[2] | 1 | ;+ |
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| 2 | ; |
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[133] | 3 | ; @file_comments |
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| 4 | ; The purpose of this function is to convert a RGB color triple |
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| 5 | ; into the equivalent 24-big long integer. |
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[2] | 6 | ; |
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[137] | 7 | ; @categories Graphics, Color |
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[2] | 8 | ; |
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[136] | 9 | ; @param rgb_triple {in}{required} |
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| 10 | ; A three-element column or row array representing |
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| 11 | ; a color triple. The values of the elements must be between 0 and 255. |
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[2] | 12 | ; |
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[136] | 13 | ; @returns |
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| 14 | ; a 24-bit long integer that is equivalent the input color. |
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| 15 | ; The color is described in terms of a hexadecimal number (e.g., FF206A) |
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[133] | 16 | ; where the left two digits represent the blue color, the |
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| 17 | ; middle two digits represent the green color, and the right |
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| 18 | ; two digits represent the red color. |
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[2] | 19 | ; |
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[136] | 20 | ; @examples |
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| 21 | ; To convert the color triple for the color YELLOW, |
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| 22 | ; (255, 255, 0), to the hexadecimal value '00FFFF'x |
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| 23 | ; or the decimal number 65535, type: |
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[2] | 24 | ; |
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[136] | 25 | ; IDL> color = COLOR24([255, 255, 0]) |
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[2] | 26 | ; |
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[136] | 27 | ; This routine was written to be used with routines like COLORS or GETCOLOR |
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[2] | 28 | ; |
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[133] | 29 | ; @history |
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[2] | 30 | ; Written by: David Fanning, 3 February 96. |
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[133] | 31 | ; |
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| 32 | ; @version $Id$ |
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| 33 | ; |
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[2] | 34 | ;- |
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[136] | 35 | FUNCTION COLOR24, rgb_triple |
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[114] | 36 | ; |
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| 37 | compile_opt idl2, strictarrsubs |
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[133] | 38 | ; |
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[2] | 39 | ON_ERROR, 1 |
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| 40 | |
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[136] | 41 | IF N_ELEMENTS(rgb_triple) NE 3 THEN $ |
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| 42 | MESSAGE, 'Argument must be a three-element vector.' |
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[2] | 43 | |
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[136] | 44 | IF MAX(rgb_triple) GT 255 OR MIN(rgb_triple) LT 0 THEN $ |
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[2] | 45 | MESSAGE, 'Argument values must be in range of 0-255' |
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| 46 | |
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| 47 | base16 = [[1L, 16L], [256L, 4096L], [65536L, 1048576L]] |
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| 48 | |
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| 49 | num24bit = 0L |
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| 50 | |
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[136] | 51 | FOR j=0,2 DO num24bit = num24bit + ((rgb_triple[j] MOD 16) * base16[0,j]) + $ |
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| 52 | (Fix(rgb_triple[j]/16) * base16[1,j]) |
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[2] | 53 | |
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| 54 | RETURN, num24bit |
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| 55 | END |
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