[.. upper level ..]

struct VG_Rect

A rectangle, with the origin at the upper left corner.

int x	x-position at left upper corner (horizontal direction)
int y	y-position at left upper corner (vertical direction)
int w	Width (horizontal direction)
int h	Height (vertical direction)

/* Draw a filled yellow rectangle onto the window at window-position 10/20
 * with a width of 100 pixels and a height of 50 pixels
 */

struct VG_Rect rect;

rect.x = 10;
rect.w = 100;
rect.y = 20;
rect.h = 50;

vg4->window->draw_rect(&rect, VG_COLOR_YELLOW, VG_TRUE);