[Scilab-users] How to create transparent polygon

[Chin Luh Tan]

the previous method is the implementation as suggested by Samuel, another approach would be using Matplot.



you could play with the last line obj1 and obj2 (alpha blending) to get the desired intersection color. 


x = zeros(100,100,3);

obj1 = x;
obj2 = x;

obj1(21:60,21:60) = 1;
obj1(:,:,2:3) = 0;

obj2(41:80,41:80,2) = 1;
obj2(:,:,[1,3]) = 0;

Matplot(obj1+obj2)







---- On Tue, 12 Nov 2019 11:39:38 +0800 Chin Luh Tan <chinluh.tan at bytecode-asia.com> wrote ----


Hi,

If it is not necessary to have real transparent color mixing, but just want to have the transparent effect, you could try to play with the "pixel_drawing_mode". 
f = figure("background", 1,"pixel_drawing_mode", "or");
plot2d(0,0,-1,"010"," ",[-2,-2,2,2]);

x=sin(2*%pi*(0:4)/5);
y=cos(2*%pi*(0:4)/5);
plot2d(0,0,-1,"010"," ",[-2,-2,2,2]);
gca().foreground = 12;
xfpoly(x,y);
gca().foreground = 27;
xfpoly(x+0.3,y+0.3)






example from https://help.scilab.org/docs/6.0.2/en_US/pixel_drawing_mode.html

rgds,
CL


---- On Sat, 09 Nov 2019 21:19:44 +0800 jaipur <mailto:acj119 at nifty.com> wrote ----










_______________________________________________ 
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Dear all 
 
When making a polygon by xpoly for example, can we set transparency effect 
as the following polygon? 
If it's possible, could you suggest the way of doing? 
 
Regards 
Hiroshi Tachihara 
 
<http://mailinglists.scilab.org/file/t497089/transparency.png> 
 
 
 
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