I created this code to draw an object and move it in the direction of x,y or z according to keyboard buttons.
It works perfect and doesn't output any error but the object just appears without moving.
Here is the code:
#include <GL/glut.h>
static GLint rotate = 0;
static GLint axis = 0;
static int xDegrees = 0;
static int yDegrees = 0;
static int zDegrees = 0;
static int direction = 0;
static int stop = 0;
void specialKeyboard( int axis, int x, int y )
{
switch( axis )
{
case GLUT_KEY_RIGHT:
direction = 1;
break;
case GLUT_KEY_LEFT:
direction = -1;
break;
}
}
void change( int* degrees )
{
*degrees = ( ( *degrees ) + direction ) % 360;
}
void rotate1()
{
switch( axis )
{
case '0':
change( &xDegrees );
break;
case '1':
change( &yDegrees );
break;
case '2':
change( &zDegrees );
break;
}
glutPostRedisplay();
}
void keyboard( unsigned char key, int x, int y )
{
switch( key )
{
case 'x':
axis = 0;
glutIdleFunc( rotate1 );
stop = 0;
break;
case 'y':
axis = 1;
glutIdleFunc( rotate1 );
stop = 0;
break;
case 'z':
axis = 2;
glutIdleFunc( rotate1 );
stop = 0;
break;
case 's':
stop = !stop;
if( stop )
glutIdleFunc( NULL );
else
glutIdleFunc( rotate1 );
break;
}
}
void resize( int w, int h )
{
glViewport( 0, 0, w, h );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 50., w / (double)h, 1., 10. );
glMatrixMode( GL_MODELVIEW );
}
void render()
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glLoadIdentity();
gluLookAt( 0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0 );
// Rotate the teapot
glRotatef( xDegrees, 1, 0, 0 );
glRotatef( yDegrees, 0, 1, 0 );
glRotatef( zDegrees, 0, 0, 1 );
glColor3f( 1.0, 1.0, 1.0 );
glutWireTeapot( 1.5 );
glutSwapBuffers();
}
int main( int argc, char* argv[] )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow( "IVI - Sesion 2" );
glEnable( GL_DEPTH_TEST );
glutDisplayFunc( render );
glutReshapeFunc( resize );
glutKeyboardFunc( keyboard );
glutSpecialFunc( specialKeyboard );
glutMainLoop();
return 0;
}
The problem is because of those
case '0':
...
case '1':
...
axis 0 and axis '0' (ASCII 48) are not the same, switch to
case 0:
...
case 1:
...
and it will work pressing x, y, z ...
Related
i have developed camshift algorithm by watching some tutorials..but unfortunately it didn't track the selected object....here is my code..i am a beginner to opencv and i need help..problem is the rectangle doesn't follow the object to track...
this my code:
bool destroy=false;
CvRect box;
CvRect track_window;
bool drawing_box = false;
cv::Mat imageROI;
IplImage *image = 0, *hsv = 0, *hue = 0, *mask = 0, *backproject = 0, *histimg = 0;
CvHistogram *hist = 0;
int hdims = 16;
float hranges_arr[] = {0,180};
float* hranges = hranges_arr;
int vmin = 10, vmax = 256, smin = 30;
IplImage *image2;
CvScalar hsv2rgb( float hue );
CvConnectedComp track_comp;
CvBox2D track_box;
void draw_box(Mat img, CvRect rect)
{
imageROI= img(cv::Rect(box.x,box.y,box.width,box.height));
cv::rectangle(img, cvPoint(box.x, box.y), cvPoint(box.x+box.width,box.y+box.height),
cvScalar(0,0,255) ,2);
}
CvScalar hsv2rgb( float hue )
{
int rgb[3], p, sector;
static const int sector_data[][3]=
{{0,2,1}, {1,2,0}, {1,0,2}, {2,0,1}, {2,1,0}, {0,1,2}};
hue *= 0.033333333333333333333333333333333f;
sector = cvFloor(hue);
p = cvRound(255*(hue - sector));
p ^= sector & 1 ? 255 : 0;
rgb[sector_data[sector][0]] = 255;
rgb[sector_data[sector][1]] = 0;
rgb[sector_data[sector][2]] = p;
