Free Hero Mesh

static void fill_circle(Uint8*p,Uint8 s,Uint8 x0,Uint8 y0,Uint32 r,Uint8 c) {
  int x,y;
  for(y=0;y<s;y++) for(x=0;x<s;x++) {
    if((x-x0)*(x-x0)+(y-y0)*(y-y0)<=r) p[y*s+x]=c;
  }
}

static void draw_ellipse(Uint8*p,Uint8 s,Uint8 x0,Uint8 y0,Uint8 x1,Uint8 y1,Uint8 c) {
  double cx,cy,rx,ry,v;
  int x,y;
  if(x1<x0) x=x1,x1=x0,x0=x;
  if(y1<y0) y=y1,y1=y0,y0=y;
  cx=0.5*(x1+x0);
  cy=0.5*(y1+y0);
  rx=0.5*(x1-x0);
  ry=0.5*(y1-y0);
  for(y=y0;y<=y1;y++) {
    v=(y-cy)/ry; v*=v;
    if(v>1.0) continue;
    v=rx*sqrt(1.0-v);
    x=round(cx-v); if(x>=0 && x<s) p[y*s+x]=c;
    x=round(cx+v); if(x>=0 && x<s) p[y*s+x]=c;
  }
  for(x=x0;x<=x1;x++) {
    v=(x-cx)/rx; v*=v;
    if(v>1.0) continue;
    v=ry*sqrt(1.0-v);
    y=round(cy-v); if(y>=0 && y<s) p[y*s+x]=c;
    y=round(cy+v); if(y>=0 && y<s) p[y*s+x]=c;
  }
}

static void fill_ellipse(Uint8*p,Uint8 s,Uint8 x0,Uint8 y0,Uint8 x1,Uint8 y1,Uint8 c) {
  double cx,cy,rx,ry;
  int x,y;
  if(x1<x0) x=x1,x1=x0,x0=x;
  if(y1<y0) y=y1,y1=y0,y0=y;
  cx=0.5*(x1+x0);
  cy=0.5*(y1+y0);
  rx=0.5*(x1-x0);
  ry=0.5*(y1-y0);
  for(y=y0;y<=y1;y++) for(x=x0;x<=x1;x++) {
    if(pow((x-cx)/rx,2.0)+pow((y-cy)/ry,2.0)<=1.0) p[y*s+x]=c;
  }
}

static inline void edit_picture_1(Picture**pict,const char*name) {
  static const Uint8 shade[64]=
    "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F"
    "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F"
    "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F"
    "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F"

            case 2: // Pick
              i=pict[sel]->data[(y+1)*pict[sel]->size+x];
              goto pick;
            case 3: // Line
              if((i&2) && xx!=-1) draw_line(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,xx,yy,cc);
              if(i&1) xx=x,yy=y;
              break;
            case 4: // Rectangle
              if(i==1) {
                xx=x; yy=y;
              } else if(xx!=-1) {
                p=pict[sel]->data+(j=pict[sel]->size);
                if(xx<x) i=x,x=xx,xx=i;
                if(yy<y) i=y,y=yy,yy=i;
                memset(p+y*j+x,cc,xx+1-x);
                memset(p+yy*j+x,cc,xx+1-x);
                while(y<yy) p[y*j+x]=p[y*j+xx]=cc,y++;
                xx=yy=-1;
              }
              break;
            case 5: // Fill rectangle
              if(i==1) {
                xx=x; yy=y;
              } else if(xx!=-1) {
                p=pict[sel]->data+(j=pict[sel]->size);
                if(xx<x) i=x,x=xx,xx=i;
                if(yy<y) i=y,y=yy,yy=i;
                while(y<yy) memset(p+y*j+x,cc,xx+1-x),y++;
                xx=yy=-1;
              }
              break;
            case 6: // Circle
              if(i==1) {
                xx=x; yy=y;
              } else if(i==2) {
                draw_circle(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,(x-xx)*(x-xx)+(y-yy)*(y-yy),cc);
              } else if(i==3) {
                draw_circle(pict[sel]->data+pict[sel]->size,pict[sel]->size,xx,yy,(x-xx)*(x-xx)+(y-yy)*(y-yy),cc);
              }
              break;
            case 7: // Fill circle
              if(i==1) {
                xx=x; yy=y;
              } else if(i==2) {
                fill_circle(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,(x-xx)*(x-xx)+(y-yy)*(y-yy),cc);
              } else if(i==3) {
                fill_circle(pict[sel]->data+pict[sel]->size,pict[sel]->size,xx,yy,(x-xx)*(x-xx)+(y-yy)*(y-yy),cc);
              }
              break;
            case 8: // Ellipse
              if(i==1) {
                xx=x; yy=y;
              } else if(xx!=-1) {
                draw_ellipse(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,xx,yy,cc);
              }
              break;
            case 9: // Fill ellipse
              if(i==1) {
                xx=x; yy=y;
              } else if(xx!=-1) {
                fill_ellipse(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,xx,yy,cc);
                draw_ellipse(pict[sel]->data+pict[sel]->size,pict[sel]->size,x,y,xx,yy,cc);
              }
              break;
          }
          goto redraw;
        }
        break;
      case SDL_KEYDOWN:
        switch(ev.key.keysym.sym) {