reactphysics3d/examples/common/Viewer.cpp
2013-12-30 01:51:46 +01:00

338 lines
10 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://code.google.com/p/reactphysics3d/ *
* Copyright (c) 2010-2013 Daniel Chappuis *
*********************************************************************************
* *
* This software is provided 'as-is', without any express or implied warranty. *
* In no event will the authors be held liable for any damages arising from the *
* use of this software. *
* *
* Permission is granted to anyone to use this software for any purpose, *
* including commercial applications, and to alter it and redistribute it *
* freely, subject to the following restrictions: *
* *
* 1. The origin of this software must not be misrepresented; you must not claim *
* that you wrote the original software. If you use this software in a *
* product, an acknowledgment in the product documentation would be *
* appreciated but is not required. *
* *
* 2. Altered source versions must be plainly marked as such, and must not be *
* misrepresented as being the original software. *
* *
* 3. This notice may not be removed or altered from any source distribution. *
* *
********************************************************************************/
// Libraries
#include "Viewer.h"
#include "openglframework.h"
#include <iostream>
using namespace openglframework;
// Initialization of static variables
const float Viewer::SCROLL_SENSITIVITY = 0.02f;
// Constructor
Viewer::Viewer() : mFPS(0), mNbFrames(0), mPreviousTime(0) {
}
// Destructor
Viewer::~Viewer() {
// Destroy the window
glfwDestroyWindow(mWindow);
// Terminate GLFW
glfwTerminate();
}
// Initialize the viewer
void Viewer::init(int argc, char** argv, const std::string& windowsTitle,
const Vector2& windowsSize, const Vector2& windowsPosition,
bool isMultisamplingActive) {
mWindowTitle = windowsTitle;
// Set the GLFW error callback method
glfwSetErrorCallback(error_callback);
// Initialize the GLFW library
if (!glfwInit()) {
exit(EXIT_FAILURE);
}
// Active the multi-sampling by default
if (isMultisamplingActive) {
glfwWindowHint(GLFW_SAMPLES, 4);
}
// Create the GLFW window
mWindow = glfwCreateWindow(static_cast<int>(windowsSize.x),
static_cast<int>(windowsSize.y), mWindowTitle.c_str(), NULL, NULL);
if (!mWindow) {
glfwTerminate();
exit(EXIT_FAILURE);
}
glfwMakeContextCurrent(mWindow);
// Disable Vertical Synchronization
glfwSwapInterval(0);
// Initialize the GLEW library
GLenum errorGLEW = glewInit();
if (errorGLEW != GLEW_OK) {
// Problem: glewInit failed, something is wrong
std::cerr << "GLEW Error : " << glewGetErrorString(errorGLEW) << std::endl;
assert(false);
exit(EXIT_FAILURE);
}
if (isMultisamplingActive) {
glEnable(GL_MULTISAMPLE);
}
}
// Set the dimension of the camera viewport
void Viewer::reshape() {
// Get the framebuffer dimension
int width, height;
glfwGetFramebufferSize(mWindow, &width, &height);
// Resize the viewport
mCamera.setDimensions(width, height);
glViewport(0, 0, width, height);
}
// Start the main loop where rendering occur
void Viewer::startMainLoop() {
// Loop until the user closes the window
while (!glfwWindowShouldClose(mWindow)) {
// Reshape the viewport
reshape();
// Call the update function
(*mUpdateFunctionPointer)();
// Swap front and back buffers
glfwSwapBuffers(mWindow);
// Poll for and process events
glfwPollEvents();
}
}
// Set the camera so that we can view the whole scene
void Viewer::resetCameraToViewAll() {
// Move the camera to the origin of the scene
mCamera.translateWorld(-mCamera.getOrigin());
// Move the camera to the center of the scene
mCamera.translateWorld(mCenterScene);
// Set the zoom of the camera so that the scene center is
// in negative view direction of the camera
mCamera.setZoom(1.0);
}
// Called when a mouse button event occurs
void Viewer::mouseButtonEvent(int button, int action) {
// Get the mouse cursor position
double x, y;
glfwGetCursorPos(mWindow, &x, &y);
// If the mouse button is pressed
if (action == GLFW_PRESS) {
mLastMouseX = x;
mLastMouseY = y;
mIsLastPointOnSphereValid = mapMouseCoordinatesToSphere(x, y, mLastPointOnSphere);
}
else { // If the mouse button is released
mIsLastPointOnSphereValid = false;
}
}
// Called when a mouse motion event occurs
void Viewer::mouseMotionEvent(double xMouse, double yMouse) {
