reactphysics3d/testbed/nanogui/src/example4.cpp

251 lines
7.3 KiB
C++

/*
src/example4.cpp -- C++ version of an example application that shows
how to use the OpenGL widget. For a Python implementation, see
'../python/example4.py'.
NanoGUI was developed by Wenzel Jakob <wenzel.jakob@epfl.ch>.
The widget drawing code is based on the NanoVG demo application
by Mikko Mononen.
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE.txt file.
*/
#include <nanogui/opengl.h>
#include <nanogui/glutil.h>
#include <nanogui/screen.h>
#include <nanogui/window.h>
#include <nanogui/layout.h>
#include <nanogui/label.h>
#include <nanogui/checkbox.h>
#include <nanogui/button.h>
#include <nanogui/toolbutton.h>
#include <nanogui/popupbutton.h>
#include <nanogui/combobox.h>
#include <nanogui/progressbar.h>
#include <nanogui/entypo.h>
#include <nanogui/messagedialog.h>
#include <nanogui/textbox.h>
#include <nanogui/slider.h>
#include <nanogui/imagepanel.h>
#include <nanogui/imageview.h>
#include <nanogui/vscrollpanel.h>
#include <nanogui/colorwheel.h>
#include <nanogui/graph.h>
#include <nanogui/tabwidget.h>
#include <nanogui/glcanvas.h>
#include <iostream>
#include <string>
// Includes for the GLTexture class.
#include <cstdint>
#include <memory>
#include <utility>
#if defined(__GNUC__)
# pragma GCC diagnostic ignored "-Wmissing-field-initializers"
#endif
#if defined(_WIN32)
# pragma warning(push)
# pragma warning(disable: 4457 4456 4005 4312)
#endif
#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>
#if defined(_WIN32)
# pragma warning(pop)
#endif
#if defined(_WIN32)
# if defined(APIENTRY)
# undef APIENTRY
# endif
# include <windows.h>
#endif
using std::cout;
using std::cerr;
using std::endl;
using std::string;
using std::vector;
using std::pair;
using std::to_string;
class MyGLCanvas : public nanogui::GLCanvas {
public:
MyGLCanvas(Widget *parent) : nanogui::GLCanvas(parent), mRotation(nanogui::Vector3f(0.25f, 0.5f, 0.33f)) {
using namespace nanogui;
mShader.init(
/* An identifying name */
"a_simple_shader",
/* Vertex shader */
"#version 330\n"
"uniform mat4 modelViewProj;\n"
"in vec3 position;\n"
"in vec3 color;\n"
"out vec4 frag_color;\n"
"void main() {\n"
" frag_color = 3.0 * modelViewProj * vec4(color, 1.0);\n"
" gl_Position = modelViewProj * vec4(position, 1.0);\n"
"}",
/* Fragment shader */
"#version 330\n"
"out vec4 color;\n"
"in vec4 frag_color;\n"
"void main() {\n"
" color = frag_color;\n"
"}"
);
MatrixXu indices(3, 12); /* Draw a cube */
indices.col( 0) << 0, 1, 3;
indices.col( 1) << 3, 2, 1;
indices.col( 2) << 3, 2, 6;
indices.col( 3) << 6, 7, 3;
indices.col( 4) << 7, 6, 5;
indices.col( 5) << 5, 4, 7;
indices.col( 6) << 4, 5, 1;
indices.col( 7) << 1, 0, 4;
indices.col( 8) << 4, 0, 3;
indices.col( 9) << 3, 7, 4;
indices.col(10) << 5, 6, 2;
indices.col(11) << 2, 1, 5;
MatrixXf positions(3, 8);
positions.col(0) << -1, 1, 1;
positions.col(1) << -1, 1, -1;
positions.col(2) << 1, 1, -1;
positions.col(3) << 1, 1, 1;
positions.col(4) << -1, -1, 1;
positions.col(5) << -1, -1, -1;
positions.col(6) << 1, -1, -1;
