I just started trying out OpenGL and I'm having a strange issue.
If I compile and execute using g++ test.c -lGL -lGLU -lglut then ./a.out, a sepearate window opens (of the size specified in the code). But instead of having the output of the code in it, it has a screenshot of the screen inside it (of the portion of the screen it overlaps).
This is definitely not something to do with the code, since it's running fine on my friend's computer. But I need to fix it on my PC.
I'm on Linux Mint 15 64bit (HP DV6 6121tx).
So I'm not able to proceed further. Here's my code:
#include <GL/gl.h>
#include <GL/glut.h>
#define drawOneLine(x1,y1,x2,y2) glBegin(GL_LINES); glVertex2f ((x1),(y1)); glVertex2f ((x2),(y2)); glEnd();
void init()
{
glClearColor(1.0,1.0,1.0,0.0);
glMatrixMode(GL_PROJECTION);
gluOrtho2D (-600,600,-400,400);
glClear(GL_COLOR_BUFFER_BIT);
}
int main(int argc, char** argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowPosition(0,0);
glutInitWindowSize(1200,800);
glutCreateWindow("ABCD");
init();
glutMainLoop();
return 0;
}
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
^^^^^^^^^^^
You've asked for a single-buffered window so you'll have to glFlush()/glFinish() to force queued output to the screen.
Add a glFinish() to the end of init().
Related
I am changing the window background color using the Glut library, which isn't working. The code works perfectly on my peer's computers but not on mine. I am using Visual Studio on Windows 10, with intel i5,8th gen, with integrated graphics.
I searched on Reddit threads, and the only thing relevant was that integrated graphics may be the issue.
Is integrated graphics really the issue or something else?
Are there any solutions to this problem, except changing the graphic cards?
Note- The library should be OpenGL, glut, glu only...
Code:
#include <GL/glut.h>
#include <gl/GLU.h>
#include <iostream>
using namespace std;
void draw() {}
void display() {
glClearColor(1.0, 1.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT);
gluOrtho2D(0, 640, 0, 480);
// draw();
glFlush();
return;
}
int main(int argc, char **argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowPosition(200, 200);
glutInitWindowSize(640, 480);
glutCreateWindow("House");
glutDisplayFunc(display);
glutMainLoop();
return 0;
}
I tried this code, and although it renders a window, it is black in color, which it should not be. It should be (as the question) any random color. Are there any solutions i can try?
Consider a very simple OpenGL program:
#include <GL/glut.h>
static void RenderScene()
{
glClear(GL_COLOR_BUFFER_BIT);
glutSwapBuffers();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowSize(500, 500);
glutCreateWindow("OpenGL Test");
glutDisplayFunc(RenderScene);
glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
glutMainLoop();
return 0;
}
This compiles and runs fine, displaying a grey window as expected.
Then, I introduce three variables into the main function, before the OpenGL processing. The code becomes:
#include <string>
#include <GL/glut.h>
static void RenderScene()
{
glClear(GL_COLOR_BUFFER_BIT);
glutSwapBuffers();
}
int main(int argc, char** argv)
{
int x = 5;
char y = 'a';
std::string z = "abc";
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowSize(500, 500);
glutCreateWindow("OpenGL Test");
glutDisplayFunc(RenderScene);
glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
glutMainLoop();
return 0;
}
Compiling this is fine, but if I run it, I receive a segmentation fault error. Now, if I comment out the line std::string z = "abc";, then it runs fine without any errors.
So, for some reason, declaring a string variable is causing a segmentation fault here, but not with any other variable types.
If I remove all the OpenGL code, then it runs fine. But if I remove all the OpenGL code except for just one line, such as glutInit(&argc, argv);, then it still causes the segmentation fault.
Any ideas on what is going on?
I'm having similar problem too, but mine was on Linux. Is your on Linux or Windows? Do you have any graphic card driver install?
For my case, I'm running on Ubuntu with nVidia installed, I notice that when I link my program with libGL.so located at /usr/lib/x86_64-linux-gnu, it will cause segmentation fault. Then I also found out there is another libGL.so located at /usr/lib/nvidia-352, this will link without crash.
Hope this help.
i want to change a wireSphere during an animation with openGL.
But it won´t work.
What must i do that it changes a color during an animation?
