x - p0->x;
   664 		float dy = p1->y - p0->y;
   665 		nsvg__normalize(&dx, &dy);
   666 		if (lineCap == NSVG_CAP_BUTT)
   667 			nsvg__buttCap(r, &right, &left, p1, -dx, -dy, lineWidth, 1);
   668 		else if (lineCap == NSVG_CAP_SQUARE)
   669 			nsvg__squareCap(r, &right, &left, p1, -dx, -dy, lineWidth, 1);
   670 		else if (lineCap == NSVG_CAP_ROUND)
   671 			nsvg__roundCap(r, &right, &left, p1, -dx, -dy, lineWidth, ncap, 1);
   672 	}
   673 }
   674 
   675 static void nsvg__prepareStroke(NSVGrasterizer* r, float miterLimit, int lineJoin)
   676 {
   677 	int i, j;
   678 	NSVGpoint* p0, *p1;
   679 
   680 	p0 = &r->points[r->npoints-1];
   681 	p1 = &r->points[0];
   682 	for (i = 0; i < r->npoints; i++) {
   683 		// Calculate segment direction and length
   684 		p0->dx = p1->x - p0->x;
   685 		p0->dy = p1->y - p0->y;
   686 		p0->len = nsvg__normalize(&p0->dx, &p0->dy);
   687 		// Advance
   688 		p0 = p1++;
   689 	}
   690 
   691 	// calculate joins
   692 	p0 = &r->points[r->npoints-1];
   693 	p1 = &r->points[0];
   694 	for (j = 0; j < r->npoints; j++) {
   695 		float dlx0, dly0, dlx1, dly1, dmr2, cross;
   696 		dlx0 = p0->dy;
   697 		dly0 = -p0->dx;
   698 		dlx1 = p1->dy;
   699 		dly1 = -p1->dx;
   700 		// Calculate extrusions
   701 		p1->dmx = (dlx0 + dlx1) * 0.5f;
   702 		p1->dmy = (dly0 + dly1) * 0.5f;
   703 		dmr2 = p1->dmx*p1->dmx + p1->dmy*p1->dmy;
   704 		if (dmr2 > 0.000001f) {
   705 			float s2 = 1.0f / dmr2;
   706 			if (s2 > 600.0f) {
   707 				s2 = 600.0f;
   708 			}
   709 			p1->dmx *= s2;
   710 			p1->dmy *= s2;
   711 		}
   712 
   713 		// Clear flags, but keep the corner.
   714 		p1->flags = (p1->flags & NSVG_PT_CORNER) ? NSVG_PT_CORNER : 0;
   715 
   716 		// Keep track of left turns.
   717 		cross = p1->dx * p0->dy - p0->dx * p1->dy;
   718 		if (cross > 0.0f)
   719 			p1->flags |= NSVG_PT_LEFT;
   720 
   721 		// Check to see if the corner needs to be beveled.
   722 		if (p1->flags & NSVG_PT_CORNER) {
   723 			if ((dmr2 * miterLimit*miterLimit) < 1.0f || lineJoin == NSVG_JOIN_BEVEL || lineJoin == NSVG_JOIN_ROUND) {
   724 				p1->flags |= NSVG_PT_BEVEL;
   725 			}
   726 		}
   727 
   728 		p0 = p1++;
   729 	}
   730 }
   731 
   732 static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float scale)
   733 {
   734 	int i, j, closed;
   735 	NSVGpath* path;
   736 	NSVGpoint* p0, *p1;
   737 	float miterLimit = shape->miterLimit;
   738 	int lineJoin = shape->strokeLineJoin;
   739 	int lineCap = shape->strokeLineCap;
   740 	float lineWidth = shape->strokeWidth * scale;
   741 
   742 	for (path = shape->paths; path != NULL; path = path->next) {
   743 		// Flatten path
   744 		r->npoints = 0;
   745 		nsvg__addPathPoint(r, path->pts[0]*scale, path->pts[1]*scale, NSVG_PT_CORNER);
   746 		for (i = 0; i < path->npts-1; i += 3) {
   747 			float* p = &path->pts[i*2];
   748 			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);
   749 		}
   750 		if (r->npoints < 2)
   751 			continue;
   752 
   753 		closed = path->closed;
   754 
   755 		// If the first and last points are the same, remove the last, mark as closed path.
