C++ (Qt)#ifndef SCENE_H#define SCENE_H #include <QGLWidget>#include <QKeyEvent> class Scene : public QGLWidget{public: Scene( QWidget *parent = 0 ); private: void initializeGL(); void paintGL(); void resizeGL( int w, int h ); void keyPressEvent( QKeyEvent *event ); private: // Rotation amounts GLfloat xRot; GLfloat yRot;}; #endif // SCENE_H
C++ (Qt) #include <math.h>#include "Scene.h" // Define a constant for the value of PI#define GL_PI 3.1415f Scene::Scene( QWidget *parent ) : QGLWidget( parent ), xRot( 0.0f ), yRot( 0.0f ){ this->setFocusPolicy( Qt::StrongFocus );} void Scene::initializeGL(){ // Black background glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); // Set drawing color to green glColor3f( 0.0f, 1.0f, 0.0f );} void Scene::paintGL(){ GLfloat y; // Storeage for varying Y coordinate GLfloat fCurrSize; // Save current size // Clear the window with current clearing color glClear( GL_COLOR_BUFFER_BIT ); // Save matrix state and do the rotation glPushMatrix(); glRotatef( xRot, 1.0f, 0.0f, 0.0f ); glRotatef( yRot, 0.0f, 1.0f, 0.0f ); // Save the smallest value glGetFloatv( GL_LINE_WIDTH_GRANULARITY, &fCurrSize ); // Step up Y axis 20 units at a time for( y = -90.0f; y < 90.0f; y += 20.0f ) { // Set the line width glLineWidth( fCurrSize ); // Draw the line glBegin( GL_LINES ); glVertex2f( -80.0f, y ); glVertex2f( 80.0f, y ); glEnd(); // Increase the line width fCurrSize += 1.0f; } // Restore transformations glPopMatrix();} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity(); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho ( -nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange ); } else { glOrtho ( -nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity();} void Scene::keyPressEvent( QKeyEvent *event ){ switch ( event->key() ) { case Qt::Key_Up: xRot -= 5.0f; break; case Qt::Key_Down: xRot += 5.0f; break; case Qt::Key_Left: yRot -= 5.0f; break; case Qt::Key_Right: yRot += 5.0f; break; } if( xRot > 356.0f ) { xRot = 0.0f; } if( xRot < -1.0f ) { xRot = 355.0f; } if( yRot > 356.0f) { yRot = 0.0f; } if( yRot < -1.0f) { yRot = 355.0f; } updateGL();}
C++ (Qt) #include <math.h>#include "Scene.h" // Define a constant for the value of PI#define GL_PI 3.1415f Scene::Scene( QWidget *parent ) : QGLWidget( parent ), xRot( 0.0f ), yRot( 0.0f ){ this->setFocusPolicy( Qt::StrongFocus );} void Scene::initializeGL(){ // Black background glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); // Set drawing color to green glColor3f( 0.0f, 1.0f, 0.0f ); // Enable Stippling glEnable( GL_LINE_STIPPLE );} void Scene::paintGL(){ GLfloat y; // Storeage for varying Y coordinate GLint factor = 3; // Stippling factor GLushort pattern = 0x5555; // Stipple pattern // Clear the window with current clearing color glClear( GL_COLOR_BUFFER_BIT ); // Save matrix state and do the rotation glPushMatrix(); glRotatef( xRot, 1.0f, 0.0f, 0.0f ); glRotatef( yRot, 0.0f, 1.0f, 0.0f ); // Step up Y axis 20 units at a time for( y = -90.0f; y < 90.0f; y += 20.0f ) { // Reset the repeat factor and pattern glLineStipple( factor, pattern ); // Draw