xref: /aosp_15_r20/external/eigen/unsupported/test/openglsupport.cpp (revision bf2c37156dfe67e5dfebd6d394bad8b2ab5804d4)
1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2010 Gael Guennebaud <[email protected]>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #include <main.h>
11 #include <iostream>
12 #include <string>
13 
14 #if defined(__APPLE_CC__)
15   // Prevent deprecation warnings caused by GLEW on MacOS.
16   #define GL_SILENCE_DEPRECATION 1
17 #endif
18 #include <GL/glew.h>
19 #include <Eigen/OpenGLSupport>
20 #if defined(__APPLE_CC__)
21   #include <GLUT/glut.h>
22 #else
23   #include <GL/freeglut.h>
24 #endif
25 
26 using namespace Eigen;
27 
28 #define VERIFY_MATRIX(CODE,REF) { \
29     glMatrixMode(GL_MODELVIEW); \
30     glLoadIdentity(); \
31     CODE; \
32     Matrix<float,4,4,ColMajor> m; m.setZero(); \
33     glGet(GL_MODELVIEW_MATRIX, m); \
34     if(!(REF).cast<float>().isApprox(m)) { \
35       std::cerr << "Expected:\n" << ((REF).cast<float>()) << "\n" << "got\n" << m << "\n\n"; \
36     } \
37     VERIFY_IS_APPROX((REF).cast<float>(), m); \
38   }
39 
40 #define VERIFY_UNIFORM(SUFFIX,NAME,TYPE) { \
41     TYPE value; value.setRandom(); \
42     TYPE data; \
43     int loc = glGetUniformLocation(prg_id, #NAME); \
44     VERIFY((loc!=-1) && "uniform not found"); \
45     glUniform(loc,value); \
46     EIGEN_CAT(glGetUniform,SUFFIX)(prg_id,loc,data.data()); \
47     if(!value.isApprox(data)) { \
48       std::cerr << "Expected:\n" << value << "\n" << "got\n" << data << "\n\n"; \
49     } \
50     VERIFY_IS_APPROX(value, data); \
51   }
52 
53 #define VERIFY_UNIFORMi(NAME,TYPE) { \
54     TYPE value = TYPE::Random().eval().cast<float>().cast<TYPE::Scalar>(); \
55     TYPE data; \
56     int loc = glGetUniformLocation(prg_id, #NAME); \
57     VERIFY((loc!=-1) && "uniform not found"); \
58     glUniform(loc,value); \
59     glGetUniformiv(prg_id,loc,(GLint*)data.data()); \
60     if(!value.isApprox(data)) { \
61       std::cerr << "Expected:\n" << value << "\n" << "got\n" << data << "\n\n"; \
62     } \
63     VERIFY_IS_APPROX(value, data); \
64   }
65 
printProgramInfoLog(GLuint objectID)66 void printProgramInfoLog(GLuint objectID)
67 {
68     int infologLength, charsWritten;
69     GLchar *infoLog;
70     glGetProgramiv(objectID, GL_INFO_LOG_LENGTH, &infologLength);
71     if(infologLength > 0)
72     {
73         infoLog = new GLchar[infologLength];
74         glGetProgramInfoLog(objectID, infologLength, &charsWritten, infoLog);
75         if (charsWritten > 0)
76           std::cerr << "Program info : \n" << infoLog << std::endl;
77         delete[] infoLog;
78     }
79 }
80 
printShaderInfoLog(GLuint objectID)81 void printShaderInfoLog(GLuint objectID)
82 {
83     int infologLength, charsWritten;
84     GLchar *infoLog;
85     glGetShaderiv(objectID, GL_INFO_LOG_LENGTH, &infologLength);
86     if(infologLength > 0)
87     {
88         infoLog = new GLchar[infologLength];
89         glGetShaderInfoLog(objectID, infologLength, &charsWritten, infoLog);
90         if (charsWritten > 0)
91           std::cerr << "Shader info : \n" << infoLog << std::endl;
92         delete[] infoLog;
93     }
94 }
95 
createProgram(const char * vtx,const char * frg,bool print_errors=true)96 GLint createProgram(const char* vtx, const char* frg, bool print_errors = true)
97 {
98   GLint prg_id = glCreateProgram();
99   GLint vtx_id = glCreateShader(GL_VERTEX_SHADER);
100   GLint frg_id = glCreateShader(GL_FRAGMENT_SHADER);
101   GLint ok;
102 
103   glShaderSource(vtx_id, 1, &vtx, 0);
104   glCompileShader(vtx_id);
105   glGetShaderiv(vtx_id, GL_COMPILE_STATUS, &ok);
106   if(!ok)
107   {
108     if (print_errors)
109     {
110       std::cerr << "vtx compilation failed\n";
111       std::cerr << "Source:\n" << vtx << "\n";
112       printShaderInfoLog(vtx_id);
113     }
114     glDeleteShader(vtx_id);
115     return GL_ZERO;
116   }
117 
118   glShaderSource(frg_id, 1, &frg, 0);
119   glCompileShader(frg_id);
120   glGetShaderiv(frg_id, GL_COMPILE_STATUS, &ok);
121   if(!ok)
122   {
123     if (print_errors)
124     {
125       std::cerr << "frg compilation failed.\n";
126       std::cerr << "Source:\n" << frg << "\n";
127       printShaderInfoLog(frg_id);
128     }
129     glDeleteShader(vtx_id);
130     glDeleteShader(frg_id);
131     return GL_ZERO;
132   }
133 
134   glAttachShader(prg_id, vtx_id);
135   glAttachShader(prg_id, frg_id);
136   glLinkProgram(prg_id);
137 
138   // Delete shaders once linked.
