return result;
}
-void draw_conicto(drawer_t*draw, FPOINT* c, FPOINT* to)
+void draw_conicTo(drawer_t*draw, FPOINT* c, FPOINT* to)
{
FPOINT* pos = &draw->pos;
FPOINT c1,c2;
c1.y = (pos->y + 2 * c->y) / 3;
c2.x = (2 * c->x + to->x) / 3;
c2.y = (2 * c->y + to->y) / 3;
- draw_cubicto(draw, &c1,&c2,to);
+ draw_cubicTo(draw, &c1,&c2,to);
draw->pos = *to;
}
const char*p = string;
while(*p) {
char*token = getToken(&p);
+ if(!token || !*token)
+ break;
if(!strncmp(token, "moveTo", 6)) {
FPOINT to;
to.x = atoi(getToken(&p));
to.y = atoi(getToken(&p));
draw->splineTo(draw, &mid, &to);
}
+ else if(!strncmp(token, "cubicTo", 5)) {
+ FPOINT mid1,mid2,to;
+ mid1.x = atoi(getToken(&p));
+ mid1.y = atoi(getToken(&p));
+ mid2.x = atoi(getToken(&p));
+ mid2.y = atoi(getToken(&p));
+ to.x = atoi(getToken(&p));
+ to.y = atoi(getToken(&p));
+ draw_cubicTo(draw, &mid1, &mid2, &to);
+ }
+ else fprintf(stderr, "drawer: Warning: unknown primitive '%s'", token);
+
free(token);
}
}
struct SPLINEPOINT end;
};
-/* move the control point so that the spline runs through the original
- control point */
-static void fixcp(struct qspline*s)
-{
- struct SPLINEPOINT mid,dir;
- mid.x = (s->end.x + s->start.x)/2;
- mid.y = (s->end.y + s->start.y)/2;
- dir.x = s->control.x - mid.x;
- dir.y = s->control.y - mid.y;
- s->control.x = mid.x + 2*dir.x;
- s->control.y = mid.y + 2*dir.y;
-}
-
-static inline struct SPLINEPOINT cspline_getpoint(struct cspline*s, double t)
+static inline struct SPLINEPOINT cspline_getpoint(const struct cspline*s, double t)
{
struct SPLINEPOINT p;
- p.x= s->end.x*t*t*t + 3*s->control2.x*t*t*(1-t)
- + 3*s->control1.x*t*(1-t)*(1-t) + s->start.x*(1-t)*(1-t)*(1-t);
- p.y= s->end.y*t*t*t + 3*s->control2.y*t*t*(1-t)
- + 3*s->control1.y*t*(1-t)*(1-t) + s->start.y*(1-t)*(1-t)*(1-t);
+ double tt = t*t;
+ double ttt = tt*t;
+ double mt = (1-t);
+ double mtmt = mt*(1-t);
+ double mtmtmt = mtmt*(1-t);
+ p.x= s->end.x*ttt + 3*s->control2.x*tt*mt
+ + 3*s->control1.x*t*mtmt + s->start.x*mtmtmt;
+ p.y= s->end.y*ttt + 3*s->control2.y*tt*mt
+ + 3*s->control1.y*t*mtmt + s->start.y*mtmtmt;
return p;
}
-static struct SPLINEPOINT qspline_getpoint(struct qspline*s, double t)
+static struct SPLINEPOINT qspline_getpoint(const struct qspline*s, double t)
{
struct SPLINEPOINT p;
p.x= s->end.x*t*t + 2*s->control.x*t*(1-t) + s->start.x*(1-t)*(1-t);
return p;
}
-static struct SPLINEPOINT cspline_getderivative(struct cspline*s, double t)
+static int approximate3(const struct cspline*s, struct qspline*q, int size, double quality2)
{
- struct SPLINEPOINT d;
- d.x = s->end.x*(3*t*t) + 3*s->control2.x*(2*t-3*t*t) +
- 3*s->control1.x*(1-4*t+3*t*t) + s->start.x*(-3+6*t-3*t*t);
- d.y = s->end.y*(3*t*t) + 3*s->control2.y*(2*t-3*t*t) +
- 3*s->control1.y*(1-4*t+3*t*t) + s->start.y*(-3+6*t-3*t*t);
- return d;
-}
+ unsigned int gran = 0;
+ unsigned int istep = 0x80000000;
+ unsigned int istart = 0;
+ int num = 0;
+ int level = 0;
+
+ while(istart<0x80000000)
+ {
+ unsigned int iend = istart + istep;
+ double start = istart/(double)0x80000000;
+ double end = iend/(double)0x80000000;
+ struct qspline test;
+ double pos,qpos;
+ char left = 0,recurse=0;
+ int t;
+ int probes = 15;
-static int approximate2(struct cspline*s, struct qspline*q, double quality, double start, double end, int max, int depth)
-{
- int num=0;
- struct SPLINEPOINT qr1,qr2,cr1,cr2;
- double dist1,dist2;
- double qquality = quality*quality;
- int t;
- int recurse = 0;
- int probes = 15;
- struct qspline test;
- char left = 0;
- test.start = cspline_getpoint(s, start);
- test.control = cspline_getpoint(s, (start+end)/2);
- test.end = cspline_getpoint(s, end);
- fixcp(&test);
-
- if(start< 0.5) {
- test.control = cspline_getderivative(s, start);
- test.control.x *= (end-start)/2;
