samples/opengl/cube/cube.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        cube.cpp
   3 // Purpose:     wxGLCanvas demo program
   4 // Author:      Julian Smart
   5 // Modified by: Vadim Zeitlin to use new wxGLCanvas API (2007-04-09)
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24 #pragma hdrstop
  25 #endif
  26
  27 #ifndef WX_PRECOMP
  28 #include "wx/wx.h"
  29 #endif
  30
  31 #if !wxUSE_GLCANVAS
  32     #error "OpenGL required: set wxUSE_GLCANVAS to 1 and rebuild the library"
  33 #endif
  34
  35 #include "cube.h"
  36
  37 #if !defined(__WXMSW__) && !defined(__WXPM__)
  38     #include "../../sample.xpm"
  39 #endif
  40
  41 // ----------------------------------------------------------------------------
  42 // helper functions
  43 // ----------------------------------------------------------------------------
  44
  45 static void CheckGLError()
  46 {
  47     GLenum errLast = GL_NO_ERROR;
  48
  49     for ( ;; )
  50     {
  51         GLenum err = glGetError();
  52         if ( err == GL_NO_ERROR )
  53             return;
  54
  55         // normally the error is reset by the call to glGetError() but if
  56         // glGetError() itself returns an error, we risk looping forever here
  57         // so check that we get a different error than the last time
  58         if ( err == errLast )
  59         {
  60             wxLogError(_T("OpenGL error state couldn't be reset."));
  61             return;
  62         }
  63
  64         errLast = err;
  65
  66         wxLogError(_T("OpenGL error %d"), err);
  67     }
  68 }
  69
  70 // function to draw the texture for cube faces
  71 static wxImage DrawDice(int size, unsigned num)
  72 {
  73     wxASSERT_MSG( num >= 1 && num <= 6, _T("invalid dice index") );
  74
  75     const int dot = size/16;        // radius of a single dot
  76     const int gap = 5*size/32;      // gap between dots
  77
  78     wxBitmap bmp(size, size);
  79     wxMemoryDC dc;
  80     dc.SelectObject(bmp);
  81     dc.SetBackground(*wxWHITE_BRUSH);
  82     dc.Clear();
  83     dc.SetBrush(*wxBLACK_BRUSH);
  84
  85     // the upper left and lower right points
  86     if ( num != 1 )
  87     {
  88         dc.DrawCircle(gap + dot, gap + dot, dot);
  89         dc.DrawCircle(size - gap - dot, size - gap - dot, dot);
  90     }
  91
  92     // draw the central point for odd dices
  93     if ( num % 2 )
  94     {
  95         dc.DrawCircle(size/2, size/2, dot);
  96     }
  97
  98     // the upper right and lower left points
  99     if ( num > 3 )
 100     {
 101         dc.DrawCircle(size - gap - dot, gap + dot, dot);
 102         dc.DrawCircle(gap + dot, size - gap - dot, dot);
 103     }
 104
 105     // finally those 2 are only for the last dice
 106     if ( num == 6 )
 107     {
 108         dc.DrawCircle(gap + dot, size/2, dot);
 109         dc.DrawCircle(size - gap - dot, size/2, dot);
 110     }
 111
 112     dc.SelectObject(wxNullBitmap);
 113
 114     return bmp.ConvertToImage();
 115 }
 116
 117 // ============================================================================
 118 // implementation
 119 // ============================================================================
 120
 121 // ----------------------------------------------------------------------------
 122 // MyApp: the application object
 123 // ----------------------------------------------------------------------------
 124
 125 IMPLEMENT_APP(MyApp)
 126
 127 bool MyApp::OnInit()
 128 {
 129     if ( !wxApp::OnInit() )
 130         return false;
 131
 132     // Create the main window
 133     new MyFrame();
 134
 135     return true;
 136 }
 137
 138 int MyApp::OnExit()
 139 {
 140     delete m_glContext;
 141
 142     return wxApp::OnExit();
 143 }
 144
 145 TestGLContext& MyApp::GetContext(wxGLCanvas *canvas)
 146 {
 147     if ( !m_glContext )
 148         m_glContext = new TestGLContext(canvas);
 149     else
 150         m_glContext->SetCurrent(*canvas);
 151
 152     return *m_glContext;
 153 }
 154
 155 // ----------------------------------------------------------------------------