the line glBegin( GL_LINES ); glVertex2f( -80.0f, y ); glVertex2f( 80.0f, y ); glEnd(); factor++; } // Restore transformations glPopMatrix();} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity(); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho ( -nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange ); } else { glOrtho ( -nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity();} void Scene::keyPressEvent( QKeyEvent *event ){ switch ( event->key() ) { case Qt::Key_Up: xRot -= 5.0f; break; case Qt::Key_Down: xRot += 5.0f; break; case Qt::Key_Left: yRot -= 5.0f; break; case Qt::Key_Right: yRot += 5.0f; break; } if( xRot > 356.0f ) { xRot = 0.0f; } if( xRot < -1.0f ) { xRot = 355.0f; } if( yRot > 356.0f) { yRot = 0.0f; } if( yRot < -1.0f) { yRot = 355.0f; } updateGL();}
C++ (Qt)#ifndef SCENE_H#define SCENE_H #include <QGLWidget>#include <QKeyEvent> class Scene : public QGLWidget{ Q_OBJECT public: Scene( QWidget *parent = 0 ); private slots: void slotShowContextMenu( const QPoint &pos ); private: void initializeGL(); void paintGL(); void resizeGL( int w, int h ); void keyPressEvent( QKeyEvent *event ); private: // Rotation amounts GLfloat xRot; GLfloat yRot; // Flags for effects int iCull; int iOutline; int iDepth;}; #endif // SCENE_H
C++ (Qt) #include <QAbstractScrollArea>#include <QMenu>#include <math.h>#include "Scene.h" // Define a constant for the value of PI#define GL_PI 3.1415f Scene::Scene( QWidget *parent ) : QGLWidget( parent ), xRot( 0.0f ), yRot( 0.0f ), iCull( 0 ), iOutline( 0 ), iDepth( 0 ){ this->setFocusPolicy( Qt::StrongFocus ); this->setContextMenuPolicy( Qt::CustomContextMenu ); connect( this, SIGNAL( customContextMenuRequested( QPoint ) ), this, SLOT( slotShowContextMenu( QPoint ) ) );} void Scene::slotShowContextMenu(const QPoint &pos){ QPoint globalPos; if ( sender()->inherits( "QAbstractScrollArea" ) ) { globalPos = ( ( QAbstractScrollArea* )sender() )-> viewport()->mapToGlobal( pos ); } else { globalPos = ( ( QWidget* )sender() )->mapToGlobal( pos ); } QString depthTestText( "Toggle depth test" ); QString cullBackfaceText( "Toggle cull backface" ); QString outlineBackText( "Toggle outline back" ); QMenu menu; QAction *actionDepthTest = new QAction( depthTestText, this ); QAction *actionCullBackface = new QAction( cullBackfaceText, this ); QAction *actionOutlineBack = new QAction( outlineBackText, this ); menu.addAction( actionDepthTest ); menu.addAction( actionCullBackface ); menu.addAction( actionOutlineBack ); QAction* selectedItem = menu.exec( globalPos ); if ( selectedItem == 0 ) { return; } if ( selectedItem->text() == depthTestText ) { iDepth = !iDepth; } else if ( selectedItem->text() == cullBackfaceText ) { iCull = !iCull; } else if ( selectedItem->text() == outlineBackText ) { iOutline = !iOutline; }} void Scene::initializeGL(){ // Black background glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); // Set drawing color to green glColor3f( 0.0f, 1.0f, 0.0f ); // Set color shading model to flat glShadeModel( GL_FLAT ); // Clock wise wound polygons are front facing, this is reversed // because we are using triangle fans glFrontFace( GL_CW );} void Scene::paintGL(){ GLfloat x, y, angle; // Storage for coordinates and angles int iPivot = 1; // Used to flag alternating colors // Clear the window and the depth buffer glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); // Turn culling on if flag is set if( iCull ) { glEnable( GL_CULL_FACE ); } else { glDisable( GL_CULL_FACE ); } // Enable depth testing if flag is set if( iDepth ) { glEnable( GL_DEPTH_TEST ); } else { glDisable( GL_DEPTH_TEST ); } // Draw back side as a polygon only, if flag is set if( iOutline ) { glPolygonMode( GL_BACK, GL_LINE ); } else { glPolygonMode( GL_BACK, GL_FILL ); } // Save matrix state and do the rotation glPushMatrix(); glRotatef( xRot, 1.0f, 0.0f, 0.0f ); glRotatef( yRot, 0.0f, 1.0f, 0.0f ); // Begin a triangle fan glBegin( GL_TRIANGLE_FAN ); // Pinnacle of cone is shared vertex for fan, moved up Z axis // to produce a cone instead of a circle glVertex3f( 0.0f, 0.0f, 75.0f ); // Loop around in a circle and specify even points along the circle // as the vertices of the triangle fan for( angle = 0.0f; angle < ( 2.0f*GL_PI ); angle += ( GL_PI/8.0f ) ) { // Calculate x and y position of the next vertex x = 50.0f * sin( angle ); y = 50.0f * cos( angle ); // Alternate color between red and green if( ( iPivot %2 ) == 0 ) { glColor3f(0.0f, 1.0f, 0.0f); } else { glColor3f(1.0f, 0.0f, 0.0f); } // Increment pivot to change color next time iPivot++; // Specify the next vertex for the triangle fan glVertex2f( x, y ); } // Done drawing fan for cone glEnd(); // Begin a new triangle fan to cover the bottom glBegin( GL_TRIANGLE_FAN ); // Center of fan is at the origin glVertex2f( 0.0f, 0.0f ); for(angle = 0.0f; angle < ( 2.0f*GL_PI ); angle += ( GL_PI/8.0f ) ) { // Calculate x and y position of the next vertex x = 50.0f * sin( angle ); y = 50.0f * cos( angle ); // Alternate color between red and green if( ( iPivot %2 ) == 0 ) { glColor3f( 0.0f, 1.0f, 0.0f ); } else { glColor3f( 1.0f, 0.0f, 0.0f ); } // Increment pivot to change color next time iPivot++; // Specify the next vertex for the triangle fan glVertex2f( x, y ); } // Done drawing the fan that covers the bottom glEnd(); // Restore transformations glPopMatrix();} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity(); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho ( -nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange ); } else { glOrtho ( -nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity();} void Scene::keyPressEvent( QKeyEvent *event ){ switch ( event->key() ) { case Qt::Key_Up: xRot -= 5.0f; break; case Qt::Key_Down: xRot += 5.0f; break; case Qt::Key_Left: yRot -= 5.0f; break; case Qt::Key_Right: yRot += 5.0f; break; } if( xRot > 356.0f ) { xRot = 0.0f; } if( xRot < -1.0f ) { xRot = 355.0f; } if( yRot > 356.0f) { yRot = 0.0f; } if( yRot < -1.0f) { yRot = 355.0f; } updateGL();}
C++ (Qt)#ifndef SCENE_H#define SCENE_H #include <QGLWidget>#include <QKeyEvent> class Scene : public QGLWidget{ Q_OBJECT public: Scene( QWidget *parent = 0 ); private: void initializeGL( ); void paintGL( ); void resizeGL( int w, int h ); void keyPressEvent( QKeyEvent *event ); private: // Rotation amounts GLfloat xRot; GLfloat yRot;}; #endif // SCENE_H