139   glDeleteShader(vtx_id);
140   glDeleteShader(frg_id);
141   glGetProgramiv(prg_id, GL_LINK_STATUS, &ok);
142   if(!ok)
143   {
144     if (print_errors)
145     {
146       std::cerr << "linking failed.\n";
147       printProgramInfoLog(prg_id);
148     }
149     glDeleteProgram(prg_id);
150     return GL_ZERO;
151   }
152 
153   glUseProgram(prg_id);
154   return prg_id;
155 }
156 
createProgram(const std::string & vtx,const std::string & frg,bool print_errors=true)157 GLint createProgram(const std::string& vtx, const std::string& frg, bool print_errors = true)
158 {
159   return createProgram(vtx.c_str(), frg.c_str(), print_errors);
160 }
161 
getGlslVersionString(int gl_major_version,int gl_minor_version)162 std::string getGlslVersionString(int gl_major_version, int gl_minor_version)
163 {
164   switch (gl_major_version)
165   {
166     case 2:
167       switch (gl_minor_version)
168       {
169         case 0:
170           return "#version 110";
171         case 1:
172           return "#version 120";
173       }
174       break;
175     case 3:
176       switch (gl_minor_version)
177       {
178         case 0:
179           return "#version 130";
180         case 1:
181           return "#version 140";
182         case 2:
183           return "#version 150";
184         case 3:
185           return "#version 330";
186       }
187       break;
188     case 4:
189       switch (gl_minor_version)
190       {
191         case 0:
192           return "#version 400";
193         case 1:
194           return "#version 410";
195         case 2:
196           return "#version 420";
197         case 3:
198           return "#version 430";
199         case 4:
200           return "#version 440";
201         case 5:
202           return "#version 450";
203         case 6:
204           return "#version 460";
205       }
206       break;
207   }
208   return "";
209 }
210 
find_and_replace(std::string & str,const std::string & find,const std::string & replace)211 void find_and_replace(
212   std::string& str,
213   const std::string& find,
214   const std::string& replace)
215 {
216   size_t loc = 0;
217   size_t flen = find.length();
218   size_t rlen = replace.length();
219   while ( (loc = str.find(find, loc)) != std::string::npos) {
220     str.replace(loc, flen, replace);
221     loc += rlen;
222   }
223 }
224 
225 // Finds and replaces a set of substrings in a string.
format(const std::string & str,const std::vector<std::string> & find,const std::vector<std::string> & replace)226 std::string format(
227   const std::string& str,
228   const std::vector<std::string>& find,
229   const std::vector<std::string>& replace)
230 {
231   std::string out = str;
232   for (std::size_t i=0; i<find.size(); ++i) {
233     find_and_replace(out, find[i], replace[i]);
234   }
235   return out;
236 }
237 
238 // GLUT display function that runs test.  Must be run within the display loop
239 // in order to properly destroy resources.
openglsupport_test_loop()240 void openglsupport_test_loop()
241 {
242   // Get context info.
243   const GLubyte* gl_version_string = glGetString(GL_VERSION);
244   std::cerr << "GL version: " << gl_version_string << std::endl;
245   std::cerr << "GLSL version: " << glGetString(GL_SHADING_LANGUAGE_VERSION) << std::endl;
246   // Parse version from string since GL_MAJOR_VERSION is only supported in GL 3.0+.
