问题描述
我正在开发一个iOS openGL ES应用程序。
I'm developing an iOS openGL ES application.
我正在做通常的EAGLView / ES2Render。
I'm doing the usual EAGLView / ES2Render stuff.
启动时，使用以下代码创建frambuffer成功：
On startup, frambuffer creation succeeds, using the following code:
- (BOOL) createFramebuffers
{
[EAGLContext setCurrentContext:_mainContext];
// [ A ] On-screen
// 1. Framebuffer
glGenFramebuffers(1, &_mainFramebuffer);
bindFramebuffer(_mainFramebuffer);
// 2. Color buffer
glGenRenderbuffers(1, &_mainColorbuffer);
bindRenderbuffer(_mainColorbuffer);
// Adjust size to view's layer:
CAEAGLLayer* layer = (CAEAGLLayer*)[_view layer];
if (![_mainContext renderbufferStorage:GL_RENDERBUFFER fromDrawable:layer]) {
// something went horribly wrong
NSLog(@"-[ES2Renderer createFramebuffers]: Failed to obtain renderbuffer storage from layer!");
return NO;
}
// Query new size:
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &_backingWidth);
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &_backingHeight);
// Attach to color:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, _mainColorbuffer);
// 3. Depth buffer
glGenRenderbuffers(1, &_depthBuffer);
bindRenderbuffer(_depthBuffer);
if (_useStencilBuffer) {
// Depth + Stencil
// Allocate storage:
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, _backingWidth, _backingHeight);
// Attach to depth:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depthBuffer);
// Attach to stencil:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _depthBuffer);
}
else{
// Depth only
// Allocate storage:
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24_OES, _backingWidth, _backingHeight);
// Attachto depth:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depthBuffer);
}
// 4. Validate the set:
GLenum framebufferStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (framebufferStatus != GL_FRAMEBUFFER_COMPLETE) {
// Something went wrong!
NSLog(@"-[ES2Renderer createFramebuffers]: Failed to make complete framebuffer object: %@",
[self stringFromFramebufferStauts:framebufferStatus]);
return NO;
}
// [ B ] Off-screen (Render-to-texture)
// 1. Framebuffer
glGenFramebuffers(1, &_transFramebuffer);
bindFramebuffer(_transFramebuffer);
// 2. Depth buffer
glGenRenderbuffers(1, &_transDepthBuffer);
bindRenderbuffer(_transDepthBuffer);
if (_useStencilBuffer) {
// Allocate storage:
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, _backingWidth, _backingHeight);
// Attach to depth:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _transDepthBuffer);
// Attach to stencil:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _transDepthBuffer);
}
else{
// Allocate storage
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24_OES, _backingWidth, _backingHeight);
// Attach to depth:
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _transDepthBuffer);
}
// 3. Textures (color buffers)
GLuint* texPtrs[2] = {&_transTexture1, &_transTexture2};
for (NSUInteger i=0; i < 2; i++) {
GLuint* texPtr = texPtrs[i];
// Create:
glGenTextures(1, texPtr);
// Bind:
bindTexture2D(*texPtr);
// Configure for pixel-aligned use:
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
// Allocate storage:
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, _backingWidth, _backingHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
// Attach:
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, *texPtr, 0);
framebufferStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
// Validate:
if ( framebufferStatus != GL_FRAMEBUFFER_COMPLETE) {
// Something went wrong!
NSLog(@"-[ES2Renderer createFramebuffers]: Failed to make complete framebuffer object: %@",
[self stringFromFramebufferStauts:framebufferStatus]);
return NO;
}
}
// Final State:
bindFramebuffer(_mainFramebuffer);
bindRenderbuffer(_mainColorbuffer);
bindTexture2D(0);
NSLog(@"-[ES2Renderer createFramebuffers] Succeeded.");
return YES;
}
不久之后， UIView -layoutSubviews 然后执行 -resizeFromLayer：：
Soon after, UIView's -layoutSubviews is called and I in turn execute -resizeFromLayer::
- (BOOL) resizeFromLayer:(CAEAGLLayer *)layer
{
// [ A ] On screen framebuffer
bindFramebuffer(_mainFramebuffer);
// 1. Resize color buffer
bindRenderbuffer(_mainColorbuffer);
if (![_mainContext renderbufferStorage:GL_RENDERBUFFER fromDrawable:layer]) {
// Something went wrong
return NO; // <-- SECOND TIME ON, THIS HAPPENS
}
// Query new size:
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &_backingWidth);
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &_backingHeight);
// 2. Resize depth buffer
bindRenderbuffer(_depthBuffer);
if (_useStencilBuffer) {
// (Depth & Stencil)
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, _backingWidth, _backingHeight);
}
else{
// (Depth only)
glRenderbufferStorage(GL_FRAMEBUFFER, GL_DEPTH_COMPONENT24_OES, _backingWidth, _backingHeight);
}
// ...Validate:
GLenum framebufferStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (framebufferStatus != GL_FRAMEBUFFER_COMPLETE) {
// Something went wrong!
