3ddeskd.cpp

一个3D桌面的实现源码

    glEnable(GL_BLEND);
    glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE);
    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);

    glBindTexture(GL_TEXTURE_2D, digit_texture );

    glBegin(GL_QUADS);
    
    glTexCoord2f (x1, y2);
    glVertex3f(-w,-w,0);
    
    glTexCoord2f (x2, y2);
    glVertex3f(w,-w,0);
    
    glTexCoord2f (x2, y1);
    glVertex3f(w,w,0);
    
    glTexCoord2f (x1, y1);
    glVertex3f(-w,w,0);
    
    glEnd();

    // Done with this special projection matrix.  Throw it away.
    glPopMatrix();
}

static void 
draw_digit (int d)
{
    // draw a digit in the middle
    draw_digit (d, 
                GLWin.get_width() / 2, 
                GLWin.get_height() - (cfg->options->digit_size / 2) );
}


// this is where the digit is located in the texture
float digit_texture_coords[] = 
{ 0, 0, .25, 0, .5, 0, .75, 0, 0, .25, .25, .25, .5, .25, .75, .25, 
  0, .5, .25, .5 };

static void
draw_digit (int d, float x_trans, float y_trans)
{
    float x1, y1, x2, y2;

    if (d >= 10) {
        msgout (DEBUG, "^^^^^^^^ above 10\n");
        x1 = 0.25;  // show zero
        y1 = 0.5;
    } else {
        x1 = digit_texture_coords[(d-1) * 2];
        y1 = digit_texture_coords[(d-1) * 2 + 1];
    }
    
    x2 = x1 + 0.25;
    y2 = y1 + 0.25;

    //msgout (DEBUG, "oooooooo d=%d  x1=%f  y1=%f  x2=%f  y2=%f\n",
    //        d, x1, y1, x2, y2);


    float w = cfg->options->digit_size/2.0;

    // But we like our current view too; so we save it here.
    glPushMatrix();
    
    // Now we set up a new projection for the text.
    glLoadIdentity();
    glOrtho(0,GLWin.get_width(),0,GLWin.get_height(),-1.0,1.0);


    glTranslatef(x_trans, y_trans, 0.0f);


    set_color (cfg->options->digit_color, digit_visibility);

    glEnable(GL_BLEND);
    glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE);
    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);

    glBindTexture(GL_TEXTURE_2D, digit_texture );

    glBegin(GL_QUADS);
    
    glTexCoord2f (x1, y2);
    glVertex3f(-w,-w,0);
    
    glTexCoord2f (x2, y2);
    glVertex3f(w,-w,0);
    
    glTexCoord2f (x2, y1);
    glVertex3f(w,w,0);
    
    glTexCoord2f (x1, y1);
    glVertex3f(-w,w,0);
    
    glEnd();

    // Done with this special projection matrix.  Throw it away.
    glPopMatrix();
}


// ------
// Routine which actually does the drawing
static void
render_scene(void)
{
    //char buf[80]; // For our strings.
    long current_time;


    // Enables, disables or otherwise adjusts as 
    // appropriate for our current settings.

    if (Texture_On)
        glEnable(GL_TEXTURE_2D);
    else
        glDisable(GL_TEXTURE_2D);

    if (Light_On) 
        glEnable(GL_LIGHTING);
    else 
        glDisable(GL_LIGHTING);

    if (Alpha_Add)
        //glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);

        //glBlendFunc(GL_ONE, GL_SRC_ALPHA); 

        //glBlendFunc(GL_ONE, GL_CONSTANT_ALPHA); 
        
        // this one is good with NO color material, disable depth test, blend on
        glBlendFunc(GL_SRC_ALPHA, GL_ONE); // GOOD!

    else
        glBlendFunc(GL_ONE, GL_ONE_MINUS_DST_ALPHA);
    
    //glBlendFunc(GL_ONE_MINUS_DST_ALPHA,GL_SRC_ALPHA); 


    // If we're blending, we don't want z-buffering.
    if (Blend_On) {
        //glEnable(GL_DEPTH_TEST); 
        glDisable(GL_DEPTH_TEST); 
        glEnable(GL_BLEND);
    } else { 
        glEnable(GL_DEPTH_TEST); 
        glDisable(GL_BLEND); 
        //glEnable(GL_DEPTH_TEST); 
    }

    glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,TexModes[Curr_TexMode]);

    // only effects gl_blend
    //float text_env_color[] = { .1, .1, .1, .1 };
    //glTexEnvfv(GL_TEXTURE_ENV,GL_TEXTURE_ENV_COLOR, text_env_color);


    // Need to manipulate the ModelView matrix to move our model around.
    glMatrixMode(GL_MODELVIEW);

