C++ drawCircle函数代码示例

int main(){
	initializePrinter();
	drawCanvas(0,0,0,255);
	int x,y;
	y = getYRes()/2;
	x = getXRes()/2;
	circle C = makeCircle(0,0,0,255,20,x,y);
	for (i=0;i<=360;i++) {
		rotateCircle(C,i,x,y);
		drawCircle(C);
	}
	printToScreen();
	finishPrinter();
}

/*!
 * \brief drawCircle
 * \param img image data
 * \param img_width image width
 * \param img_height image height
 * \param x x coordinate
 * \param y y coordinate
 * \param radius radius of the circle
 * \param r red
 * \param g green
 * \param b blue
 * \param line_width width of the line
 */
void drawing::drawCircle(
    unsigned char* img,
    int img_width,
    int img_height,
    int x,
    int y,
    int radius,
    int r,
    int g,
    int b,
    int line_width)
{
    drawCircle(img, img_width, img_height, (float)x, (float)y, (float)radius, r, g, b, line_width);
}

// Draw graphs      -- todo, adjust to fit in window
void Painting::drawGraph()
{
    // Paint the canvas white
    cvZero(mImage);
    cvRectangleR(mImage,cvRect(0,0,500,500),cvScalar(255,255,255), -1);

    CvFont font;
    double hScale=0.5;
    double vScale=0.5;
    int    lineWidth=1;
    cvInitFont(&font,CV_FONT_HERSHEY_SIMPLEX|CV_FONT_ITALIC, hScale,vScale,0,lineWidth);

    // Add text to canvas
    cvPutText (mImage,"Left",cvPoint(20,50), &font, cvScalar(200,0,0));
    cvPutText (mImage,"Right",cvPoint(420,50), &font, cvScalar(0,200,0));

    // Iterate the vector of data and center the selected objects
    if(mData.size())
    {
        int xScale = 200;
        int yScale = 20;
        int xOffSet = 250 - mData[mSelect].timeStamp * xScale;
        int yOffSet1 = 240 + mData[mSelect].pulsefreq * yScale;
        int yOffSet2 = 250 + mData[mSelect].blinkingfreq * yScale;
        int yOffSet3 = 260 + mData[mSelect].breathingfreq * yScale;
        int t = 1; //thick

        if(mSelect == 0)
            t = -1;

        drawCircle(mImage,cvPoint(mData[0].timeStamp * xScale + xOffSet,yOffSet1 - mData[0].pulsefreq * yScale),0,t);
        drawCircle(mImage,cvPoint(mData[0].timeStamp * xScale + xOffSet,yOffSet2 - mData[0].blinkingfreq * yScale),1,t);
        drawCircle(mImage,cvPoint(mData[0].timeStamp * xScale + xOffSet,yOffSet3 - mData[0].breathingfreq * yScale),2,t);

        for(unsigned int i = 1; i<mData.size(); i++)
        {
            int thick = 1;
            if((unsigned)mSelect == i)
                thick = -1;
            // Pulse
            drawCircle(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet1 - mData[i].pulsefreq * yScale),0,thick);
            cvLine(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet1 - mData[i].pulsefreq * yScale),
                   cvPoint(mData[i-1].timeStamp * xScale + xOffSet, yOffSet1 - mData[i-1].pulsefreq * yScale),cvScalar(0,0,255));
            // Blinking
            drawCircle(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet2 - mData[i].blinkingfreq * yScale),1,thick);
            cvLine(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet2 - mData[i].blinkingfreq * yScale),
                   cvPoint(mData[i-1].timeStamp * xScale + xOffSet, yOffSet2 - mData[i-1].blinkingfreq * yScale),cvScalar(0,255,0));
            // Breathing
            drawCircle(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet3 - mData[i].breathingfreq * yScale),2,thick);
            cvLine(mImage,cvPoint(mData[i].timeStamp * xScale + xOffSet, yOffSet3 - mData[i].breathingfreq * yScale),
                   cvPoint(mData[i-1].timeStamp * xScale + xOffSet, yOffSet3 - mData[i-1].breathingfreq * yScale),cvScalar(255,0,0));
        }
    }

    cvShowImage(WindowName, mImage);

