mkdir ~/opengl-minimal
cd ~/opengl-minimalUse the first example in https://wiki.wxwidgets.org/WxGLCanvas
//main.h
#ifndef _glpane_
#define _glpane_
#include "wx/wx.h"
#include "wx/glcanvas.h"
class BasicGLPane : public wxGLCanvas
{
wxGLContext* m_context;
public:
BasicGLPane(wxFrame* parent, int* args);
virtual ~BasicGLPane();
void resized(wxSizeEvent& evt);
int getWidth();
int getHeight();
void render(wxPaintEvent& evt);
void prepare3DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y);
void prepare2DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y);
// events
void mouseMoved(wxMouseEvent& event);
void mouseDown(wxMouseEvent& event);
void mouseWheelMoved(wxMouseEvent& event);
void mouseReleased(wxMouseEvent& event);
void rightClick(wxMouseEvent& event);
void mouseLeftWindow(wxMouseEvent& event);
void keyPressed(wxKeyEvent& event);
void keyReleased(wxKeyEvent& event);
DECLARE_EVENT_TABLE()
};
#endif
//main.cpp
#include "wx/wx.h"
#include "wx/sizer.h"
#include "wx/glcanvas.h"
#include "main.h"
// include OpenGL
#ifdef __WXMAC__
#include "OpenGL/glu.h"
#include "OpenGL/gl.h"
#else
#include <GL/glu.h>
#include <GL/gl.h>
#endif
class MyApp: public wxApp
{
virtual bool OnInit();
wxFrame *frame;
BasicGLPane * glPane;
public:
};
IMPLEMENT_APP(MyApp)
bool MyApp::OnInit()
{
wxBoxSizer* sizer = new wxBoxSizer(wxHORIZONTAL);
frame = new wxFrame((wxFrame *)NULL, -1, wxT("Hello GL World"), wxPoint(50,50), wxSize(400,200));
int args[] = {WX_GL_RGBA, WX_GL_DOUBLEBUFFER, WX_GL_DEPTH_SIZE, 16, 0};
glPane = new BasicGLPane( (wxFrame*) frame, args);
sizer->Add(glPane, 1, wxEXPAND);
frame->SetSizer(sizer);
frame->SetAutoLayout(true);
frame->Show();
return true;
}
BEGIN_EVENT_TABLE(BasicGLPane, wxGLCanvas)
EVT_MOTION(BasicGLPane::mouseMoved)
EVT_LEFT_DOWN(BasicGLPane::mouseDown)
EVT_LEFT_UP(BasicGLPane::mouseReleased)
EVT_RIGHT_DOWN(BasicGLPane::rightClick)
EVT_LEAVE_WINDOW(BasicGLPane::mouseLeftWindow)
EVT_SIZE(BasicGLPane::resized)
EVT_KEY_DOWN(BasicGLPane::keyPressed)
EVT_KEY_UP(BasicGLPane::keyReleased)
EVT_MOUSEWHEEL(BasicGLPane::mouseWheelMoved)
EVT_PAINT(BasicGLPane::render)
END_EVENT_TABLE()
// some useful events to use
void BasicGLPane::mouseMoved(wxMouseEvent& event) {}
void BasicGLPane::mouseDown(wxMouseEvent& event) {}
void BasicGLPane::mouseWheelMoved(wxMouseEvent& event) {}
void BasicGLPane::mouseReleased(wxMouseEvent& event) {}
void BasicGLPane::rightClick(wxMouseEvent& event) {}
void BasicGLPane::mouseLeftWindow(wxMouseEvent& event) {}
void BasicGLPane::keyPressed(wxKeyEvent& event) {}
void BasicGLPane::keyReleased(wxKeyEvent& event) {}
// Vertices and faces of a simple cube to demonstrate 3D render
// source: http://www.opengl.org/resources/code/samples/glut_examples/examples/cube.c
GLfloat v[8][3];
GLint faces[6][4] = { /* Vertex indices for the 6 faces of a cube. */
{0, 1, 2, 3}, {3, 2, 6, 7}, {7, 6, 5, 4},
{4, 5, 1, 0}, {5, 6, 2, 1}, {7, 4, 0, 3} };
BasicGLPane::BasicGLPane(wxFrame* parent, int* args) :
wxGLCanvas(parent, wxID_ANY, args, wxDefaultPosition, wxDefaultSize, wxFULL_REPAINT_ON_RESIZE)
{
m_context = new wxGLContext(this);
// prepare a simple cube to demonstrate 3D render
// source: http://www.opengl.org/resources/code/samples/glut_examples/examples/cube.c
