// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2010 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// Eigen is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// Alternatively, you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License and a copy of the GNU General Public License along with
// Eigen. If not, see <http://www.gnu.org/licenses/>.

#include <main.h>
#include <iostream>
#include <GL/glew.h>
#include <Eigen/OpenGLSupport>
#include <GL/glut.h>
using namespace Eigen;


#define VERIFY_MATRIX(CODE,REF) { \
    glLoadIdentity(); \
    CODE; \
    Matrix<float,4,4,ColMajor> m; m.setZero(); \
    glGet(GL_MODELVIEW_MATRIX, m); \
    if(!(REF).cast<float>().isApprox(m)) { \
      std::cerr << "Expected:\n" << ((REF).cast<float>()) << "\n" << "got\n" << m << "\n\n"; \
    } \
    VERIFY_IS_APPROX((REF).cast<float>(), m); \
  }

#define VERIFY_UNIFORM(SUFFIX,NAME,TYPE) { \
    TYPE value; value.setRandom(); \
    TYPE data; \
    int loc = glGetUniformLocation(prg_id, #NAME); \
    VERIFY((loc!=-1) && "uniform not found"); \
    glUniform(loc,value); \
    EIGEN_CAT(glGetUniform,SUFFIX)(prg_id,loc,data.data()); \
    if(!value.isApprox(data)) { \
      std::cerr << "Expected:\n" << value << "\n" << "got\n" << data << "\n\n"; \
    } \
    VERIFY_IS_APPROX(value, data); \
  }
  
#define VERIFY_UNIFORMi(NAME,TYPE) { \
    TYPE value = TYPE::Random().eval().cast<float>().cast<TYPE::Scalar>(); \
    TYPE data; \
    int loc = glGetUniformLocation(prg_id, #NAME); \
    VERIFY((loc!=-1) && "uniform not found"); \
    glUniform(loc,value); \
    glGetUniformiv(prg_id,loc,(GLint*)data.data()); \
    if(!value.isApprox(data)) { \
      std::cerr << "Expected:\n" << value << "\n" << "got\n" << data << "\n\n"; \
    } \
    VERIFY_IS_APPROX(value, data); \
  }
  
void printInfoLog(GLuint objectID)
{
    int infologLength, charsWritten;
    GLchar *infoLog;
    glGetProgramiv(objectID,GL_INFO_LOG_LENGTH, &infologLength);
    if(infologLength > 0)
    {
        infoLog = new GLchar[infologLength];
        glGetProgramInfoLog(objectID, infologLength, &charsWritten, infoLog);
        if (charsWritten>0)
          std::cerr << "Shader info : \n" << infoLog << std::endl;
        delete[] infoLog;
    }
}

GLint createShader(const char* vtx, const char* frg)
{
  GLint prg_id = glCreateProgram();
  GLint vtx_id = glCreateShader(GL_VERTEX_SHADER);
  GLint frg_id = glCreateShader(GL_FRAGMENT_SHADER);
  GLint ok;
  
  glShaderSource(vtx_id, 1, &vtx, 0);
  glCompileShader(vtx_id);
  glGetShaderiv(vtx_id,GL_COMPILE_STATUS,&ok);
  if(!ok)
  {
    std::cerr << "vtx compilation failed\n";
  }
  
  glShaderSource(frg_id, 1, &frg, 0);
  glCompileShader(frg_id);
  glGetShaderiv(frg_id,GL_COMPILE_STATUS,&ok);
  if(!ok)
  {
    std::cerr << "frg compilation failed\n";
  }
  
  glAttachShader(prg_id, vtx_id);
  glAttachShader(prg_id, frg_id);
  glLinkProgram(prg_id);
  glGetProgramiv(prg_id,GL_LINK_STATUS,&ok);
  if(!ok)
  {
    std::cerr << "linking failed\n";
  }
  printInfoLog(prg_id);
  
  glUseProgram(prg_id);
  return prg_id;
}

void test_openglsupport()
{
  int argc = 0;
  glutInit(&argc, 0);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutInitWindowPosition (0,0);
  glutInitWindowSize(10, 10);

  if(glutCreateWindow("Eigen") <= 0)
  {
    std::cerr << "Error: Unable to create GLUT Window.\n";
    exit(1);
  }
  
  glewExperimental = GL_TRUE;
  if(glewInit() != GLEW_OK)
  {
    std::cerr << "Warning: Failed to initialize GLEW\n";
  }

  Vector3f v3f;
  Matrix3f rot;
  glBegin(GL_POINTS);
  
  glVertex(v3f);
  glVertex(2*v3f+v3f);
  glVertex(rot*v3f);
  
  glEnd();
  
  // 4x4 matrices
  Matrix4f mf44; mf44.setRandom();
  VERIFY_MATRIX(glLoadMatrix(mf44), mf44);
  VERIFY_MATRIX(glMultMatrix(mf44), mf44);
  Matrix4d md44; md44.setRandom();
  VERIFY_MATRIX(glLoadMatrix(md44), md44);
  VERIFY_MATRIX(glMultMatrix(md44), md44);
  
