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-rw-r--r--src/color.cpp468
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diff --git a/src/color.cpp b/src/color.cpp
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+++ b/src/color.cpp
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+#define __SP_COLOR_C__
+
+/** \file
+ * Colors and colorspaces.
+ *
+ * Author:
+ * Lauris Kaplinski <lauris@kaplinski.com>
+ * bulia byak <buliabyak@users.sf.net>
+ *
+ * Copyright (C) 2001-2002 Lauris Kaplinski
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include <math.h>
+#include "color.h"
+
+/// A color space is just a name.
+struct SPColorSpace {
+ gchar const *name;
+};
+
+static SPColorSpace const RGB = {"RGB"};
+static SPColorSpace const CMYK = {"CMYK"};
+
+/**
+ * Returns one of three values depending on if color is valid and if it
+ * has a valid color space. Likely redundant as soon as this is C++.
+ */
+SPColorSpaceClass
+sp_color_get_colorspace_class(SPColor const *color)
+{
+ g_return_val_if_fail (color != NULL, SP_COLORSPACE_CLASS_INVALID);
+
+ if (color->colorspace == &RGB) return SP_COLORSPACE_CLASS_PROCESS;
+ if (color->colorspace == &CMYK) return SP_COLORSPACE_CLASS_PROCESS;
+
+ return SP_COLORSPACE_CLASS_UNKNOWN;
+}
+
+/**
+ * Returns the SPColorSpaceType corresponding to color's color space.
+ * \todo color->colorspace should simply be a named enum.
+ */
+SPColorSpaceType
+sp_color_get_colorspace_type(SPColor const *color)
+{
+ g_return_val_if_fail (color != NULL, SP_COLORSPACE_TYPE_INVALID);
+
+ if (color->colorspace == &RGB) return SP_COLORSPACE_TYPE_RGB;
+ if (color->colorspace == &CMYK) return SP_COLORSPACE_TYPE_CMYK;
+
+ return SP_COLORSPACE_TYPE_UNKNOWN;
+}
+
+/**
+ * Shallow copy of color struct with NULL check.
+ */
+void
+sp_color_copy(SPColor *dst, SPColor const *src)
+{
+ g_return_if_fail (dst != NULL);
+ g_return_if_fail (src != NULL);
+
+ *dst = *src;
+}
+
+/**
+ * Returns TRUE if c0 or c1 is NULL, or if colors/opacities differ.
+ */
+gboolean
+sp_color_is_equal (SPColor const *c0, SPColor const *c1)
+{
+ g_return_val_if_fail (c0 != NULL, TRUE);
+ g_return_val_if_fail (c1 != NULL, TRUE);
+
+ if (c0->colorspace != c1->colorspace) return FALSE;
+ if (c0->v.c[0] != c1->v.c[0]) return FALSE;
+ if (c0->v.c[1] != c1->v.c[1]) return FALSE;
+ if (c0->v.c[2] != c1->v.c[2]) return FALSE;
+ if ((c0->colorspace == &CMYK) && (c0->v.c[3] != c1->v.c[3])) return FALSE;
+
+ return TRUE;
+}
+
+/**
+ * Returns TRUE if no RGB value differs epsilon or more in both colors,
+ * with CMYK aditionally comparing opacity, or if c0 or c1 is NULL.
+ * \note Do we want the latter?
+ */
+gboolean
+sp_color_is_close (SPColor const *c0, SPColor const *c1, float epsilon)
+{
+ g_return_val_if_fail (c0 != NULL, TRUE);
+ g_return_val_if_fail (c1 != NULL, TRUE);
+
+ if (c0->colorspace != c1->colorspace) return FALSE;
+ if (fabs ((c0->v.c[0]) - (c1->v.c[0])) >= epsilon) return FALSE;
+ if (fabs ((c0->v.c[1]) - (c1->v.c[1])) >= epsilon) return FALSE;
+ if (fabs ((c0->v.c[2]) - (c1->v.c[2])) >= epsilon) return FALSE;
+ if ((c0->colorspace == &CMYK) && (fabs ((c0->v.c[3]) - (c1->v.c[3])) >= epsilon)) return FALSE;
+
+ return TRUE;
+}
+
+/**
+ * Sets RGB values and colorspace in color.
