From 021102c67a600af605e689f75fb382eacf340d2b Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Sat, 25 May 2019 22:49:59 -0500
Subject: [PATCH] Oh man, The Cheat. This is gonna be bro-awesome.

---
 examples/Makefile  |   2 +-
 examples/cluster.c | 148 ++++++++++++++++++++++++++-------------------
 2 files changed, 86 insertions(+), 64 deletions(-)

diff --git a/examples/Makefile b/examples/Makefile
index 4fc4daa..3f10185 100644
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -18,7 +18,7 @@ $(EXAMPLES): %: %.c $(STATIC)
 	$(CC) $(CFLAGS) $< -o $@ $(STATIC)
 
 cluster: cluster.c $(STATIC)
-	$(CC) $(CFLAGS) $< -o $@ $(STATIC) $(shell pkg-config --cflags --libs cairo x11)
+	$(CC) $(CFLAGS) $< -o $@ $(STATIC) $(shell pkg-config --cflags --libs cairo x11) -lm
 
 view: view.c $(STATIC)
 	$(CC) $(CFLAGS) $< -o $@ $(STATIC) -lncurses
diff --git a/examples/cluster.c b/examples/cluster.c
index 06eace0..4fc97b0 100644
--- a/examples/cluster.c
+++ b/examples/cluster.c
@@ -28,79 +28,102 @@ static void draw_needle(cairo_t *cr,
     cairo_stroke(cr);
 }
 
-static void redraw(cairo_t *ctx) {
-    /*
-     * Paint canvas black
-     */
-    cairo_set_source_rgb(ctx, 0, 0, 0);
-    cairo_paint(ctx);
+static void draw_face_number(cairo_t *cr,
+                             double x,
+                             double y,
+                             double r,
+                             double min_angle,
+                             double max_angle,
+                             double value,
+                             const char *text) {
+    double angle = min_angle + ((max_angle - min_angle) * value) - 95;
 
-    /*
-     * Draw two identical circles
-     */
-    cairo_set_source_rgb(ctx, 1, 1, 1);
-    cairo_arc(ctx, 208, 240, 192, 0, 360);
-    cairo_stroke(ctx);
+    cairo_set_source_rgb(cr, 1, 1, 1);
 
-    /*
-     * Draw a gauge needle
-     */
-    draw_needle(ctx, 208, 240, 176, 232, 502, 0.0);
+    cairo_move_to(cr,
+                  x + r * cos((M_PI/180.0) * angle),
+                  y + r * sin((M_PI/180.0) * angle));
 
-    /*
-     * Draw another circle
-     */
-    cairo_set_source_rgb(ctx, 1, 1, 1);
-    cairo_arc(ctx, 816, 240, 192, 0, 360);
-    cairo_stroke(ctx);
-
-    /*
-     * Draw two smaller circles
-     */
-    cairo_arc(ctx, 442, 368, 64, 0, 360 * (M_PI/180));
-    cairo_stroke(ctx);
-
-    cairo_arc(ctx, 582, 368, 64, 0, 360 * (M_PI/180));
-    cairo_stroke(ctx);
-
-    /*
-     * Draw a rectangle
-     */
-    cairo_move_to(ctx, 432, 48);
-    cairo_line_to(ctx, 592, 48);
-    cairo_line_to(ctx, 592, 288);
-    cairo_line_to(ctx, 432, 288);
-    cairo_line_to(ctx, 432, 48);
-    cairo_set_source_rgb(ctx, 0.75, 0, 0);
-    cairo_fill(ctx);
-
-    cairo_move_to(ctx, 432, 48);
-    cairo_line_to(ctx, 592, 48);
-    cairo_line_to(ctx, 592, 288);
-    cairo_line_to(ctx, 432, 288);
-    cairo_line_to(ctx, 432, 48);
-    cairo_set_source_rgb(ctx, 1, 1, 1);
-    cairo_stroke(ctx);
+    cairo_save(cr);
+    cairo_rotate(cr, (M_PI/180.0) * (angle + 95));
+    cairo_show_text(cr, text);
+    cairo_restore(cr);
 }
 
-static void draw_text(cairo_t *cr) {
+static void redraw(cairo_t *cr) {
+    int i;
+
+    /*
+     * Set up text
+     */
     cairo_select_font_face(cr, "Helvetica",
       CAIRO_FONT_SLANT_NORMAL,
       CAIRO_FONT_WEIGHT_NORMAL);
 
-    cairo_set_font_size(cr, 13);
+    cairo_set_font_size(cr, 24);
 
-    cairo_move_to(cr, 208 + 192, 240);
-    cairo_save(cr);
-    cairo_rotate(cr, 45.0 * (M_PI/180));
-    cairo_show_text(cr, "10");
-    cairo_restore(cr);
+    /*
+     * Paint canvas black
+     */
+    cairo_set_source_rgb(cr, 0, 0, 0);
+    cairo_paint(cr);
 
-    cairo_move_to(cr, 208, 240 + 192);
-    cairo_save(cr);
-    cairo_rotate(cr, 90.0 * (M_PI/180));
-    cairo_show_text(cr, "20");
-    cairo_restore(cr);
+    /*
+     * Draw two identical circles
+     */
+    cairo_set_source_rgb(cr, 1, 1, 1);
+    cairo_arc(cr, 208, 240, 192, 0, 360);
+    cairo_stroke(cr);
+
+    /*
+     * Draw a face number
+     */
+    for (i=0; i<=80; i+=10) {
+        char text[4];
+
+        snprintf(text, 3, "%02d", i);
+        draw_face_number(cr, 208, 240, 162, 232, 488, i / 80.0, text);
+    }
+
+    /*
+     * Draw a gauge needle
+     */
+    draw_needle(cr, 208, 240, 148, 232, 488, 0.0);
+
+    /*
+     * Draw another circle
+     */
+    cairo_set_source_rgb(cr, 1, 1, 1);
+    cairo_arc(cr, 816, 240, 192, 0, 360);
+    cairo_stroke(cr);
+
+    /*
+     * Draw two smaller circles
+     */
+    cairo_arc(cr, 442, 368, 64, 0, 360 * (M_PI/180));
+    cairo_stroke(cr);
+
+    cairo_arc(cr, 582, 368, 64, 0, 360 * (M_PI/180));
+    cairo_stroke(cr);
+
+    /*
+     * Draw a rectangle
+     */
+    cairo_move_to(cr, 432, 48);
+    cairo_line_to(cr, 592, 48);
+    cairo_line_to(cr, 592, 288);
+    cairo_line_to(cr, 432, 288);
+    cairo_line_to(cr, 432, 48);
+    cairo_set_source_rgb(cr, 0.75, 0, 0);
+    cairo_fill(cr);
+
+    cairo_move_to(cr, 432, 48);
+    cairo_line_to(cr, 592, 48);
+    cairo_line_to(cr, 592, 288);
+    cairo_line_to(cr, 432, 288);
+    cairo_line_to(cr, 432, 48);
+    cairo_set_source_rgb(cr, 1, 1, 1);
+    cairo_stroke(cr);
 }
 
 int main(int argc, char **argv) {
@@ -139,7 +162,6 @@ int main(int argc, char **argv) {
     ctx = cairo_create(sfc);
 
     redraw(ctx);
-    draw_text(ctx);
 
     while (1) {
         XExposeEvent *expose;