return cvScalar(rgb[2], rgb[1], rgb[0],0);
}
void my_mouse_callback( int event, int x, int y, int flags, void* param )
{
IplImage* frame = (IplImage*) param;
switch( event )
{
case CV_EVENT_MOUSEMOVE:
{
if( drawing_box )
{
box.width = x-box.x;
box.height = y-box.y;
}
}
break;
case CV_EVENT_LBUTTONDOWN:
{
drawing_box = true;
box = cvRect( x, y, 0, 0 );
}
break;
case CV_EVENT_LBUTTONUP:
{
drawing_box = false;
if( box.width < 0 )
{
box.x += box.width;
box.width *= -1;
}
if( box.height < 0 )
{
box.y += box.height;
box.height *= -1;
}
draw_box(frame, box);
}
break;
case CV_EVENT_RBUTTONUP:
{
destroy=true;
}
break;
default:
break;
} }
int _tmain(int argc, _TCHAR* argv[])
{
VideoCapture cap(0);
if(!cap.isOpened())
return -1;
Mat image;
Mat frame;
//cv::Mat image= cv::imread("1.jpg");
cap>>image;
if (!image.data)
return 0;
// Display image
cv::namedWindow("Image");
cv::imshow("Image",image);
IplImage* img = new IplImage(image);
cvSmooth(img,img,CV_GAUSSIAN,3,0,0.0,0.0);
IplImage* temp = cvCloneImage(img);
cvSetMouseCallback("Image", my_mouse_callback, (void*) img);
while( 1 )
{
if (destroy)
{
cvDestroyWindow("Image"); break;
}
cvCopyImage(img, temp);
if (drawing_box)
draw_box(temp, box);
cvShowImage("Image", temp);
if (cvWaitKey(15) == 27)
break;
}
cvReleaseImage(&temp);
cvDestroyWindow("Image");
for(;;)
{
int i, bin_w, c;
cap >> frame;
IplImage* frame_ipl = new IplImage(frame);
hsv = cvCreateImage( cvGetSize(frame_ipl), 8, 3 );
image2 = cvCreateImage( cvGetSize(frame_ipl), 8, 3 );
hue = cvCreateImage( cvGetSize(frame_ipl), 8, 1 );
mask = cvCreateImage( cvGetSize(frame_ipl), 8, 1 );
backproject = cvCreateImage( cvGetSize(frame_ipl), 8, 1 );
hist = cvCreateHist( 1, &hdims, CV_HIST_ARRAY, &hranges, 1 );
histimg = cvCreateImage( cvSize(320,200), 8, 3 );
cvZero( histimg );
cvCopy( frame_ipl, image2, 0 );
cvCvtColor( image2, hsv, CV_BGR2HSV );
int _vmin = vmin, _vmax = vmax;
cvInRangeS( hsv, cvScalar(0,smin,MIN(_vmin,_vmax),0),
cvScalar(180,256,MAX(_vmin,_vmax),0), mask );
cvSplit( hsv, hue, 0, 0, 0 );
float max_val = 0.f;
cvSetImageROI( hue, box );
cvSetImageROI( mask, box );
cvCalcHist( &hue, hist, 0, mask );
cvGetMinMaxHistValue( hist, 0, &max_val, 0, 0 );
cvConvertScale( hist->bins, hist->bins, max_val ? 255. / max_val : 0., 0 );
cvResetImageROI( hue );
cvResetImageROI( mask );
track_window = box;
cvZero( histimg );
bin_w = histimg->width / hdims;
for( i = 0; i < hdims; i++ )
{
int val = cvRound( cvGetReal1D(hist->bins,i)*histimg->height/255 );
CvScalar color = hsv2rgb(i*180.f/hdims);
cvRectangle( histimg, cvPoint(i*bin_w,histimg->height),
cvPoint((i+1)*bin_w,histimg->height - val),
color, -1, 8, 0 );
}
cvCalcBackProject( &hue, backproject, hist );
cvAnd( backproject, mask, backproject, 0 );
cvCamShift( backproject, track_window, cvTermCriteria( CV_TERMCRIT_EPS | CV_TERMCRIT_ITER, 10, 1 ), &track_comp, &track_box );
track_window = track_comp.rect;
cv::rectangle(frame, track_window, cv::Scalar(0,255,0));
cv::namedWindow("result");
cv::imshow("result",frame);
if(waitKey(30) >= 0) break;
}
return 0;
}
but I use the c-api
What might this code be changed to IplImage :
void draw_box(Mat img, CvRect rect)
{
imageROI= img(cv::Rect(box.x,box.y,box.width,box.height));
cv::rectangle(img, cvPoint(box.x, box.y), cvPoint(box.x+box.width,box.y+box.height),
cvScalar(0,0,255) ,2);
}
I want to rotate a simple cube in OpenGL using GLUT in C. The rotation will occur when I press a key.
