Help with NSOpenGL: Window resizing
Post: #1
I've created a basic NSView subclass that creates an NSOpenGLContext and attatches it to itself. This works great, except that resizing the view is totally broken. Anything outside the view's original frame is filled with random garbage. When I minimize the window to the dock and restore it, it has fixed itself... until I resize it again, of course. I'm calling glViewport every frame, so I really don't know what the problem is. There must be something really simple I'm forgetting to do, but I've been trying to fix this for three days and I've simply run out of ideas. Here's the code.
PHP Code:
#import "GLView.h"
#import <OpenGL/gl.h>
#import <OpenGL/glu.h>
@implementation GLView
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (!self) {
NSLog(@"Hello, my name is GLView, and I don't exist.");
return nil;
}
NSOpenGLPixelFormatAttribute attrs[] =
{
NSOpenGLPFADoubleBuffer,
NSOpenGLPFAAccelerated,
NSOpenGLPFADepthSize, 16,
NSOpenGLPFASingleRenderer,
NSOpenGLPFAScreenMask, CGDisplayIDToOpenGLDisplayMask(kCGDirectMainDisplay),
NSOpenGLPFANoRecovery,
0
};
NSOpenGLPixelFormat *pf = [[[NSOpenGLPixelFormat alloc] initWithAttributes:attrs] autorelease];
context = [[NSOpenGLContext alloc] initWithFormat:pf shareContext:nil];
[NSTimer scheduledTimerWithTimeInterval:0.0
target:self
selector:@selector(draw:)
userInfo:nil
repeats:YES];
return self;
}
- (void)draw:(id)sender {
[self setNeedsDisplay:YES];
}
- (void)drawRect:(NSRect)rect {
static BOOL firstRender = YES;
if(firstRender) {
[context setView:self];
firstRender = NO;
}
[context makeCurrentContext];
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
glClearColor(0.0, 0.5, 1.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT |GL_DEPTH_BUFFER_BIT);
glBegin(GL_POLYGON);
glColor3f(1.0, 0.0, 0.0);
glVertex3f(0.25, 0.25, 0.0);
glVertex3f(0.75, 0.25, 0.0);
glVertex3f(0.75, 0.75, 0.0);
glVertex3f(0.25, 0.75, 0.0);
glEnd();
glViewport([self bounds].origin.x, [self bounds].origin.y, [self bounds].size.width, [self bounds].size.height);
[context flushBuffer];
}
- (void)dealloc {
[context release];
}
@end
Post: #2
You shouldn't need to call Viewport every frame, only when the window is resized. (also, you should call it before you draw anything).
You need to call -update on your OpenGL context when the view it's attached to resizes. See the NSOpenGLContext docs for more info...
You need to call -update on your OpenGL context when the view it's attached to resizes. See the NSOpenGLContext docs for more info...
Post: #3
Thanks, that's exactly what I needed.
I simplified the original code somewhat before I posted it here, so that's why it's so strange (calling glViewport every frame, and calling it after I draw my geometry).
I simplified the original code somewhat before I posted it here, so that's why it's so strange (calling glViewport every frame, and calling it after I draw my geometry).
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