Adding color to test/mandelbrot (#634)

test/mandelbrot.cxx

@@ -1,7 +1,7 @@
 //
 // Mandelbrot set demo for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2010 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -21,6 +21,43 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+const unsigned int palette[] = {
+  0xCC0000, 0xCA0002, 0xC90004, 0xC70006, 0xC60008, 0xC4000A, 0xC3000C, 0xC1000E, 0xBF0010, 0xBE0012,
+  0xBC0014, 0xBB0016, 0xB90018, 0xB8001A, 0xB6001B, 0xB4001D, 0xB3001F, 0xB10021, 0xB00023, 0xAE0025,
+  0xAD0027, 0xAB0029, 0xA9002B, 0xA8002D, 0xA6002F, 0xA50031, 0xA30033, 0xA20035, 0xA00037, 0x9E0039,
+  0x9D003B, 0x9B003D, 0x9A003F, 0x980041, 0x970043, 0x950045, 0x940047, 0x920049, 0x90004B, 0x8F004D,
+  0x8D004E, 0x8C0050, 0x8A0052, 0x890054, 0x870056, 0x850058, 0x84005A, 0x82005C, 0x81005E, 0x7F0060,
+  0x7E0062, 0x7C0064, 0x7A0066, 0x790068, 0x77006A, 0x76006C, 0x74006E, 0x730070, 0x710072, 0x6F0074,
+  0x6E0076, 0x6C0078, 0x6B007A, 0x69007C, 0x68007E, 0x660080, 0x640081, 0x630083, 0x610085, 0x600087,
+  0x5E0089, 0x5D008B, 0x5B008D, 0x59008F, 0x580091, 0x560093, 0x550095, 0x530097, 0x520099, 0x50009B,
+  0x4E009D, 0x4D009F, 0x4B00A1, 0x4A00A3, 0x4800A5, 0x4700A7, 0x4500A9, 0x4300AB, 0x4200AD, 0x4000AF,
+  0x3F00B1, 0x3D00B3, 0x3C00B4, 0x3A00B6, 0x3800B8, 0x3700BA, 0x3500BC, 0x3400BE, 0x3200C0, 0x3100C2,
+  0x2F00C4, 0x2E00C6, 0x2C00C8, 0x2A00CA, 0x2900CC, 0x2700CE, 0x2600D0, 0x2400D2, 0x2300D4, 0x2100D6,
+  0x1F00D8, 0x1E00DA, 0x1C00DC, 0x1B00DE, 0x1900E0, 0x1800E2, 0x1600E4, 0x1400E6, 0x1300E7, 0x1100E9,
+  0x1000EB, 0x0E00ED, 0x0D00EF, 0x0B00F1, 0x0900F3, 0x0800F5, 0x0600F7, 0x0500F9, 0x0300FB, 0x0200FD,
+  0x0000FF, 0x0202FD, 0x0404FB, 0x0606F9, 0x0808F7, 0x0A0AF5, 0x0C0CF3, 0x0E0EF1, 0x1010EF, 0x1212ED,
+  0x1414EB, 0x1616E9, 0x1818E7, 0x1A1AE6, 0x1B1BE4, 0x1D1DE2, 0x1F1FE0, 0x2121DE, 0x2323DC, 0x2525DA,
+  0x2727D8, 0x2929D6, 0x2B2BD4, 0x2D2DD2, 0x2F2FD0, 0x3131CE, 0x3333CC, 0x3535CA, 0x3737C8, 0x3939C6,
+  0x3B3BC4, 0x3D3DC2, 0x3F3FC0, 0x4141BE, 0x4343BC, 0x4545BA, 0x4747B8, 0x4949B6, 0x4B4BB4, 0x4D4DB3,
+  0x4E4EB1, 0x5050AF, 0x5252AD, 0x5454AB, 0x5656A9, 0x5858A7, 0x5A5AA5, 0x5C5CA3, 0x5E5EA1, 0x60609F,
+  0x62629D, 0x64649B, 0x666699, 0x686897, 0x6A6A95, 0x6C6C93, 0x6E6E91, 0x70708F, 0x72728D, 0x74748B,
+  0x767689, 0x787887, 0x7A7A85, 0x7C7C83, 0x7E7E81, 0x808080, 0x81817E, 0x83837C, 0x85857A, 0x878778,
+  0x898976, 0x8B8B74, 0x8D8D72, 0x8F8F70, 0x91916E, 0x93936C, 0x95956A, 0x979768, 0x999966, 0x9B9B64,
+  0x9D9D62, 0x9F9F60, 0xA1A15E, 0xA3A35C, 0xA5A55A, 0xA7A758, 0xA9A956, 0xABAB54, 0xADAD52, 0xAFAF50,
+  0xB1B14E, 0xB3B34D, 0xB4B44B, 0xB6B649, 0xB8B847, 0xBABA45, 0xBCBC43, 0xBEBE41, 0xC0C03F, 0xC2C23D,
+  0xC4C43B, 0xC6C639, 0xC8C837, 0xCACA35, 0xCCCC33, 0xCECE31, 0xD0D02F, 0xD2D22D, 0xD4D42B, 0xD6D629,
+  0xD8D827, 0xDADA25, 0xDCDC23, 0xDEDE21, 0xE0E01F, 0xE2E21D, 0xE4E41B, 0xE6E61A, 0xE7E718, 0xE9E916,
+  0xEBEB14, 0xEFEF10, 0xF3F30C, 0xF7F708, 0xFBFB04, 0xFFFF00
+};
+
+const size_t palette_size = sizeof(palette)/sizeof(palette[0]);
+
+void get_color(float t, uchar& r, uchar& g, uchar& b) {
+  int index = (1-t) * palette_size;
+  Fl_Color c = palette[index % palette_size] << 8;
+  Fl::get_color(c, r, g, b);
+}
+
 Drawing_Window mbrot;
 Drawing_Window jbrot;
 