If I use glRotatef(angle, 0.0f, 1.0f, 0.0f) the cube will rotate instantly without an animation. I would like to rotate it slowly so it takes about 2 seconds to complete the rotation.
Create a keyboard callback that toggles a bool and a timer callback that updates an angle:
#include <GL/glut.h>
char spin = 0;
void keyboard( unsigned char key, int x, int y )
{
if( key == ' ' )
{
spin = !spin;
}
}
float angle = 0;
void timer( int value )
{
if( spin )
{
angle += 3;
}
glutTimerFunc( 16, timer, 0 );
glutPostRedisplay();
}
void display()
{
double w = glutGet( GLUT_WINDOW_WIDTH );
double h = glutGet( GLUT_WINDOW_HEIGHT );
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 45, w / h, 0.1, 10 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt( 2, 2, 2, 0, 0, 0, 0, 0, 1 );
glColor3ub( 255, 0, 0 );
glRotatef( angle, 0, 0, 1 );
glutWireCube( 1 );
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutKeyboardFunc( keyboard );
glutTimerFunc( 0, timer, 0 );
glutMainLoop();
return 0;
}
The following code doesn't show the circle on the screen, why doesn't work?
I can't see any error.
void display(void){
glClear(GL_COLOR_BUFFER_BIT);
int circle_points=100;
int i;
double theta,cx=200, cy=300,r=100;
int MyCircle(){
glBegin(GL_LINE_LOOP);
glColor3f(1.0,1.0,1.0); //preto
for(i=0;i<circle_points;i++){
theta=(2*pi*i)/circle_points;
glVertex2f(cx+r*cos(theta),cy+r*sin(theta));
}
glEnd();
}
glFlush();
}
No idea why you are trying to declare a function inside a function. I'm not quite sure how that compiled, much less ran.
The logic is sound though:
#include <GL/glut.h>
#include <math.h>
void MyCircle( void )
{
const int circle_points=100;
const float cx=0, cy=0, r=100;
const float pi = 3.14159f;
int i = 0;
glBegin(GL_LINE_LOOP);
glColor3f(1.0,1.0,1.0); //preto
for(i=0;i<circle_points;i++)
{
const float theta=(2*pi*i)/circle_points;
glVertex2f(cx+r*cos(theta),cy+r*sin(theta));
}
glEnd();
}
void display( void )
{
const double w = glutGet( GLUT_WINDOW_WIDTH );
const double h = glutGet( GLUT_WINDOW_HEIGHT );
const double ar = w / h;
glClear( GL_COLOR_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho( -150 * ar, 150 * ar, -150, 150, -1, 1 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
MyCircle();
glutSwapBuffers();
}
int main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow( "GLUT" );
glutDisplayFunc( display );
glutMainLoop();
return 0;
}
this is my draw() function written in C, using vertex arrays:
void draw(float x1, float x2, float y1, float y2)
{
glPushMatrix();
glScalef(1.0 / (x2 - x1), 1.0 / (y2 - y1), 1.0);
glTranslatef(-x1, -y1, 0.0);
glColor3f(1.0, 1.0, 1.0);
if( pts.size > 0 )
{
glEnableClientState( GL_VERTEX_ARRAY );
glVertexPointer( 2, GL_FLOAT, 0, (float*)pts.data );
glDrawArrays( GL_LINE_STRIP, 0, pts.size / 2 );
glDisableClientState( GL_VERTEX_ARRAY );
}
glPopMatrix();
};
before calling draw(), pts get's updated inside the update() function:
void update(double (* func)(double x), float x1, float x2, int N)
{
double x, dx = (double)1.0/(double)N;
vector_cleanup( &pts );
m = 0;
for(x = x1; x < x2; x += dx)
{
vector_resize( &pts, pts.size + 2 );
*(float*)vector_get( &pts, pts.size-2 ) = (float)x;
*(float*)vector_get( &pts, pts.size-1 ) = (float)func3(x);
m++;
}
}
I hope that by converting this code to use VBO, my graphics performance will increase.