}

// ---
void QGAMES::Screen::drawCircle (const QGAMES::Position& p, const QGAMES::Vector& o, 
	QGAMES::bdata a1, QGAMES::bdata a2, const QGAMES::Color& c, bool f)
{
	// Calculates the real position at the screen
	// It would depend on the scale, and where the visual position f the screen is fixed.
	QGAMES::Position nP = p.projectOver (_position, _orientation);
	QGAMES::bdata x = nP.posX () - _position.posX ();
	QGAMES::bdata y = nP.posY () - _position.posY ();
	QGAMES::bdata a1D = a1; QGAMES::bdata a2D = a2;

	// It is too mcuh difficult to verify whether
	// the final eelipse fits or not the window...

	// Scale the objects...if any
	if ((int) _scale._value != 1) // To speed the code up in normal situations...
	{
		x = _scale.effectToX (x);
		y = _scale.effectToY (y);
		if (_scale._scaleByAlgorithm)
		{
			a1D = a1 * _scale._value; // axis 1 and axis 2 have to be scaled also...
			a2D = a2 * _scale._value;
		}
	}

	// Draw the objects...
	if ((int) _scale._value == 1)
		drawCircle ((int) x, (int) y, (int) a1D, (int) a2D, c, f);
	else
	{
		if (!_scale._scaleByAlgorithm)
			activeScale ();
		drawCircle ((int) x, (int) y, (int) a1D, (int) a2D, c, f);
		if (!_scale._scaleByAlgorithm)
			desactiveScale ();
	}
}

void Garmata()
{
		//jadro
    glColor3f(0.0, 0.0, 0.0);                     
    drawCircle( gfPyshkaX, gfPyshkaY, 14,60);
    glEnd();
		//kinec garmatu
    glColor3f(0.0, 0.0, 0.0);                     
    drawCircle( -70+gfPyshkaX1, 44+gfPyshkaY1, 14,60);
    glEnd();         
        //Garmata zamalovka
    glBegin(GL_QUADS);                     
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(-70+gfPyshkaX1, 30+gfPyshkaY1);
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(200+gfPyshkaX1, 30+gfPyshkaY1);
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(200+gfPyshkaX1, 58+gfPyshkaY1);
        glColor3f(1.0, 1.0, 1.0);
        glVertex2i(-70+gfPyshkaX1, 58+gfPyshkaY1);
    glEnd();
        //Garmata
    glBegin(GL_LINE_LOOP);                     
        glColor3f(0.0, 0.0, 0.0);
        glVertex2i(-70+gfPyshkaX1, 30+gfPyshkaY1);
        glColor3f(0.0, 0.0, 0.0);
        glVertex2i(200+gfPyshkaX1, 30+gfPyshkaY1);
        glColor3f(0.0, 0.0, 0.0);
        glVertex2i(200+gfPyshkaX1, 58+gfPyshkaY1);
        glColor3f(0.0, 0.0, 0.0);
        glVertex2i(-70+gfPyshkaX1, 58+gfPyshkaY1);
    glEnd();
		//koleso vid pushki 
    glColor3f(0.0, 0.0, 0.0);                     
    drawCircle(0+gfPyshkaX1, 0+gfPyshkaY1, 30,60);
}

void DeviceAddScreen::render()
{
    uint16_t schcolor = color565(142,35,35);
    fillScreen(BLACK);
    makeRectangle(15,15, 200,280, BLACK, 5);
    drawPgmString(210,50 , PSTR("ADD ADAPTERS"), schcolor, BLACK, 2);
    drawPgmString(180,50, PSTR("While this screen is open, devices will"), WHITE, BLACK, 1);
    drawPgmString(170,50, PSTR("synchronize with the basestation. Press"), WHITE, BLACK, 1);
    drawPgmString(160,50, PSTR("and hold HOME or BACK to exit."), WHITE, BLACK, 1);