 156 // TestGLContext
 157 // ----------------------------------------------------------------------------
 158
 159 TestGLContext::TestGLContext(wxGLCanvas *canvas)
 160              : wxGLContext(canvas)
 161 {
 162     SetCurrent(*canvas);
 163
 164     // set up the parameters we want to use
 165     glEnable(GL_DEPTH_TEST);
 166     glEnable(GL_LIGHTING);
 167     glEnable(GL_LIGHT0);
 168     glEnable(GL_TEXTURE_2D);
 169
 170     // add slightly more light, the default lightning is rather dark
 171     GLfloat ambient[] = { 0.5, 0.5, 0.5, 0.5 };
 172     glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
 173
 174     // set viewing projection
 175     glMatrixMode(GL_PROJECTION);
 176     glLoadIdentity();
 177     glFrustum(-0.5f, 0.5f, -0.5f, 0.5f, 1.0f, 3.0f);
 178
 179     // create the textures to use for cube sides: they will be reused by all
 180     // canvases (which is probably not critical in the case of simple textures
 181     // we use here but could be really important for a real application where
 182     // each texture could take many megabytes)
 183     glGenTextures(WXSIZEOF(m_textures), m_textures);
 184
 185     for ( unsigned i = 0; i < WXSIZEOF(m_textures); i++ )
 186     {
 187         glBindTexture(GL_TEXTURE_2D, m_textures[i]);
 188
 189         glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 190         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 191         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 192         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 193         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 194
 195         const wxImage img(DrawDice(256, i + 1));
 196
 197         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 198         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img.GetWidth(), img.GetHeight(),
 199                      0, GL_RGB, GL_UNSIGNED_BYTE, img.GetData());
 200     }
 201
 202     CheckGLError();
 203 }
 204
 205 void TestGLContext::DrawRotatedCube(float xangle, float yangle)
 206 {
 207     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 208
 209     glMatrixMode(GL_MODELVIEW);
 210     glLoadIdentity();
 211     glTranslatef(0.0f, 0.0f, -2.0f);
 212     glRotatef(xangle, 1.0f, 0.0f, 0.0f);
 213     glRotatef(yangle, 0.0f, 1.0f, 0.0f);
 214
 215     // draw six faces of a cube of size 1 centered at (0, 0, 0)
 216     glBindTexture(GL_TEXTURE_2D, m_textures[0]);
 217     glBegin(GL_QUADS);
 218         glNormal3f( 0.0f, 0.0f, 1.0f);
 219         glTexCoord2f(0, 0); glVertex3f( 0.5f, 0.5f, 0.5f);
 220         glTexCoord2f(1, 0); glVertex3f(-0.5f, 0.5f, 0.5f);
 221         glTexCoord2f(1, 1); glVertex3f(-0.5f,-0.5f, 0.5f);
 222         glTexCoord2f(0, 1); glVertex3f( 0.5f,-0.5f, 0.5f);
 223     glEnd();
 224
 225     glBindTexture(GL_TEXTURE_2D, m_textures[1]);
 226     glBegin(GL_QUADS);
 227         glNormal3f( 0.0f, 0.0f,-1.0f);
 228         glTexCoord2f(0, 0); glVertex3f(-0.5f,-0.5f,-0.5f);
 229         glTexCoord2f(1, 0); glVertex3f(-0.5f, 0.5f,-0.5f);
 230         glTexCoord2f(1, 1); glVertex3f( 0.5f, 0.5f,-0.5f);
 231         glTexCoord2f(0, 1); glVertex3f( 0.5f,-0.5f,-0.5f);
 232     glEnd();
 233
 234     glBindTexture(GL_TEXTURE_2D, m_textures[2]);
 235     glBegin(GL_QUADS);
 236         glNormal3f( 0.0f, 1.0f, 0.0f);
 237         glTexCoord2f(0, 0); glVertex3f( 0.5f, 0.5f, 0.5f);
 238         glTexCoord2f(1, 0); glVertex3f( 0.5f, 0.5f,-0.5f);
 239         glTexCoord2f(1, 1); glVertex3f(-0.5f, 0.5f,-0.5f);
 240         glTexCoord2f(0, 1); glVertex3f(-0.5f, 0.5f, 0.5f);
 241     glEnd();
 242
 243     glBindTexture(GL_TEXTURE_2D, m_textures[3]);
 244     glBegin(GL_QUADS);
 245         glNormal3f( 0.0f,-1.0f, 0.0f);
 246         glTexCoord2f(0, 0); glVertex3f(-0.5f,-0.5f,-0.5f);
 247         glTexCoord2f(1, 0); glVertex3f( 0.5f,-0.5f,-0.5f);
 248         glTexCoord2f(1, 1); glVertex3f( 0.5f,-0.5f, 0.5f);
 249         glTexCoord2f(0, 1); glVertex3f(-0.5f,-0.5f, 0.5f);
 250     glEnd();
 251
 252     glBindTexture(GL_TEXTURE_2D, m_textures[4]);
 253     glBegin(GL_QUADS);
 254         glNormal3f( 1.0f, 0.0f, 0.0f);