247   // Version string guaranteed to be <major>.<minor><vender extension>.
248   GLint gl_major_version = gl_version_string[0] - '0';
249   GLint gl_minor_version = gl_version_string[2] - '0';
250   bool legacy_gl = gl_major_version < 3 || (gl_major_version == 3 && gl_minor_version < 2);
251 
252   // Fixed-function pipeline removed in OpenGL 3.2.
253   if (legacy_gl)
254   {
255     // Draw a basic triangle.
256     Vector3f v3f;
257     Matrix3f rot;
258     glBegin(GL_POINTS);
259     {
260       glVertex(v3f);
261       glVertex(2*v3f+v3f);
262       glVertex(rot*v3f);
263     }
264     glEnd();
265 
266     // 4x4 matrices
267     Matrix4f mf44; mf44.setRandom();
268     VERIFY_MATRIX(glLoadMatrix(mf44), mf44);
269     VERIFY_MATRIX(glMultMatrix(mf44), mf44);
270     Matrix4d md44; md44.setRandom();
271     VERIFY_MATRIX(glLoadMatrix(md44), md44);
272     VERIFY_MATRIX(glMultMatrix(md44), md44);
273 
274     // Quaternion
275     Quaterniond qd(AngleAxisd(internal::random<double>(), Vector3d::Random()));
276     VERIFY_MATRIX(glRotate(qd), Projective3d(qd).matrix());
277 
278     Quaternionf qf(AngleAxisf(internal::random<double>(), Vector3f::Random()));
279     VERIFY_MATRIX(glRotate(qf), Projective3f(qf).matrix());
280 
281     // 3D Transform
282     Transform<float,3,AffineCompact> acf3; acf3.matrix().setRandom();
283     VERIFY_MATRIX(glLoadMatrix(acf3), Projective3f(acf3).matrix());
284     VERIFY_MATRIX(glMultMatrix(acf3), Projective3f(acf3).matrix());
285 
286     Transform<float,3,Affine> af3(acf3);
287     VERIFY_MATRIX(glLoadMatrix(af3), Projective3f(af3).matrix());
288     VERIFY_MATRIX(glMultMatrix(af3), Projective3f(af3).matrix());
289 
290     Transform<float,3,Projective> pf3; pf3.matrix().setRandom();
291     VERIFY_MATRIX(glLoadMatrix(pf3), Projective3f(pf3).matrix());
292     VERIFY_MATRIX(glMultMatrix(pf3), Projective3f(pf3).matrix());
293 
294     Transform<double,3,AffineCompact> acd3; acd3.matrix().setRandom();
295     VERIFY_MATRIX(glLoadMatrix(acd3), Projective3d(acd3).matrix());
296     VERIFY_MATRIX(glMultMatrix(acd3), Projective3d(acd3).matrix());
297 
298     Transform<double,3,Affine> ad3(acd3);
299     VERIFY_MATRIX(glLoadMatrix(ad3), Projective3d(ad3).matrix());
300     VERIFY_MATRIX(glMultMatrix(ad3), Projective3d(ad3).matrix());
301 
302     Transform<double,3,Projective> pd3; pd3.matrix().setRandom();
303     VERIFY_MATRIX(glLoadMatrix(pd3), Projective3d(pd3).matrix());
304     VERIFY_MATRIX(glMultMatrix(pd3), Projective3d(pd3).matrix());
305 
306     // translations (2D and 3D)
307     {
308       Vector2f vf2; vf2.setRandom(); Vector3f vf23; vf23 << vf2, 0;
309       VERIFY_MATRIX(glTranslate(vf2), Projective3f(Translation3f(vf23)).matrix());
310       Vector2d vd2; vd2.setRandom(); Vector3d vd23; vd23 << vd2, 0;
311       VERIFY_MATRIX(glTranslate(vd2), Projective3d(Translation3d(vd23)).matrix());
312 
313       Vector3f vf3; vf3.setRandom();
314       VERIFY_MATRIX(glTranslate(vf3), Projective3f(Translation3f(vf3)).matrix());
315       Vector3d vd3; vd3.setRandom();
316       VERIFY_MATRIX(glTranslate(vd3), Projective3d(Translation3d(vd3)).matrix());
317 
318       Translation<float,3> tf3; tf3.vector().setRandom();
319       VERIFY_MATRIX(glTranslate(tf3), Projective3f(tf3).matrix());
320 
