ref: d0c5e1bb15cdd6d57bef2c1086b87c48d9c0adcd
dir: /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(void);
// 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(void)
{
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) {
lx1 = p1->x - p1->dmx * w;
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);
rx1 = p1->x + p1->dmx * w;
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;
NSVGedge *e;
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