 255         glTexCoord2f(0, 0); glVertex3f( 0.5f, 0.5f, 0.5f);
 256         glTexCoord2f(1, 0); glVertex3f( 0.5f,-0.5f, 0.5f);
 257         glTexCoord2f(1, 1); glVertex3f( 0.5f,-0.5f,-0.5f);
 258         glTexCoord2f(0, 1); glVertex3f( 0.5f, 0.5f,-0.5f);
 259     glEnd();
 260
 261     glBindTexture(GL_TEXTURE_2D, m_textures[5]);
 262     glBegin(GL_QUADS);
 263         glNormal3f(-1.0f, 0.0f, 0.0f);
 264         glTexCoord2f(0, 0); glVertex3f(-0.5f,-0.5f,-0.5f);
 265         glTexCoord2f(1, 0); glVertex3f(-0.5f,-0.5f, 0.5f);
 266         glTexCoord2f(1, 1); glVertex3f(-0.5f, 0.5f, 0.5f);
 267         glTexCoord2f(0, 1); glVertex3f(-0.5f, 0.5f,-0.5f);
 268     glEnd();
 269
 270     glFlush();
 271
 272     CheckGLError();
 273 }
 274
 275 // ----------------------------------------------------------------------------
 276 // TestGLCanvas
 277 // ----------------------------------------------------------------------------
 278
 279 BEGIN_EVENT_TABLE(TestGLCanvas, wxGLCanvas)
 280     EVT_SIZE(TestGLCanvas::OnSize)
 281     EVT_PAINT(TestGLCanvas::OnPaint)
 282
 283     EVT_KEY_DOWN(TestGLCanvas::OnKeyDown)
 284 END_EVENT_TABLE()
 285
 286 TestGLCanvas::TestGLCanvas(wxWindow *parent)
 287             : wxGLCanvas(parent, wxID_ANY, NULL /* attribs */)
 288 {
 289     m_xangle =
 290     m_yangle = 30;
 291 }
 292
 293 void TestGLCanvas::OnPaint(wxPaintEvent& WXUNUSED(event))
 294 {
 295     wxPaintDC dc(this);
 296
 297     wxGetApp().GetContext(this).DrawRotatedCube(m_xangle, m_yangle);
 298
 299     SwapBuffers();
 300 }
 301
 302 void TestGLCanvas::OnSize(wxSizeEvent& event)
 303 {
 304     // don't prevent default processing from taking place
 305     event.Skip();
 306
 307     if ( !IsShownOnScreen() )
 308         return;
 309
 310     // set GL viewport (not called by wxGLCanvas::OnSize on all platforms...)
 311     int w, h;
 312     GetClientSize(&w, &h);
 313
 314     wxGetApp().GetContext(this);
 315     glViewport(0, 0, w, h);
 316 }
 317
 318 void TestGLCanvas::OnKeyDown( wxKeyEvent& event )
 319 {
 320     float *p = NULL;
 321
 322     bool inverse = false;
 323
 324     switch ( event.GetKeyCode() )
 325     {
 326         case WXK_RIGHT:
 327             inverse = true;
 328             // fall through
 329
 330         case WXK_LEFT:
 331             // rotate around Y axis
 332             p = &m_yangle;
 333             break;
 334
 335         case WXK_DOWN:
 336             inverse = true;
 337             // fall through
 338
 339         case WXK_UP:
 340             // rotate around X axis
 341             p = &m_xangle;
 342             break;
 343
 344         default:
 345             event.Skip();
 346             return;
 347     }
 348
 349     float angle = 5;
 350     if ( inverse )
 351         angle = -angle;
 352
 353     *p += angle;
 354
 355     Refresh(false);
 356 }
 357
 358 // ----------------------------------------------------------------------------
 359 // MyFrame: main application window
 360 // ----------------------------------------------------------------------------
 361
 362 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 363     EVT_MENU(wxID_NEW, MyFrame::OnNewWindow)
 364     EVT_MENU(wxID_CLOSE, MyFrame::OnClose)
 365 END_EVENT_TABLE()
 366
 367 MyFrame::MyFrame()
 368        : wxFrame(NULL, wxID_ANY, _T("wxWidgets OpenGL Cube Sample"))
 369 {
 370     new TestGLCanvas(this);
 371
 372     SetIcon(wxICON(sample));
 373
 374     // Make a menubar
 375     wxMenu *menu = new wxMenu;
 376     menu->Append(wxID_NEW);
 377     menu->AppendSeparator();
 378     menu->Append(wxID_CLOSE);
 379     wxMenuBar *menuBar = new wxMenuBar;
 380     menuBar->Append(menu, _T("&Cube"));
 381
 382     SetMenuBar(menuBar);
 383
 384     CreateStatusBar();
 385
 386     SetClientSize(400, 400);
 387     Show();
 388 }
 389
 390 void MyFrame::OnClose(wxCommandEvent& WXUNUSED(event))
 391 {
 392     // true is to force the frame to close
 393     Close(true);
 394 }
 395
 396 void MyFrame::OnNewWindow( wxCommandEvent& WXUNUSED(event) )
 397 {
 398     (void) new MyFrame();
 399 }
 400