   756 		p0 = &r->points[r->npoints-1];
   757 		p1 = &r->points[0];
   758 		if (nsvg__ptEquals(p0->x,p0->y, p1->x,p1->y, r->distTol)) {
   759 			r->npoints--;
   760 			p0 = &r->points[r->npoints-1];
   761 			closed = 1;
   762 		}
   763 
   764 		if (shape->strokeDashCount > 0) {
   765 			int idash = 0, dashState = 1;
   766 			float totalDist = 0, dashLen, allDashLen, dashOffset;
   767 			NSVGpoint cur;
   768 
   769 			if (closed)
   770 				nsvg__appendPathPoint(r, r->points[0]);
   771 
   772 			// Duplicate points -> points2.
   773 			nsvg__duplicatePoints(r);
   774 
   775 			r->npoints = 0;
   776  			cur = r->points2[0];
   777 			nsvg__appendPathPoint(r, cur);
   778 
   779 			// Figure out dash offset.
   780 			allDashLen = 0;
   781 			for (j = 0; j < shape->strokeDashCount; j++)
   782 				allDashLen += shape->strokeDashArray[j];
   783 			if (shape->strokeDashCount & 1)
   784 				allDashLen *= 2.0f;
   785 			// Find location inside pattern
   786 			dashOffset = fmodf(shape->strokeDashOffset, allDashLen);
   787 			if (dashOffset < 0.0f)
   788 				dashOffset += allDashLen;
   789 
   790 			while (dashOffset > shape->strokeDashArray[idash]) {
   791 				dashOffset -= shape->strokeDashArray[idash];
   792 				idash = (idash + 1) % shape->strokeDashCount;
   793 			}
   794 			dashLen = (shape->strokeDashArray[idash] - dashOffset) * scale;
   795 
   796 			for (j = 1; j < r->npoints2; ) {
   797 				float dx = r->points2[j].x - cur.x;
   798 				float dy = r->points2[j].y - cur.y;
   799 				float dist = sqrtf(dx*dx + dy*dy);
   800 
   801 				if ((totalDist + dist) > dashLen) {
   802 					// Calculate intermediate point
   803 					float d = (dashLen - totalDist) / dist;
   804 					float x = cur.x + dx * d;
   805 					float y = cur.y + dy * d;
   806 					nsvg__addPathPoint(r, x, y, NSVG_PT_CORNER);
   807 
   808 					// Stroke
   809 					if (r->npoints > 1 && dashState) {
   810 						nsvg__prepareStroke(r, miterLimit, lineJoin);
   811 						nsvg__expandStroke(r, r->points, r->npoints, 0, lineJoin, lineCap, lineWidth);
   812 					}
   813 					// Advance dash pattern
   814 					dashState = !dashState;
   815 					idash = (idash+1) % shape->strokeDashCount;
   816 					dashLen = shape->strokeDashArray[idash] * scale;
   817 					// Restart
   818 					cur.x = x;
   819 					cur.y = y;
   820 					cur.flags = NSVG_PT_CORNER;
   821 					totalDist = 0.0f;
   822 					r->npoints = 0;
   823 					nsvg__appendPathPoint(r, cur);
   824 				} else {
   825 					totalDist += dist;
   826 					cur = r->points2[j];
   827 					nsvg__appendPathPoint(r, cur);
   828 					j++;
   829 				}
   830 			}
   831 			// Stroke any leftover path
   832 			if (r->npoints > 1 && dashState)
   833 				nsvg__expandStroke(r, r->points, r->npoints, 0, lineJoin, lineCap, lineWidth);
   834 		} else {
   835 			nsvg__prepareStroke(r, miterLimit, lineJoin);
   836 			nsvg__expandStroke(r, r->points, r->npoints, closed, lineJoin, lineCap, lineWidth);
   837 		}
   838 	}
   839 }
   840 
   841 static int nsvg__cmpEdge(const void *p, const void *q)
   842 {
   843 	const NSVGedge* a = (const NSVGedge*)p;
   844 	const NSVGedge* b = (const NSVGedge*)q;
   845 
   846 	if (a->y0 < b->y0) return -1;
   847 	if (a->y0 > b->y0) return  1;
   848 	return 0;
   849 }
   850 
   851 
   852 static NSVGactiveEdge* nsvg__addActive(NSVGrasterizer* r, NSVGedge* e, float startPoint)
   853 {
   854 	 NSVGactiveEdge* z;
   855 	 float dxdy;
   856 
   857 	if (r->freelist != NULL) {
   858 		// Restore from freelist.
   859 		z = r->freelist;
   860 		r->freelist = z->next;
   861 	} else {
   862 		// Alloc new edge.
