From 0af22d23f860d7ab1c0e9355f55cade310afd748 Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Sat, 21 Jul 2018 14:54:13 -0400
Subject: ising example now has a setting for drawing the state to the screen

---
 CMakeLists.txt      |  2 +-
 lib/cluster.h       |  2 --
 lib/ising.h         |  1 +
 src/wolff_ising.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f9ee423..b225d39 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,7 +29,7 @@ if (OPENMP_FOUND)
 endif()
 
 target_link_libraries(wolff_finite gsl cblas fftw3 m)
-target_link_libraries(wolff_ising gsl cblas fftw3 m)
+target_link_libraries(wolff_ising gsl cblas fftw3 m glut GL GLU)
 target_link_libraries(wolff_heisenberg gsl cblas fftw3 m)
 target_link_libraries(wolff_planar gsl cblas fftw3 m)
 target_link_libraries(analyze_correlations gsl cblas fftw3 m)
diff --git a/lib/cluster.h b/lib/cluster.h
index d90dc64..cc2dc70 100644
--- a/lib/cluster.h
+++ b/lib/cluster.h
@@ -23,8 +23,6 @@
 #include "measurement.h"
 #include "vector.h"
 #include "orthogonal.h"
-#include "ising.h"
-#include "z2.h"
 #include "dihedral.h"
 #include "dihinf.h"
 #include "yule_walker.h"
diff --git a/lib/ising.h b/lib/ising.h
index e09b39e..4ad88f4 100644
--- a/lib/ising.h
+++ b/lib/ising.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cmath>
+#include <stdio.h>
 
 #include "types.h"
 
diff --git a/src/wolff_ising.cpp b/src/wolff_ising.cpp
index e9d0185..f4073da 100644
--- a/src/wolff_ising.cpp
+++ b/src/wolff_ising.cpp
@@ -1,6 +1,12 @@
 
 #include <getopt.h>
+#include <GL/glut.h>
 
+// include your group and spin space
+#include <z2.h>
+#include <ising.h>
+
+// include wolff.h
 #include <wolff.h>
 
 int main(int argc, char *argv[]) {
@@ -13,10 +19,11 @@ int main(int argc, char *argv[]) {
   double H = 0.0;
 
   bool silent = false;
+  bool draw = false;
 
   int opt;
 
-  while ((opt = getopt(argc, argv, "N:q:D:L:T:J:H:s")) != -1) {
+  while ((opt = getopt(argc, argv, "N:D:L:T:H:sd")) != -1) {
     switch (opt) {
     case 'N': // number of steps
       N = (count_t)atof(optarg);
@@ -36,6 +43,9 @@ int main(int argc, char *argv[]) {
     case 's': // don't print anything during simulation. speeds up slightly
       silent = true;
       break;
+    case 'd':
+      draw = true;
+      break;
     default:
       exit(EXIT_FAILURE);
     }
@@ -74,10 +84,41 @@ int main(int argc, char *argv[]) {
   };
 
   // define function that updates any number of measurements
+  std::function <void(const state_t <z2_t, ising_t> *)> measurement;
+
   double average_M = 0;
-  std::function <void(const state_t <z2_t, ising_t> *)> measurement = [&] (const state_t <z2_t, ising_t> *s) {
-    average_M += (double)s->M / (double)N / (double)s->nv;
-  };
+  if (!draw) {
+    // a very simple example: measure the average magnetization
+    measurement = [&] (const state_t <z2_t, ising_t> *s) {
+      average_M += (double)s->M / (double)N / (double)s->nv;
+    };
+  } else {
+    // a more complex example: measure the average magnetization, and draw the spin configuration to the screen
+
+    // initialize glut
+    glutInit(&argc, argv);
+    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
+    glutInitWindowSize(L,L);
+    glutCreateWindow("null");
+    glClearColor(0.0,0.0,0.0,0.0);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluOrtho2D(0.0, L, 0.0, L);
+
+    measurement = [&] (const state_t <z2_t, ising_t> *s) {
+      average_M += (double)s->M / (double)N / (double)s->nv;
+      glClear(GL_COLOR_BUFFER_BIT);
+      for (v_t i = 0; i < pow(L, 2); i++) {
+        if (s->spins[i].x == s->R.x) {
+          glColor3f(0.0, 0.0, 0.0);
+        } else {
+          glColor3f(1.0, 1.0, 1.0);
+        }
+        glRecti(i / L, i % L, (i / L) + 1, (i % L) + 1);
+      }
+      glFlush();
+    };
+  }
 
   // run wolff for N cluster flips
   wolff(N, &s, gen_R, measurement, r, silent);
@@ -88,6 +129,9 @@ int main(int argc, char *argv[]) {
   // free the random number generator
   gsl_rng_free(r);
 
+  if (draw) {
+  }
+
   return 0;
 
 }
-- 
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