From 98f1ff740af109f99cd35ae44108f3fc5842a4d5 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Wed, 11 Nov 2009 14:26:34 -0500 Subject: Make dmnsn_illuminate_color() work, with sRGB for now. --- libdimension/color.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) (limited to 'libdimension') diff --git a/libdimension/color.c b/libdimension/color.c index 2089326..79def12 100644 --- a/libdimension/color.c +++ b/libdimension/color.c @@ -298,28 +298,15 @@ dmnsn_color_mul(double n, dmnsn_color color) dmnsn_color dmnsn_color_illuminate(dmnsn_color light, dmnsn_color color) { - dmnsn_CIE_Lab Lab1 = dmnsn_Lab_from_color(light, dmnsn_whitepoint); - dmnsn_CIE_Lab Lab2 = dmnsn_Lab_from_color(color, dmnsn_whitepoint); + /* TODO: make this work in a perceptually uniform colorspace */ + dmnsn_sRGB sRGB1 = dmnsn_sRGB_from_color(light); + dmnsn_sRGB sRGB2 = dmnsn_sRGB_from_color(color); - /* - * This is derived from the simple illumination equation for RGB color: - * RGB' = (R_light*R_color, G_light*G_color, B_light*B_color) - * - * CIE L*a*b* may be transformed to an RGB colorspace by considering `a' - * to be the green -> magenta opponent process (from negative to positive), - * and `b' to be the blue -> yellow opponent process: - * RGB = (L + a + b, L - a + b, L + a - b) - * - * The reverse transformation is: - * Lab = ((G + B)/2, (R - G)/2, (R - B)/2) - */ - dmnsn_CIE_Lab Lab = { - .L = (Lab1.L*Lab2.L + (Lab1.b - Lab1.a)*(Lab2.b - Lab2.a))/100.0, - .a = (Lab1.a*(Lab2.L + Lab2.b) + Lab2.a*(Lab1.L + Lab1.b))/100.0, - .b = (Lab1.b*(Lab2.L + Lab2.a) + Lab2.b*(Lab1.L + Lab1.a))/100.0 - }; + dmnsn_sRGB sRGB = { .R = sRGB1.R*sRGB2.R, + .G = sRGB1.G*sRGB2.G, + .B = sRGB1.B*sRGB2.B }; - dmnsn_color ret = dmnsn_color_from_Lab(Lab, dmnsn_whitepoint); + dmnsn_color ret = dmnsn_color_from_sRGB(sRGB); ret.filter = color.filter; ret.trans = color.trans; -- cgit v1.2.3