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Topic: "Color math"? (Read 238 times) |
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kevinP
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"Color math"?
« on: Feb 13th, 2004, 9:48pm » |
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Hi,
If I'm storing colors in a color object how can I do "color math" (e.g. "take existing values in c and subtract 10 from R and G")? This might be useful for defining a constant that I can use for modifying all colors...
Something like this? (doesn't work)
color c = (100, 100, 100);
color lighten = (10, 10, 0);
c = c - lighten;
// now c is (90, 90, 0);
-K
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| « Last Edit: Feb 13th, 2004, 9:49pm by kevinP » |
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Kevin Pfeiffer
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bryan
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Re: "Color math"?
« Reply #1 on: Feb 13th, 2004, 10:54pm » |
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if you are using the color object it may help to store red green and blue values as seperate variables.
int rr = 100;
int gg = 100;
int bb = 100;
int ltn = 10; //lighten value
color c = (rr, gg, bb);
c = (rr-ltn, gg-ltn, bb-ltn);
here you still have a constants ltn and rr gg bb
they can always change of course. but for the scope of this script they dont. wonder if this helps?
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bryan
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Re: "Color math"?
« Reply #2 on: Feb 13th, 2004, 11:31pm » |
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i couldnt run the code because im in a computer lab.
looks like it should work though. you can add more such as divide and multiply. im not sure how useful those would be though.
<CODE>
color substract ( color _c1, color _c2 ) {
color[] c0 = { _c1, _c2 }; //original color objects
float[][] c1 = new float[3][3]; //original color objects split into seperate rgb values for each color,
//first dimension third index is for resulting color
color c2;
for( int i = 0; i < 2; i++ ) {
c1[i][0] = red(c0[i]);
c1[i][1] = green(c0[i]);
c1[i][2] = blue(c0[i]);
}
c1[2][0] = c1[0][0] - c1[1][0];
c1[2][1] = c1[0][1] - c1[1][1];
c1[2][2] = c1[0][2] - c1[1][2];
return color( c1[2][0], c1[2][1], c1[2][2] );
}
color add ( color _c1, color _c2 ) {
color[] c0 = { _c1, _c2 }; //original color objects
float[][] c1 = new float[3][3]; //original color objects split into seperate rgb values for each color,
//first dimension third index is for resulting color
color c2;
for( int i = 0; i < 2; i++ ) {
c1[i][0] = red(c0[i]);
c1[i][1] = green(c0[i]);
c1[i][2] = blue(c0[i]);
}
c1[2][0] = c1[0][0] + c1[1][0];
c1[2][1] = c1[0][1] + c1[1][1];
c1[2][2] = c1[0][2] + c1[1][2];
return color( c1[2][0], c1[2][1], c1[2][2] );
}
</CODE>
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kevinP
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Re: "Color math"?
« Reply #3 on: Feb 14th, 2004, 5:04pm » |
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Looks good. Don't know why it didn't occur ot me that I could just write these myself (or use your first solution).
Txs!
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Kevin Pfeiffer
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