Albrecht Schlosser wrote:
> I still don't know more about glut, but reading the FLTK 1.3 (!) docs
> about "Mixing GLUT and FLTK Code"
>
> <http://www.fltk.org/doc-1.3/glut.html#glut_mixing>
>
> your code seems to be faulty. I understand the docs so that you
> shall not call glutInit() if (and only if?) you want to "make your
> GLUT window a child of a Fl_Window". Then you must also show() your
> main window *before* you add the glut subwindow (this is not correct
> in your example code).
I still get an error about calling glutInit()..
1) Changed the code to use a GlutWindow(),
2) Define the glut window after show()ing the fltk window
3) Not calling glutInit() because it's a child of Fl_Window
The FLTK2 docs for GlutWindow refer to docs in glut.h,
but I don't see much there in the way of docs.
New code below; feel free to tweak; it still gives the 'glutInit'
runtime error "ERROR: Function <xxx> called without first calling
'glutInit'".
I'm pretty sure glut's glutInit() must be setting a static flag that has
to be set, or the rest of the lib won't work. So unless you set that,
it's gonna bitch about glutInit() not being called.
And I /think/ fltk's glutInit() eclipses the real glutInit(),
so calling it doesn't make the error go away, cause you're calling the
FLTK2 one, not glut's. And I don't think fltk2's glutInit() calls
the real glut's (how can it when it eclipses it?).
#ifdef _WIN32
#include <windows.h>
#endif
#include <math.h>
#include <fltk/glut.h> // GlutWindow(), glutSolidSphere()
#include <fltk/DoubleBufferWindow.h>
#include <fltk/run.h>
//
// Render a simple opengl shaded sphere with a single side light -- erco
11/28/08
// translated to fltk2 -- erco 03/14/11
//
class MyGlutWindow : public fltk::GlutWindow {
public:
// RESHAPE THE VIEWPORT
void Reshape(GLfloat W, GLfloat H) {
// (REFERENCE: SGI light.c DEMO)
GLfloat ratio = W / H;
glViewport(0, 0, (GLsizei)W, (GLsizei)H);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1.5*ratio, 1.5*ratio, -1.5, 1.5, -10.0, 10.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void draw() {
if (!valid()) {
valid(1);
Reshape(w(), h());
// (REFERENCE: SGI 'light.c' EXAMPLE)
GLfloat mat_ambient[] = { 1.0, 1.0, 1.0, 1.0 }; // RGBA
GLfloat mat_diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; // RGBA
GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 }; // RGBA
GLfloat light_position[] = { 5.0, 5.0, 0.0, 0.0 }; // XYZ
glClearColor(0.0, 0.0, 0.4, 0.0); // bg color
glShadeModel(GL_SMOOTH);
//
glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialf(GL_FRONT, GL_SHININESS, 20.0);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
//
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
}
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glColor3f(0.5, 0.5, 0.5);
glutSolidSphere(0.5, 30, 30);
glPopMatrix();
}
// CTOR
MyGlutWindow(int X,int Y,int W,int H,const char*L=0) :
fltk::GlutWindow(X,Y,W,H,L) {
}
};
int main(int argc, char **argv) {
fltk::DoubleBufferWindow dwin(640, 480, "sphere");
dwin.resizable(dwin);
// Call show() first
dwin.show();
// Add glut window next
dwin.begin();
MyGlutWindow myglut(10, 10, dwin.w()-20, dwin.h()-20);
myglut.show();
dwin.end();
return(fltk::run());
}
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