EDIT: func3() can be anything, e.g. sin(x) or just some linear mapping. All I'm currently trying to do is, to find out how quickly I can plot a bunch of points.
Using GLEW for extension wrangling:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glew.h>
#include <GL/glut.h>
typedef struct vector /*dynamic vector of void* pointers. This one is used only by the deflate compressor*/
{
void* data;
size_t size; /*in groups of bytes depending on type*/
size_t allocsize; /*in bytes*/
unsigned typesize; /*sizeof the type you store in data*/
} vector;
static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
{
if(size * p->typesize > p->allocsize)
{
size_t newsize = size * p->typesize * 2;
void* data = realloc(p->data, newsize);
if(data)
{
p->allocsize = newsize;
p->data = data;
p->size = size;
}
else return 0;
}
else p->size = size;
return 1;
}
static void vector_cleanup(void* p)
{
((vector*)p)->size = ((vector*)p)->allocsize = 0;
free(((vector*)p)->data);
((vector*)p)->data = NULL;
}
static void vector_init(vector* p, unsigned typesize)
{
p->data = NULL;
p->size = p->allocsize = 0;
p->typesize = typesize;
}
static void* vector_get(vector* p, size_t index)
{
return &((char*)p->data)[index * p->typesize];
}
/* function to calculate each data point */
float func(float x)
{
return (float)sin(x);
}
GLuint vbo = 0;
GLsizei vertcount = 0;
void update(float (* func)(float x), float x1, float x2, int N)
{
float x, dx = 1.0f/N;
vector pts;
vector_init( &pts, sizeof( float ) );
for(x = x1; x < x2; x += dx)
{
vector_resize( &pts, pts.size + 2 );
*(float*)vector_get( &pts, pts.size-2 ) = x;
*(float*)vector_get( &pts, pts.size-1 ) = func(x);
}
vertcount = (GLsizei)( pts.size / 2 );
glBindBuffer( GL_ARRAY_BUFFER, vbo );
glBufferData( GL_ARRAY_BUFFER, pts.size * pts.typesize, pts.data, GL_DYNAMIC_DRAW );
glBindBuffer( GL_ARRAY_BUFFER, 0 );
vector_cleanup( &pts );
}
/* plotting function - very slow */
void draw(float x1, float x2, float y1, float y2)
{
glPushMatrix();
glScalef( 1.0f / (x2 - x1), 1.0f / (y2 - y1), 1.0f );
glTranslatef( -x1, -y1, 0.0f );
glColor3f( 1.0f, 1.0f, 1.0f );
glBindBuffer( GL_ARRAY_BUFFER, vbo );
glEnableClientState( GL_VERTEX_ARRAY );
glVertexPointer( 2, GL_FLOAT, 0, 0 );
glDrawArrays( GL_LINE_STRIP, 0, vertcount );
glDisableClientState( GL_VERTEX_ARRAY );
glBindBuffer( GL_ARRAY_BUFFER, 0 );
glPopMatrix();
};
/* Redrawing func */
float xmin = -10, xmax = 10, ymin = -5, ymax = 5;
void redraw(void)
{
glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// -x, +x, -y, +y, number points
draw(xmin, xmax, ymin, ymax);
glutSwapBuffers();
};
/* Idle proc. Redisplays, if called. */
int nPoints = 3000;
void idle(void)
{
// shift 'xmin' & 'xmax' by one.