+ * \pre color != NULL && 0 <={r,g,b}<=1
+ */
+void
+sp_color_set_rgb_float(SPColor *color, float r, float g, float b)
+{
+ g_return_if_fail(color != NULL);
+ g_return_if_fail(r >= 0.0);
+ g_return_if_fail(r <= 1.0);
+ g_return_if_fail(g >= 0.0);
+ g_return_if_fail(g <= 1.0);
+ g_return_if_fail(b >= 0.0);
+ g_return_if_fail(b <= 1.0);
+
+ color->colorspace = &RGB;
+ color->v.c[0] = r;
+ color->v.c[1] = g;
+ color->v.c[2] = b;
+ color->v.c[3] = 0;
+}
+
+/**
+ * Converts 32bit value to RGB floats and sets color.
+ * \pre color != NULL
+ */
+void
+sp_color_set_rgb_rgba32(SPColor *color, guint32 value)
+{
+ g_return_if_fail (color != NULL);
+
+ color->colorspace = &RGB;
+ color->v.c[0] = (value >> 24) / 255.0F;
+ color->v.c[1] = ((value >> 16) & 0xff) / 255.0F;
+ color->v.c[2] = ((value >> 8) & 0xff) / 255.0F;
+ color->v.c[3] = 0;
+}
+
+/**
+ * Sets CMYK values and colorspace in color.
+ * \pre color != NULL && 0 <={c,m,y,k}<=1
+ */
+void
+sp_color_set_cmyk_float(SPColor *color, float c, float m, float y, float k)
+{
+ g_return_if_fail(color != NULL);
+ g_return_if_fail(c >= 0.0);
+ g_return_if_fail(c <= 1.0);
+ g_return_if_fail(m >= 0.0);
+ g_return_if_fail(m <= 1.0);
+ g_return_if_fail(y >= 0.0);
+ g_return_if_fail(y <= 1.0);
+ g_return_if_fail(k >= 0.0);
+ g_return_if_fail(k <= 1.0);
+
+ color->colorspace = &CMYK;
+ color->v.c[0] = c;
+ color->v.c[1] = m;
+ color->v.c[2] = y;
+ color->v.c[3] = k;
+}
+
+/**
+ * Convert SPColor with integer alpha value to 32bit RGBA value.
+ * \pre color != NULL && alpha < 256
+ */
+guint32
+sp_color_get_rgba32_ualpha(SPColor const *color, guint32 alpha)
+{
+ guint32 rgba;
+
+ g_return_val_if_fail (color != NULL, 0x0);
+ g_return_val_if_fail (alpha <= 0xff, 0x0);
+
+ if (color->colorspace == &RGB) {
+ rgba = SP_RGBA32_U_COMPOSE(SP_COLOR_F_TO_U(color->v.c[0]),
+ SP_COLOR_F_TO_U(color->v.c[1]),
+ SP_COLOR_F_TO_U(color->v.c[2]),
+ alpha);
+ } else {
+ float rgb[3];
+ sp_color_get_rgb_floatv (color, rgb);
+ rgba = SP_RGBA32_U_COMPOSE(SP_COLOR_F_TO_U(rgb[0]),
+ SP_COLOR_F_TO_U(rgb[1]),
+ SP_COLOR_F_TO_U(rgb[2]),
+ alpha);
+ }
+
+ return rgba;
+}
+
+/**
+ * Convert SPColor with float alpha value to 32bit RGBA value.
