Cannot seem to get GLFW/OpenGL Depth Testing working - opengl

Question

I cannot get Depth testing working with GLFW using codeblocks in any project, even using the default template provided by codeblocks when you start a new project, as below.
Any help is much appreciated as I know I must be doing something wrong but I haven't been able to find it.
#include <GL/glfw.h>
int main()
{
int width, height;
int frame = 0;
bool running = true;
glfwInit();
if( !glfwOpenWindow( 512, 512, 0, 0, 0, 0, 0, 0, GLFW_WINDOW ) )
{
glfwTerminate();
return 0;
}
glfwSetWindowTitle("GLFW Application");
glEnable(GL_DEPTH_TEST);
while(running)
{
frame++;
glfwGetWindowSize( &width, &height );
height = height > 0 ? height : 1;
glViewport( 0, 0, width, height );
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 65.0f, (GLfloat)width/(GLfloat)height, 1.0f, 100.0f );
// Draw some rotating garbage
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt(0.0f, -10.0f, 0.0f,
0.0f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f );
//glTranslatef( 1.0f, 1.0f, 0.0f );
glRotatef(frame, 0.25f, 1.0f, 0.75f);
glBegin( GL_TRIANGLES );
glColor3f(0.1f, 0.0f, 0.0f );
glVertex3f(0.0f, 3.0f, -4.0f);
glColor3f(0.0f, 1.0f, 0.0f );
glVertex3f(3.0f, -2.0f, -4.0f);
glColor3f(0.0f, 0.0f, 1.0f );
glVertex3f(-3.0f, -2.0f, -4.0f);
glEnd();
glBegin( GL_TRIANGLES );
glColor3f(0.0f, 0.1f, 0.0f );
glVertex3f(0.0f, 3.0f, -3.0f);
glColor3f(0.0f, 0.0f, 1.0f );
glVertex3f(3.0f, -2.0f, -2.0f);
glColor3f(1.0f, 0.0f, 0.0f );
glVertex3f(-3.0f, -2.0f, 2.0f);
glEnd();
glfwSwapBuffers();
// exit if ESC was pressed or window was closed
running = !glfwGetKey(GLFW_KEY_ESC) && glfwGetWindowParam( GLFW_OPENED);
}
glfwTerminate();
return 0;
}

Answer 1

From the GLFW2 documentation (emphasis mine):
int glfwOpenWindow
(
int width, int height,
int redbits, int greenbits, int bluebits,
int alphabits,
int depthbits,
int stencilbits,
int mode
)
depthbits: The number of bits to use for the depth buffer (0 means no depth buffer).
And your code:
glfwOpenWindow( 512, 512, 0, 0, 0, 0, 0, 0, GLFW_WINDOW )
^ no depth bits
You can't (usefully) use the depth buffer without any depth bits.