NSLog(@"-[ES2Renderer resizeFromLayer:]: Failed to make complete framebuffer object: %@",
[self stringFromFramebufferStauts:glCheckFramebufferStatus(GL_FRAMEBUFFER)]);
return NO;
}
// [ B ] Off screen (render-to-terxture) framebuffer
bindFramebuffer(_transFramebuffer);
// 1. Resize depth buffer
bindRenderbuffer(_transDepthBuffer);
if (_useStencilBuffer) {
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, _backingWidth, _backingHeight);
}
else{
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24_OES, _backingWidth, _backingHeight);
}
// 2. Resize textures
GLuint* texPtrs[2] = {&_transTexture1, &_transTexture2};
for (NSUInteger i=0; i < 2; i++) {
GLuint* texPtr = texPtrs[i];
// Bind:
bindTexture2D(*texPtr);
// Configure for pixel-aligned use:
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
// Allocate storage:
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, _backingWidth, _backingHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
// Attach:
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, *texPtr, 0);
// Validate:
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
// Something went wrong!
NSString* statusString = [self stringFromFramebufferStauts:glCheckFramebufferStatus(GL_FRAMEBUFFER)];
NSLog(@"-[ES2Renderer resizeFromLayer:]: Failed to make complete framebuffer object: %@", statusString);
return NO;
}
}
bindFramebuffer(_mainFramebuffer);
bindRenderbuffer(_mainColorbuffer);
// Pass new ortho projection to shaders
[self initializeModelViewMatrix];
[self initializeSpriteProgram];
// Set new viewport
glViewport(0, 0, _backingWidth, _backingHeight);
NSLog(@"-[ES2Renderer resizeFromLayer:]: Succeeded.");
return YES;
}
我所做的一切都不是特别的。我有一个单独的帧缓冲区渲染场景过渡，有两个纹理附加到颜色和深度。
Nothing of what I'm doing is special. I have a separate framebuffer to render scene transitions, with two textures to attach to color, and depth.
第二次 -renderbufferStorage：fromDrawable：调用（ -layoutSubviews - > resizeFromLayer：），它总是失败（返回 NO ）;在此之前调用 glGetError（）导致没有错误，但在返回 GL_INVALID_OPERATION 之后立即调用它。
如果我忽略了这一点并继续， glGetRenderbufferParameteriv（）仍然可以获得正确的宽度和高度（iPhone 5上分别为640和1136），但 glCheckFramebufferStatus（）将返回 GL_FRAMEBUFFER_UNSUPPORTED 。
The second time -renderbufferStorage:fromDrawable: is called (-layoutSubviews -> resizeFromLayer:), it invariably fails (returns NO); Calling glGetError() right before that results in no error, but calling it right after returns GL_INVALID_OPERATION.If I ignore this and proceed, glGetRenderbufferParameteriv() still gets me the right width and height (640 and 1136, respectively, on an iPhone 5), but glCheckFramebufferStatus() will return GL_FRAMEBUFFER_UNSUPPORTED.
或者，我跳过上面的 resizeFromLayer：并将其替换为：
Alternatively, I skipped the above resizeFromLayer: and replaced it with this:
- (BOOL) resizeFromLayer:(CAEAGLLayer *)layer
{
[self destroyFramebuffers];
return [self createFramebuffers];
}
...但同样的错误仍然存在（ - renderStorage：fromDrawable：失败;这次在 -createFramebuffers 中。
...but the same error persists (-renderStorage:fromDrawable: fails; this time inside -createFramebuffers).
目前，我只返回 YES （我的应用只支持肖像，所以实际上没有发生屏幕尺寸变化），但我真的想修复它因为有一天我需要支持格局等...
For now, I just return YES (my app only supports portrait, so no screen size change actually ever happens), but I really want to fix it because one day I'll need to support landscape, etc...
推荐答案
一个可能的原因 renderbufferStorage ：fromDrawable：失败的是 _mainContext 不是当时的当前上下文。即使看起来似乎没有其他上下文可以窃取当前状态，我建议在任何 gl之前调用 [EAGLContext setCurrentContext：_mainContext] / code>或 EAGL 对与该上下文关联的对象进行操作的代码（例如，在 resizeFromLayer的开头：方法）。
One possible reason that renderbufferStorage:fromDrawable: is failing is that the _mainContext is not the current context at that time. Even though it may seem that no other context could have stolen the 'current' status, I recommend calling [EAGLContext setCurrentContext:_mainContext] before any gl or EAGL code that operates on objects associated with that context (e.g. at the beginning of the resizeFromLayer: method).
这篇关于 - [EAGLContext renderbufferStorage：fromDrawable：]第二次失败？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！