iPhone OpenGL ES Contexts and Framebuffers - iphone

Question

I'm attempting to setup a framebuffer properly in order to support depth and correct perspective. I'm using the OpenGL ES Application template in XCode and I have been following the guidelines in the OpenGL ES Programming Guide.
I have my renderer set to ES1 manually since I just want to get something rendering with depth using the FFP.
This is my current code:
#import "ES1Renderer.h"
#import "water.h"
//#import "EAGLError.h"
#define PRINT_GLERR(error) ((error == GL_NO_ERROR) ? NSLog(#"No error") : NSLog(#"GL Error: %d", (error)))
//#define GLE(X) {X; eglGetError(); }
#implementation ES1Renderer
// Create an OpenGL ES 1.1 context
- (id)init
{
if ((self = [super init]))
{
context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
if (!context || ![EAGLContext setCurrentContext:context])
{
[self release];
return nil;
}
glGenFramebuffersOES(1, &framebuffer);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, framebuffer);
glGenRenderbuffersOES(1, &colorRenderbuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, colorRenderbuffer);
glViewport(0, 0, backingWidth, backingHeight);
// Start in projection mode.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
double xmin, xmax, ymin, ymax;
ymax = NEAR_PLANE * tanf(DEGREES_TO_RADIANS(FOV) / 2.0f);
ymin = -ymax;
xmin = ymin * ((float)backingWidth / (float)backingHeight);
xmax = ymax * ((float)backingWidth / (float)backingHeight);
glFrustumf(xmin, xmax, ymin, ymax, NEAR_PLANE, FAR_PLANE);
glViewport(0, 0, backingWidth, backingHeight);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glDepthRangef(0.0f, 1.0f);
glDepthMask(TRUE);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
return self;
}
- (void)render
{
static const GLfloat squareVertices[] = {
-0.5f, -0.33f, -1.0f,
0.5f, -0.33f, -1.0f,
-0.5f, 0.33f, -1.0f,
0.5f, 0.33f, -1.0f,
};
static const GLubyte squareColors[] = {
255, 255, 0, 255,
0, 255, 255, 255,
0, 0, 0, 0,
255, 0, 255, 255,
};
static float transY = 0.0f;
[EAGLContext setCurrentContext:context];
glBindFramebufferOES(GL_FRAMEBUFFER_OES, framebuffer);
glViewport(0, 0, backingWidth, backingHeight);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, (GLfloat)(sinf(transY)/2.0f), 0.0f);
transY += 0.075f;
glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glVertexPointer(3, GL_FLOAT, 0, squareVertices);
glEnableClientState(GL_VERTEX_ARRAY);
glColorPointer(4, GL_UNSIGNED_BYTE, 0, squareColors);
glEnableClientState(GL_COLOR_ARRAY);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
[context presentRenderbuffer:GL_RENDERBUFFER_OES];
}
- (BOOL)resizeFromLayer:(CAEAGLLayer *)layer
{
glGenFramebuffersOES(1, &framebuffer);
glGenRenderbuffersOES(1, &colorRenderbuffer);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, framebuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
[context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:layer];
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, colorRenderbuffer);
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);
glGenRenderbuffersOES(1, &depthRenderbuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);
if(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES)
{
NSLog(#"failed to make complete framebuffer object %x", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
return NO;
}
return YES;
}
- (void)dealloc
{
if (framebuffer)
{
glDeleteFramebuffersOES(1, &framebuffer);
framebuffer = 0;
}
if (colorRenderbuffer)
{
glDeleteRenderbuffersOES(1, &colorRenderbuffer);
colorRenderbuffer = 0;
}
if (depthRenderbuffer)
{
glDeleteRenderbuffersOES(1, &depthRenderbuffer);
depthRenderbuffer = 0;
}
if ([EAGLContext currentContext] == context)
[EAGLContext setCurrentContext:nil];
[context release];
context = nil;
[super dealloc];
}
#end
When I commend out this part of the code:
glGenRenderbuffersOES(1, &depthRenderbuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);
I get a quad that bounces up and down and renders correctly. Any help on the depth issue would be awesome!