我正在编写一个iPhone应用程序,它使用UIView作为其层,并使用CAEAGLayer作为其图层。一切都很好,工作正常,除了一个小问题:有时会崩溃并显示EXC_BAD_ACCESS错误,以下是堆栈跟踪:
[EAGLView draw]
glDrawArrays_Exec
PrepareToDraw
DrawFramebufferMakeResident
AttachmentMakeResident
TextureMakeResident
memmove
在这一行代码处,系统崩溃了:
glVertexPointer(3, GL_FLOAT, 0, vertexCoordinates);
glTexCoordPointer(2, GL_FLOAT, 0, textureCoordinates);
glBindTexture(GL_TEXTURE_2D, textures[kActiveSideLeft]);
glDrawArrays(GL_TRIANGLE_STRIP, 0, totalPoints); //<--Crash here
应用程序仅在界面旋转更改期间崩溃(这也是视图框架更改的唯一情况)。它不经常崩溃; 大多数情况下需要旋转设备3-5分钟才能重现此问题。
我认为我犯了一个错误,与CAEAGLLayer初始化/框架更改有关,因为那是它崩溃的地方(我认为)。
因此,这里是init和layout subviews方法:
...
CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;
eaglLayer.opaque = TRUE;
context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
if (!context || ![EAGLContext setCurrentContext:context])
{
[self release];
return nil;
}
glGenFramebuffersOES(1, &defaultFramebuffer);
glGenRenderbuffersOES(1, &colorRenderbuffer);
glGenRenderbuffersOES(1, &depthRenderbuffer);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, defaultFramebuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, colorRenderbuffer);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);
...
在设置帧时,我只设置了GL_MODELVIEW和GL_POJECTION矩阵,因此我想那里不会发生什么问题。
LayoutSubviews:
- (void)layoutSubviews
{
[EAGLContext setCurrentContext:context];
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
[context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(CAEAGLLayer*)self.layer];
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
NSAssert1(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) == GL_FRAMEBUFFER_COMPLETE_OES, @"Failed to make complete framebuffer object: %X", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
}
绘制方法本身看起来像:
if ([EAGLContext currentContext] != context) {
[EAGLContext setCurrentContext:context];
}
glBindFramebufferOES(GL_FRAMEBUFFER_OES, defaultFramebuffer);
glViewport(0, 0, backingWidth, backingHeight);
...//drawing different triangle strips here
glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorRenderbuffer);
[context presentRenderbuffer:GL_RENDERBUFFER_OES];
我希望您能就以下代码提出任何意见或建议,以及如何找出此错误的原因。