Thread: Glut Camera/stray error: need tutorial/advice

Hello, I am new to C++ and Glut (I know some C), and I have made an attempt to add a camera to a basic Glut program. However, when I compile, I get these following errors:

C:\Users\drewtoby\Desktop\cube\main.cpp|25|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|25|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|31|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|31|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|37|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|37|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|47|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|47|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|57|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|57|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|63|error: stray '\221' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp|63|error: stray '\222' in program|
C:\Users\drewtoby\Desktop\cube\main.cpp||In function 'void keyboard(unsigned char, int, int)':|
C:\Users\drewtoby\Desktop\cube\main.cpp|25|error: 'q' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|27|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|31|error: 'z' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|33|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|37|error: 'w' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|40|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|41|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|42|error: 'xpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|42|error: 'sin' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|43|error: 'zpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|43|error: 'cos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|44|error: 'ypos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|47|error: 's' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|50|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|51|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|52|error: 'xpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|52|error: 'sin' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|53|error: 'zpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|53|error: 'cos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|54|error: 'ypos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|57|error: 'd' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|59|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|63|error: 'a' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|65|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp||In function 'int main(int, char**)':|
C:\Users\drewtoby\Desktop\cube\main.cpp|82|error: 'display' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|84|error: 'variables' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|84|error: expected ';' before 'to'|
C:\Users\drewtoby\Desktop\cube\main.cpp|85|error: 'reshape' was not declared in this scope|
||=== Build finished: 40 errors, 1 warnings ===|

with this code:

Code:

#include <GL/glut.h>
#include <iostream>

void enable (void) {
    glEnable (GL_DEPTH_TEST); //enable the depth testing
    glEnable (GL_LIGHTING); //enable the lighting
    glEnable (GL_LIGHT0); //enable LIGHT0, our Diffuse Light
    glShadeModel (GL_SMOOTH); //set the shader to smooth shader
    }


void renderScene(void) {
   glClear(GL_COLOR_BUFFER_BIT);
   glBegin(GL_TRIANGLES);
   glColor3f(1,0,0);//Change the object color to red
      glVertex3f(-2.0,-0.1,0.0);
      glVertex3f(0.4,0.0,0.0);
      glVertex3f(0.0,0.0,0.0);
   glEnd();
   glFlush();
}


void keyboard (unsigned char key, int x, int y) {
    if (key==‘q’)
    {
    xrot += 1;
    if (xrot >360) xrot -= 360;
    }

    if (key==‘z’)
    {
    xrot -= 1;
    if (xrot < -360) xrot += 360;
    }

    if (key==‘w’)
    {
    float xrotrad, yrotrad;
    yrotrad = (yrot / 180 * 3.141592654f);
    xrotrad = (xrot / 180 * 3.141592654f);
    xpos += float(sin(yrotrad)) ;
    zpos -= float(cos(yrotrad)) ;
    ypos -= float(sin(xrotrad)) ;
    }

    if (key==‘s’)
    {
    float xrotrad, yrotrad;
    yrotrad = (yrot / 180 * 3.141592654f);
    xrotrad = (xrot / 180 * 3.141592654f);
    xpos -= float(sin(yrotrad));
    zpos += float(cos(yrotrad)) ;
    ypos += float(sin(xrotrad));
    }

    if (key==‘d’)
    {
    yrot += 1;
    if (yrot >360) yrot -= 360;
    }

    if (key==‘a’)
    {
    yrot -= 1;
    if (yrot < -360)yrot += 360;
    }
    if (key==27)
    {
    exit(0);
    }
}


int main(int argc, char **argv) {
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_DEPTH | GLUT_SINGLE | GLUT_RGBA);
   glutInitWindowPosition(100,100);
   glutInitWindowSize(800,800);
   glutCreateWindow("MynDrawn: An Open Source Alternative to Minecraft");
   glutDisplayFunc(renderScene);
glutIdleFunc (display); //update any variables in display,
//display can be changed to anyhing, as long as you move the
variables to be updated, in this case, angle++;
glutReshapeFunc (reshape); //reshape the window accordingly
glutKeyboardFunc (keyboard); //check the keyboard
glutMainLoop (); //call the main loop
return 0;
}

Could you let me know what I am doing wrong, and/or reccomend a glut camera tutorial? Thanks!!!!!

Code is adapted from: 23. OpenGL Camera Part 2 | Swiftless Tutorials

Look closely at the following code note the single quotation marks. These are not the normal single quote mark ' notice how yours are not straight up and down. You will need to replace all of your single quotes with the proper single quote, both the start and end single quote seem wrong.