+ * \pre color != NULL && 0 <= alpha <= 1
+ */
+guint32
+sp_color_get_rgba32_falpha(SPColor const *color, float alpha)
+{
+ g_return_val_if_fail(color != NULL, 0x0);
+ g_return_val_if_fail(alpha >= 0.0, 0x0);
+ g_return_val_if_fail(alpha <= 1.0, 0x0);
+
+ return sp_color_get_rgba32_ualpha(color, SP_COLOR_F_TO_U(alpha));
+}
+
+/**
+ * Fill rgb float array with values from SPColor.
+ * \pre color != NULL && rgb != NULL && rgb[0-2] is meaningful
+ */
+void
+sp_color_get_rgb_floatv(SPColor const *color, float *rgb)
+{
+ g_return_if_fail (color != NULL);
+ g_return_if_fail (rgb != NULL);
+
+ if (color->colorspace == &RGB) {
+ rgb[0] = color->v.c[0];
+ rgb[1] = color->v.c[1];
+ rgb[2] = color->v.c[2];
+ } else if (color->colorspace == &CMYK) {
+ sp_color_cmyk_to_rgb_floatv(rgb,
+ color->v.c[0],
+ color->v.c[1],
+ color->v.c[2],
+ color->v.c[3]);
+ }
+}
+
+/**
+ * Fill cmyk float array with values from SPColor.
+ * \pre color != NULL && cmyk != NULL && cmyk[0-3] is meaningful
+ */
+void
+sp_color_get_cmyk_floatv(SPColor const *color, float *cmyk)
+{
+ g_return_if_fail (color != NULL);
+ g_return_if_fail (cmyk != NULL);
+
+ if (color->colorspace == &CMYK) {
+ cmyk[0] = color->v.c[0];
+ cmyk[1] = color->v.c[1];
+ cmyk[2] = color->v.c[2];
+ cmyk[3] = color->v.c[3];
+ } else if (color->colorspace == &RGB) {
+ sp_color_rgb_to_cmyk_floatv(cmyk,
+ color->v.c[0],
+ color->v.c[1],
+ color->v.c[2]);
+ }
+}
+
+/* Plain mode helpers */
+
+/**
+ * Fill hsv float array from r,g,b float values.
+ */
+void
+sp_color_rgb_to_hsv_floatv (float *hsv, float r, float g, float b)
+{
+ float max, min, delta;
+
+ max = MAX (MAX (r, g), b);
+ min = MIN (MIN (r, g), b);
+ delta = max - min;
+
+ hsv[2] = max;
+
+ if (max > 0) {
+ hsv[1] = delta / max;
+ } else {
+ hsv[1] = 0.0;
+ }
+
+ if (hsv[1] != 0.0) {
+ if (r == max) {
+ hsv[0] = (g - b) / delta;
+ } else if (g == max) {
+ hsv[0] = 2.0 + (b - r) / delta;
+ } else {
+ hsv[0] = 4.0 + (r - g) / delta;
+ }
+
+ hsv[0] = hsv[0] / 6.0;
+
+ if (hsv[0] < 0) hsv[0] += 1.0;
+ }
+}
+
+/**
+ * Fill rgb float array from h,s,v float values.
+ */
+void
+sp_color_hsv_to_rgb_floatv (float *rgb, float h, float s, float v)
+{
+ gdouble f, w, q, t, d;
+
+ d = h * 5.99999999;
+ f = d - floor (d);
+ w = v * (1.0 - s);
+ q = v * (1.0 - (s * f));
+ t = v * (1.0 - (s * (1.0 - f)));
+
+ if (d < 1.0) {
+ *rgb++ = v;
+ *rgb++ = t;
+ *rgb++ = w;
+ } else if (d < 2.0) {
+ *rgb++ = q;
+ *rgb++ = v;
+ *rgb++ = w;
+ } else if (d < 3.0) {
+ *rgb++ = w;
+ *rgb++ = v;
+ *rgb++ = t;
+ } else if (d < 4.0) {
+ *rgb++ = w;
+ *rgb++ = q;
+ *rgb++ = v;
+ } else if (d < 5.0) {
+ *rgb++ = t;
+ *rgb++ = w;
+ *rgb++ = v;
+ } else {
+ *rgb++ = v;
+ *rgb++ = w;
+ *rgb++ = q;
+ }
+}
+
+/**
+ * Fill hsl float array from r,g,b float values.