positions.col(7) << 1, -1, 1;
MatrixXf colors(3, 12);
colors.col( 0) << 1, 0, 0;
colors.col( 1) << 0, 1, 0;
colors.col( 2) << 1, 1, 0;
colors.col( 3) << 0, 0, 1;
colors.col( 4) << 1, 0, 1;
colors.col( 5) << 0, 1, 1;
colors.col( 6) << 1, 1, 1;
colors.col( 7) << 0.5, 0.5, 0.5;
colors.col( 8) << 1, 0, 0.5;
colors.col( 9) << 1, 0.5, 0;
colors.col(10) << 0.5, 1, 0;
colors.col(11) << 0.5, 1, 0.5;
mShader.bind();
mShader.uploadIndices(indices);
mShader.uploadAttrib("position", positions);
mShader.uploadAttrib("color", colors);
}
~MyGLCanvas() {
mShader.free();
}
void setRotation(nanogui::Vector3f vRotation) {
mRotation = vRotation;
}
virtual void drawGL() override {
using namespace nanogui;
mShader.bind();
Matrix4f mvp;
mvp.setIdentity();
float fTime = (float)glfwGetTime();
mvp.topLeftCorner<3,3>() = Eigen::Matrix3f(Eigen::AngleAxisf(mRotation[0]*fTime, Vector3f::UnitX()) *
Eigen::AngleAxisf(mRotation[1]*fTime, Vector3f::UnitY()) *
Eigen::AngleAxisf(mRotation[2]*fTime, Vector3f::UnitZ())) * 0.25f;
mShader.setUniform("modelViewProj", mvp);
glEnable(GL_DEPTH_TEST);
/* Draw 12 triangles starting at index 0 */
mShader.drawIndexed(GL_TRIANGLES, 0, 12);
glDisable(GL_DEPTH_TEST);
}
private:
nanogui::GLShader mShader;
Eigen::Vector3f mRotation;
};
class ExampleApplication : public nanogui::Screen {
public:
ExampleApplication() : nanogui::Screen(Eigen::Vector2i(800, 600), "NanoGUI Test", false) {
using namespace nanogui;
Window *window = new Window(this, "GLCanvas Demo");
window->setPosition(Vector2i(15, 15));
window->setLayout(new GroupLayout());
mCanvas = new MyGLCanvas(window);
mCanvas->setBackgroundColor({100, 100, 100, 255});
mCanvas->setSize({400, 400});
Widget *tools = new Widget(window);
tools->setLayout(new BoxLayout(Orientation::Horizontal,
Alignment::Middle, 0, 5));
Button *b0 = new Button(tools, "Random Color");
b0->setCallback([this]() { mCanvas->setBackgroundColor(Vector4i(rand() % 256, rand() % 256, rand() % 256, 255)); });
Button *b1 = new Button(tools, "Random Rotation");
b1->setCallback([this]() { mCanvas->setRotation(nanogui::Vector3f((rand() % 100) / 100.0f, (rand() % 100) / 100.0f, (rand() % 100) / 100.0f)); });
performLayout();
}
virtual bool keyboardEvent(int key, int scancode, int action, int modifiers) {
if (Screen::keyboardEvent(key, scancode, action, modifiers))
return true;
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) {
setVisible(false);
return true;
}
return false;
}
virtual void draw(NVGcontext *ctx) {
/* Draw the user interface */
Screen::draw(ctx);
}
private:
MyGLCanvas *mCanvas;
};
int main(int /* argc */, char ** /* argv */) {
try {
nanogui::init();
/* scoped variables */ {
nanogui::ref<ExampleApplication> app = new ExampleApplication();
app->drawAll();
app->setVisible(true);
nanogui::mainloop();
}
nanogui::shutdown();
} catch (const std::runtime_error &e) {
std::string error_msg = std::string("Caught a fatal error: ") + std::string(e.what());
#if defined(_WIN32)
MessageBoxA(nullptr, error_msg.c_str(), NULL, MB_ICONERROR | MB_OK);
#else
std::cerr << error_msg << endl;
#endif
return -1;
}
return 0;
}