Code:

if (key==‘d’)

Jim

Okay, I will try that. Thanks!!! Anything else?

I Made the adjustments, now only 24 errors

Errors:

C:\Users\drewtoby\Desktop\cube\main.cpp||In function 'void keyboard(unsigned char, int, int)':|
C:\Users\drewtoby\Desktop\cube\main.cpp|30|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|30|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|32|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|36|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|36|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|38|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|42|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|42|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|45|error: invalid operands of types 'const char [5]' and 'int' to binary 'operator/'|
C:\Users\drewtoby\Desktop\cube\main.cpp|46|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|47|error: 'xpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|48|error: 'zpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|49|error: 'ypos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|52|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|52|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|55|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|56|error: 'xrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|57|error: 'xpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|58|error: 'zpos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|59|error: 'ypos' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|62|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|62|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|64|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|68|warning : comparison with string literal results in unspecified behaviour|
C:\Users\drewtoby\Desktop\cube\main.cpp|68|error: ISO C++ forbids comparison between pointer and integer|
C:\Users\drewtoby\Desktop\cube\main.cpp|70|error: 'yrot' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp||In function 'int main(int, char**)':|
C:\Users\drewtoby\Desktop\cube\main.cpp|87|error: 'display' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|89|error: 'variables' was not declared in this scope|
C:\Users\drewtoby\Desktop\cube\main.cpp|89|error: expected ';' before 'to'|
C:\Users\drewtoby\Desktop\cube\main.cpp|90|error: 'reshape' was not declared in this scope|
||=== Build finished: 24 errors, 7 warnings ===|

Code:

Code:

#include <GL/glut.h>
#include <iostream>
#include <math.h>
#include <stdlib.h>
using namespace std;


void enable (void) {
    glEnable (GL_DEPTH_TEST); //enable the depth testing
    glEnable (GL_LIGHTING); //enable the lighting
    glEnable (GL_LIGHT0); //enable LIGHT0, our Diffuse Light
    glShadeModel (GL_SMOOTH); //set the shader to smooth shader
    }


void renderScene(void) {
   glClear(GL_COLOR_BUFFER_BIT);
   glBegin(GL_TRIANGLES);
   glColor3f(1,0,0);//Change the object color to red
      glVertex3f(-2.0,-0.1,0.0);
      glVertex3f(0.4,0.0,0.0);
      glVertex3f(0.0,0.0,0.0);
   glEnd();
   glFlush();
}


void keyboard (unsigned char key, int x, int y) {

    if (key=="q")
    {
    xrot += 1;
    if (xrot >360) xrot -= 360;
    }

    if (key=="z")
    {
    xrot -= 1;
    if (xrot < -360) xrot += 360;
    }

    if (key=="w")
    {
    float xrotrad, yrotrad;
    yrotrad = (yrot / 180 * 3.141592654f);
    xrotrad = (xrot / 180 * 3.141592654f);
    xpos += float(sin(yrotrad)) ;
    zpos -= float(cos(yrotrad)) ;
    ypos -= float(sin(xrotrad)) ;
    }

    if (key=="s")
    {
    float xrotrad, yrotrad;
    yrotrad = (yrot / 180 * 3.141592654f);
    xrotrad = (xrot / 180 * 3.141592654f);
    xpos -= float(sin(yrotrad));
    zpos += float(cos(yrotrad)) ;
    ypos += float(sin(xrotrad));
    }

    if (key=="d")
    {
    yrot += 1;
    if (yrot >360) yrot -= 360;
    }

    if (key=="a")
    {
    yrot -= 1;
    if (yrot < -360)yrot += 360;
    }
    if (key==27)
    {
    exit(0);
    }
}


int main(int argc, char **argv) {
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_DEPTH | GLUT_SINGLE | GLUT_RGBA);
   glutInitWindowPosition(100,100);
   glutInitWindowSize(800,800);
   glutCreateWindow("MynDrawn: An Open Source Alternative to Minecraft");
   glutDisplayFunc(renderScene);
glutIdleFunc (display); //update any variables in display,
//display can be changed to anyhing, as long as you move the
variables to be updated, in this case, angle++;
glutReshapeFunc (reshape); //reshape the window accordingly
glutKeyboardFunc (keyboard); //check the keyboard
glutMainLoop (); //call the main loop
return 0;
}

You seem to have replaced the problem single quotes with double quotes. Double quotes denote a C-string not a character. They need to be single quotes.

Jim

The single quote is on the same key as the double quote if your using standard keyboard... so " pressing shift and ' without... you want without.

Thanks again everyone! Used C when it should have been C++... lol

Only a handful of errors now, I'll go fix em!!!