321       Translation<double,3> td3;  td3.vector().setRandom();
322       VERIFY_MATRIX(glTranslate(td3), Projective3d(td3).matrix());
323     }
324 
325     // scaling (2D and 3D)
326     {
327       Vector2f vf2; vf2.setRandom(); Vector3f vf23; vf23 << vf2, 1;
328       VERIFY_MATRIX(glScale(vf2), Projective3f(Scaling(vf23)).matrix());
329       Vector2d vd2; vd2.setRandom(); Vector3d vd23; vd23 << vd2, 1;
330       VERIFY_MATRIX(glScale(vd2), Projective3d(Scaling(vd23)).matrix());
331 
332       Vector3f vf3; vf3.setRandom();
333       VERIFY_MATRIX(glScale(vf3), Projective3f(Scaling(vf3)).matrix());
334       Vector3d vd3; vd3.setRandom();
335       VERIFY_MATRIX(glScale(vd3), Projective3d(Scaling(vd3)).matrix());
336 
337       UniformScaling<float> usf(internal::random<float>());
338       VERIFY_MATRIX(glScale(usf), Projective3f(usf).matrix());
339 
340       UniformScaling<double> usd(internal::random<double>());
341       VERIFY_MATRIX(glScale(usd), Projective3d(usd).matrix());
342     }
343   } else {
344     std::cerr << "Warning: fixed-function pipeline was not tested.\n";
345   }
346 
347   // Dynamic shader substitution variables.
348   // Modern shaders require a version string, and newer runtimes fail to
349   // compile old GLSL versions. Thus, we dynamically set the GLSL version
350   // string based on runtime. Also, pre OpenGL 3.0, the output gl_FragColor was
351   // built-in. This was deprecated in OpenGL 3.0, requiring us to explicitly
352   // define the output variable.
353   std::vector<std::string> glsl_vars;
354   glsl_vars.push_back("${GLSL_VERSION}");
355   glsl_vars.push_back("${FRAG_OUTPUT_DECLARATION}");
356   glsl_vars.push_back("${FRAG_OUTPUT_VARIABLE}");
357 
358   std::vector<std::string> glsl_vals;
359   glsl_vals.push_back(getGlslVersionString(gl_major_version, gl_minor_version));
360   if (gl_major_version >= 3) {
361     glsl_vals.push_back("out vec4 fragColor;");
362     glsl_vals.push_back("fragColor");
363   } else {
364     glsl_vals.push_back("");
365     glsl_vals.push_back("gl_FragColor");
366   }
367 
368   // uniform
369   {
370     // vertex shader.
371     std::string vtx = format(
372       "${GLSL_VERSION}\n"
373       "void main(void) {\n"
374       "  gl_Position = vec4(0,0,0,1);\n"
375       "}\n",
376       glsl_vars, glsl_vals);
377 
378 #ifdef GL_VERSION_2_0
379     if(GLEW_VERSION_2_0 && GL_VERSION_2_0)
380     {
381       std::string frg = format(
382         "${GLSL_VERSION}\n"
383         "uniform vec2 v2f;\n"
384         "uniform vec3 v3f;\n"
385         "uniform vec4 v4f;\n"
386         "uniform ivec2 v2i;\n"
387         "uniform ivec3 v3i;\n"
388         "uniform ivec4 v4i;\n"
389         "uniform mat2 m2f;\n"
390         "uniform mat3 m3f;\n"
391         "uniform mat4 m4f;\n"
392         "${FRAG_OUTPUT_DECLARATION}\n"
393         "void main(void) { \n"
394         "  ${FRAG_OUTPUT_VARIABLE} = vec4(v2f[0]+v3f[0]+v4f[0])+vec4(v2i[0]+v3i[0]+v4i[0])+vec4(m2f[0][0]+m3f[0][0]+m4f[0][0]);\n"
395         "}\n",
396         glsl_vars, glsl_vals);
397 
398       GLint prg_id = createProgram(vtx, frg);
399       VERIFY(prg_id > 0 && "Failed to create program.");
400       VERIFY_UNIFORM(fv, v2f, Vector2f);
401       VERIFY_UNIFORM(fv, v3f, Vector3f);
402       VERIFY_UNIFORM(fv, v4f, Vector4f);