- test.control.y *= (end-start)/2;
- test.control.x += test.start.x;
- test.control.y += test.start.y;
- } else {
- test.control = cspline_getderivative(s, end);
- test.control.x *= -(end-start)/2;
- test.control.y *= -(end-start)/2;
- test.control.x += test.end.x;
- test.control.y += test.end.y;
- }
+ /* create simple approximation: a qspline which run's through the
+ qspline point at 0.5 */
+ test.start = cspline_getpoint(s, start);
+ test.control = cspline_getpoint(s, (start+end)/2);
+ test.end = cspline_getpoint(s, end);
+ /* fix the control point:
+ move it so that the new spline does runs through it */
+ test.control.x = -(test.end.x + test.start.x)/2 + 2*(test.control.x);
+ test.control.y = -(test.end.y + test.start.y)/2 + 2*(test.control.y);
- for(t=0;t<probes;t++) {
- double pos = 0.5/(probes*2)*(t*2+1);
- double dx,dy;
- qr1 = qspline_getpoint(&test, pos);
- cr1 = cspline_getpoint(s, start+pos*(end-start));
+ /* depending on where we are in the spline, we either try to match
+ the left or right tangent */
+ if(start<0.5)
+ left=1;
+ /* get derivative */
+ pos = left?start:end;
+ qpos = pos*pos;
+ test.control.x = s->end.x*(3*qpos) + 3*s->control2.x*(2*pos-3*qpos) +
+ 3*s->control1.x*(1-4*pos+3*qpos) + s->start.x*(-3+6*pos-3*qpos);
+ test.control.y = s->end.y*(3*qpos) + 3*s->control2.y*(2*pos-3*qpos) +
+ 3*s->control1.y*(1-4*pos+3*qpos) + s->start.y*(-3+6*pos-3*qpos);
+ if(left) {
+ test.control.x *= (end-start)/2;
+ test.control.y *= (end-start)/2;
+ test.control.x += test.start.x;
+ test.control.y += test.start.y;
+ } else {
+ test.control.x *= -(end-start)/2;
+ test.control.y *= -(end-start)/2;
+ test.control.x += test.end.x;
+ test.control.y += test.end.y;
+ }
- dx = qr1.x - cr1.x;
- dy = qr1.y - cr1.y;
- dist1 = dx*dx+dy*dy;
+ /* measure the spline's accurancy, by taking a number of probes */
- if(dist1>qquality) {
- recurse=1;break;
- }
- qr2 = qspline_getpoint(&test, (1-pos));
- cr2 = cspline_getpoint(s, start+(1-pos)*(end-start));
+ for(t=0;t<probes;t++) {
+ struct SPLINEPOINT qr1,qr2,cr1,cr2;
+ double pos = 0.5/(probes*2)*(t*2+1);
+ double dx,dy;
+ double dist1,dist2;
+ qr1 = qspline_getpoint(&test, pos);
+ cr1 = cspline_getpoint(s, start+pos*(end-start));
- dx = qr2.x - cr2.x;
- dy = qr2.y - cr2.y;
- dist2 = dx*dx+dy*dy;
+ dx = qr1.x - cr1.x;
+ dy = qr1.y - cr1.y;
+ dist1 = dx*dx+dy*dy;
- if(dist2>qquality) {
- recurse=1;break;
+ if(dist1>quality2) {
+ recurse=1;break;
+ }
+ qr2 = qspline_getpoint(&test, (1-pos));
+ cr2 = cspline_getpoint(s, start+(1-pos)*(end-start));
+
+ dx = qr2.x - cr2.x;
+ dy = qr2.y - cr2.y;
+ dist2 = dx*dx+dy*dy;
+
+ if(dist2>quality2) {
+ recurse=1;break;
+ }
}
- }
- if(recurse && (end-start)>1.0/120 && max-depth > 0) {
- /* quality is too bad, split it up recursively */
- num += approximate2(s, q, quality, start, (start+end)/2, max, depth+1);
- q+=num;
- max-=num;
- num += approximate2(s, q, quality, (start+end)/2, end, max, depth+1);
- return num;
- } else {
- *q = test;
- return 1;
+ if(recurse && istep>1 && size-level > num) {
+ istep >>= 1;
+ level++;
+ } else {
+ *q++ = test;
+ num++;
+ istart += istep;
+ while(!(istart & istep)) {
+ level--;
+ istep <<= 1;
+ }
+ }
}
+ return num;
}
-void draw_cubicto(drawer_t*draw, FPOINT* control1, FPOINT* control2, FPOINT* to)
+void draw_cubicTo(drawer_t*draw, FPOINT* control1, FPOINT* control2, FPOINT* to)
{
struct qspline q[128];
struct cspline c;
c.control2.y = control2->y;
c.end.x = to->x;
c.end.y = to->y;
- double quality = 0.8;
+ double quality = 80;
double maxerror = (500-(quality*5)>1?500-(quality*5):1)/20.0;
- int num = approximate2(&c, q, maxerror, 0.0, 1.0, 128, 0);
+ int num = approximate3(&c, q, 128, maxerror*maxerror);
int t;
for(t=0;t<num;t++) {
FPOINT mid;