So far i only have this :
glColor3f(1.0,1.0,0.0); //yellow color
glutWireSphere(0.5,60,50);
Works for me. Here's a minimal GLUT program that uses your code, and successfully displays a yellow sphere on my Mac:
#include <GLUT/glut.h>
static void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glColor3f(1.0f, 1.0f, 0.0f);
glutWireSphere(0.5f, 50, 60);
glutSwapBuffers();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
glutCreateWindow("WireSphere");
glutDisplayFunc(display);
glutMainLoop();
return 0;
}
I suspect that there's some state you're setting outside the code you copied that prevents this from working for you. But it's hard to speculate what that could be. I think you'll need to post more code, or at least be more specific about the unexpected behavior than "it won't work".
I have attempted to start programming with OpenGl using this tutorial, and have the following code so far:
#include <gl/glut.h> // Include the GLUT header file
void display (void)
{
}
int main(int argc, char **argv)
{
glutInit(&argc, argv); // Initialize GLUT
// Set up a basic display buffer (only single buffered for now)
glutInitDisplayMode (GLUT_SINGLE);
glutInitWindowSize (500, 500); // Set the width and height of the window
glutInitWindowPosition (100, 100); // Set the position of the window
// Set the title for the window
glutCreateWindow("Your first OpenGL Window!");
glutDisplayFunc(display);
glutMainLoop();
glClearColor(1.f, 0.f, 0.f, 1.f); // Clear the background of our window to red
return 0;
}
I build and run the project in Eclipse, it compiles all fine, but nothing happens (no windows pop up or anything). Can anybody tell me what I could be doing wrong?
glutInitDisplayMode (GLUT_SINGLE);
You also need to define the kind of framebuffer format you want, i.e. add a GLUT_RGBA, at least (and you probably also want a depth buffer). And there are only few cases where one not wants a double buffer. So: glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
Then your display function will not be called, unless you add a glutDisplayFunc(display); after glutCreateWindow.
glutMainLoop();
glClearColor(1.f, 0.f, 0.f, 1.f);
glutMainLoop does not return. And even if it did, glClearColor had no effect at that place in the program.
I had OpenGL project for finding a convex hull written in Windows.
Now i'm using Ubuntu 10.10 and i tried to port the code (It's C++ code) and run it.
I saw that, it should be compiled this way :
g++ convex.cpp -lm -lglut -lGLU -o convex_hull_project
It compiles the file, but when i run the file ./convex_hull_project it starts the program, shows the title but there is nothing - it only docks for the bottom task line and when i click it - nothing shows. There is no window with the program.
Any idea ?
Here's the code that uses OpenGL stuff :
int main(int argc, char* argv[]) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE | GLUT_DEPTH); // color, buffer
glutInitWindowPosition(100,100);
glutInitWindowSize(window_size_width,window_size_height);
glutCreateWindow("Convex hull");
glutDisplayFunc(renderScene);
glutMouseFunc(mouse);
glutMainLoop();
return 0;
}
void renderScene(void) {
// clear framebuffer
glClearColor(0.f,0.f,0.f,0.f);
glClear(GL_COLOR_BUFFER_BIT);
// set-up matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0,window_size_width,window_size_height,0,-1,1);
glViewport(0,0,window_size_width,window_size_height);
//drawing ...
}
And includes are :
#include<GL/glut.h>
#include<GL/glu.h>
#include<stdio.h>
#include<vector>
#include<algorithm>
#include<math.h>
You have to call glutCreateWindow before you set windows's properties. Your code, fixed (I've replaced width and height constants with 300 just to get it to compile and commented out mouse handler registration):
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <GL/glut.h>
#include <GL/glu.h>
void renderScene(void) {
// clear framebuffer
glClearColor (0.f,0.f,0.f,0.f);
glClear (GL_COLOR_BUFFER_BIT);
// set-up matrix
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glOrtho (0, 300, 300, 0,-1,1);
glViewport (0,0,300, 300);
//drawing ...
}
int main(int argc, char* argv[])
{
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_RGBA | GLUT_SINGLE | GLUT_DEPTH); // color, buffer
glutCreateWindow ("Convex hull");
glutInitWindowPosition (100, 100);
glutInitWindowSize (300, 300);
glutDisplayFunc (renderScene);
//glutMouseFunc (mouse);
glutMainLoop ();
}