    // Reset to 0,0,0; no rotation, no scaling.
    glLoadIdentity(); 


    current_time = get_milli_time();

    // this gives us semi-precise/consistent timing of the movements
    // 
    if (current_time - last_time > cfg->options->animation_speed) {

        if (state == STATE_EXIT) {

            //if (!cfg->options->entry_exit_movement || faces->is_exit_movement_done()) {
            


            if (faces->is_exit_movement_done()) {
                // quit (the z offset was changed to match the screen)

                end_X_event_loop = True;
                em.trigger_event (EXIT_MOVEMENT_STOP);
                return;
                
            } else {
                faces->entry_exit_move();
            }

        } else if (state == STATE_ENTRY) {

            if ( faces->is_entry_movement_done() ) {
                state = STATE_NORMAL;
                em.trigger_event (ENTRY_MOVEMENT_STOP);

            } else {
                faces->entry_exit_move();

            }

        } 

        // change state to normal from goto if done goto
        if (state == STATE_GOTO) {
            if ( !faces->in_goto() ) {
                state = STATE_NORMAL;
                em.trigger_event (GOTO_FACE_COMPLETE);
            }
        }

        
        if (cfg->options->use_breathing) {
            if (breathing.at_destination()) {
                breathing.init(&ambient_value, 1.7, 3.0, 200, Movement::MOVE_TYPE_SINE);
            } else {
                breathing.change_a_bit();
                light_ambient2[0] = light_ambient2[1] = light_ambient2[2] = ambient_value;
            }

        }

        if (!digit_vis.at_destination())
            digit_vis.change_a_bit();


        faces->do_movement();

        last_time = get_milli_time();

    } // end animation step
 

    // FIXME: use event to accomplish this?

    // after some seconds start some fun ;)
    if (cfg->options->random_fun_delay &&
        current_time - last_keypress > cfg->options->random_fun_delay * 1000) 
    {
        if ((unsigned long)current_time >= (unsigned long)next_action) {

            //msgout(DEBUG, "having some fun...\n");
            faces->goto_random_face();
            
            next_action = current_time + get_randomi(350, 600);
        }
    }

    glLoadIdentity();

    // adjust the faces the necessary amount
    faces->do_position_GL();

    // Clear the color and depth buffers.
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    faces->render();

    //glPushMatrix();

    glLoadIdentity();

    glColor3f(0.0, 0.0, 1.0);
    glPointSize(5.0);
    glBegin(GL_POINTS);
    glVertex4fv(light_position2);
    glVertex4fv(light_position);
    glEnd();


    // lighting (light2 is for ambient only)
    glLightfv(GL_LIGHT2, GL_POSITION, light_position2);
    glLightfv(GL_LIGHT2, GL_AMBIENT,  light_ambient2);
    //glLightfv(GL_LIGHT2, GL_DIFFUSE,  Light_Diffuse2); 
    glEnable (GL_LIGHT2);

    // lighting (light1 is diffuse only)
    glLightfv(GL_LIGHT1, GL_POSITION, light_position);

    //glLightfv(GL_LIGHT1, GL_AMBIENT,  Light_Ambient);
    //glLightfv(GL_LIGHT1, GL_DIFFUSE,  light_diffuse);

    //float halfs[] = { .50, .50, .50, .50 };
    float ones[] = { 1.0, 1.0, 1.0, 1.0 };


    glLightfv(GL_LIGHT1, GL_DIFFUSE,  ones);
    glLightfv(GL_LIGHT1, GL_SPECULAR,  ones);

    glEnable (GL_LIGHT1);


    //glPopMatrix();

    // We need to change the projection matrix for the text rendering.  
    glMatrixMode(GL_PROJECTION);

    // But we like our current view too; so we save it here.
    glPushMatrix();

    // Now we set up a new projection for the text.
    glLoadIdentity();
    glOrtho(0,GLWin.get_width(),0,GLWin.get_height(),-1.0,1.0);

    // Lit or textured text looks awful.
    glDisable(GL_TEXTURE_2D);
    glDisable(GL_LIGHTING);

    // We don't want depth-testing either.
    glDisable(GL_DEPTH_TEST); 


    // Now we want to render the calulated FPS at the top.
   
    // To ease, simply translate up.  Note we're working in screen
    // pixels in this projection.
   