v[0][0] = v[1][0] = v[2][0] = v[3][0] = -1;
v[4][0] = v[5][0] = v[6][0] = v[7][0] = 1;
v[0][1] = v[1][1] = v[4][1] = v[5][1] = -1;
v[2][1] = v[3][1] = v[6][1] = v[7][1] = 1;
v[0][2] = v[3][2] = v[4][2] = v[7][2] = 1;
v[1][2] = v[2][2] = v[5][2] = v[6][2] = -1;
// To avoid flashing on MSW
SetBackgroundStyle(wxBG_STYLE_CUSTOM);
}
BasicGLPane::~BasicGLPane()
{
delete m_context;
}
void BasicGLPane::resized(wxSizeEvent& evt)
{
// wxGLCanvas::OnSize(evt);
Refresh();
}
/** Inits the OpenGL viewport for drawing in 3D. */
void BasicGLPane::prepare3DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y)
{
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glEnable(GL_COLOR_MATERIAL);
glViewport(topleft_x, topleft_y, bottomrigth_x-topleft_x, bottomrigth_y-topleft_y);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
float ratio_w_h = (float)(bottomrigth_x-topleft_x)/(float)(bottomrigth_y-topleft_y);
gluPerspective(45 /*view angle*/, ratio_w_h, 0.1 /*clip close*/, 200 /*clip far*/);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
/** Inits the OpenGL viewport for drawing in 2D. */
void BasicGLPane::prepare2DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y)
{
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Black Background
glEnable(GL_TEXTURE_2D); // textures
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
glViewport(topleft_x, topleft_y, bottomrigth_x-topleft_x, bottomrigth_y-topleft_y);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(topleft_x, bottomrigth_x, bottomrigth_y, topleft_y);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
int BasicGLPane::getWidth()
{
return GetSize().x;
}
int BasicGLPane::getHeight()
{
return GetSize().y;
}
void BasicGLPane::render( wxPaintEvent& evt )
{
if(!IsShown()) return;
wxGLCanvas::SetCurrent(*m_context);
wxPaintDC(this); // only to be used in paint events. use wxClientDC to paint outside the paint event
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// ------------- draw some 2D ----------------
prepare2DViewport(0,0,getWidth()/2, getHeight());
glLoadIdentity();
// white background
glColor4f(1, 1, 1, 1);
glBegin(GL_QUADS);
glVertex3f(0,0,0);
glVertex3f(getWidth(),0,0);
glVertex3f(getWidth(),getHeight(),0);
glVertex3f(0,getHeight(),0);
glEnd();
// red square
glColor4f(1, 0, 0, 1);
glBegin(GL_QUADS);
glVertex3f(getWidth()/8, getHeight()/3, 0);
glVertex3f(getWidth()*3/8, getHeight()/3, 0);
glVertex3f(getWidth()*3/8, getHeight()*2/3, 0);
glVertex3f(getWidth()/8, getHeight()*2/3, 0);
glEnd();
// ------------- draw some 3D ----------------
prepare3DViewport(getWidth()/2,0,getWidth(), getHeight());
glLoadIdentity();
glColor4f(0,0,1,1);
glTranslatef(0,0,-5);
glRotatef(50.0f, 0.0f, 1.0f, 0.0f);
glColor4f(1, 0, 0, 1);
for (int i = 0; i < 6; i++)
{
glBegin(GL_LINE_STRIP);
glVertex3fv(&v[faces[i][0]][0]);
glVertex3fv(&v[faces[i][1]][0]);
glVertex3fv(&v[faces[i][2]][0]);
glVertex3fv(&v[faces[i][3]][0]);
glVertex3fv(&v[faces[i][0]][0]);
glEnd();
}
glFlush();
SwapBuffers();
}
g++ main.cpp `wx-config --cxxflags --libs --gl-libs` -lGL -lGLU -lglut -o main
./mainShould compile and run without errors. Tested on wxWidgets 3.0.5 compiled with --with-opengl option.