   863 		z = (NSVGactiveEdge*)nsvg__alloc(r, sizeof(NSVGactiveEdge));
   864 		if (z == NULL) return NULL;
   865 	}
   866 
   867 	dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
   868 //	STBTT_assert(e->y0 <= start_point);
   869 	// round dx down to avoid going too far
   870 	if (dxdy < 0)
   871 		z->dx = (int)(-floorf(NSVG__FIX * -dxdy));
   872 	else
   873 		z->dx = (int)floorf(NSVG__FIX * dxdy);
   874 	z->x = (int)floorf(NSVG__FIX * (e->x0 + dxdy * (startPoint - e->y0)));
   875 //	z->x -= off_x * FIX;
   876 	z->ey = e->y1;
   877 	z->next = 0;
   878 	z->dir = e->dir;
   879 
   880 	return z;
   881 }
   882 
   883 static void nsvg__freeActive(NSVGrasterizer* r, NSVGactiveEdge* z)
   884 {
   885 	z->next = r->freelist;
   886 	r->freelist = z;
   887 }
   888 
   889 static void nsvg__fillScanline(unsigned char* scanline, int len, int x0, int x1, int maxWeight, int* xmin, int* xmax)
   890 {
   891 	int i = x0 >> NSVG__FIXSHIFT;
   892 	int j = x1 >> NSVG__FIXSHIFT;
   893 	if (i < *xmin) *xmin = i;
   894 	if (j > *xmax) *xmax = j;
   895 	if (i < len && j >= 0) {
   896 		if (i == j) {
   897 			// x0,x1 are the same pixel, so compute combined coverage
   898 			scanline[i] = (unsigned char)(scanline[i] + ((x1 - x0) * maxWeight >> NSVG__FIXSHIFT));
   899 		} else {
   900 			if (i >= 0) // add antialiasing for x0
   901 				scanline[i] = (unsigned char)(scanline[i] + (((NSVG__FIX - (x0 & NSVG__FIXMASK)) * maxWeight) >> NSVG__FIXSHIFT));
   902 			else
   903 				i = -1; // clip
   904 
   905 			if (j < len) // add antialiasing for x1
   906 				scanline[j] = (unsigned char)(scanline[j] + (((x1 & NSVG__FIXMASK) * maxWeight) >> NSVG__FIXSHIFT));
   907 			else
   908 				j = len; // clip
   909 
   910 			for (++i; i < j; ++i) // fill pixels between x0 and x1
   911 				scanline[i] = (unsigned char)(scanline[i] + maxWeight);
   912 		}
   913 	}
   914 }
   915 
   916 // note: this routine clips fills that extend off the edges... ideally this
   917 // wouldn't happen, but it could happen if the truetype glyph bounding boxes
   918 // are wrong, or if the user supplies a too-small bitmap
   919 static void nsvg__fillActiveEdges(unsigned char* scanline, int len, NSVGactiveEdge* e, int maxWeight, int* xmin, int* xmax, char fillRule)
   920 {
   921 	// non-zero winding fill
   922 	int x0 = 0, w = 0;
   923 
   924 	if (fillRule == NSVG_FILLRULE_NONZERO) {
   925 		// Non-zero
   926 		while (e != NULL) {
   927 			if (w == 0) {
   928 				// if we're currently at zero, we need to record the edge start point
   929 				x0 = e->x; w += e->dir;
   930 			} else {
   931 				int x1 = e->x; w += e->dir;
   932 				// if we went to zero, we need to draw
   933 				if (w == 0)
   934 					nsvg__fillScanline(scanline, len, x0, x1, maxWeight, xmin, xmax);
   935 			}
   936 			e = e->next;
   937 		}
   938 	} else if (fillRule == NSVG_FILLRULE_EVENODD) {
   939 		// Even-odd
   940 		while (e != NULL) {
   941 			if (w == 0) {
   942 				// if we're currently at zero, we need to record the edge start point
   943 				x0 = e->x; w = 1;
   944 			} else {
   945 				int x1 = e->x; w = 0;
   946 				nsvg__fillScanline(scanline, len, x0, x1, maxWeight, xmin, xmax);
   947 			}
   948 			e = e->next;
   949 		}
   950 	}
   951 }
   952 
   953 static float nsvg__clampf(float a, float mn, float mx) { return a < mn ? mn : (a > mx ? mx : a); }
   954 
   955 static unsigned int nsvg__RGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
   956 {
   957 	return (r) | (g << 8) | (b << 16) | (a << 24);
   958 }
   959 