    drawCircle(100, 100, 30, WHITE);
    drawCircle(100, 220, 30, WHITE);
    drawHorizontalLine(100, 130, 60, WHITE, 1);
    // 100, 190 is point of arrow
    for(int8_t i=0; i < 8; i++) {
        drawPixel(100-i, 190-i, WHITE);
        drawPixel(100+i, 190-i, WHITE);
    }

    for(int8_t i=0; i < 8; i++) {
        drawPixel(100-i, 130+i, WHITE);
        drawPixel(100+i, 130+i, WHITE);
    }
}

void drawLine(int x2, int y2, int x1, int y1){
  int dx = x1 - x2;
  int dy = y1 - y2;

  int t_max = abs(dx);
  if (abs(dy) > abs(dx))
    t_max = abs(dy);

  if (t_max == 0){
    drawCircle(x1, y1);
  }
  else{
    double ddx = double(dx)/double(t_max);
    double ddy = double(dy)/double(t_max);
    
    double x=x2;
    double y=y2;
    for(int t=0;t<=t_max;++t){
      drawCircle((int)round(x),(int)round(y));
      x += ddx;
      y += ddy;
    }
  }
}

void CustomCircle::takePoint(Point p)
{
    p2.x = p.x;
    p2.y = p.y;

    if (!On)
    {
        On = true;
        p1.x = p.x;
        p1.y = p.y;
    }

    clear_to_color(bmp, TRANSPARENT);
    drawCircle(bmp, p1, pointDistance(p1, p2), GREEN);
}

//---------------------------------------------------------------------
void TitleDraw::update()
{
    //---- main content
    int state = title_state->getNowState();
    if (state == TitleState::STATE_CIRCLE) { drawCircle(); }
    if (state == TitleState::STATE_TITLE) { drawTitle(); }

    //---- fadeout/fadein
    SetDrawBlendMode(DX_BLENDMODE_ALPHA, title_state->getAlpha());
    DrawBox(0, 0,
        SystemData::getInstance()->getWindowWidth(),
        SystemData::getInstance()->getWindowHeight(),
        GetColor(0, 0, 0), TRUE);
    SetDrawBlendMode(DX_BLENDMODE_NOBLEND, 0);
}

int main( void )
{
    GLFWwindow *window;
    
    // Initialize the library
    if ( !glfwInit( ) )
    {
        return -1;
    }
    
    // Create a windowed mode window and its OpenGL context
    window = glfwCreateWindow( SCREEN_WIDTH, SCREEN_HEIGHT, "Hello World", NULL, NULL );
    
    if ( !window )
    {
        glfwTerminate( );
        return -1;
    }
    
    // Make the window's context current
    glfwMakeContextCurrent( window );
    
    glViewport( 0.0f, 0.0f, SCREEN_WIDTH, SCREEN_HEIGHT ); // specifies the part of the window to which OpenGL will draw (in pixels), convert from normalised to pixels
    glMatrixMode( GL_PROJECTION ); // projection matrix defines the properties of the camera that views the objects in the world coordinate frame. Here you typically set the zoom factor, aspect ratio and the near and far clipping planes
    glLoadIdentity( ); // replace the current matrix with the identity matrix and starts us a fresh because matrix transforms such as glOrpho and glRotate cumulate, basically puts us at (0, 0, 0)
    glOrtho( 0, SCREEN_WIDTH, 0, SCREEN_HEIGHT, 0, 1 ); // essentially set coordinate system
    glMatrixMode( GL_MODELVIEW ); // (default matrix mode) modelview matrix defines how your objects are transformed (meaning translation, rotation and scaling) in your world
    glLoadIdentity( ); // same as above comment
    
