set_rgba — Set the color definition via RGBA values.
set_rgba( : : WindowHandle, Red, Green, Blue, Alpha : )
set_rgba sets the output color(s) or the gray values, respectively,
for region output for the window. The colors are defined with
the red, green, blue, and alpha components. If only one combination is
passed, all output takes place in that color. If a tuple is passed,
region output and output of geometric objects takes place modulo the
passed colors.
For every call of an output operator, output is started with the
first color. If only one object is displayed per call, it will
always be displayed in the first color. This is even true for
objects with multiple connection components. If multiple objects are
displayed per operator call, multiple colors are used. The defined
colors are used until set_color, set_rgba, or
set_rgb is called again. The
values are used by operators like disp_region,
disp_line,
disp_rectangle1, disp_rectangle2,
disp_arrow, etc.
set_rgba depends on the library libcanvas, which might not be
available on embedded systems.
WindowHandle (input_control) window → (handle)
Window handle.
Red (input_control) integer(-array) → (integer)
Red component of the color.
Default: 255
Value range:
0
≤
Red
≤
255
Restriction:
0 <= Red && Red <= 255
Green (input_control) integer(-array) → (integer)
Green component of the color.
Default: 0
Value range:
0
≤
Green
≤
255
Restriction:
0 <= Green && Green <= 255
Blue (input_control) integer(-array) → (integer)
Blue component of the color.
Default: 0
Value range:
0
≤
Blue
≤
255
Restriction:
0 <= Blue && Blue <= 255
Alpha (input_control) integer(-array) → (integer)
Alpha component of the color.
Default: 255
Value range:
0
≤
Alpha
≤
255
Restriction:
0 <= Alpha && Alpha <= 255
set_rgba returns 2 (
H_MSG_TRUE)
if the window is valid and all
passed colors are available and displayable. Otherwise an exception
is raised.
Foundation