403       VERIFY_UNIFORMi(v2i, Vector2i);
404       VERIFY_UNIFORMi(v3i, Vector3i);
405       VERIFY_UNIFORMi(v4i, Vector4i);
406       VERIFY_UNIFORM(fv, m2f, Matrix2f);
407       VERIFY_UNIFORM(fv, m3f, Matrix3f);
408       VERIFY_UNIFORM(fv, m4f, Matrix4f);
409       glDeleteProgram(prg_id);
410     }
411     else
412 #endif
413       std::cerr << "Warning: opengl 2.0 was not tested.\n";
414 
415 #ifdef GL_VERSION_2_1
416     if(GLEW_VERSION_2_1 && GL_VERSION_2_1 &&
417         (gl_major_version > 2 || (gl_major_version == 2 && gl_minor_version >= 1)))
418     {
419       std::string frg = format(
420         "${GLSL_VERSION}\n"
421         "uniform mat2x3 m23f;\n"
422         "uniform mat3x2 m32f;\n"
423         "uniform mat2x4 m24f;\n"
424         "uniform mat4x2 m42f;\n"
425         "uniform mat3x4 m34f;\n"
426         "uniform mat4x3 m43f;\n"
427         "${FRAG_OUTPUT_DECLARATION}\n"
428         "void main(void) {\n"
429         "  ${FRAG_OUTPUT_VARIABLE} = vec4(m23f[0][0]+m32f[0][0]+m24f[0][0]+m42f[0][0]+m34f[0][0]+m43f[0][0]);\n"
430         "}\n",
431         glsl_vars, glsl_vals);
432 
433       GLint prg_id = createProgram(vtx, frg);
434       VERIFY(prg_id > 0 && "Failed to create program.");
435       typedef Matrix<float,2,3> Matrix23f;
436       typedef Matrix<float,3,2> Matrix32f;
437       typedef Matrix<float,2,4> Matrix24f;
438       typedef Matrix<float,4,2> Matrix42f;
439       typedef Matrix<float,3,4> Matrix34f;
440       typedef Matrix<float,4,3> Matrix43f;
441 
442       VERIFY_UNIFORM(fv, m23f, Matrix23f);
443       VERIFY_UNIFORM(fv, m32f, Matrix32f);
444       VERIFY_UNIFORM(fv, m24f, Matrix24f);
445       VERIFY_UNIFORM(fv, m42f, Matrix42f);
446       VERIFY_UNIFORM(fv, m34f, Matrix34f);
447       VERIFY_UNIFORM(fv, m43f, Matrix43f);
448       glDeleteProgram(prg_id);
449     }
450     else
451 #endif
452       std::cerr << "Warning: opengl 2.1 was not tested.\n";
453 
454 #ifdef GL_VERSION_3_0
455     if(GLEW_VERSION_3_0 && GL_VERSION_3_0 && gl_major_version >= 3)
456     {
457       std::string frg = format(
458         "${GLSL_VERSION}\n"
459         "uniform uvec2 v2ui;\n"
460         "uniform uvec3 v3ui;\n"
461         "uniform uvec4 v4ui;\n"
462         "${FRAG_OUTPUT_DECLARATION}\n"
463         "void main(void) {\n"
464         "  ${FRAG_OUTPUT_VARIABLE} = vec4(v2ui[0]+v3ui[0]+v4ui[0]);\n"
465         "}\n",
466         glsl_vars, glsl_vals);
467 
468       GLint prg_id = createProgram(vtx, frg);
469       VERIFY(prg_id > 0 && "Failed to create program.");
470       typedef Matrix<unsigned int,2,1> Vector2ui;
471       typedef Matrix<unsigned int,3,1> Vector3ui;
472       typedef Matrix<unsigned int,4,1> Vector4ui;
473 
474       VERIFY_UNIFORMi(v2ui, Vector2ui);
475       VERIFY_UNIFORMi(v3ui, Vector3ui);
476       VERIFY_UNIFORMi(v4ui, Vector4ui);
477       glDeleteProgram(prg_id);
478     }
479     else
480 #endif
481       std::cerr << "Warning: opengl 3.0 was not tested.\n";
482 
483     // dvecn supported if >= 4.1 or ARB_vertex_attrib_64bit
484     bool has_fp64_native = (gl_major_version == 4 && gl_minor_version >= 1);
485     bool has_fp64_extension = false;
486 #ifdef GLEW_ARB_gpu_shader_fp64
487     if(GLEW_ARB_gpu_shader_fp64)
488     {
489       // Check that extension can actually be compiled.
