demos/opengl/gpuhelper.cpp

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "gpuhelper.h"
#include "icosphere.h"
#include <GL/glu.h>
// PLEASE don't look at this old code... ;)

#include <fstream>
#include <algorithm>

GpuHelper gpu;

GpuHelper::GpuHelper() {
  mVpWidth = mVpHeight = 0;
  mCurrentMatrixTarget = 0;
  mInitialized = false;
}

GpuHelper::~GpuHelper() {}

void GpuHelper::pushProjectionMode2D(ProjectionMode2D pm) {
  // switch to 2D projection
  pushMatrix(Matrix4f::Identity(), GL_PROJECTION);

  if (pm == PM_Normalized) {
    // glOrtho(-1., 1., -1., 1., 0., 1.);
  } else if (pm == PM_Viewport) {
    GLint vp[4];
    glGetIntegerv(GL_VIEWPORT, vp);
    glOrtho(0., vp[2], 0., vp[3], -1., 1.);
  }

  pushMatrix(Matrix4f::Identity(), GL_MODELVIEW);
}

void GpuHelper::popProjectionMode2D(void) {
  popMatrix(GL_PROJECTION);
  popMatrix(GL_MODELVIEW);
}

void GpuHelper::drawVector(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect /* = 50.*/) {
  static GLUquadricObj* cylinder = gluNewQuadric();
  glColor4fv(color.data());
  float length = vec.norm();
  pushMatrix(GL_MODELVIEW);
  glTranslatef(position.x(), position.y(), position.z());
  Vector3f ax = Matrix3f::Identity().col(2).cross(vec);
  ax.normalize();
  Vector3f tmp = vec;
  tmp.normalize();
  float angle = 180.f / M_PI * acos(tmp.z());
  if (angle > 1e-3) glRotatef(angle, ax.x(), ax.y(), ax.z());
  gluCylinder(cylinder, length / aspect, length / aspect, 0.8 * length, 10, 10);
  glTranslatef(0.0, 0.0, 0.8 * length);
  gluCylinder(cylinder, 2.0 * length / aspect, 0.0, 0.2 * length, 10, 10);

  popMatrix(GL_MODELVIEW);
}

void GpuHelper::drawVectorBox(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect) {
  static GLUquadricObj* cylinder = gluNewQuadric();
  glColor4fv(color.data());
  float length = vec.norm();
  pushMatrix(GL_MODELVIEW);
  glTranslatef(position.x(), position.y(), position.z());
  Vector3f ax = Matrix3f::Identity().col(2).cross(vec);
  ax.normalize();
  Vector3f tmp = vec;
  tmp.normalize();
  float angle = 180.f / M_PI * acos(tmp.z());
  if (angle > 1e-3) glRotatef(angle, ax.x(), ax.y(), ax.z());
  gluCylinder(cylinder, length / aspect, length / aspect, 0.8 * length, 10, 10);
  glTranslatef(0.0, 0.0, 0.8 * length);
  glScalef(4.0 * length / aspect, 4.0 * length / aspect, 4.0 * length / aspect);
  drawUnitCube();
  popMatrix(GL_MODELVIEW);
}

void GpuHelper::drawUnitCube(void) {
  static float vertices[][3] = {{-0.5, -0.5, -0.5}, {0.5, -0.5, -0.5}, {-0.5, 0.5, -0.5}, {0.5, 0.5, -0.5},
                                {-0.5, -0.5, 0.5},  {0.5, -0.5, 0.5},  {-0.5, 0.5, 0.5},  {0.5, 0.5, 0.5}};

  glBegin(GL_QUADS);
  glNormal3f(0, 0, -1);
  glVertex3fv(vertices[0]);
  glVertex3fv(vertices[2]);
  glVertex3fv(vertices[3]);
  glVertex3fv(vertices[1]);
  glNormal3f(0, 0, 1);
  glVertex3fv(vertices[4]);
  glVertex3fv(vertices[5]);
  glVertex3fv(vertices[7]);
  glVertex3fv(vertices[6]);
  glNormal3f(0, -1, 0);
  glVertex3fv(vertices[0]);
  glVertex3fv(vertices[1]);
  glVertex3fv(vertices[5]);
  glVertex3fv(vertices[4]);
  glNormal3f(0, 1, 0);
  glVertex3fv(vertices[2]);
  glVertex3fv(vertices[6]);
  glVertex3fv(vertices[7]);
  glVertex3fv(vertices[3]);
  glNormal3f(-1, 0, 0);
  glVertex3fv(vertices[0]);
  glVertex3fv(vertices[4]);
  glVertex3fv(vertices[6]);
  glVertex3fv(vertices[2]);
  glNormal3f(1, 0, 0);
  glVertex3fv(vertices[1]);
  glVertex3fv(vertices[3]);
  glVertex3fv(vertices[7]);
  glVertex3fv(vertices[5]);
  glEnd();
}

void GpuHelper::drawUnitSphere(int level) {
  static IcoSphere sphere;
  sphere.draw(level);
}