hacks/gl/basic_gl_pane.cc

   1 #include "wx/wx.h"
   2 #include "wx/sizer.h"
   3 #include "wx/glcanvas.h"
   4
   5 #include "basic_gl_pane.h"
   6 #include "image.h"
   7 #include "drawable.h"
   8
   9 // include OpenGL
  10 #ifdef __WXMAC__
  11 #include "OpenGL/glu.h"
  12 #include "OpenGL/gl.h"
  13 #else
  14 #include <GL/glu.h>
  15 #include <GL/gl.h>
  16 #endif
  17
  18 class MyApp: public wxApp
  19 {
  20     virtual bool OnInit();
  21
  22     wxFrame *frame;
  23     BasicGLPane * glPane;
  24 public:
  25
  26 };
  27
  28 IMPLEMENT_APP(MyApp)
  29
  30 Image* image = NULL;
  31 DrawableThing* sprite;
  32
  33 bool MyApp::OnInit()
  34 {
  35     wxBoxSizer* sizer = new wxBoxSizer(wxHORIZONTAL);
  36     frame = new wxFrame((wxFrame *)NULL, -1,  wxT("Hello GL World"), wxPoint(50,50), wxSize(400,200));
  37
  38     int args[] = {WX_GL_RGBA, WX_GL_DOUBLEBUFFER, WX_GL_DEPTH_SIZE, 16, 0};
  39
  40     glPane = new BasicGLPane( (wxFrame*) frame, args);
  41     sizer->Add(glPane, 1, wxEXPAND);
  42
  43     frame->SetSizer(sizer);
  44     frame->SetAutoLayout(true);
  45
  46     frame->Show();
  47     return true;
  48 }
  49
  50 BEGIN_EVENT_TABLE(BasicGLPane, wxGLCanvas)
  51 EVT_MOTION(BasicGLPane::mouseMoved)
  52 EVT_LEFT_DOWN(BasicGLPane::mouseDown)
  53 EVT_LEFT_UP(BasicGLPane::mouseReleased)
  54 EVT_RIGHT_DOWN(BasicGLPane::rightClick)
  55 EVT_LEAVE_WINDOW(BasicGLPane::mouseLeftWindow)
  56 EVT_SIZE(BasicGLPane::resized)
  57 EVT_KEY_DOWN(BasicGLPane::keyPressed)
  58 EVT_KEY_UP(BasicGLPane::keyReleased)
  59 EVT_MOUSEWHEEL(BasicGLPane::mouseWheelMoved)
  60 EVT_PAINT(BasicGLPane::render)
  61 END_EVENT_TABLE()
  62
  63
  64 // some useful events to use
  65 void BasicGLPane::mouseMoved(wxMouseEvent& event) {}
  66 void BasicGLPane::mouseDown(wxMouseEvent& event) {}
  67 void BasicGLPane::mouseWheelMoved(wxMouseEvent& event) {}
  68 void BasicGLPane::mouseReleased(wxMouseEvent& event) {}
  69 void BasicGLPane::rightClick(wxMouseEvent& event) {}
  70 void BasicGLPane::mouseLeftWindow(wxMouseEvent& event) {}
  71 void BasicGLPane::keyPressed(wxKeyEvent& event) {}
  72 void BasicGLPane::keyReleased(wxKeyEvent& event) {}
  73
  74 BasicGLPane::BasicGLPane(wxFrame* parent, int* args) :
  75 wxGLCanvas(parent, wxID_ANY,  wxDefaultPosition, wxDefaultSize, 0, wxT("GLCanvas"),  args)
  76 {
  77 }
  78
  79 void BasicGLPane::resized(wxSizeEvent& evt)
  80 {
  81     wxGLCanvas::OnSize(evt);
  82
  83     Refresh();
  84 }
  85
  86 void BasicGLPane::prepare3DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y)
  87 {
  88     /*
  89      *  Inits the OpenGL viewport for drawing in 3D.
  90      */
  91
  92     glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Black Background
  93     glClearDepth(1.0f); // Depth Buffer Setup
  94     glEnable(GL_DEPTH_TEST); // Enables Depth Testing
  95     glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
  96     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
  97
  98     glEnable(GL_COLOR_MATERIAL);
  99
 100     glViewport(topleft_x, topleft_y, bottomrigth_x-topleft_x, bottomrigth_y-topleft_y);
 101     glMatrixMode(GL_PROJECTION);
 102     glLoadIdentity();
 103
 104     float ratio_w_h = (float)(bottomrigth_x-topleft_x)/(float)(bottomrigth_y-topleft_y);
 105     gluPerspective(45 /*view angle*/, ratio_w_h, 0.1 /*clip close*/, 200 /*clip far*/);
 106     glMatrixMode(GL_MODELVIEW);
 107     glLoadIdentity();
 108
 109 }
 110
 111 void BasicGLPane::prepare2DViewport(int topleft_x, int topleft_y, int bottomrigth_x, int bottomrigth_y)
 112 {
 113
 114     /*
 115      *  Inits the OpenGL viewport for drawing in 2D
 116      */
 117
 118     glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Black Background
 119     glEnable(GL_TEXTURE_2D);   // textures
 120     glEnable(GL_COLOR_MATERIAL);
 121     glEnable(GL_BLEND);
 122     glDisable(GL_DEPTH_TEST);
 123     glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 124
 125     glViewport(topleft_x, topleft_y, bottomrigth_x-topleft_x, bottomrigth_y-topleft_y);
 126     glMatrixMode(GL_PROJECTION);
 127     glLoadIdentity();
 128
 129     gluOrtho2D(topleft_x, bottomrigth_x, bottomrigth_y, topleft_y);
 130     glMatrixMode(GL_MODELVIEW);
 131     glLoadIdentity();
 132 }
 133
 134 int BasicGLPane::getWidth()
 135 {
 136     return GetSize().x;
 137 }
 138
 139 int BasicGLPane::getHeight()
 140 {
 141     return GetSize().y;
 142 }
 143
 144 void BasicGLPane::render( wxPaintEvent& evt )
 145 {
 146     if(!IsShown()) return;
 147
 148     wxGLCanvas::SetCurrent();
 149
 150
 151     if(image == NULL)
 152     {
 153         image = new Image( wxT("myfile.png") );
 154         sprite = new DrawableThing(image);
 155     }
 156
 157     wxPaintDC(this); // only to be used in paint events. use wxClientDC to paint outside the paint event
 158
 159     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 160
 161     // render loaded image
 162     prepare2DViewport(0,0,getWidth(), getHeight());
 163     sprite->render();
 164
 165     glFlush();
 166     SwapBuffers();
 167 }