  // Quaternion
  Quaterniond qd(AngleAxisd(internal::random<double>(), Vector3d::Random()));
  VERIFY_MATRIX(glRotate(qd), Projective3d(qd).matrix());
  
  Quaternionf qf(AngleAxisf(internal::random<double>(), Vector3f::Random()));
  VERIFY_MATRIX(glRotate(qf), Projective3f(qf).matrix());
  
  // 3D Transform
  Transform<float,3,AffineCompact> acf3; acf3.matrix().setRandom();
  VERIFY_MATRIX(glLoadMatrix(acf3), Projective3f(acf3).matrix());
  VERIFY_MATRIX(glMultMatrix(acf3), Projective3f(acf3).matrix());
  
  Transform<float,3,Affine> af3(acf3);
  VERIFY_MATRIX(glLoadMatrix(af3), Projective3f(af3).matrix());
  VERIFY_MATRIX(glMultMatrix(af3), Projective3f(af3).matrix());
  
  Transform<float,3,Projective> pf3; pf3.matrix().setRandom();
  VERIFY_MATRIX(glLoadMatrix(pf3), Projective3f(pf3).matrix());
  VERIFY_MATRIX(glMultMatrix(pf3), Projective3f(pf3).matrix());
  
  Transform<double,3,AffineCompact> acd3; acd3.matrix().setRandom();
  VERIFY_MATRIX(glLoadMatrix(acd3), Projective3d(acd3).matrix());
  VERIFY_MATRIX(glMultMatrix(acd3), Projective3d(acd3).matrix());
  
  Transform<double,3,Affine> ad3(acd3);
  VERIFY_MATRIX(glLoadMatrix(ad3), Projective3d(ad3).matrix());
  VERIFY_MATRIX(glMultMatrix(ad3), Projective3d(ad3).matrix());
  
  Transform<double,3,Projective> pd3; pd3.matrix().setRandom();
  VERIFY_MATRIX(glLoadMatrix(pd3), Projective3d(pd3).matrix());
  VERIFY_MATRIX(glMultMatrix(pd3), Projective3d(pd3).matrix());
  
  // translations (2D and 3D)
  {
    Vector2f vf2; vf2.setRandom(); Vector3f vf23; vf23 << vf2, 0;
    VERIFY_MATRIX(glTranslate(vf2), Projective3f(Translation3f(vf23)).matrix());
    Vector2d vd2; vd2.setRandom(); Vector3d vd23; vd23 << vd2, 0;
    VERIFY_MATRIX(glTranslate(vd2), Projective3d(Translation3d(vd23)).matrix());
    
    Vector3f vf3; vf3.setRandom();
    VERIFY_MATRIX(glTranslate(vf3), Projective3f(Translation3f(vf3)).matrix());
    Vector3d vd3; vd3.setRandom();
    VERIFY_MATRIX(glTranslate(vd3), Projective3d(Translation3d(vd3)).matrix());
    
    Translation<float,3> tf3; tf3.vector().setRandom();
    VERIFY_MATRIX(glTranslate(tf3), Projective3f(tf3).matrix());
    
    Translation<double,3> td3;  td3.vector().setRandom();
    VERIFY_MATRIX(glTranslate(td3), Projective3d(td3).matrix());
  }
  
  // scaling (2D and 3D)
  {
    Vector2f vf2; vf2.setRandom(); Vector3f vf23; vf23 << vf2, 1;
    VERIFY_MATRIX(glScale(vf2), Projective3f(Scaling(vf23)).matrix());
    Vector2d vd2; vd2.setRandom(); Vector3d vd23; vd23 << vd2, 1;
    VERIFY_MATRIX(glScale(vd2), Projective3d(Scaling(vd23)).matrix());
    
    Vector3f vf3; vf3.setRandom();
    VERIFY_MATRIX(glScale(vf3), Projective3f(Scaling(vf3)).matrix());
    Vector3d vd3; vd3.setRandom();
    VERIFY_MATRIX(glScale(vd3), Projective3d(Scaling(vd3)).matrix());
    
    UniformScaling<float> usf(internal::random<float>());
    VERIFY_MATRIX(glScale(usf), Projective3f(usf).matrix());
    
    UniformScaling<double> usd(internal::random<double>());
    VERIFY_MATRIX(glScale(usd), Projective3d(usd).matrix());
  }
  
  // uniform
  {
    const char* vtx = "void main(void) { gl_Position = gl_Vertex; }\n";
    
    if(GLEW_VERSION_2_0)
    {
      #ifdef GL_VERSION_2_0
      const char* frg = ""
        "uniform vec2 v2f;\n"
        "uniform vec3 v3f;\n"
        "uniform vec4 v4f;\n"
        "uniform ivec2 v2i;\n"
        "uniform ivec3 v3i;\n"
        "uniform ivec4 v4i;\n"
        "uniform mat2 m2f;\n"
        "uniform mat3 m3f;\n"
        "uniform mat4 m4f;\n"
        "void main(void) { gl_FragColor = 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";
        
