Initial revision

2026-01-04 21:04:18 +01:00 · 1998-09-29 22:36:29 +00:00
commit 9d2e6ef9f1
527 changed files with 138651 additions and 0 deletions
--- a/wrlib/color.c
+++ b/wrlib/color.c
@@ -0,0 +1,134 @@
+/* color.c - color stuff (rgb -> hsv convertion etc.)
+ * 
+ *  Raster graphics library
+ * 
+ *  Copyright (c) 1998 Alfredo K. Kojima
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *  
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <X11/Xlib.h>
+
+#include <assert.h>
+
+#include "wraster.h"
+
+
+
+#define MIN(a,b)	((a)<(b) ? (a) : (b))
+#define MAX(a,b)	((a)>(b) ? (a) : (b))
+
+#define MIN3(a,b,c)	MIN(MIN(a,b), c)
+#define MAX3(a,b,c)	MAX(MAX(a,b), c)
+
+
+void
+RHSVtoRGB(RHSVColor *hsv, RColor *rgb)
+{
+    int h = hsv->hue % 360;
+    int s = hsv->saturation;
+    int v = hsv->value;
+    int i, f;
+    int p, q, t;
+
+    if (s == 0) {
+	rgb->red = rgb->green = rgb->blue = v;
+	return;
+    }
+    i = h / 60;
+    f = h % 60;
+    p = v * (255 - s) / 255;
+    q = v * (255 - s * f / 60) / 255;
+    t = v * (255 - s * (60 - f) / 60) / 255;
+
+    switch (i) {
+      case 0:
+	rgb->red = v;
+	rgb->green = t;
+	rgb->blue = p;
+	break;
+      case 1:
+	rgb->red = q;
+	rgb->green = v;
+	rgb->blue = p;
+	break;
+      case 2:
+	rgb->red = p;
+	rgb->green = v;
+	rgb->blue = t;
+	break;
+      case 3:
+	rgb->red = p;
+	rgb->green = q;
+	rgb->blue = v;
+	break;
+      case 4:
+	rgb->red = t;
+	rgb->green = p;
+	rgb->blue = v;
+	break;
+      case 5:
+	rgb->red = v;
+	rgb->green = p;
+	rgb->blue = q;
+	break;
+    }
+}
+
+
+void
+RRGBtoHSV(RColor *rgb, RHSVColor *hsv)
+{
+    int h, s, v;
+    int max = MAX3(rgb->red, rgb->green, rgb->blue);
+    int min = MIN3(rgb->red, rgb->green, rgb->blue);
+
+    v = max;
+
+    if (max == 0)
+	s = 0;
+    else
+	s = (max - min) * 255 / max;
+
+    if (s == 0)
+	h = 0;
+    else {
+	int rc, gc, bc;
+
+	rc = (max - rgb->red) * 255 / (max - min);
+	gc = (max - rgb->green) * 255 / (max - min);
+	bc = (max - rgb->blue) * 255 / (max - min);
+
+	if (rgb->red == max) {
+	    h = ((bc - gc) * 60 / 255);
+	} else if (rgb->green == max) {
+	    h = 2*60 + ((rc - bc) * 60 / 255);
+	} else {
+	    h = 4*60 + ((gc - rc) * 60 / 255);
+	}
+	if (h < 0)
+	    h += 360;
+    }
+
+    hsv->hue = h;
+    hsv->saturation = s;
+    hsv->value = v;
+}