#if 0
    if (cfg->options->show_fps) {
        glTranslatef(6.0f, GLWin.get_height() - 14,0.0f);
        
        // Make sure we can read the FPS section by first placing a 
        // dark, mostly opaque backdrop rectangle.
        glColor4f(0.2,0.2,0.2,0.75);
        
        glBegin(GL_QUADS);
        glVertex3f(  0.0f, -2.0f, 0.0f);
        glVertex3f(  0.0f, 12.0f, 0.0f);
        glVertex3f(140.0f, 12.0f, 0.0f);
        glVertex3f(140.0f, -2.0f, 0.0f);
        glEnd();
        
        glColor4f(0.9,0.2,0.2,.75);
        char buf[50];
        sprintf(buf,"FPS: %f F: %2d", FrameRate, FrameCount);
        glRasterPos2i(6,0);
        ourPrintString(GLUT_BITMAP_HELVETICA_12,buf);
    }
#endif // if 0

    // Done with this special projection matrix.  Throw it away.
    glPopMatrix();



    if (cfg->options->show_digits) {

        // We need to change the projection matrix for the text rendering.  
        glMatrixMode(GL_PROJECTION);

        // Lit or textured text looks awful.
        glEnable(GL_TEXTURE_2D);
        glDisable(GL_LIGHTING);

        // We don't want depth-testing either.
        glDisable(GL_DEPTH_TEST); 



        // Now we want to render the calulated FPS at the top.
   
        // To ease, simply translate up.  Note we're working in screen
        // pixels in this projection.
   
        if (faces->get_number_of_columns() > 1 &&
            faces->get_number_of_rows() > 1) 
        {
            draw_digits (faces->get_current_row() + 1,
                         faces->get_current_column() + 1);
        } else {
            int n = 1;
            if (faces->get_number_of_columns() > 1)
                n = faces->get_current_column() + 1;
            else
                n = faces->get_current_row() + 1;

            draw_digit (n);
        }

#if 0  // use a string rather then the digit

        // FIXME: do this if the digit texture didn't load

        char buf[50];

        // use N x N if both rows and columns otherwise use juse N
        // (representing columns or rows depending on which is being
        // used)
        if (faces->get_number_of_columns() > 1 &&
            faces->get_number_of_rows() > 1) 
        {
            sprintf(buf,"%d x %d", 
                    faces->get_current_row() + 1,
                    faces->get_current_column() + 1);
        } else {
            int n = 1;
            if (faces->get_number_of_columns() > 1)
                n = faces->get_current_column() + 1;
            else
                n = faces->get_current_row() + 1;

            sprintf(buf,"%d", n);
        }
        
        glRasterPos2i(6,0);
        ourPrintString(GLUT_BITMAP_TIMES_ROMAN_24,buf);
#endif
        

    }



    // All done drawing.  Let's show it.
    glXSwapBuffers(GLWin.get_display(), GLWin.get_window());

    // And collect our statistics.
    if (cfg->options->show_fps)
        calc_fps();

    last_renderscene_time = get_milli_time();

} // END render_scene



static void
mouse_pressed(unsigned int button)
{
    last_keypress = get_milli_time();

    //msgout (DEBUG, "button pressed %d - 0x%x\n", button, button);

    switch (button) {
    case 1: // left
    case 5: // mouse wheel down
        faces->goto_left();
        break;

    case 3: // right
    case 4: // mouse wheel up
        faces->goto_right();
        break;

    case 2: // middle

        begin_exit();

        break;
    }
} // END mouse_pressed


// ------
// Callback function called when a normal key is pressed.

static void
key_pressed(KeySym key)
{
    static KeySym last_key_pressed = 0;

    if (cfg->disable_keys_in_goto &&
        goto_on_flag)
        return;

    last_keypress = get_milli_time();

    next_action = 0;

    switch (key) {
    case 130: case 98: // B - Blending.
        Blend_On = Blend_On ? 0 : 1; 
        if (!Blend_On)
            glDisable(GL_BLEND); 
        else
            glEnable(GL_BLEND);
        break;

    case 108: case 76:  // L - Lighting
        Light_On = Light_On ? 0 : 1; 
        break;

    case 109: case 77:  // M - Mode of Blending
        if ( ++ Curr_TexMode > 3 )
            Curr_TexMode=0;
        glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,TexModes[Curr_TexMode]);
        msgout (DEBUG, "glTexEnv mode=%s (%d)\n", TexModesStr[Curr_TexMode],
                TexModes[Curr_TexMode]);
        break;

    case 116: case 84: // T - Texturing.
        Texture_On = Texture_On ? 0 : 1; 
        break;

    case 97: case 65:  // A - Alpha-blending hack.
        Alpha_Add = Alpha_Add ? 0 : 1; 
        break;

    case 114: case 82: // R - random
        faces->goto_random_face();
        break;

#if 1 // for debugging best light position...
    case 119: // w
        light_position[0] -= 0.5;
        msgout (DEBUG, "light x at %f\n", light_position[0]);
        break;