Guru
Joined: 11/12/2012
Location: United KingdomPosts: 11033
| Posted: 03:50pm 16 Feb 2022 |
MMBasic for Windows V5.07.03a0
MMBasic.zip
The MMBasic for Windows code is now officially past the pre-alpha phase and enters alpha. i.e. most of the functionality is now there and there are not too many reports of issues but there is still work to do.
The big change in V5.07.03a0 is support for proper transparency as per the CMM2
The mode command is changed as follows to follow the CMM2 as closely as possible:
MODE modeno [,alphaenabled] [,background colour]
By default alphaenabled is 0 and the background colour is BLACK
To use the second layer set alphaenabled to 1 and optionally choose a background colour
Unlike the CMM2 MMbasic for windows uses full ARGB8888 colour in all modes and has a transparency value (A) of 0-255
When you change the mode to alpha by default you are still writing to page 0 and it is cleared to RGB(BLACK)which is opaque. If you want to see the background colour pixels on page 0 must be written with a transparency of less than 255. Use CLS RGB(BLANK) to clear a page to completely transparent.
If you set to write to page 1 this will overlay page 0 and the background to the extent that the alpha value of the pixels on PAGE 1 are set (between 0=transparent and 255=opaque).
Note when playing with this at the command line you can get very confused so it is easier to understand what is happening with a very simple program.
mode 14,1,rgb(magenta) 'set into 2 layer mode with the background set to magenta
font 3
print "Click to get focus"
mouseclick
print "now we will clear page 0 to blank"
print "click to continue"
mouseclick
cls rgb(blank)
colour rgb(black),rgb(blank)
print "This text is written on page 0 with transparent backgound"
print "click to continue"
mouseclick
print "Now we will write to the top page"
print "click to continue"
mouseclick
page write 1
cls rgb(blank)
sprite loadpng 1,"apple"
sprite write 1,50,10,1
sprite transparency 1,128 'change the transparency of the sprite
sprite write 1,200,10,1
page write 0
print @(0,mm.info(fontheight)*4)"You can see the page 0 text through the right hand apple"
print
print "Click to exit and remember to click again to get focus"
mouseclick
sprite close all
mode 14
colour rgb(white),rgb(black)
end
sub mouseclick
do
loop until mouse(l)
do
loop until not mouse(l)
end sub
font 3
print "Click to get focus"
mouseclick
print "now we will clear page 0 to blank"
print "click to continue"
mouseclick
cls rgb(blank)
colour rgb(black),rgb(blank)
print "This text is written on page 0 with transparent backgound"
print "click to continue"
mouseclick
print "Now we will write to the top page"
print "click to continue"
mouseclick
page write 1
cls rgb(blank)
sprite loadpng 1,"apple"
sprite write 1,50,10,1
sprite transparency 1,128 'change the transparency of the sprite
sprite write 1,200,10,1
page write 0
print @(0,mm.info(fontheight)*4)"You can see the page 0 text through the right hand apple"
print "Click to exit and remember to click again to get focus"
mouseclick
sprite close all
mode 14
colour rgb(white),rgb(black)
end
sub mouseclick
do
loop until mouse(l)
do
loop until not mouse(l)
end sub
apple.zip
Finally a note on the RGB function.
RGB(COLOURNAME) will return a fully opaque representation of that colour
RGB(red, green, blue) will return a fully opaque representation of that colour
use RGB(red, green, blue, trans) to set a partially transparent colour
If you must, you can use numerical values directly as colours e.g CLS &H80607080
This will set the transparency to &H80, the blue level to &H60, the green level to &H70 and the red level to &H80. Note that red and blue are reversed compared to the CMM2 if a direct numerical value is used in this way i.e ABRG8888
