My take on it
Code:
// JT: Essential filled rectangle
// makes a rectangle of any color
//@param1:wet 'opacity' 1.0 0 1 0.5 0.01
//@param2:R 'Red' 0.5 0 1 0.5 0.01
//@param3:G 'Green' 0.5 0 1 0.5 0.01
//@param4:B 'Blue' 0.5 0 1 0.5 0.01
//@param6:w1 'Width' 50 2 1920 50 2
//@param7:h1 'Height' 50 2 1080 50 2
//@param9:P1 'X position' 50 0 100 50 1
//@param10:P2 'Y position2' 50 0 100 50 1
src=0;
PW=Project_w/100;
PH=Project_h/100;
gfx_blit(0);
gfx_mode=1;
gfx_set(R,G,B,wet);
//line
gfx_gradrect((PW*P1-(w1/2)),(PH*P2-(h1/2)),w1,h1,R,G,B,wet);