+ */
+void
+sp_color_rgb_to_hsl_floatv (float *hsl, float r, float g, float b)
+{
+ float max = MAX (MAX (r, g), b);
+ float min = MIN (MIN (r, g), b);
+ float delta = max - min;
+
+ hsl[2] = (max + min)/2.0;
+
+ if (delta == 0) {
+ hsl[0] = 0;
+ hsl[1] = 0;
+ } else {
+ if (hsl[2] <= 0.5)
+ hsl[1] = delta / (max + min);
+ else
+ hsl[1] = delta / (2 - max - min);
+
+ if (r == max) hsl[0] = (g - b) / delta;
+ else if (g == max) hsl[0] = 2.0 + (b - r) / delta;
+ else if (b == max) hsl[0] = 4.0 + (r - g) / delta;
+
+ hsl[0] = hsl[0] / 6.0;
+
+ if (hsl[0] < 0) hsl[0] += 1;
+ if (hsl[0] > 1) hsl[0] -= 1;
+ }
+}
+
+float
+hue_2_rgb (float v1, float v2, float h)
+{
+ if (h < 0) h += 6.0;
+ if (h > 6) h -= 6.0;
+
+ if (h < 1) return v1 + (v2 - v1) * h;
+ if (h < 3) return v2;
+ if (h < 4) return v1 + (v2 - v1) * (4 - h);
+ return v1;
+}
+
+/**
+ * Fill rgb float array from h,s,l float values.
+ */
+void
+sp_color_hsl_to_rgb_floatv (float *rgb, float h, float s, float l)
+{
+ if (s == 0) {
+ rgb[0] = l;
+ rgb[1] = l;
+ rgb[2] = l;
+ } else {
+ float v2;
+ if (l < 0.5) {
+ v2 = l * (1 + s);
+ } else {
+ v2 = l + s - l*s;
+ }
+ float v1 = 2*l - v2;
+
+ rgb[0] = hue_2_rgb (v1, v2, h*6 + 2.0);
+ rgb[1] = hue_2_rgb (v1, v2, h*6);
+ rgb[2] = hue_2_rgb (v1, v2, h*6 - 2.0);
+ }
+}
+
+/**
+ * Fill cmyk float array from r,g,b float values.
+ */
+void
+sp_color_rgb_to_cmyk_floatv (float *cmyk, float r, float g, float b)
+{
+ float c, m, y, k, kd;
+
+ c = 1.0 - r;
+ m = 1.0 - g;
+ y = 1.0 - b;
+ k = MIN (MIN (c, m), y);
+
+ c = c - k;
+ m = m - k;
+ y = y - k;
+
+ kd = 1.0 - k;
+
+ if (kd > 1e-9) {
+ c = c / kd;
+ m = m / kd;
+ y = y / kd;
+ }
+
+ cmyk[0] = c;
+ cmyk[1] = m;
+ cmyk[2] = y;
+ cmyk[3] = k;
+}
+
+/**
+ * Fill rgb float array from c,m,y,k float values.
+ */
+void
+sp_color_cmyk_to_rgb_floatv (float *rgb, float c, float m, float y, float k)
+{
+ float kd;
+
+ kd = 1.0 - k;
+
+ c = c * kd;
+ m = m * kd;
+ y = y * kd;
+
+ c = c + k;
+ m = m + k;
+ y = y + k;
+
+ rgb[0] = 1.0 - c;
+ rgb[1] = 1.0 - m;
+ rgb[2] = 1.0 - y;
+}
+
+/*
+ Local Variables:
+ mode:c++
+ c-file-style:"stroustrup"
+ c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+ indent-tabs-mode:nil
+ fill-column:99
+ End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
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