490       if (has_fp64_extension)
491       {
492         std::string frg = format(
493           "${GLSL_VERSION}\n"
494           "#extension GL_ARB_gpu_shader_fp64 : enable\n"
495           "uniform dvec2 dv2;\n"
496           "${FRAG_OUTPUT_DECLARATION}\n"
497           "void main(void) {\n"
498           "  ${FRAG_OUTPUT_VARIABLE} = vec4(dv2.x, dv2.y, dv2.x, dv2.y);\n"
499           "}\n",
500           glsl_vars, glsl_vals);
501         GLint prg_id = createProgram(vtx, frg, /*print_errors=*/false);
502         if (prg_id)
503         {
504           has_fp64_extension = true;
505           glDeleteProgram(prg_id);
506         }
507       }
508     }
509 #endif
510 
511     if( has_fp64_native || has_fp64_extension )
512     {
513       std::vector<std::string> glsl_vars_with_extension = glsl_vars;
514       glsl_vars_with_extension.push_back("${GLSL_EXTENSIONS}");
515       std::vector<std::string> glsl_vals_with_extension = glsl_vals;
516       if (has_fp64_extension)
517       {
518         glsl_vals_with_extension.push_back("#extension GL_ARB_gpu_shader_fp64 : enable");
519       }
520       else
521       {
522         glsl_vals_with_extension.push_back("");
523       }
524 
525       std::string frg = format(
526         "${GLSL_VERSION}\n"
527         "${GLSL_EXTENSIONS}\n"
528         "uniform dvec2 v2d;\n"
529         "uniform dvec3 v3d;\n"
530         "uniform dvec4 v4d;\n"
531         "${FRAG_OUTPUT_DECLARATION}\n"
532         "void main(void) {\n"
533         "  ${FRAG_OUTPUT_VARIABLE} = vec4(v2d[0]+v3d[0]+v4d[0]);\n"
534         "}\n",
535         glsl_vars_with_extension, glsl_vals_with_extension);
536 
537       GLint prg_id = createProgram(vtx,frg);
538       VERIFY(prg_id > 0 && "Failed to create program.");
539       VERIFY_UNIFORM(dv, v2d, Vector2d);
540       VERIFY_UNIFORM(dv, v3d, Vector3d);
541       VERIFY_UNIFORM(dv, v4d, Vector4d);
542       glDeleteProgram(prg_id);
543     }
544     else
545       std::cerr << "Warning: dvec (fp64) was not tested.\n";
546   }
547 
548   // Exit loop - Leaving main loop is supported by freeglut, otherwise we
549   // are forced to exit.
550 #ifdef FREEGLUT
551   glutLeaveMainLoop();
552   // Trigger another display loop iteration. Otherwise, it just hangs.
553   glutPostRedisplay();
554 #else
555   exit(0);
556 #endif
557 }
558 
EIGEN_DECLARE_TEST(openglsupport)559 EIGEN_DECLARE_TEST(openglsupport)
560 {
561   int argc = 0;
562   glutInit(&argc, 0);
563 
564   GLint glut_display_mode = GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH;
565 
566 #ifndef EIGEN_LEGACY_OPENGL
567   // Initialize 3.2+ OpenGL context.
568 #if defined(__APPLE_CC__)
569   glut_display_mode |= GLUT_3_2_CORE_PROFILE;
570 #elif defined(FREEGLUT)
571   glutInitContextVersion(3, 2);
572   glutInitContextFlags(GLUT_FORWARD_COMPATIBLE);
573   glutInitContextProfile(GLUT_CORE_PROFILE);
574 #endif
575 #endif
576 
577   glutInitDisplayMode(glut_display_mode);
578   glutInitWindowPosition(0, 0);
579   glutInitWindowSize(10, 10);
580 
581   int window = glutCreateWindow("Eigen");
582   if(window <= 0)
583   {
584     std::cerr << "Error: Unable to create GLUT Window.\n";
585     exit(1);
586   }
587 
588   glewExperimental = GL_TRUE;
589   if(glewInit() != GLEW_OK)
590   {
591     std::cerr << "Warning: Failed to initialize GLEW.\n";
592     exit(1);
593   }
594 
595   // Run test in display, otherwise GLUT fails to clean up and leads to memory
596   // access errors on exit.
597   glutDisplayFunc(openglsupport_test_loop);
598   glutMainLoop();
599   glutDestroyWindow(window);
600 }
601