OpenGLView.m

/*
 
File: OpenGLView.m
 
Abstract: Main rendering class
             
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*/
 
#import "OpenGLView.h"
 
@implementation OpenGLView
 
- (void) heartbeat
{
    if(![[NSApplication sharedApplication] isHidden])
        [self setNeedsDisplay:YES];
}
 
- (id) initWithFrame: (NSRect) theFrame
{
    NSOpenGLPixelFormatAttribute attribs [] = {
        NSOpenGLPFADoubleBuffer,
        NSOpenGLPFADepthSize, 24,
        NSOpenGLPFAStencilSize, 8,
        0
   };
   NSOpenGLPixelFormat *fmt;
   
   {
    /* Create a pre-flight context to check for GLSL hardware support */
    fmt = [[NSOpenGLPixelFormat alloc] initWithAttributes: attribs];
    NSOpenGLContext *preflight = [[NSOpenGLContext alloc] initWithFormat:fmt shareContext:nil];
    [preflight makeCurrentContext];
    [fmt release];
 
    const GLubyte* extensions = glGetString(GL_EXTENSIONS);
    if ((GL_FALSE == gluCheckExtension((GLubyte *)"GL_ARB_shader_objects",       extensions)) ||
        (GL_FALSE == gluCheckExtension((GLubyte *)"GL_ARB_shading_language_100", extensions)) ||
        (GL_FALSE == gluCheckExtension((GLubyte *)"GL_ARB_vertex_shader",        extensions)) ||
        (GL_FALSE == gluCheckExtension((GLubyte *)"GL_ARB_fragment_shader",      extensions)))
        {
            /* Force software rendering, so fragment shaders will execute */
            attribs [3] = NSOpenGLPFARendererID;
            attribs [4] = kCGLRendererGenericFloatID;
        }
    [preflight release];
   }
    
   /* Create a GL Context to use - i.e. init the superclass */
   fmt = [[NSOpenGLPixelFormat alloc] initWithAttributes: attribs];
   [super initWithFrame: theFrame pixelFormat: fmt];
   [[super openGLContext] makeCurrentContext];
   [fmt release];
    
    /* Set up the projection */
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-0.3, 0.3, 0.0, 0.6, 1.0, 8.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.0, 0.0, -2.0);
 
#ifdef USE_BLENDING
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
#endif
 
    /* Turn on depth test */
    glEnable(GL_DEPTH_TEST);
    
    [self setFrameSize: theFrame.size];
 
    /* Create an update timer */
    timer = [NSTimer scheduledTimerWithTimeInterval: (1.0f/150.0f) target: self
                    selector: @selector(heartbeat) userInfo: nil
                    repeats: YES];
    [timer retain];
 
    [[NSRunLoop currentRunLoop] addTimer: timer forMode: NSDefaultRunLoopMode];
    [[NSRunLoop currentRunLoop] addTimer: timer forMode: NSEventTrackingRunLoopMode];
 
    /* Create the podium */
    podium = [[Podium alloc] init];
    
    lastFrameReferenceTime = -1;
    leftMouseIsDown = NO;
    rightMouseIsDown = NO;
    
    angle = 0;
    pitch = 25;
    zoom = 1;
    
    {
        /* Sync to VBL to avoid tearing. */
        long VBL = 1;
        [[self openGLContext] setValues:&VBL forParameter:NSOpenGLCPSwapInterval];
    }
    
    return self;
}
 
- (void) dealloc
{
    /* Release the update timer */
    if (timer) {
        [timer invalidate];
        [timer release];
    }
    
    /* Release the podium */
    [podium release];
    
    /* Dealloc the superclass */
    [super dealloc];
}
 
- (void)renewGState
{
    /* Overload this function to ensure the NSOpenGLView doesn't
       flicker when you resize it.                               */
    NSWindow *window;
    [super renewGState];
    window = [self window];
 
    /* Only available in 10.4 and later, so check that it exists */
    if([window respondsToSelector:@selector(disableScreenUpdatesUntilFlush)])
        [window disableScreenUpdatesUntilFlush];
}
 
#define VIEW_ROTATION_DEGREES_PER_SECOND 20.0
#define EXHIBIT_HEIGHT_MOVEMENT_UNITS_PER_SECOND 0.5
 
- (void) drawRect: (NSRect) theRect
{
    NSRect bounds = [self bounds];
    double now, deltaTime;
 
    float aspect = NSWidth(bounds) / NSHeight(bounds);
 