xmin++;
xmax++;
update(func, xmin, xmax, nPoints);
glutPostRedisplay();
};
/* Key press processing */
void key(unsigned char c, int x, int y)
{
if(c == 27) exit(0);
};
/* Window reashape */
void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 1, 0, 1, -1, 1);
glMatrixMode(GL_MODELVIEW);
};
/* Main function */
int main(int argc, char **argv)
{
GLenum err;
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
glutCreateWindow("Graph plotter");
glutReshapeWindow(1024, 800);
// init GLEW and output some GL info
err = glewInit();
printf("GL_VERSION : %s\n", glGetString(GL_VERSION) );
printf("GL_VENDOR : %s\n", glGetString(GL_VENDOR) );
printf("GL_RENDERER : %s\n", glGetString(GL_RENDERER) );
if( GLEW_OK != err )
{
printf("glewInit failed: %s", glewGetErrorString(err));
return EXIT_FAILURE;
}
if( !glewIsSupported("GL_VERSION_1_5") )
{
printf("OpenGL version 1.5 or greater required.\n");
return EXIT_FAILURE;
}
glGenBuffers( 1, &vbo );
/* Register GLUT callbacks. */
glutDisplayFunc(redraw);
glutKeyboardFunc(key);
glutReshapeFunc(reshape);
glutIdleFunc(idle);
/* Init the GL state */
glLineWidth(2.0);
/* Main loop */
glutMainLoop();
return 0;
}
I am trying to animate random point that i have created so they move across the screen and re-appear this is what i have done so far but does not work.the code is not the completed version of what i have i have only posted what i thought would be enough for this question could anyone help me animated the points
void TimerFunc(int value)
{
xpos[0]=xpos[0]+0.25;
glutPostRedisplay();
glutTimerFunc(25, TimerFunc, 1);
}
struct Point
{
float rship;
};
std::vector< Point > points;
void display(void)
{
glClear (GL_COLOR_BUFFER_BIT); /* clear window */
glColor3f(1.0, 1.0, 1.0); /* white drawing objects */
/* define object to be drawn as a square polygon */
//Draw points
glEnableClientState( GL_VERTEX_ARRAY );
glVertexPointer( 2, GL_FLOAT, sizeof(Point), &points[0].x );
glPointSize( 1 ); //1 pixel dot
glDrawArrays( GL_POINTS, 0, points.size() );
glDisableClientState( GL_VERTEX_ARRAY );
//glEnable( GL_POINT_SMOOTH );/*round smooth points*/
glFlush(); /* execute drawing commands in buffer */
}
int main(int argc, char** argv)
for( int i = 0; i <250; ++i )
{
Point pt;
pt.x = -100 + (rand() % 200);
pt.y = -100 + (rand() % 200);
points.push_back(pt);
xpos[i] = pt.x;
ypos[i] = pt.y;
}
Quick 'n dirty:
#include <GL/glut.h>
#include <vector>
#include <cstdlib>
struct Point
{
float x, y;
unsigned char r, g, b, a;
};
std::vector< Point > points;
void timer( int value )
{
// move all points left each frame
for( size_t i = 0; i < points.size(); ++i )
{
points[i].x -= 1;
// wrap point around if it's moved off
// the edge of our 100x100 area
if( points[i].x < -50 )
{
points[i].x = 100 + points[i].x;
}
}
glutPostRedisplay();
glutTimerFunc(30, timer, 1);
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-50, 50, -50, 50, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// draw
glColor3ub( 255, 255, 255 );
glEnableClientState( GL_VERTEX_ARRAY );
glEnableClientState( GL_COLOR_ARRAY );
glVertexPointer( 2, GL_FLOAT, sizeof(Point), &points[0].x );
glColorPointer( 4, GL_UNSIGNED_BYTE, sizeof(Point), &points[0].r );
glPointSize( 3.0 );
glDrawArrays( GL_POINTS, 0, points.size() );
glDisableClientState( GL_VERTEX_ARRAY );
glDisableClientState( GL_COLOR_ARRAY );
glFlush();
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, w, h);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutInitWindowSize(640,480);
glutCreateWindow("Scrolling Points");
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutTimerFunc(30, timer, 1);
// populate points
for( size_t i = 0; i < 1000; ++i )
{
Point pt;
pt.x = -50 + (rand() % 100);
pt.y = -50 + (rand() % 100);
pt.r = rand() % 255;
pt.g = rand() % 255;
pt.b = rand() % 255;
pt.a = 255;
points.push_back(pt);
}
glutMainLoop();
return 0;
}