   960 static unsigned int nsvg__lerpRGBA(unsigned int c0, unsigned int c1, float u)
   961 {
   962 	int iu = (int)(nsvg__clampf(u, 0.0f, 1.0f) * 256.0f);
   963 	int r = (((c0) & 0xff)*(256-iu) + (((c1) & 0xff)*iu)) >> 8;
   964 	int g = (((c0>>8) & 0xff)*(256-iu) + (((c1>>8) & 0xff)*iu)) >> 8;
   965 	int b = (((c0>>16) & 0xff)*(256-iu) + (((c1>>16) & 0xff)*iu)) >> 8;
   966 	int a = (((c0>>24) & 0xff)*(256-iu) + (((c1>>24) & 0xff)*iu)) >> 8;
   967 	return nsvg__RGBA((unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a);
   968 }
   969 
   970 static unsigned int nsvg__applyOpacity(unsigned int c, float u)
   971 {
   972 	int iu = (int)(nsvg__clampf(u, 0.0f, 1.0f) * 256.0f);
   973 	int r = (c) & 0xff;
   974 	int g = (c>>8) & 0xff;
   975 	int b = (c>>16) & 0xff;
   976 	int a = (((c>>24) & 0xff)*iu) >> 8;
   977 	return nsvg__RGBA((unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a);
   978 }
   979 
   980 static int nsvg__div255(int x)
   981 {
   982     return ((x+1) * 257) >> 16;
   983 }
   984 
   985 static void nsvg__scanlineSolid(unsigned char* dst, int count, unsigned char* cover, int x, int y,
   986 								float tx, float ty, float scale, NSVGcachedPaint* cache)
   987 {
   988 
   989 	if (cache->type == NSVG_PAINT_COLOR) {
   990 		int i, cr, cg, cb, ca;
   991 		cr = cache->colors[0] & 0xff;
   992 		cg = (cache->colors[0] >> 8) & 0xff;
   993 		cb = (cache->colors[0] >> 16) & 0xff;
   994 		ca = (cache->colors[0] >> 24) & 0xff;
   995 
   996 		for (i = 0; i < count; i++) {
   997 			int r,g,b;
   998 			int a = nsvg__div255((int)cover[0] * ca);
   999 			int ia = 255 - a;
  1000 			// Premultiply
  1001 			r = nsvg__div255(cr * a);
  1002 			g = nsvg__div255(cg * a);
  1003 			b = nsvg__div255(cb * a);
  1004 
  1005 			// Blend over
  1006 			r += nsvg__div255(ia * (int)dst[0]);
  1007 			g += nsvg__div255(ia * (int)dst[1]);
  1008 			b += nsvg__div255(ia * (int)dst[2]);
  1009 			a += nsvg__div255(ia * (int)dst[3]);
  1010 
  1011 			dst[0] = (unsigned char)r;
  1012 			dst[1] = (unsigned char)g;
  1013 			dst[2] = (unsigned char)b;
  1014 			dst[3] = (unsigned char)a;
  1015 
  1016 			cover++;
  1017 			dst += 4;
  1018 		}
  1019 	} else if (cache->type == NSVG_PAINT_LINEAR_GRADIENT) {
  1020 		// TODO: spread modes.
  1021 		// TODO: plenty of opportunities to optimize.
  1022 		float fx, fy, dx, gy;
  1023 		float* t = cache->xform;
  1024 		int i, cr, cg, cb, ca;
  1025 		unsigned int c;
  1026 
  1027 		fx = ((float)x - tx) / scale;
  1028 		fy = ((float)y - ty) / scale;
  1029 		dx = 1.0f / scale;
  1030 
  1031 		for (i = 0; i < count; i++) {
  1032 			int r,g,b,a,ia;
  1033 			gy = fx*t[1] + fy*t[3] + t[5];
  1034 			c = cache->colors[(int)nsvg__clampf(gy*255.0f, 0, 255.0f)];
  1035 			cr = (c) & 0xff;
  1036 			cg = (c >> 8) & 0xff;
  1037 			cb = (c >> 16) & 0xff;
  1038 			ca = (c >> 24) & 0xff;
  1039 
  1040 			a = nsvg__div255((int)cover[0] * ca);
  1041 			ia = 255 - a;
  1042 
  1043 			// Premultiply
  1044 			r = nsvg__div255(cr * a);
  1045 			g = nsvg__div255(cg * a);
  1046 			b = nsvg__div255(cb * a);
  1047 
  1048 			// Blend over
  1049 			r += nsvg__div255(ia * (int)dst[0]);
  1050 			g += nsvg__div255(ia * (int)dst[1]);
  1051 			b += nsvg__div255(ia * (int)dst[2]);
  1052 			a += nsvg__div255(ia * (int)dst[3]);
  1053 
  1054 			dst[0] = (unsigned char)r;
  1055 			dst[1] = (unsigned char)g;
  1056 			dst[2] = (unsigned char)b;
  1057 			dst[3] = (unsigned char)a;
  1058 
  1059 			cover++;
  1060 			dst += 4;
  1061 			fx += dx;
  1062 		}
  1063 	} else if (cache->type == NSVG_PAINT_RADIAL_GRADIENT) {
  1064 		// TODO: spread modes.