@@ -34,8 +71,7 @@ void set_idle() {
 
 static void window_callback(Fl_Widget*, void*) {exit(0);}
 
-static void print(Fl_Widget *o, void *data)
+static void print(Fl_Widget *o, void *data) {
-{
   Fl_Printer printer;
   Fl_Window *win = o->window();
   if(!win->visible()) return;
@@ -50,13 +86,21 @@ static void print(Fl_Widget *o, void *data)
   printer.end_job();
 }
 
+static void toggle_color(Fl_Widget *o, void *data) {
+  mbrot.d->use_colors = !mbrot.d->use_colors; mbrot.d->new_buffer();
+  if(jbrot.d) { jbrot.d->use_colors = mbrot.d->use_colors; jbrot.d->new_buffer(); }
+}
+
 int main(int argc, char **argv) {
   mbrot.make_window();
-    mbrot.window->begin();
+  mbrot.window->begin();
-    Fl_Button* o = new Fl_Button(0, 0, 0, 0, NULL);
+  Fl_Button* o = new Fl_Button(0, 0, 0, 0, NULL);
-    o->callback(print,NULL);
+  o->callback(print,NULL);
-    o->shortcut(FL_CTRL+'p');
+  o->shortcut(FL_CTRL+'p');
-    mbrot.window->end();
+  o = new Fl_Button(0, 0, 0, 0, NULL);
+  o->callback(toggle_color,NULL);
+  o->shortcut(FL_CTRL+'m');
+  mbrot.window->end();
 
   mbrot.d->X = -.75;
   mbrot.d->scale = 2.5;
@@ -78,6 +122,14 @@ void Drawing_Window::update_label() {
 }
 
 void Drawing_Area::draw() {
+  if (!dx) {
+    dx = Fl::box_dx(box());
+    dy = Fl::box_dy(box());
+    dw = Fl::box_dw(box());
+    dh = Fl::box_dh(box());
+    W -= dw;
+    H -= dh;
+  }
   draw_box();
   drawn = 0;
   set_idle();
@@ -87,37 +139,52 @@ int Drawing_Area::idle() {
   if (!window()->visible()) return 0;
   if (drawn < nextline) {
     window()->make_current();
-    int yy = drawn+y()+4;
+    int yy = drawn+y()+dy;
     if (yy >= sy && yy <= sy+sh) erase_box();
-    fl_draw_image_mono(buffer+drawn*W,x()+3,yy,W,1,1,W);
+    if (use_colors)
+      fl_draw_image(buffer+drawn*W*3, x()+dx, yy, W, 1, 3);
+    else
+      fl_draw_image_mono(buffer+drawn*W, x()+dx, yy, W, 1, 1, W);
     drawn++;
     return 1;
   }
+  int linebytes = use_colors ? W*3 : W;
   if (nextline < H) {
-    if (!buffer) buffer = new uchar[W*H];
+    if (!buffer) buffer = new uchar[linebytes*H];
     double yy = Y+(H/2-nextline)*scale/W;
     double yi = yy; if (julia) yy = jY;
-    uchar *p = buffer+nextline*W;
+    uchar *p = buffer+nextline*linebytes;
     for (int xi = 0; xi < W; xi++) {
       double xx = X+(xi-W/2)*scale/W;
       double wx = xx; double wy = yi;
       if (julia) xx = jX;
       for (int i=0; ; i++) {
-        if (i >= iterations) {*p = 0; break;}
+        if (i >= iterations) {
+          *p = 0;
+          if (use_colors) {
+           *(p+1) = 0;
+           *(p+2) = 0;
+          }
+          break;
+        }
         double t = wx*wx - wy*wy + xx;
         wy = 2*wx*wy + yy;
         wx = t;
         if (wx*wx + wy*wy > 4) {
           wx = t = 1-double(i)/(1<<10);
           if (t <= 0) t = 0; else for (i=brightness; i--;) t*=wx;
-          *p = 255-int(254*t);
+          if (use_colors) {
+            get_color(t, *p, *(p+1), *(p+2));
+          } else {
+            *p = 255 - int(254*t);
+          }
           break;
         }
       }
-      p++;
+      p += use_colors ? 3 : 1;
     }
     nextline++;
-    return nextline < H;
+    return nextline <= H;
   }
   return 0;
 }
@@ -182,6 +249,7 @@ int Drawing_Area::handle(int event) {
         jbrot.d->X = 0;
         jbrot.d->Y = 0;
         jbrot.d->scale = 4;
+        jbrot.d->use_colors = mbrot.d->use_colors;
         jbrot.update_label();
       }
       jbrot.d->jX = X + (ix-x()-W/2)*scale/W;
@@ -202,10 +270,14 @@ void Drawing_Area::new_display() {
   set_idle();
 }
 
