From b850ddd28996880181db1740d63e81cfdf57b918 Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Mon, 27 May 2019 01:32:21 -0500
Subject: [PATCH] Whoah, you're loaded!

---
 examples/cluster.c | 100 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 76 insertions(+), 24 deletions(-)

diff --git a/examples/cluster.c b/examples/cluster.c
index 5d2b09b..505f2fc 100644
--- a/examples/cluster.c
+++ b/examples/cluster.c
@@ -1,12 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
 #include <X11/Xlib.h>
 #include <X11/Xatom.h>
 #include <X11/Xutil.h>
 #include <cairo.h>
 #include <cairo-xlib.h>
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <math.h>
+#include <hexagram/can.h>
 
 static void draw_needle(cairo_t *cr,
                         double x,
@@ -53,9 +56,14 @@ static void draw_face_number(cairo_t *cr,
 static void draw_tachometer(cairo_t *cr,
                             double x,
                             double y,
-                            double r) {
+                            double r,
+                            double rpm) {
     int i;
 
+    if (rpm > 8000) {
+        rpm = 8000;
+    }
+
     cairo_select_font_face(cr, "Helvetica",
       CAIRO_FONT_SLANT_NORMAL,
       CAIRO_FONT_WEIGHT_NORMAL);
@@ -87,7 +95,8 @@ static void draw_tachometer(cairo_t *cr,
      */
     draw_needle(cr, x, y,   0.77 * r,
                           232    * (M_PI/180),
-                          488    * (M_PI/180), 0.0);
+                          488    * (M_PI/180),
+                          rpm / 8000);
 
     /*
      * Draw a tiny boi circle
@@ -144,10 +153,17 @@ static void draw_mfd(cairo_t *cr,
 }
 
 static void draw_gauge_cluster(cairo_t *cr,
+                               struct can_frame *frame,
                                double x,
                                double y,
                                double width,
                                double height) {
+    static double rpm = 0;
+    
+    if (frame->can_id == 0x280) {
+        rpm = 0.25 * (double)(frame->data[2] | (frame->data[3] << 8));
+    }
+
     /*
      * Paint canvas black
      */
@@ -157,7 +173,8 @@ static void draw_gauge_cluster(cairo_t *cr,
     draw_tachometer(cr,
                     x + width  * 0.2,
                     y + height * 0.5,
-                        height * 0.4);
+                        height * 0.4,
+                        rpm);
 
     draw_speedometer(cr,
                      x + width  * 0.8,
@@ -186,8 +203,11 @@ int main(int argc, char **argv) {
     Window win;
     Pixmap buf;
     GC gc;
+    fd_set rfds, wfds, rready, wready;
 
-    int screen,
+    hexagram_can_if *can_if;
+
+    int screen, fd, fd2,
         width  = 1024,
         height =  480;
 
@@ -200,11 +220,15 @@ int main(int argc, char **argv) {
     cairo_surface_t *sfc;
     cairo_t *cr;
 
-    XEvent e;
+    if ((can_if = hexagram_can_if_open("vcan0")) == NULL)
+        exit(1);
 
     if ((display = XOpenDisplay(NULL)) == NULL)
         exit(1);
 
+    fd  = hexagram_can_if_fd(can_if);
+    fd2 = ConnectionNumber(display);
+
     screen = DefaultScreen(display);
     win = XCreateSimpleWindow(display, DefaultRootWindow(display), 0, 0, width, height, 0, 0, 0);
     gc  = XCreateGC(display, win, GCForeground | GCBackground | GCGraphicsExposures, &values);
@@ -218,29 +242,57 @@ int main(int argc, char **argv) {
 
     cr = cairo_create(sfc);
 
-    draw_gauge_cluster(cr, 0, 0, width, height);
+    FD_ZERO(&rfds);
+
+    FD_SET(fd, &rfds);
+    FD_SET(fd2, &rfds);
 
     while (1) {
-        XExposeEvent *expose;
+        int nready, pending;
 
-        XNextEvent(cairo_xlib_surface_get_display(sfc), &e);
+        while ((pending = XPending(display)) != 0) {
+            XEvent e;
 
-        switch (e.type) {
-            case Expose:
-                expose = (XExposeEvent *)&e;
+            XNextEvent(display, &e);
 
-                XCopyArea(display, buf, win, gc, expose->x, expose->y,
-                          expose->width, expose->height,
-                          expose->x, expose->y);
+            switch (e.type) {
+                case Expose:
+                    fprintf(stderr, "Event %d\n", e.type);
 
-                break;
-                    
-            case ButtonPress:
-            case KeyPress:
-                goto done;
+                    XCopyArea(display, buf, win, gc,
+                              e.xexpose.x,
+                              e.xexpose.y,
+                              e.xexpose.width,
+                              e.xexpose.height,
+                              e.xexpose.x,
+                              e.xexpose.y);
 
-            default:
-                fprintf(stderr, "Dropping unhandled XEvent.type = %d.\n", e.type);
+                    break;
+                        
+                case ButtonPress:
+                case KeyPress:
+                    break;
+
+                default:
+                    fprintf(stderr, "Dropping unhandled XEvent.type = %d.\n", e.type);
+            }
+        }
+
+        memcpy(&rready, &rfds, sizeof(rfds));
+
+        if (select(fd2, &rready, NULL, NULL, NULL) < 0) {
+            break;
+        }
+
+        if (FD_ISSET(fd, &rready)) {
+            struct can_frame frame;
+
+            hexagram_can_if_read(can_if, &frame);
+            draw_gauge_cluster(cr, &frame, 0, 0, width, height);
+
+            XCopyArea(display, buf, win, gc, 0, 0,
+                      1024, 480,
+                      0, 0);
         }
     }