typedef struct {
    float x;
    float y;
} point2D_t;

typedef struct {
    float r;
    float g;
    float b;
} color_t;

void setColor(color_t col);

void drawDot(point2D_t pt);

void drawLine(point2D_t p1,point2D_t p2);
void drawLine(float x1,float y1,float x2,float y2);

//n: number of points
void drawPolyline(point2D_t pnt[],int n);

//n: number of vertices
void drawPolygon(point2D_t pnt[],int n);

// The function fillPolygon can fills only convex polygons
//n: number of vertices
void fillPolygon(point2D_t pnt[],int n,color_t color);

// The function gradatePolygon can fills only convex polygons
// The vertices will be painted with corresponding given colors.
// The points inside the polygon will be painted with the mixed color.
//n: number of vertices
void gradatePolygon(point2D_t pnt[],color_t col[],int num);