+void Drawing_Area::new_buffer() {
+  if (buffer) {delete[] buffer; buffer = 0; new_display();}
+}
+
 void Drawing_Area::resize(int XX,int YY,int WW,int HH) {
   if (WW != w() || HH != h()) {
-    W = WW-6;
+    W = WW - dw;
-    H = HH-8;
+    H = HH - dh;
     if (buffer) {delete[] buffer; buffer = 0; new_display();}
   }
   Fl_Box::resize(XX,YY,WW,HH);

test/mandelbrot.h

@@ -1,7 +1,7 @@
 //
 // Mandelbrot set header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2010 by Bill Spitzak and others.
+// Copyright 1998-2023 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -20,11 +20,15 @@
 #include <FL/Fl_Double_Window.H>
 #include <FL/Fl_Input.H>
 
+#define USE_COLORS 0 // change to 1 to start in color mode
+
 class Drawing_Area : public Fl_Box {
   void draw() FL_OVERRIDE;
 public:
   uchar *buffer;
+  int use_colors;
   int W,H;
+  int dx, dy, dw, dh; // drawing box offsets
   int nextline;
   int drawn;
   int julia;
@@ -37,23 +41,28 @@ public:
   int handle(int) FL_OVERRIDE;
   void resize(int,int,int,int) FL_OVERRIDE;
   void new_display();
+  void new_buffer();
   enum {
     MAX_BRIGHTNESS = 16,
     DEFAULT_BRIGHTNESS = 16,
+    DEFAULT_BRIGHTNESS_COLOR = 8,
     MAX_ITERATIONS = 14,
     DEFAULT_ITERATIONS = 7
   };
   Drawing_Area(int x,int y,int w,int h) : Fl_Box(x,y,w,h) {
     buffer = 0;
-    W = w-6;
+    use_colors = USE_COLORS;
-    H = h-8;
+    W = w;
+    H = h;
+    dx = dy = 0; // NOTE: as the box type is set *after* the constructor
+    dw = dh = 0; //       the actual offsets are determined in draw()
     nextline = 0;
     drawn = 0;
     julia = 0;
     X = Y = 0;
     scale = 4.0;
     iterations = 1<<DEFAULT_ITERATIONS;
-    brightness = DEFAULT_BRIGHTNESS;
+    brightness = use_colors ? DEFAULT_BRIGHTNESS_COLOR : DEFAULT_BRIGHTNESS;
   }
   int idle();
 };

test/mandelbrot_ui.fl

@@ -13,8 +13,8 @@ class Drawing_Window {open
   Function {make_window()} {open return_type void
   } {
     Fl_Window window {open
-      xywh {515 343 450 520} type Single hide resizable
+      xywh {255 66 450 520} type Single resizable
-      code0 {o->size_range(220,220);}
+      code0 {o->size_range(220,220);} visible
     } {
       Fl_Box d {
         user_data this user_data_type {void*}
@@ -48,13 +48,13 @@ d->new_display();}
 d->new_display();}
         xywh {80 50 160 15} type Horizontal box THIN_DOWN_BOX labelsize 10 align 4 step 1 slider_size 0.1
         code0 {o->bounds(0,d->MAX_BRIGHTNESS);}
-        code2 {o->value(d->DEFAULT_BRIGHTNESS);}
+        code2 {o->value(d->brightness);}
         code3 {o->slider(FL_UP_BOX);}
       }
       Fl_Box {} {
-        label {left: click = zoom out, drag = zoom in
+        label {left click: zoom out, drag: zoom in
-right click: Julia set, ctrl-P: Print} selected
+right click: Julia set, ctrl-M: mode, ctrl-P: Print} selected
-        xywh {240 50 190 30} labelsize 8 align 24 deactivate
+        xywh {240 50 190 30} labelsize 8 align 24
       }
       Fl_Slider {} {
         label {iterations:}