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In BBC BASIC, what is (are) the command(s) to output a filled
rectangle with a colour in 256 colour mode 13.
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GCOL 0,%00abcdef TINT %gh000000 for plot foreground colour and
GCOL 0,%10abcdef TINT %gh000000 for plot background colour
I will try to use that tonight.
I should have said my machine is a BBCA3000 with RISC OS 3.11.
(old VIDC with its not freely selectable 256 colour screen modes).
My understanding of the VIDC system colour system is that you only
have a total of 64 colours but their shade can be altered with the
TINT keyword. This gives 256 possible colour variations (64 different
colours multiplied by 4 shades). Although the TINT keyword can handle
256 variations it only has 4 distinct levels.....
(0-64,64-128,128-192,192-255). So a TINT range of 0-63 for example only
gives a single effective TINT level (no additional brightness). You can
see this action with a simple example...
PRINT "Press any key to new display tint value"
FOR x = 0 TO 128
GCOL 0,3 TINT x
RECTANGLE FILL 200,200,100
g = GET
PRINT TAB(0,30)"Tint value = ";x
TINT transitions are at 63(64-1) and 127(128-1).
***@mdfs.net examples show the binary equivalent - this is useful
because it shows the bits that need setting for GCOL - bit 7 sets
foreground/background colour (0 for foreground, 1 for background).
The TINT statement requires bits 6 and 7 to be set to 00 (0-64),01
(64-128),10 (128-192) and 11 (192-255).