      GLint prg_id = createShader(vtx,frg);
      
      VERIFY_UNIFORM(fv,v2f, Vector2f);
      VERIFY_UNIFORM(fv,v3f, Vector3f);
      VERIFY_UNIFORM(fv,v4f, Vector4f);
      VERIFY_UNIFORMi(v2i, Vector2i);
      VERIFY_UNIFORMi(v3i, Vector3i);
      VERIFY_UNIFORMi(v4i, Vector4i);
      VERIFY_UNIFORM(fv,m2f, Matrix2f);
      VERIFY_UNIFORM(fv,m3f, Matrix3f);
      VERIFY_UNIFORM(fv,m4f, Matrix4f);
      #endif
    }
    else
      std::cerr << "Warning: opengl 2.0 was not tested\n";
    
    if(GLEW_VERSION_2_1)
    {
      #ifdef GL_VERSION_2_1
      const char* frg = "#version 120\n"
        "uniform mat2x3 m23f;\n"
        "uniform mat3x2 m32f;\n"
        "uniform mat2x4 m24f;\n"
        "uniform mat4x2 m42f;\n"
        "uniform mat3x4 m34f;\n"
        "uniform mat4x3 m43f;\n"
        "void main(void) { gl_FragColor = vec4(m23f[0][0]+m32f[0][0]+m24f[0][0]+m42f[0][0]+m34f[0][0]+m43f[0][0]); }\n";
        
      GLint prg_id = createShader(vtx,frg);
      
      typedef Matrix<float,2,3> Matrix23f;
      typedef Matrix<float,3,2> Matrix32f;
      typedef Matrix<float,2,4> Matrix24f;
      typedef Matrix<float,4,2> Matrix42f;
      typedef Matrix<float,3,4> Matrix34f;
      typedef Matrix<float,4,3> Matrix43f;
      
      VERIFY_UNIFORM(fv,m23f, Matrix23f);
      VERIFY_UNIFORM(fv,m32f, Matrix32f);
      VERIFY_UNIFORM(fv,m24f, Matrix24f);
      VERIFY_UNIFORM(fv,m42f, Matrix42f);
      VERIFY_UNIFORM(fv,m34f, Matrix34f);
      VERIFY_UNIFORM(fv,m43f, Matrix43f);
      #endif
    }
    else
      std::cerr << "Warning: opengl 2.1 was not tested\n";
    
    if(GLEW_VERSION_3_0)
    {
      #ifdef GL_VERSION_3_0
      const char* frg = "#version 150\n"
        "uniform uvec2 v2ui;\n"
        "uniform uvec3 v3ui;\n"
        "uniform uvec4 v4ui;\n"
        "out vec4 data;\n"
        "void main(void) { data = vec4(v2ui[0]+v3ui[0]+v4ui[0]); }\n";
        
      GLint prg_id = createShader(vtx,frg);
      
      typedef Matrix<unsigned int,2,1> Vector2ui;
      typedef Matrix<unsigned int,3,1> Vector3ui;
      typedef Matrix<unsigned int,4,1> Vector4ui;
      
      VERIFY_UNIFORMi(v2ui, Vector2ui);
      VERIFY_UNIFORMi(v3ui, Vector3ui);
      VERIFY_UNIFORMi(v4ui, Vector4ui);
      #endif
    }
    else
      std::cerr << "Warning: opengl 3.0 was not tested\n";
    
    #ifdef GLEW_ARB_gpu_shader_fp64
    if(GLEW_ARB_gpu_shader_fp64)
    {
      #ifdef GL_ARB_gpu_shader_fp64
      const char* frg = "#version 150\n"
        "uniform dvec2 v2d;\n"
        "uniform dvec3 v3d;\n"
        "uniform dvec4 v4d;\n"
        "out vec4 data;\n"
        "void main(void) { data = vec4(v2d[0]+v3d[0]+v4d[0]); }\n";
        
      GLint prg_id = createShader(vtx,frg);
      
      typedef Vector2d Vector2d;
      typedef Vector3d Vector3d;
      typedef Vector4d Vector4d;
      
      VERIFY_UNIFORM(dv,v2d, Vector2d);
      VERIFY_UNIFORM(dv,v3d, Vector3d);
      VERIFY_UNIFORM(dv,v4d, Vector4d);
      #endif
    }
    else
      std::cerr << "Warning: GLEW_ARB_gpu_shader_fp64 was not tested\n";
    #else
      std::cerr << "Warning: GLEW_ARB_gpu_shader_fp64 was not tested\n";
    #endif
  }
  
}