C++ (Qt) #include "Scene.h" // Define a constant for the value of PI#define GL_PI 3.1415f // Bitmap of camp fireGLubyte fire[128] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x00, 0x00, 0x01, 0xf0, 0x00, 0x00, 0x07, 0xf0, 0x0f, 0x00, 0x1f, 0xe0, 0x1f, 0x80, 0x1f, 0xc0, 0x0f, 0xc0, 0x3f, 0x80, 0x07, 0xe0, 0x7e, 0x00, 0x03, 0xf0, 0xff, 0x80, 0x03, 0xf5, 0xff, 0xe0, 0x07, 0xfd, 0xff, 0xf8, 0x1f, 0xfc, 0xff, 0xe8, 0xff, 0xe3, 0xbf, 0x70, 0xde, 0x80, 0xb7, 0x00, 0x71, 0x10, 0x4a, 0x80, 0x03, 0x10, 0x4e, 0x40, 0x02, 0x88, 0x8c, 0x20, 0x05, 0x05, 0x04, 0x40, 0x02, 0x82, 0x14, 0x40, 0x02, 0x40, 0x10, 0x80, 0x02, 0x64, 0x1a, 0x80, 0x00, 0x92, 0x29, 0x00, 0x00, 0xb0, 0x48, 0x00, 0x00, 0xc8, 0x90, 0x00, 0x00, 0x85, 0x10, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00 }; Scene::Scene( QWidget *parent ) : QGLWidget( parent ), xRot( 0.0f ), yRot( 0.0f ){} void Scene::initializeGL( ){ // Black background glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); // Set drawing color to green glColor3f( 1.0f, 0.0f, 0.0f ); // Enable polygon stippling glEnable( GL_POLYGON_STIPPLE ); // Specify a specific stipple pattern glPolygonStipple( fire );} void Scene::paintGL( ){ // Clear the window glClear( GL_COLOR_BUFFER_BIT ); // Save matrix state and do the rotation glPushMatrix( ); glRotatef( xRot, 1.0f, 0.0f, 0.0f ); glRotatef( yRot, 0.0f, 1.0f, 0.0f ); // Begin the stop sign shape, // use a standard polygon for simplicity glBegin( GL_POLYGON ); glVertex2f( -20.0f, 50.0f ); glVertex2f( 20.0f, 50.0f ); glVertex2f( 50.0f, 20.0f ); glVertex2f( 50.0f, -20.0f ); glVertex2f( 20.0f, -50.0f ); glVertex2f( -20.0f, -50.0f ); glVertex2f( -50.0f, -20.0f ); glVertex2f( -50.0f, 20.0f ); glEnd( ); // Restore transformations glPopMatrix( );} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if ( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity( ); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho( -nRange, nRange, -nRange * h / w, nRange * h / w, -nRange, nRange ); } else { glOrtho( -nRange * w / h, nRange * w / h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity( );} void Scene::keyPressEvent( QKeyEvent *event ){ switch ( event->key( ) ) { case Qt::Key_Up: xRot -= 5.0f; break; case Qt::Key_Down: xRot += 5.0f; break; case Qt::Key_Left: yRot -= 5.0f; break; case Qt::Key_Right: yRot += 5.0f; break; } if ( xRot > 356.0f ) { xRot = 0.0f; } if ( xRot < -1.0f ) { xRot = 355.0f; } if ( yRot > 356.0f ) { yRot = 0.0f; } if ( yRot < -1.0f ) { yRot = 355.0f; } updateGL( );}
C++ (Qt)#ifndef SCENE_H#define SCENE_H #include <QGLWidget>#include <QKeyEvent> class Scene : public QGLWidget{ Q_OBJECT public: Scene( QWidget *parent = 0 ); private slots: void slotShowContextMenu( const QPoint &pos ); private: void initializeGL( ); void paintGL( ); void resizeGL( int w, int h ); void keyPressEvent( QKeyEvent *event ); private: // Rotation amounts GLfloat xRot; GLfloat yRot; int iMode; GLboolean bEdgeFlag; // Flags for effects int iCull; int iOutline; int iDepth;}; #endif // SCENE_H
