[openbeos] Tracker bug and screen saver question

  • From: Fredrik Ekdahl <fekdahl@xxxxxxxxx>
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Wed, 17 Jan 2007 19:51:16 +0100

Since trac is unavailable at the moment I'll report the bug here instead. As can be seen in the attached image, dragging files from "Screen Savers" under /boot/home/ to the equivalent folder under /boot/beos/ makes Tracker think that I'm trying to move the mime settings.
On to the screen saver question. My problem is that every screen saver I write that uses OpenGL crashes.. :) I don't know if I'm doing anything wrong or if there is a bug outside of my screen savers. I've attached a small example saver. Can anyone spot any obvious errors? Should be possible to temporarily replace the screen saver "Haiku" with this source file and just make sure it links against libGL.so. All crashes happens when exiting the savers, either by selecting another in preferences or by moving the mouse to exit the test mode. 

/Fredrik Ekdahl

PNG image

#include <GL/gl.h>
#include <GLView.h>
#include <ScreenSaver.h>
#include <StringView.h>
#include <View.h>


class ScreenSaver : public BScreenSaver
{
public:
                                ScreenSaver(BMessage *archive, image_id id)
                                        : BScreenSaver(archive, id) {};
                                ~ScreenSaver();

        void            Draw(BView *view, int32 frame);
        void            StartConfig(BView *view);
        status_t        StartSaver(BView *view, bool preview);
        
private:
        BGLView         *fGLView;
};


BScreenSaver *instantiate_screen_saver(BMessage *msg, image_id image) 
{ 
        return new ScreenSaver(msg, image);
} 


void
ScreenSaver::StartConfig(BView *view) 
{ 
        view->AddChild(new BStringView(BRect(20, 10, 200, 35), "", "OpenGL 
screen saver test"));
} 


status_t
ScreenSaver::StartSaver(BView *view, bool preview)
{
        // set redraw delay in microseconds
        SetTickSize(1000);

        fGLView = new BGLView(view->Bounds(), "GLView", B_FOLLOW_ALL_SIDES, 0, 
BGL_DOUBLE | BGL_DEPTH);

        fGLView->LockGL();
                glViewport(0, 0, (GLsizei)view->Bounds().Width(), 
(GLsizei)view->Bounds().Height());
        fGLView->UnlockGL();
        
        view->AddChild(fGLView);
        
        return B_OK;
}


ScreenSaver::~ScreenSaver()
{
                delete fGLView;
}


void 
ScreenSaver::Draw(BView *view, int32 frame)
{
        fGLView->LockGL();
                // set the background color to purple
                glClearColor(1.0f, 0.0f, 1.0f, 0.0f);
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                
                glLoadIdentity();
                // rotate the square round the z axis
                glRotatef((float)frame/5.0f, 0.0f, 0.0f, 1.0f);
                // draw the square
                glBegin(GL_QUADS);
                        glColor3f(1.0f, 0.0f, 0.0f); glVertex2f(-0.6f,  0.8f);
                        glColor3f(1.0f, 1.0f, 0.0f); glVertex2f( 0.6f,  0.8f);
                        glColor3f(0.0f, 1.0f, 0.0f); glVertex2f( 0.6f, -0.8f);
                        glColor3f(0.0f, 0.0f, 1.0f); glVertex2f(-0.6f, -0.8f);
                glEnd();
        fGLView->UnlockGL();
        fGLView->SwapBuffers();
}

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