/* #include <GL/freeglut.h> */
#include <GL/glut.h>

#include <math.h>

#ifndef M_PI
#  define M_PI (3.141592653589793)
#endif

#define ROTATION_RADIAN (M_PI/6.0)
#define RATIO_EXPANSION (1.6)
#define RATIO_SHRINK (0.6)

#define BLUR_NUM (2)
#define VERTEX_NUM (5)

static double g_matrix[BLUR_NUM][2][3];
static int g_current;
static double g_object[VERTEX_NUM][2];

static void makeStarA(double vertex[][2], double r0);

static void initMatrix(double matrix[2][3]);
static void makeTranslationMatrix(double matrix[2][3], const double tx, const double ty);
static void makeRotationMatrix(double matrix[2][3], const double r);
static void makeScaleMatrix(double matrix[2][3], const double sx, const double sy);
static void makeTransformationMatrix(double matrix[2][3], const double lhs[2][3], const double rhs[2][3]);
static void transform(double vertex[][2], int nv, const double matrix[2][3], const double input[][2]);

static void display(void);
static void key(unsigned char key , int x , int y);

static void init(void);

void makeStarA(double vertex[][2], double r0)
{
  double theta;
  int i;
  for (i = 0; i < VERTEX_NUM; ++i) {
    theta = M_PI/2.0 + (2.0*M_PI / VERTEX_NUM * 2)*i;
    vertex[i][0] = cos(theta) * r0;
    vertex[i][1] = sin(theta) * r0;
  }
}

void initMatrix(double m[2][3])
{
  m[0][0] = 1.0; m[0][1] = 0.0; m[0][2] = 0.0;
  m[1][0] = 0.0; m[1][1] = 1.0; m[1][2] = 0.0;
}

void makeTranslationMatrix(double matrix[2][3], const double tx, const double ty)
{
  matrix[0][0] = 1.0; matrix[0][1] = 0.0; matrix[0][2] =  tx;
  matrix[1][0] = 0.0; matrix[1][1] = 1.0; matrix[1][2] =  ty;
}

void makeRotationMatrix(double matrix[2][3], const double r)
{
  double c, s;
  c = cos(r);
  s = sin(r);
  matrix[0][0] =   c; matrix[0][1] =  -s; matrix[0][2] = 0.0;
  matrix[1][0] =   s; matrix[1][1] =   c; matrix[1][2] = 0.0;
}

void makeTransformationMatrix(double matrix[2][3], const double l[2][3], const double r[2][3])
{
  matrix[0][0] = l[0][0]*r[0][0] + l[0][1]*r[1][0];
  matrix[0][1] = l[0][0]*r[0][1] + l[0][1]*r[1][1];
  matrix[0][2] = l[0][0]*r[0][2] + l[0][1]*r[1][2] + l[0][2];

  matrix[1][0] = l[1][0]*r[0][0] + l[1][1]*r[1][0];
  matrix[1][1] = l[1][0]*r[0][1] + l[1][1]*r[1][1];
  matrix[1][2] = l[1][0]*r[0][2] + l[1][1]*r[1][2] + l[1][2];
}

void transform(double vertex[][2], int nv, const double matrix[2][3], const double input[][2])
{
  int i;
  for (i = 0; i < nv; ++i) {
    vertex[i][0] = matrix[0][0]*input[i][0] + matrix[0][1]*input[i][1] + matrix[0][2];
    vertex[i][1] = matrix[1][0]*input[i][0] + matrix[1][1]*input[i][1] + matrix[1][2];
  }
}

void display(void)
{
  glClear(GL_COLOR_BUFFER_BIT);

  /* Axis */
  glBegin(GL_LINES);
  {
    glColor3f(1.0, 1.0, 1.0);
    /* X */
    glVertex2d(-1.0, 0.0);
    glVertex2d(1.0, 0.0);
    /* Y */
    glVertex2d(0.0, -1.0);
    glVertex2d(0.0, 1.0);
  }
  glEnd();

  /* Object */
  {
    double vertex[VERTEX_NUM][2];
    transform(vertex, VERTEX_NUM, g_matrix[g_current], g_object);
    glBegin(GL_LINE_LOOP);
    {
      int i;
      glColor3f(0.0f, 1.0f, 0.0f);
      for(i = 0; i < VERTEX_NUM; ++i) {
        glVertex2d(vertex[i][0], vertex[i][1]);
      }
    }
    glEnd();
  }

  glFlush();
}

void key(unsigned char key , int x , int y) {
  switch (key) {
    case '\033': /* Key ESC */
      glutLeaveMainLoop();
      break;
    case 'a': { /* -X */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeTranslationMatrix(m, -0.1,  0.0);
      makeTransformationMatrix(g_matrix[g_current], m, g_matrix[p]);
      break;
    }
    case 'd': { /* +X */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeTranslationMatrix(m,  0.1,  0.0);
      makeTransformationMatrix(g_matrix[g_current], m, g_matrix[p]);
      break;
    }
    case 'w': { /* +Y */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeTranslationMatrix(m,  0.0,  0.1);
      makeTransformationMatrix(g_matrix[g_current], m, g_matrix[p]);
      break;
    }
    case 's': { /* -Y */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeTranslationMatrix(m,  0.0, -0.1);
      makeTransformationMatrix(g_matrix[g_current], m, g_matrix[p]);
      break;
    }
    case 'j': { /* counterclockwise local */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeRotationMatrix(m,  ROTATION_RADIAN);
      makeTransformationMatrix(g_matrix[g_current], g_matrix[p], m);
      break;
    }
    case 'J': { /* clockwise local */
      double m[2][3];
      int p = g_current;
      if (BLUR_NUM <= ++g_current) { g_current = 0; }
      makeRotationMatrix(m, -ROTATION_RADIAN);
      makeTransformationMatrix(g_matrix[g_current], g_matrix[p], m);
      break;
    }
    case 'r':   /* reset */
      init();
      break;
    default:
      break;
  }
  glutPostRedisplay();
}

void init(void)
{
  int i;
  for (i = 0; i < BLUR_NUM; ++i) {
    initMatrix(g_matrix[i]);
  }
  g_current = 0;
  makeStarA(g_object, 0.5);
}

int main(int argc, char *argv[])
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGBA);
  glutCreateWindow(argv[0]);
  glutDisplayFunc(display);
  glutKeyboardFunc(key);
  glClearColor(0.0, 0.0, 0.0, 0.0);

  init();

  glutMainLoop();
  return 0;
}

Line 20: error: GL/glut.h: No such file or directory
In function 'display':
Line 89: error: 'GL_COLOR_BUFFER_BIT' undeclared (first use in this function)
Line 89: error: (Each undeclared identifier is reported only once
Line 89: error: for each function it appears in.)
Line 92: error: 'GL_LINES' undeclared (first use in this function)
Line 107: warning: passing argument 3 of 'transform' from incompatible pointer type
Line 107: warning: passing argument 4 of 'transform' from incompatible pointer type
Line 108: error: 'GL_LINE_LOOP' undeclared (first use in this function)
In function 'key':
Line 132: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 132: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
Line 140: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 140: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
Line 148: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 148: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
Line 156: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 156: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
Line 164: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 164: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
Line 172: warning: passing argument 2 of 'makeTransformationMatrix' from incompatible pointer type
Line 172: warning: passing argument 3 of 'makeTransformationMatrix' from incompatible pointer type
In function 'main':
Line 197: error: 'GLUT_RGBA' undeclared (first use in this function)