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Issue #20: better handling of miter joins

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- better handling if stroke miter joins (inner bevel)
- correct default miter 4
This commit is contained in:
Mikko Mononen 2014-11-05 10:47:35 +02:00
parent ae51200111
commit 205d5197d2
2 changed files with 94 additions and 5 deletions
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2
example/example2.c
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@ -32,7 +32,7 @@ int main()
NSVGrasterizer *rast = NULL;
unsigned char* img = NULL;
int w, h;
const char* filename = "../example/23.svg";
const char* filename = "../example/_web-spit.svg";
printf("parsing %s\n", filename);
image = nsvgParseFromFile(filename, "px", 96.0f);

97
src/nanosvgrast.h
View File

@ -360,6 +360,7 @@ 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)
@ -472,6 +473,42 @@ static void nsvg__bevelJoin(NSVGrasterizer* r, NSVGpoint* left, NSVGpoint* right
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;
@ -540,7 +577,7 @@ static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float
int s, e;
NSVGpath* path;
NSVGpoint* p0, *p1;
float miterLimit = 10;
float miterLimit = 4;
int lineJoin = shape->strokeLineJoin;
int lineCap = shape->strokeLineCap;
float lineWidth = shape->strokeWidth * scale;
@ -582,7 +619,7 @@ static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float
p0 = &r->points[r->npoints-1];
p1 = &r->points[0];
for (j = 0; j < r->npoints; j++) {
float dlx0, dly0, dlx1, dly1, dmr2;
float dlx0, dly0, dlx1, dly1, dmr2, cross;
dlx0 = p0->dy;
dly0 = -p0->dx;
dlx1 = p1->dy;
@ -603,6 +640,11 @@ static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float
// 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) {
@ -646,11 +688,14 @@ static void nsvg__flattenShapeStroke(NSVGrasterizer* r, NSVGshape* shape, float
}
for (j = s; j < e; ++j) {
if (p1->flags & NSVG_PT_BEVEL) {
// if (p1->flags & NSVG_PT_BEVEL) {
if (p1->flags & NSVG_PT_CORNER) {
if (lineJoin == NSVG_JOIN_ROUND)
nsvg__roundJoin(r, &left, &right, p0, p1, lineWidth, ncap);
else
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);
}
@ -1131,6 +1176,48 @@ static void nsvg__initPaint(NSVGcachedPaint* cache, NSVGpaint* paint, float opac
}
/*
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)
@ -1186,6 +1273,8 @@ void nsvgRasterize(NSVGrasterizer* r,
nsvg__flattenShapeStroke(r, shape, scale);
// dumpEdges(r, "edge.svg");
// Scale and translate edges
for (i = 0; i < r->nedges; i++) {
e = &r->edges[i];