int leftButtonState = glfwGetMouseButton(mWindow, GLFW_MOUSE_BUTTON_LEFT);
int rightButtonState = glfwGetMouseButton(mWindow, GLFW_MOUSE_BUTTON_RIGHT);
int middleButtonState = glfwGetMouseButton(mWindow, GLFW_MOUSE_BUTTON_MIDDLE);
int altKeyState = glfwGetKey(mWindow, GLFW_KEY_LEFT_ALT);
// Zoom
if (leftButtonState == GLFW_PRESS && altKeyState == GLFW_PRESS) {
// Get the window dimension
int width, height;
glfwGetWindowSize(mWindow, &width, &height);
float dy = static_cast<float>(yMouse - mLastMouseY);
float h = static_cast<float>(height);
// Zoom the camera
zoom(-dy / h);
}
// Translation
else if (middleButtonState == GLFW_PRESS || rightButtonState == GLFW_PRESS ||
(leftButtonState == GLFW_PRESS && altKeyState == GLFW_PRESS)) {
translate(xMouse, yMouse);
}
// Rotation
else if (leftButtonState == GLFW_PRESS) {
rotate(xMouse, yMouse);
}
// Remember the mouse position
mLastMouseX = xMouse;
mLastMouseY = yMouse;
mIsLastPointOnSphereValid = mapMouseCoordinatesToSphere(xMouse, yMouse, mLastPointOnSphere);
}
// Called when a scrolling event occurs
void Viewer::scrollingEvent(float scrollAxis) {
zoom(scrollAxis * SCROLL_SENSITIVITY);
}
// Map the mouse x,y coordinates to a point on a sphere
bool Viewer::mapMouseCoordinatesToSphere(double xMouse, double yMouse, Vector3& spherePoint) const {
// Get the window dimension
int width, height;
glfwGetWindowSize(mWindow, &width, &height);
if ((xMouse >= 0) && (xMouse <= width) && (yMouse >= 0) && (yMouse <= height)) {
float x = float(xMouse - 0.5f * width) / float(width);
float y = float(0.5f * height - yMouse) / float(height);
float sinx = sin(PI * x * 0.5f);
float siny = sin(PI * y * 0.5f);
float sinx2siny2 = sinx * sinx + siny * siny;
// Compute the point on the sphere
spherePoint.x = sinx;
spherePoint.y = siny;
spherePoint.z = (sinx2siny2 < 1.0) ? sqrt(1.0f - sinx2siny2) : 0.0f;
return true;
}
return false;
}
// Zoom the camera
void Viewer::zoom(float zoomDiff) {
// Zoom the camera
mCamera.setZoom(zoomDiff);
}
// Translate the camera
void Viewer::translate(int xMouse, int yMouse) {
float dx = static_cast<float>(xMouse - mLastMouseX);
float dy = static_cast<float>(yMouse - mLastMouseY);
// Translate the camera
mCamera.translateCamera(-dx / float(mCamera.getWidth()),
-dy / float(mCamera.getHeight()), mCenterScene);
}
// Rotate the camera
void Viewer::rotate(int xMouse, int yMouse) {
if (mIsLastPointOnSphereValid) {
Vector3 newPoint3D;
bool isNewPointOK = mapMouseCoordinatesToSphere(xMouse, yMouse, newPoint3D);
if (isNewPointOK) {
Vector3 axis = mLastPointOnSphere.cross(newPoint3D);
float cosAngle = mLastPointOnSphere.dot(newPoint3D);
float epsilon = std::numeric_limits<float>::epsilon();
if (fabs(cosAngle) < 1.0f && axis.length() > epsilon) {
axis.normalize();
float angle = 2.0f * acos(cosAngle);
// Rotate the camera around the center of the scene
mCamera.rotateAroundLocalPoint(axis, -angle, mCenterScene);
}
}
}
}
// Check the OpenGL errors
void Viewer::checkOpenGLErrors() {
GLenum glError;
// Get the OpenGL errors
glError = glGetError();
// While there are errors
while (glError != GL_NO_ERROR) {
// Get the error string
const GLubyte* stringError = gluErrorString(glError);
// Display the error
if (stringError)
std::cerr << "OpenGL Error #" << glError << "(" << gluErrorString(glError) << std::endl;
else
std::cerr << "OpenGL Error #" << glError << " (no message available)" << std::endl;
// Get the next error
glError = glGetError();
}
}
// Compute the FPS
void Viewer::computeFPS() {
mNbFrames++;
// Get the number of milliseconds since glutInit called
mCurrentTime = glfwGetTime();
// Calculate time passed
double timeInterval = mCurrentTime - mPreviousTime;
// Update the FPS counter each second
if(timeInterval > 1.0) {
// calculate the number of frames per second
mFPS = static_cast<double>(mNbFrames) / timeInterval;
// Set time
mPreviousTime = mCurrentTime;
// Reset frame count
mNbFrames = 0;
}
}
// GLFW error callback method
void Viewer::error_callback(int error, const char* description) {
fputs(description, stderr);
}
// Display the GUI
void Viewer::displayGUI() {
// Display the FPS
displayFPS();
}
// Display the FPS
void Viewer::displayFPS() {
std::string windowTitle = mWindowTitle + " | FPS : " + std::to_string(mFPS);
glfwSetWindowTitle(mWindow, windowTitle.c_str());
}