  1065 		// TODO: plenty of opportunities to optimize.
  1066 		// TODO: focus (fx,fy)
  1067 		float fx, fy, dx, gx, gy, gd;
  1068 		float* t = cache->xform;
  1069 		int i, cr, cg, cb, ca;
  1070 		unsigned int c;
  1071 
  1072 		fx = ((float)x - tx) / scale;
  1073 		fy = ((float)y - ty) / scale;
  1074 		dx = 1.0f / scale;
  1075 
  1076 		for (i = 0; i < count; i++) {
  1077 			int r,g,b,a,ia;
  1078 			gx = fx*t[0] + fy*t[2] + t[4];
  1079 			gy = fx*t[1] + fy*t[3] + t[5];
  1080 			gd = sqrtf(gx*gx + gy*gy);
  1081 			c = cache->colors[(int)nsvg__clampf(gd*255.0f, 0, 255.0f)];
  1082 			cr = (c) & 0xff;
  1083 			cg = (c >> 8) & 0xff;
  1084 			cb = (c >> 16) & 0xff;
  1085 			ca = (c >> 24) & 0xff;
  1086 
  1087 			a = nsvg__div255((int)cover[0] * ca);
  1088 			ia = 255 - a;
  1089 
  1090 			// Premultiply
  1091 			r = nsvg__div255(cr * a);
  1092 			g = nsvg__div255(cg * a);
  1093 			b = nsvg__div255(cb * a);
  1094 
  1095 			// Blend over
  1096 			r += nsvg__div255(ia * (int)dst[0]);
  1097 			g += nsvg__div255(ia * (int)dst[1]);
  1098 			b += nsvg__div255(ia * (int)dst[2]);
  1099 			a += nsvg__div255(ia * (int)dst[3]);
  1100 
  1101 			dst[0] = (unsigned char)r;
  1102 			dst[1] = (unsigned char)g;
  1103 			dst[2] = (unsigned char)b;
  1104 			dst[3] = (unsigned char)a;
  1105 
  1106 			cover++;
  1107 			dst += 4;
  1108 			fx += dx;
  1109 		}
  1110 	}
  1111 }
  1112 
  1113 static void nsvg__rasterizeSortedEdges(NSVGrasterizer *r, float tx, float ty, float scale, NSVGcachedPaint* cache, char fillRule)
  1114 {
  1115 	NSVGactiveEdge *active = NULL;
  1116 	int y, s;
  1117 	int e = 0;
  1118 	int maxWeight = (255 / NSVG__SUBSAMPLES);  // weight per vertical scanline
  1119 	int xmin, xmax;
  1120 
  1121 	for (y = 0; y < r->height; y++) {
  1122 		memset(r->scanline, 0, r->width);
  1123 		xmin = r->width;
  1124 		xmax = 0;
  1125 		for (s = 0; s < NSVG__SUBSAMPLES; ++s) {
  1126 			// find center of pixel for this scanline
  1127 			float scany = (float)(y*NSVG__SUBSAMPLES + s) + 0.5f;
  1128 			NSVGactiveEdge **step = &active;
  1129 
  1130 			// update all active edges;
  1131 			// remove all active edges that terminate before the center of this scanline
  1132 			while (*step) {
  1133 				NSVGactiveEdge *z = *step;
  1134 				if (z->ey <= scany) {
  1135 					*step = z->next; // delete from list
  1136 //					NSVG__assert(z->valid);
  1137 					nsvg__freeActive(r, z);
  1138 				} else {
  1139 					z->x += z->dx; // advance to position for current scanline
  1140 					step = &((*step)->next); // advance through list
  1141 				}
  1142 			}
  1143 
  1144 			// resort the list if needed
  1145 			for (;;) {
  1146 				int changed = 0;
  1147 				step = &active;
  1148 				while (*step && (*step)->next) {
  1149 					if ((*step)->x > (*step)->next->x) {
  1150 						NSVGactiveEdge* t = *step;
  1151 						NSVGactiveEdge* q = t->next;
  1152 						t->next = q->next;
  1153 						q->next = t;
  1154 						*step = q;
  1155 						changed = 1;
  1156 					}
  1157 					step = &(*step)->next;
  1158 				}
  1159 				if (!changed) break;