C++ (Qt)#include <QAbstractScrollArea>#include <QMenu>#include <math.h>#include "Scene.h" // Define a constant for the value of PI#define GL_PI 3.1415f // Flags for effects#define MODE_SOLID 0#define MODE_LINE 1#define MODE_POINT 2 Scene::Scene( QWidget *parent ) : QGLWidget( parent ), xRot( 0.0f ), yRot( 0.0f ), iCull( 0 ), iOutline( 0 ), iDepth( 0 ){ iMode = MODE_SOLID; bEdgeFlag = TRUE; this->setFocusPolicy( Qt::StrongFocus ); this->setContextMenuPolicy( Qt::CustomContextMenu ); connect( this, SIGNAL( customContextMenuRequested( QPoint ) ), this, SLOT( slotShowContextMenu( QPoint ) ) );} void Scene::slotShowContextMenu( const QPoint &pos ){ QPoint globalPos; if ( sender( )->inherits( "QAbstractScrollArea" ) ) { globalPos = ( ( QAbstractScrollArea* ) sender( ) )-> viewport( )->mapToGlobal( pos ); } else { globalPos = ( ( QWidget* ) sender( ) )->mapToGlobal( pos ); } QString solidText( "Solid" ); QString outlineText( "Outline" ); QString pointsText( "Points" ); QString onEdgesText( "On" ); QString offEdgesText( "Off" ); QMenu *menu = new QMenu( ); QAction *solidAction = new QAction( solidText, this ); QAction *outlineAction = new QAction( outlineText, this ); QAction *pointsAction = new QAction( pointsText, this ); QAction *onEdgesAction = new QAction( onEdgesText, this ); QAction *offEdgesAction = new QAction( offEdgesText, this ); QMenu *modeSubmenu = menu->addMenu( "Mode" ); QMenu *edgesSubmenu = menu->addMenu( "Edges" ); modeSubmenu->addAction( solidAction ); modeSubmenu->addAction( outlineAction ); modeSubmenu->addAction( pointsAction ); edgesSubmenu->addAction( onEdgesAction ); edgesSubmenu->addAction( offEdgesAction ); QAction* selectedItem = menu->exec( globalPos ); if ( selectedItem == 0 ) { return; } if ( selectedItem->text( ) == solidText ) { iMode = MODE_SOLID; } else if ( selectedItem->text( ) == outlineText ) { iMode = MODE_LINE; } else if ( selectedItem->text( ) == pointsText ) { iMode = MODE_POINT; } else if ( selectedItem->text( ) == onEdgesText ) { bEdgeFlag = TRUE; } else if ( selectedItem->text( ) == offEdgesText ) { bEdgeFlag = FALSE; }} void Scene::initializeGL( ){ // Black background glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); // Set drawing color to green glColor3f( 0.0f, 1.0f, 0.0f ); // Set color shading model to flat glShadeModel( GL_FLAT ); // Clock wise wound polygons are front facing, this is reversed // because we are using triangle fans glFrontFace( GL_CW );} void Scene::paintGL( ){ // Clear the window glClear( GL_COLOR_BUFFER_BIT ); // Draw back side as a polygon only, if flag is set if ( iMode == MODE_LINE ) glPolygonMode( GL_FRONT_AND_BACK, GL_LINE ); if ( iMode == MODE_POINT ) glPolygonMode( GL_FRONT_AND_BACK, GL_POINT ); if ( iMode == MODE_SOLID ) glPolygonMode( GL_FRONT_AND_BACK, GL_FILL ); // Save matrix state and do the rotation glPushMatrix( ); glRotatef( xRot, 1.0f, 0.0f, 0.0f ); glRotatef( yRot, 0.0f, 1.0f, 0.0f ); // Begin the triangles glBegin( GL_TRIANGLES ); glEdgeFlag( bEdgeFlag ); glVertex2f( -20.0f, 