+
+gfxbbox_t* gfxline_isrectangle(gfxline_t*_l)
+{
+ if(!_l)
+ return 0;
+
+ gfxline_t*l = gfxline_clone(_l);
+ gfxline_optimize(l);
+
+ double x1,x2,y1,y2;
+ int xc=0,yc=0;
+ char corners=0;
+
+ char prev=0;
+ char fail=0;
+ for(;l; l=l->next) {
+ double x = l->x;
+ double y = l->y;
+
+ char top=0,left=0;
+
+ if(xc==2 && x!=x1 && x!=x2) {fail=1;break;}
+ else if(xc>=1 && x==x1) {left=0;}
+ else if(xc==2 && x==x2) {left=1;}
+ else if(xc==1 && x!=x1) {x2 = x; xc=2; left=1;}
+ else if(xc==0) {x1 = x; xc=1;left=0;}
+ else {fprintf(stderr, "Internal error in rectangle detection\n");}
+
+ if(yc==2 && y!=y1 && y!=y2) {fail=1;break;}
+ else if(yc>=1 && y==y1) {top=0;}
+ else if(yc==2 && y==y2) {top=1;}
+ else if(yc==1 && y!=y1) {y2 = y; yc=2; top=1;}
+ else if(yc==0) {y1 = y; yc=1;top=0;}
+ else {fprintf(stderr, "Internal error in rectangle detection\n");}
+
+ char pos=top<<1|left;
+
+ if((pos^prev)==3) {
+ /* diagonal lines not allowed */
+ fail=1;break;
+ }
+ prev = pos;
+
+ /* no corner except the first one may be touched twice */
+ if(pos && (corners & 1<<pos)) {
+ fail=1;break;
+ }
+ /* mark which corners have been touched so far */
+ corners |= 1<<pos;
+ }
+ if(fail) {
+ gfxline_free(l);
+ return 0;
+ }
+
+ if(corners!=0x0f) return 0; // not all 4 corners reached
+
+ if(x2<x1) {double x = x2;x2=x1;x1=x;}
+ if(y2<y1) {double y = y2;y2=y1;y1=y;}
+
+ gfxbbox_t*r = malloc(sizeof(gfxbbox_t));
+ r->xmin = x1; r->ymin = y1;
+ r->xmax = x2; r->ymax = y2;
+ return r;
+}
+
+void gfximage_transform(gfximage_t*img, gfxcxform_t*cxform)
+{
+ int t;
+ int size = img->width*img->height;
+
+ int rr,rg,rb,ra, tr;
+ int gr,gg,gb,ga, tg;
+ int br,bg,bb,ba, tb;
+ int ar,ag,ab,aa, ta;
+ rr = (int)(cxform->rr*256);gr = (int)(cxform->gr*256);
+ rg = (int)(cxform->rg*256);gg = (int)(cxform->gg*256);
+ rb = (int)(cxform->rb*256);gb = (int)(cxform->gb*256);
+ ra = (int)(cxform->ra*256);ga = (int)(cxform->ga*256);
+ br = (int)(cxform->br*256);ar = (int)(cxform->ar*256);tr = (int)(cxform->tr*256);
+ bg = (int)(cxform->bg*256);ag = (int)(cxform->ag*256);tg = (int)(cxform->tg*256);
+ bb = (int)(cxform->bb*256);ab = (int)(cxform->ab*256);tb = (int)(cxform->tb*256);
+ ba = (int)(cxform->ba*256);aa = (int)(cxform->aa*256);ta = (int)(cxform->ta*256);
+
+ for(t=0;t<size;t++) {
+ gfxcolor_t*pixel = &img->data[t];
+ unsigned char r = (pixel->r * rr + pixel->g * rg + pixel->b * rb + pixel->a * ra + tr) / 256;
+ unsigned char g = (pixel->r * gr + pixel->g * gg + pixel->b * gb + pixel->a * ga + tg) / 256;
+ unsigned char b = (pixel->r * br + pixel->g * bg + pixel->b * bb + pixel->a * ba + tb) / 256;
+ unsigned char a = (pixel->r * ar + pixel->g * ag + pixel->b * ab + pixel->a * aa + ta) / 256;
+ pixel->r = r;
+ pixel->g = g;
+ pixel->b = b;
+ pixel->a = a;
+ }
+}
+void gfxline_dump(gfxline_t*line, FILE*fi, char*prefix)
+{
+ while(line) {
+ if(line->type == gfx_moveTo) {
+ fprintf(fi, "%smoveTo %.2f %.2f\n", prefix, line->x, line->y);
+ } else if(line->type == gfx_lineTo) {
+ fprintf(fi, "%slineTo %.2f %.2f\n", prefix, line->x, line->y);
+ } else if(line->type == gfx_splineTo) {
+ fprintf(fi, "%ssplineTo (%.2f %.2f) %.2f %.2f\n", prefix, line->sx, line->sy, line->x, line->y);
+ }
+ line = line->next;
+ }
+}
+