  1160 			}
  1161 
  1162 			// insert all edges that start before the center of this scanline -- omit ones that also end on this scanline
  1163 			while (e < r->nedges && r->edges[e].y0 <= scany) {
  1164 				if (r->edges[e].y1 > scany) {
  1165 					NSVGactiveEdge* z = nsvg__addActive(r, &r->edges[e], scany);
  1166 					if (z == NULL) break;
  1167 					// find insertion point
  1168 					if (active == NULL) {
  1169 						active = z;
  1170 					} else if (z->x < active->x) {
  1171 						// insert at front
  1172 						z->next = active;
  1173 						active = z;
  1174 					} else {
  1175 						// find thing to insert AFTER
  1176 						NSVGactiveEdge* p = active;
  1177 						while (p->next && p->next->x < z->x)
  1178 							p = p->next;
  1179 						// at this point, p->next->x is NOT < z->x
  1180 						z->next = p->next;
  1181 						p->next = z;
  1182 					}
  1183 				}
  1184 				e++;
  1185 			}
  1186 
  1187 			// now process all active edges in non-zero fashion
  1188 			if (active != NULL)
  1189 				nsvg__fillActiveEdges(r->scanline, r->width, active, maxWeight, &xmin, &xmax, fillRule);
  1190 		}
  1191 		// Blit
  1192 		if (xmin < 0) xmin = 0;
  1193 		if (xmax > r->width-1) xmax = r->width-1;
  1194 		if (xmin <= xmax) {
  1195 			nsvg__scanlineSolid(&r->bitmap[y * r->stride] + xmin*4, xmax-xmin+1, &r->scanline[xmin], xmin, y, tx,ty, scale, cache);
  1196 		}
  1197 	}
  1198 
  1199 }
  1200 
  1201 static void nsvg__unpremultiplyAlpha(unsigned char* image, int w, int h, int stride)
  1202 {
  1203 	int x,y;
  1204 
  1205 	// Unpremultiply
  1206 	for (y = 0; y < h; y++) {
  1207 		unsigned char *row = &image[y*stride];
  1208 		for (x = 0; x < w; x++) {
  1209 			int r = row[0], g = row[1], b = row[2], a = row[3];
  1210 			if (a != 0) {
  1211 				row[0] = (unsigned char)(r*255/a);
  1212 				row[1] = (unsigned char)(g*255/a);
  1213 				row[2] = (unsigned char)(b*255/a);
  1214 			}
  1215 			row += 4;
  1216 		}
  1217 	}
  1218 
  1219 	// Defringe
  1220 	for (y = 0; y < h; y++) {
  1221 		unsigned char *row = &image[y*stride];
  1222 		for (x = 0; x < w; x++) {
  1223 			int r = 0, g = 0, b = 0, a = row[3], n = 0;
  1224 			if (a == 0) {
  1225 				if (x-1 > 0 && row[-1] != 0) {
  1226 					r += row[-4];
  1227 					g += row[-3];
  1228 					b += row[-2];
  1229 					n++;
  1230 				}
  1231 				if (x+1 < w && row[7] != 0) {
  1232 					r += row[4];
  1233 					g += row[5];
  1234 					b += row[6];
  1235 					n++;
  1236 				}
  1237 				if (y-1 > 0 && row[-stride+3] != 0) {
  1238 					r += row[-stride];
  1239 					g += row[-stride+1];
  1240 					b += row[-stride+2];
  1241 					n++;
  1242 				}
  1243 				if (y+1 < h && row[stride+3] != 0) {
  1244 					r += row[stride];
  1245 					g += row[stride+1];
  1246 					b += row[stride+2];
  1247 					n++;
  1248 				}
  1249 				if (n > 0) {
  1250 					row[0] = (unsigned char)(r/n);
  1251 					row[1] = (unsigned char)(g/n);
  1252 					row[2] = (unsigned char)(b/n);
  1253 				}
  1254 			}
  1255 			row += 4;
  1256 		}
  1257 	}
  1258 }
  1259 
  1260 
