////////////// OpenGL drawtools for 2D Functions ver 1 /////////////////
typedef struct {
    float x;
    float y;
} point2D_t;

typedef struct {
	float v[3];
} vector2D_t;

typedef struct {
	float m[3][3];
} matrix2D_t;

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

matrix2D_t createIdentity(void);

matrix2D_t multiply(matrix2D_t a,matrix2D_t b);
matrix2D_t operator * (matrix2D_t a, matrix2D_t b);

vector2D_t multiply(matrix2D_t a, vector2D_t b);
vector2D_t operator * (matrix2D_t a, vector2D_t b);

matrix2D_t translationMTX(float dx,float dy);

matrix2D_t rotationMTX(float theta);

matrix2D_t scalingMTX(float factorx,float factory);

vector2D_t Point2Vector(point2D_t pnt);

void setColor(color_t col);

void drawDot(point2D_t pt);
void drawDot(vector2D_t vc);

void drawLine(point2D_t p1,point2D_t p2);
void drawLine(vector2D_t v1,vector2D_t v2);
void drawLine(float	x1,float y1,float x2,float y2);

//n: number of points
void drawPolyline(point2D_t pnt[],int n);
void drawPolyline(vector2D_t vct[],int n);

//n: number of vertices
void drawPolygon(point2D_t pnt[],int n);
void drawPolygon(vector2D_t vct[],int n);

// The function fillPolygon can fills only convex polygons
//n: number of vertices
void fillPolygon(point2D_t pnt[],int n,color_t color);
void fillPolygon(vector2D_t vct[],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);
void gradatePolygon(vector2D_t vct[],color_t col[],int num);