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    {
        float lr, bt;
        
        if (aspect > 1)
        {
            lr = 0.3 * aspect * zoom;
            bt = 0.3 * zoom;
        }
        else
        {
            lr = 0.3 * zoom;
            bt = 0.3 / aspect * zoom;
        }
        
        glFrustum(-lr, lr, -bt, bt, 1.0, 8.0);
    }
    glMatrixMode(GL_MODELVIEW);
 
    glViewport(0, 0, NSWidth(bounds), NSHeight(bounds));
    
    now = (double)[NSDate timeIntervalSinceReferenceDate];
    
    if (lastFrameReferenceTime < 0)
    {
        deltaTime = 0;
    }
    else
    {
        deltaTime = now - lastFrameReferenceTime;
    }
    
    lastFrameReferenceTime = now;
 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    
    glPushMatrix();
    
    /* Constant rotation of the subject */
    if (!leftMouseIsDown && !rightMouseIsDown)
    {
        angle += VIEW_ROTATION_DEGREES_PER_SECOND * deltaTime;
        if (angle >= 360.0f)
            angle -= 360.0f;
    }
    
    if (pitch < -45.f)
    {
        pitch = -45.f;
    }
    else if (pitch > 90.f)
    {
        pitch = 90.f;
    }
 
    glRotatef(pitch, 1.0f, 0.0f, 0.0f);
    glTranslatef(0.0f, -0.5f, -.15f);
    glRotatef(angle, 0.0f, 1.0f, 0.0f);
 
    /* Draw the exhibit */
    if (target_exhibit) {
        exhibit_height -= EXHIBIT_HEIGHT_MOVEMENT_UNITS_PER_SECOND * deltaTime;
        if (exhibit_height < 0.0f) {
            exhibit_height = 0.0f;
            current_exhibit = target_exhibit;
            target_exhibit  = NULL;
        }
    } else {
        exhibit_height += EXHIBIT_HEIGHT_MOVEMENT_UNITS_PER_SECOND * deltaTime;
        if (exhibit_height > 0.5f)
            exhibit_height = 0.5f;
    }
 
    /* Draw only the top of the podium with
       the stencil being set as well. */
    [podium drawReflectionStencil];
 
    if(!(exhibit_height < 0.4f) && [current_exhibit reflect])
    {
        /* Draw the reflection only where the podium top is.
           A clipping plane can also be used here, but be
           sure to set the gl_ClipVertex in your shaders when
           doing so. */
 
        glPushAttrib(GL_STENCIL_BUFFER_BIT | GL_POLYGON_BIT);
        glFrontFace(GL_CW);
        glEnable(GL_STENCIL_TEST);
        glStencilFunc(GL_EQUAL, 1, 0xffffffff);
        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
        glPushMatrix();
        glScalef(1.0f, -1.0f, 1.0f);
        glTranslatef(0.0f, exhibit_height - 0.5f, 0.0f);
        glScalef(0.4f, 0.4f, 0.4f);
        if (current_exhibit)
            [current_exhibit renderFrame];
        glPopMatrix();
        glPopAttrib();
    }
 
    /* Draw the granite podium */
    
    [podium renderFrame:((exhibit_height - 0.4f) / 0.1f)];
 
    glPushMatrix();
    glTranslatef(0.0f, exhibit_height, 0.0f);
    glScalef(0.4f, 0.4f, 0.4f);
    if (current_exhibit)
        [current_exhibit renderFrame];
    glPopMatrix();
    
    glPopMatrix();
 
    [[self openGLContext] flushBuffer];
}
 
- (void) setExhibit: (Exhibit *) new_exhibit
{
    target_exhibit  = new_exhibit;
}
 
- (void)mouseDown:(NSEvent *)event
{
    lastMousePoint = [self convertPoint:[event locationInWindow] fromView:nil];
    leftMouseIsDown = YES;
}
 
- (void)rightMouseDown:(NSEvent *)event
{
    lastMousePoint = [self convertPoint:[event locationInWindow] fromView:nil];
    rightMouseIsDown = YES;
}
 
- (void)mouseUp:(NSEvent *)event
{
    leftMouseIsDown = NO;
}
 
- (void)rightMouseUp:(NSEvent *)event
{
    rightMouseIsDown = NO;
}
 
- (void)mouseDragged:(NSEvent *)event
{
    if ([event modifierFlags] & 1)
    {
        [self rightMouseDragged:event];
    }
    else
    {
        NSPoint mouse = [self convertPoint:[event locationInWindow] fromView:nil];
        
        pitch += lastMousePoint.y - mouse.y;
        angle -= lastMousePoint.x - mouse.x;
 
        lastMousePoint = mouse;
        
        [self setNeedsDisplay:YES];
    }
}
 
- (void)rightMouseDragged:(NSEvent *)event
{
    NSPoint mouse = [self convertPoint:[event locationInWindow] fromView:nil];
    
    zoom += .01f * (lastMousePoint.y - mouse.y);
    if (zoom < .05f)
    {
        zoom = .05f;
    }
    else if (zoom > 2.0f)
    {
        zoom = 2.0f;
    }
 
    lastMousePoint = mouse;
 
    [self setNeedsDisplay:YES];
}
 
@end


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