  1261 static void nsvg__initPaint(NSVGcachedPaint* cache, NSVGpaint* paint, float opacity)
  1262 {
  1263 	int i, j;
  1264 	NSVGgradient* grad;
  1265 
  1266 	cache->type = paint->type;
  1267 
  1268 	if (paint->type == NSVG_PAINT_COLOR) {
  1269 		cache->colors[0] = nsvg__applyOpacity(paint->color, opacity);
  1270 		return;
  1271 	}
  1272 
  1273 	grad = paint->gradient;
  1274 
  1275 	cache->spread = grad->spread;
  1276 	memcpy(cache->xform, grad->xform, sizeof(float)*6);
  1277 
  1278 	if (grad->nstops == 0) {
  1279 		for (i = 0; i < 256; i++)
  1280 			cache->colors[i] = 0;
  1281 	} if (grad->nstops == 1) {
  1282 		for (i = 0; i < 256; i++)
  1283 			cache->colors[i] = nsvg__applyOpacity(grad->stops[i].color, opacity);
  1284 	} else {
  1285 		unsigned int ca, cb = 0;
  1286 		float ua, ub, du, u;
  1287 		int ia, ib, count;
  1288 
  1289 		ca = nsvg__applyOpacity(grad->stops[0].color, opacity);
  1290 		ua = nsvg__clampf(grad->stops[0].offset, 0, 1);
  1291 		ub = nsvg__clampf(grad->stops[grad->nstops-1].offset, ua, 1);
  1292 		ia = (int)(ua * 255.0f);
  1293 		ib = (int)(ub * 255.0f);
  1294 		for (i = 0; i < ia; i++) {
  1295 			cache->colors[i] = ca;
  1296 		}
  1297 
  1298 		for (i = 0; i < grad->nstops-1; i++) {
  1299 			ca = nsvg__applyOpacity(grad->stops[i].color, opacity);
  1300 			cb = nsvg__applyOpacity(grad->stops[i+1].color, opacity);
  1301 			ua = nsvg__clampf(grad->stops[i].offset, 0, 1);
  1302 			ub = nsvg__clampf(grad->stops[i+1].offset, 0, 1);
  1303 			ia = (int)(ua * 255.0f);
  1304 			ib = (int)(ub * 255.0f);
  1305 			count = ib - ia;
  1306 			if (count <= 0) continue;
  1307 			u = 0;
  1308 			du = 1.0f / (float)count;
  1309 			for (j = 0; j < count; j++) {
  1310 				cache->colors[ia+j] = nsvg__lerpRGBA(ca,cb,u);
  1311 				u += du;
  1312 			}
  1313 		}
  1314 
  1315 		for (i = ib; i < 256; i++)
  1316 			cache->colors[i] = cb;
  1317 	}
  1318 
  1319 }
  1320 
  1321 /*
  1322 static void dumpEdges(NSVGrasterizer* r, const char* name)
  1323 {
  1324 	float xmin = 0, xmax = 0, ymin = 0, ymax = 0;
  1325 	NSVGedge *e = NULL;
  1326 	int i;
  1327 	if (r->nedges == 0) return;
  1328 	FILE* fp = fopen(name, "w");
  1329 	if (fp == NULL) return;
  1330 
  1331 	xmin = xmax = r->edges[0].x0;
  1332 	ymin = ymax = r->edges[0].y0;
  1333 	for (i = 0; i < r->nedges; i++) {
  1334 		e = &r->edges[i];
  1335 		xmin = nsvg__minf(xmin, e->x0);
  1336 		xmin = nsvg__minf(xmin, e->x1);
  1337 		xmax = nsvg__maxf(xmax, e->x0);
  1338 		xmax = nsvg__maxf(xmax, e->x1);
  1339 		ymin = nsvg__minf(ymin, e->y0);
  1340 		ymin = nsvg__minf(ymin, e->y1);
  1341 		ymax = nsvg__maxf(ymax, e->y0);
  1342 		ymax = nsvg__maxf(ymax, e->y1);
  1343 	}
  1344 
  1345 	fprintf(fp, "<svg viewBox=\"%f %f %f %f\" xmlns=\"http://www.w3.org/2000/svg\">", xmin, ymin, (xmax - xmin), (ymax - ymin));
  1346 
  1347 	for (i = 0; i < r->nedges; i++) {
  1348 		e = &r->edges[i];
  1349 		fprintf(fp ,"<line x1=\"%f\" y1=\"%f\" x2=\"%f\" y2=\"%f\" style=\"stroke:#000;\" />", e->x0,e->y0, e->x1,e->y1);
  1350 	}
  1351 
  1352 	for (i = 0; i < r->npoints; i++) {
