png 20 30 gray.png

position 4  -1 -2 -3 4  1 3.5 3 4  2 0 0 2  -1 0.5 0 1
# viewport and division by double moves (x,y,z,w) to ((x/w+1)*width/2, (y/w+1)*height/2)
# meaning we have xy positions (7.5,7.5) and (12.5, 28.125) and (20,15) and (0,22.5)

color 3     1 1 1       1 1 1      0 0 0     0 0 0


drawArraysTriangles 0 3
# y=8,  x from 7.621... (rgb=1) to  8.333... (rgb=0.933...)
# y=9,  x from 7.863... (rgb=1) to 10        (rgb=0.8)
# y=10, x from 8.106... (rgb=1) to 11.666... (rgb=0.666...)
# ... and so on until reach mid-height vertex
# y=15, x from 9.318... (rgb=1) to 20        (rgb=0)
# y=16, x from 9.560... (rgb=1) to 19.428... (rgb=0.076...)
# ...

drawArraysTriangles 1 3
# last draw goes on top of first draw (because no depth buffer)