0.0f ); glEdgeFlag( TRUE ); glVertex2f( 20.0f, 0.0f ); glVertex2f( 0.0f, 40.0f ); glVertex2f( -20.0f, 0.0f ); glVertex2f( -60.0f, -20.0f ); glEdgeFlag( bEdgeFlag ); glVertex2f( -20.0f, -40.0f ); glEdgeFlag( TRUE ); glVertex2f( -20.0f, -40.0f ); glVertex2f( 0.0f, -80.0f ); glEdgeFlag( bEdgeFlag ); glVertex2f( 20.0f, -40.0f ); glEdgeFlag( TRUE ); glVertex2f( 20.0f, -40.0f ); glVertex2f( 60.0f, -20.0f ); glEdgeFlag( bEdgeFlag ); glVertex2f( 20.0f, 0.0f ); glEdgeFlag( TRUE ); // Center square as two triangles glEdgeFlag( bEdgeFlag ); glVertex2f( -20.0f, 0.0f ); glVertex2f( -20.0f, -40.0f ); glVertex2f( 20.0f, 0.0f ); glVertex2f( -20.0f, -40.0f ); glVertex2f( 20.0f, -40.0f ); glVertex2f( 20.0f, 0.0f ); glEdgeFlag( TRUE ); // Done drawing Triangles glEnd( ); // Restore transformations glPopMatrix( );} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if ( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity( ); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho( -nRange, nRange, -nRange * h / w, nRange * h / w, -nRange, nRange ); } else { glOrtho( -nRange * w / h, nRange * w / h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity( );} void Scene::keyPressEvent( QKeyEvent *event ){ switch ( event->key( ) ) { case Qt::Key_Up: xRot -= 5.0f; break; case Qt::Key_Down: xRot += 5.0f; break; case Qt::Key_Left: yRot -= 5.0f; break; case Qt::Key_Right: yRot += 5.0f; break; } if ( xRot > 356.0f ) { xRot = 0.0f; } if ( xRot < -1.0f ) { xRot = 355.0f; } if ( yRot > 356.0f ) { yRot = 0.0f; } if ( yRot < -1.0f ) { yRot = 355.0f; } updateGL( );}
C++ (Qt)#ifndef SCENE_H#define SCENE_H #include <QGLWidget> class Scene : public QGLWidget{ Q_OBJECT public: Scene( QWidget *parent = 0 ); private: void initializeGL( ); void paintGL( ); void resizeGL( int w, int h );}; #endif // SCENE_H
C++ (Qt)#include <QAbstractScrollArea>#include <QMenu>#include <math.h>#include "Scene.h" Scene::Scene( QWidget *parent ) : QGLWidget( parent ){} void Scene::initializeGL( ){} void Scene::paintGL( ){ // Clear blue window glClearColor( 0.0f, 0.0f, 1.0f, 0.0f ); glClear( GL_COLOR_BUFFER_BIT ); // Now set scissor to smaller red sub region glClearColor( 1.0f, 0.0f, 0.0f, 0.0f ); glScissor( 100, 100, 600, 400 ); glEnable( GL_SCISSOR_TEST ); glClear( GL_COLOR_BUFFER_BIT ); // Finally, an even smaller green rectangle glClearColor( 0.0f, 1.0f, 0.0f, 0.0f ); glScissor( 200, 200, 400, 200 ); glClear( GL_COLOR_BUFFER_BIT ); // Turn scissor back off for next render glDisable( GL_SCISSOR_TEST );} void Scene::resizeGL( int w, int h ){ // Prevent a divide by zero if ( h == 0 ) { h = 1; } // Set Viewport to window dimensions glViewport( 0, 0, w, h ); // Reset projection matrix stack glMatrixMode( GL_PROJECTION ); glLoadIdentity( ); GLfloat nRange = 100.0f; // Establish clipping volume (left, right, bottom, top, near, far) if ( w <= h ) { glOrtho( -nRange, nRange, -nRange * h / w, nRange * h / w, -nRange, nRange ); } else { glOrtho( -nRange * w / h, nRange * w / h, -nRange, nRange, -nRange, nRange ); } // Reset Model view matrix stack glMatrixMode( GL_MODELVIEW ); glLoadIdentity( );}