  1353 		if (i+1 < r->npoints)
  1354 			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);
  1355 		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");
  1356 	}
  1357 
  1358 	fprintf(fp, "</svg>");
  1359 	fclose(fp);
  1360 }
  1361 */
  1362 
  1363 void nsvgRasterize(NSVGrasterizer* r,
  1364 				   NSVGimage* image, float tx, float ty, float scale,
  1365 				   unsigned char* dst, int w, int h, int stride)
  1366 {
  1367 	NSVGshape *shape = NULL;
  1368 	NSVGedge *e = NULL;
  1369 	NSVGcachedPaint cache;
  1370 	int i;
  1371 
  1372 	r->bitmap = dst;
  1373 	r->width = w;
  1374 	r->height = h;
  1375 	r->stride = stride;
  1376 
  1377 	if (w > r->cscanline) {
  1378 		r->cscanline = w;
  1379 		r->scanline = (unsigned char*)realloc(r->scanline, w);
  1380 		if (r->scanline == NULL) return;
  1381 	}
  1382 
  1383 	for (i = 0; i < h; i++)
  1384 		memset(&dst[i*stride], 0, w*4);
  1385 
  1386 	for (shape = image->shapes; shape != NULL; shape = shape->next) {
  1387 		if (!(shape->flags & NSVG_FLAGS_VISIBLE))
  1388 			continue;
  1389 
  1390 		if (shape->fill.type != NSVG_PAINT_NONE) {
  1391 			nsvg__resetPool(r);
  1392 			r->freelist = NULL;
  1393 			r->nedges = 0;
  1394 
  1395 			nsvg__flattenShape(r, shape, scale);
  1396 
  1397 			// Scale and translate edges
  1398 			for (i = 0; i < r->nedges; i++) {
  1399 				e = &r->edges[i];
  1400 				e->x0 = tx + e->x0;
  1401 				e->y0 = (ty + e->y0) * NSVG__SUBSAMPLES;
  1402 				e->x1 = tx + e->x1;
  1403 				e->y1 = (ty + e->y1) * NSVG__SUBSAMPLES;
  1404 			}
  1405 
  1406 			// Rasterize edges
  1407 			qsort(r->edges, r->nedges, sizeof(NSVGedge), nsvg__cmpEdge);
  1408 
  1409 			// now, traverse the scanlines and find the intersections on each scanline, use non-zero rule
  1410 			nsvg__initPaint(&cache, &shape->fill, shape->opacity);
  1411 
  1412 			nsvg__rasterizeSortedEdges(r, tx,ty,scale, &cache, shape->fillRule);
  1413 		}
  1414 		if (shape->stroke.type != NSVG_PAINT_NONE && (shape->strokeWidth * scale) > 0.01f) {
  1415 			nsvg__resetPool(r);
  1416 			r->freelist = NULL;
  1417 			r->nedges = 0;
  1418 
  1419 			nsvg__flattenShapeStroke(r, shape, scale);
  1420 
  1421 //			dumpEdges(r, "edge.svg");
  1422 
  1423 			// Scale and translate edges
  1424 			for (i = 0; i < r->nedges; i++) {
  1425 				e = &r->edges[i];
  1426 				e->x0 = tx + e->x0;
  1427 				e->y0 = (ty + e->y0) * NSVG__SUBSAMPLES;
  1428 				e->x1 = tx + e->x1;
  1429 				e->y1 = (ty + e->y1) * NSVG__SUBSAMPLES;
  1430 			}
  1431 
  1432 			// Rasterize edges
  1433 			qsort(r->edges, r->nedges, sizeof(NSVGedge), nsvg__cmpEdge);
  1434 
  1435 			// now, traverse the scanlines and find the intersections on each scanline, use non-zero rule
  1436 			nsvg__initPaint(&cache, &shape->stroke, shape->opacity);
  1437 
  1438 			nsvg__rasterizeSortedEdges(r, tx,ty,scale, &cache, NSVG_FILLRULE_NONZERO);
  1439 		}
  1440 	}
  1441 
  1442 	nsvg__unpremultiplyAlpha(dst, w, h, stride);
  1443 
  1444 	r->bitmap = NULL;
  1445 	r->width = 0;
  1446 	r->height = 0;
  1447 	r->stride = 0;
  1448 }
  1449 
  1450 #endif