enable using setting colors by colornn with 0<=nn<=22

The name list of colors is given by
https://www.codeproject.com/Articles/1276/Naming-Common-Colors

examples/utf-8/стекло/ext-utf8-c.cir

@@ -26,16 +26,21 @@ set color0=black
 plot y vs x xlabel '我能吞下玻璃而不伤身体' ylabel 'Я могу есть стекло, оно мне не вредит' title ' أنا قادر على أكل الزجاج و هذا لا يؤلمني.'
 * With Linux the next one requires: export LC_CTYPE ="de_DE.UTF-8"
 *gnuplot test.gn y vs x xlabel 'Labellisé X' ylabel 'tüTÄtö Äü @µ€~' title 'ฉันกินกระจกได้ แต่มันไม่ทำให้ฉันเจ็บ '
-set color0=yellow
-set color1=black
-set color2=blue
+set color0=Blue
+set color1=Yellow
+set color2=Lime
 set gridwidth=1
 set xbrushwidth=4
 plot y vs x+0.001 xlabel 'Labellisé X' ylabel 'Labellisé Y' title 'Titré 私はガラスを食べられます。それは私を傷つけません' loglog
-*plot y vs x+0.001 xlabel 'Labellisé X' title 'Titré' loglog
+unset color1
+set color0=MediumBlue
+set color2=Magenta
+plot y vs x+0.001 xlabel 'Labellisé X' title 'Titré' loglog
+set color0=GreenYellow
+set color2=Magenta
+plot y vs x+0.001 xlabel 'Labellisé X' title 'Titré' loglog
 set color0=black
 set color2=pink
-unset color1
 plot y vs x xlabel '래도 아프지 않아요' ylabel '私はガラスを食べられます' title ' أنا قادر على أكل الزجاج و هذا لا يؤلمني.'
 
 * With Linux the next one requires: export LC_CTYPE ="de_DE.UTF-8"

src/frontend/wdisp/wincolor.c

@@ -0,0 +1,146 @@
+/* Copyright: Holger Vogt, 2020 */
+/* Three Clause BSD */
+/* Universal color table and retrival */
+
+
+#include "ngspice/ngspice.h"
+#include "ngspice/cpextern.h"
+#include "ngspice/hash.h"
+#include "ngspice/macros.h"
+#undef BOOLEAN
+#include <windows.h>
+#include "ngspice/wincolornames.h"
+
+
+
+static NGHASHPTR color_p; /* color hash table */
+static COLORREF get_wincolor(char* name, int nocolor);
+
+void wincolor_init_hash(COLORREF *ColorTable, int noc)
+{
+    int i;
+    char buf[BSIZE_SP], colorstring[BSIZE_SP];
+    int nocolor = NUMELEMS(ctable);
+    color_p = nghash_init(nocolor);
+    nghash_unique(color_p, FALSE);
+    for (i = 0; i < nocolor; i++) {
+        strtolower(ctable[i].name);
+        ctable[i].rgbc = RGB(ctable[i].R, ctable[i].G, ctable[i].B);
+        nghash_insert(color_p, ctable[i].name, &(ctable[i].rgbc));
+    }
+
+    for (i = 0; i < noc; i++) {
+        (void) sprintf(buf, "color%d", i);
+        if (!cp_getvar(buf, CP_STRING, colorstring, sizeof(colorstring)))
+            (void) strcpy(colorstring, stdcolornames[i]);
+        COLORREF* val = (COLORREF*)nghash_find(color_p, colorstring);
+        if(val)
+            ColorTable[i] = *val;
+        else
+            ColorTable[i] = 0; 
+    }
+}
+
+
+/* ColorTable[0]: background, ColorTable[1]: grid, text */
+void wincolor_init(COLORREF* ColorTable, int noc)
+{
+    int i;
+    static bool bgisblack = TRUE;
+    char buf[BSIZE_SP], colorstring[BSIZE_SP];
+    int nocolor = NUMELEMS(ctable);
+
+    for (i = 0; i < nocolor; i++) {
+        strtolower(ctable[i].name);
+        ctable[i].rgbc = RGB(ctable[i].R, ctable[i].G, ctable[i].B);
+    }
+    i = 0;
+    while(i < noc) {
+        /* when color0 is set to white and color1 is not given, set ColorTable[2] to black */
+        (void)sprintf(buf, "color%d", i);
+        if (!cp_getvar(buf, CP_STRING, colorstring, sizeof(colorstring))) {
+            if (i == 1) {
+                /* switch the grid and text color depending on background */
+                int tcolor = GetRValue(ColorTable[0]) + GetGValue(ColorTable[0]) + GetBValue(ColorTable[0]);
+                if (tcolor > 250) {
+                    ColorTable[1] = RGB(0, 0, 0);
+                    i++;
+                    bgisblack = FALSE;
+                    continue;
+                }
+                else {
+                    ColorTable[1] = RGB(255, 255, 255);
+                    i++;
+                    bgisblack = TRUE;
+                    continue;
+                }
+            }
+            /* old code: beginning with 12 the colors are repeated */
+            else if (!bgisblack && (i == 12))
+                (void)strcpy(colorstring, "black");
+            else
+                (void)strcpy(colorstring, stdcolornames[i]);
+        }
+        ColorTable[i] =  get_wincolor(colorstring, nocolor);
+        i++;
+    }
+}
+
+void wincolor_redo(COLORREF* ColorTable, int noc)
+{
+    int i = 0;
+    static bool bgisblack = TRUE;
+    char buf[BSIZE_SP], colorstring[BSIZE_SP];
+    int nocolor = NUMELEMS(ctable);
+
+    while (i < noc) {
+        /* when color0 is set to white and color1 is not given, set ColorTable[2] to black */
+        (void)sprintf(buf, "color%d", i);
+        if (!cp_getvar(buf, CP_STRING, colorstring, sizeof(colorstring))) {
+            if (i == 1) {
+                /* switch the grid and text color depending on background */
+                int tcolor = GetRValue(ColorTable[0]) + GetGValue(ColorTable[0]) + GetBValue(ColorTable[0]);
+                if (tcolor > 250) {
+                    ColorTable[1] = RGB(0, 0, 0);
+                    i++;
+                    bgisblack = FALSE;
+                    continue;
+                }
+                else {
+                    ColorTable[1] = RGB(255, 255, 255);
+                    i++;
+                    bgisblack = TRUE;
+                    continue;
+                }
+            }
+            /* old code: beginning with 12 the colors are repeated */
+            else if (!bgisblack && (i == 12))
+                (void)strcpy(colorstring, "black");
+            else
+                (void)strcpy(colorstring, stdcolornames[i]);
+        }
+        ColorTable[i] = get_wincolor(colorstring, nocolor);
+        i++;
+    }
+}
+
+COLORREF *get_wincolor_hash(char *name)
+{
+    return nghash_find(color_p, name);
+}
+
+static COLORREF get_wincolor(char *name, int nocolor)
+{
+    
+    int i;
+    for (i = 0; i < nocolor; i++) {
+        if (ciprefix(name, ctable[i].name)) {
+            return ctable[i].rgbc;
+        }
+    }
+    fprintf(stderr, "Warning: Color %s is not available\n", name);
+    fprintf(stderr, "    Color 'green' is returned instead!\n");
+    return RGB(0, 255, 0);
+}
+
+