    // Loop until the user closes the window
    while ( !glfwWindowShouldClose( window ) )
    {
        glClear( GL_COLOR_BUFFER_BIT );

        // render OpenGL here
        drawCircle( SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, 0, 120, 10 );
        
        // Swap front and back buffers
        glfwSwapBuffers( window );
        
        // Poll for and process events
        glfwPollEvents( );
    }
    
    glfwTerminate( );
    
    return 0;
}

void QgsPointDisplacementRenderer::drawGroup( QPointF centerPoint, QgsRenderContext& context, const ClusteredGroup& group )
{

  //calculate max diagonal size from all symbols in group
  double diagonal = 0;

  Q_FOREACH ( const GroupedFeature& feature, group )
  {
    if ( QgsMarkerSymbol* symbol = feature.symbol )
    {
      diagonal = qMax( diagonal, context.convertToPainterUnits( M_SQRT2 * symbol->size(),
                       symbol->sizeUnit(), symbol->sizeMapUnitScale() ) );
    }
  }

  QgsSymbolRenderContext symbolContext( context, QgsUnitTypes::RenderMillimeters, 1.0, false );

  QList<QPointF> symbolPositions;
  QList<QPointF> labelPositions;
  double circleRadius = -1.0;
  calculateSymbolAndLabelPositions( symbolContext, centerPoint, group.size(), diagonal, symbolPositions, labelPositions, circleRadius );

  //draw circle
  if ( circleRadius > 0 )
    drawCircle( circleRadius, symbolContext, centerPoint, group.size() );

  if ( group.size() > 1 )
  {
    //draw mid point
    QgsFeature firstFeature = group.at( 0 ).feature;
    if ( mCenterSymbol )
    {
      mCenterSymbol->renderPoint( centerPoint, &firstFeature, context, -1, false );
    }
    else
    {
      context.painter()->drawRect( QRectF( centerPoint.x() - symbolContext.outputLineWidth( 1 ), centerPoint.y() - symbolContext.outputLineWidth( 1 ), symbolContext.outputLineWidth( 2 ), symbolContext.outputLineWidth( 2 ) ) );
    }
  }

  //draw symbols on the circle
  drawSymbols( group, context, symbolPositions );
  //and also the labels
  if ( mLabelIndex >= 0 )
  {
    drawLabels( centerPoint, symbolContext, labelPositions, group );
  }
}

extern void myMouse(int button, int state, int x, int y)
{
        if (state == GLUT_DOWN) {
                if (button == GLUT_LEFT_BUTTON) {
                        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
                        glClear(GL_COLOR_BUFFER_BIT);
                        drawAxis();
                        glFlush();
                } else if (button == GLUT_RIGHT_BUTTON) {
                        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
                        glClear(GL_COLOR_BUFFER_BIT);
                        drawCircle();
                        glFlush();
                }
        }
}

void Particle::drawCircle(float x, float y, float diam) {
    //center circles
    
        ofSetCircleResolution(100);
        ofNoFill();
    
        ofDrawCircle(x,y,diam,diam);
    
        diam = diam*.7;
   
    
        if(diam>1){
            drawCircle(x,y,diam++);
        }
    
}

void Joystick::draw()
{
    if (_simpleDrawEnabled) {
        CC_NODE_DRAW_SETUP();
        switch (_state) {
            case jsTouched:
                drawCircle();
                break;
            case jsTouchMoved:
                drawArrow();
                break;
            default:
                break;
        }
    }
}

void Enemy::render(){
	glLoadIdentity();
	glColor3f(0,1,0);
	switch(shape){
	case S_CIRCLE:
	drawCircle(x,y,size,40,2,0,fill);	
		break;
	case S_RECT:
	drawRectangle(x,y,size*2,size*2,angle,fill);
		break;
	case S_SMILEY:
	drawSmileyFace(x,y,size);	
		break;
	}
	
}