added another method for spline-approximation error-estimation.

[swftools.git] / lib / drawer.c

diff --git a/lib/drawer.c b/lib/drawer.c
index d371657..1b4f7e9 100644 (file)
--- a/lib/drawer.c
+++ b/lib/drawer.c
@@ -22,6 +22,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <memory.h>
 #include <math.h>
 #include "drawer.h"
@@ -83,6 +84,14 @@ void draw_string(drawer_t*draw, const char*string)
            to.y = atoi(getToken(&p));
            draw->splineTo(draw, &mid, &to);
        }
+       else if(!strncmp(token, "conicTo", 5)) {
+           FPOINT mid,to;
+           mid.x = atoi(getToken(&p));
+           mid.y = atoi(getToken(&p));
+           to.x = atoi(getToken(&p));
+           to.y = atoi(getToken(&p));
+           draw_conicTo(draw, &mid, &to);
+       }
        else if(!strncmp(token, "cubicTo", 5)) {
            FPOINT mid1,mid2,to;
            mid1.x = atoi(getToken(&p));
@@ -93,7 +102,7 @@ void draw_string(drawer_t*draw, const char*string)
            to.y = atoi(getToken(&p));
            draw_cubicTo(draw, &mid1, &mid2, &to);
        }
-       else fprintf(stderr, "drawer: Warning: unknown primitive '%s'", token);
+       else fprintf(stderr, "drawer: Warning: unknown primitive '%s'\n", token);
        
        free(token);
     }
@@ -159,6 +168,7 @@ static int approximate3(const struct cspline*s, struct qspline*q, int size, doub
        char left = 0,recurse=0;
        int t;
        int probes = 15;
+       double dx,dy;
 
        /* create simple approximation: a qspline which run's through the
           qspline point at 0.5 */
@@ -193,8 +203,9 @@ static int approximate3(const struct cspline*s, struct qspline*q, int size, doub
            test.control.y += test.end.y;
        }
 
+#define PROBES
+#ifdef PROBES
        /* measure the spline's accurancy, by taking a number of probes */
-
        for(t=0;t<probes;t++) {
            struct SPLINEPOINT qr1,qr2,cr1,cr2;
            double pos = 0.5/(probes*2)*(t*2+1);
@@ -221,6 +232,19 @@ static int approximate3(const struct cspline*s, struct qspline*q, int size, doub
                recurse=1;break;
            }
        }
+#else // quadratic error: *much* faster!
+
+       /* convert control point representation to 
+          d*x^3 + c*x^2 + b*x + a */
+       dx= s->end.x  - s->control2.x*3 + s->control1.x*3 - s->start.x;
+       dy= s->end.y  - s->control2.y*3 + s->control1.y*3 - s->start.y;
+       
+       /* use the integral over (f(x)-g(x))^2 between 0 and 1
+          to measure the approximation quality. 
+          (it boils down to const*d^2)
+        */
+       recurse = (dx*dx + dy*dy > quality2);
+#endif
 
        if(recurse && istep>1 && size-level > num) {
            istep >>= 1;
@@ -242,6 +266,10 @@ void draw_cubicTo(drawer_t*draw, FPOINT*  control1, FPOINT* control2, FPOINT*  t
 {
     struct qspline q[128];
     struct cspline c;
+    double quality = 80;
+    double maxerror = (500-(quality*5)>1?500-(quality*5):1)/20.0;
+    int t,num;
+
     c.start.x = draw->pos.x;
     c.start.y = draw->pos.y;
     c.control1.x = control1->x;
@@ -250,11 +278,9 @@ void draw_cubicTo(drawer_t*draw, FPOINT*  control1, FPOINT* control2, FPOINT*  t
     c.control2.y = control2->y;
     c.end.x = to->x;
     c.end.y = to->y;
-    double quality = 80;
-    double maxerror = (500-(quality*5)>1?500-(quality*5):1)/20.0;
+    
+    num = approximate3(&c, q, 128, maxerror*maxerror);
 
-    int num = approximate3(&c, q, 128, maxerror*maxerror);
-    int t;
     for(t=0;t<num;t++) {
        FPOINT mid;
        FPOINT to;