Alpha not working on Vector graphics

[Bugala]

StartPath(1)
AddArcToPath(1, 100, 100, 50, 50, 120, 220)
DrawPath(1, 0, 0, ARGB(10, #RED))
DrawPath(1, 100, 100, ARGB(90, #RED))
DrawPath(1, 200, 200, ARGB(190, #RED))
WaitLeftMouse()

Hollywood 9.1 Windows 11 - All Arcs look exactly same colored, even to my understanding some of them should look clearly fainter.

[Flinx]

I have no explanation, but a workaround:

Code: Select all

DrawPath(1, 200, 200, #RED, {Transparency=90})

[plouf]

i think (not 100% sure) that alpha works with layers only i.e. dither alpha based on previous layer

Code: Select all

EnableLayers()

StartPath(1)
AddArcToPath(1, 100, 100, 50, 50, 120, 220)
DrawPath(1, 0, 0, ARGB(10, #RED))
DrawPath(1, 100, 100, ARGB(90, #RED))
DrawPath(1, 200, 200, ARGB(190, #RED))

WaitLeftMouse()

[Bugala]

@Andreas

Just noticed the DrawTo example code from the manual has a small problem too:

Code: Select all

SetFillStyle(#FILLNONE)
SetFormStyle(#ANTIALIAS)
x=25.6 y=128.0
x1=102.4 y1=230.4
x2=153.6 y2=25.6
x3=230.4 y3=128.0

StartPath(1)
MoveTo(1, x, y)
CurveTo(1, x1, y1, x2, y2, x3, y3)
SetLineWidth(10)
DrawPath(1, 0, 0, #BLACK)

ClearPath(1)
MoveTo(1, x, y)
LineTo(1, x1, y1)
MoveTo(1, x2, y2)
LineTo(1, x3, y3)
SetLineWidth(6)
DrawPath(1, 0, 0, ARGB(128, #RED))

WaitLeftMouse()

In addition to ARGB not working, the first CurveTo is drawn using BLACK color, which is problematic since the Background by default is BLACK too, meaning you don't see what it is doing with this example code until you first change that #BLACK color into something else.

[Bugala]

@Flinx, thanks for the workaround! Thought I couldnt get my program to do what I wanted, bu this solves the problem.

[airsoftsoftwair]

i think (not 100% sure) that alpha works with layers only

No, it should work. It's definitely a bug, though it only happens with layers off.