ios – 将CIFilter应用于OpenGL渲染到纹理

概述我试图在我的全屏渲染输出上应用Core Image过滤器,但是看起来像我缺少一些东西,因为我将黑屏作为输出. 首先我将整个场景画成纹理.然后我从这个纹理创建CoreImage,我终于画出来了.但我所得到的只是黑屏.我正在遵循苹果指南线绘制纹理,并将CoreImage与OpenGLES集成：WWDC2012 511和https://developer.apple.com/library/ios/do 我试图在我的全屏渲染输出上应用Core Image过滤器,但是看起来像我缺少一些东西,因为我将黑屏作为输出.

首先我将整个场景画成纹理.然后我从这个纹理创建CoreImage,我终于画出来了.但我所得到的只是黑屏.我正在遵循苹果指南线绘制纹理,并将CoreImage与OpenGLES集成：WWDC2012 511和https://developer.apple.com/library/ios/documentation/3ddrawing/conceptual/opengles_programmingguide/WorkingwithEAGLContexts/WorkingwithEAGLContexts.html

这里是相关代码：

渲染：

@interface Renderer () {  EAGLContext* _context;  gluint _defaultFramebuffer,_drawFramebuffer,_depthRenderbuffer,_colorRenderbuffer,_drawTexture;  Glint _backingWIDth,_backingHeight;  CIImage *_coreImage;  CIFilter *_coreFilter;  CIContext *_coreContext;}

初始化方法：

- (BOol)initopenGL{  _context = [[EAGLContext alloc] initWithAPI:kEAglrenderingAPIOpenGLES2];  if (!_context) return NO;  [EAGLContext setCurrentContext:_context];  glGenFramebuffers(1,&_defaultFramebuffer);  glBindFramebuffer(GL_FRAMEBUFFER,_defaultFramebuffer);  glGenRenderbuffers(1,&_colorRenderbuffer);  glBindRenderbuffer(GL_RENDERBUFFER,_colorRenderbuffer);  glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_color_ATTACHMENT0,GL_RENDERBUFFER,_colorRenderbuffer);  glGenFramebuffers(1,&_drawFramebuffer);  glBindFramebuffer(GL_FRAMEBUFFER,_drawFramebuffer);  glGenTextures(1,&_drawTexture);  glBindTexture(GL_TEXTURE_2D,_drawTexture);  glFramebufferTexture2D(GL_FRAMEBUFFER,GL_TEXTURE_2D,_drawTexture,0);  glGenRenderbuffers(1,&_depthRenderbuffer);  glBindRenderbuffer(GL_RENDERBUFFER,_depthRenderbuffer);  glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_DEPTH_ATTACHMENT,_depthRenderbuffer);  _coreFilter = [CIFilter filterWithname:@"CIcolorInvert"];  [_coreFilter setDefaults];  NSDictionary *opts = @{ kCIContextWorkingcolorSpace : [NSNull null] };  _coreContext = [CIContext contextWithEAGLContext:_context options:opts];  return YES;}

每当层大小更改(在init和方向更改时)分配内存：

- (voID)resizefromLayer:(CAEAGLLayer *)layer{  layer.contentsScale = 1;  glBindFramebuffer(GL_FRAMEBUFFER,_defaultFramebuffer);  glBindRenderbuffer(GL_RENDERBUFFER,_colorRenderbuffer);  [_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:layer];  glGetRenderbufferParameteriv(GL_RENDERBUFFER,GL_RENDERBUFFER_WIDTH,&_backingWIDth);  glGetRenderbufferParameteriv(GL_RENDERBUFFER,GL_RENDERBUFFER_HEIGHT,&_backingHeight);  // glCheckFramebufferStatus ... SUCCESS  glBindFramebuffer(GL_FRAMEBUFFER,_drawFramebuffer);  glBindTexture(GL_TEXTURE_2D,_drawTexture);  glTexImage2D(GL_TEXTURE_2D,GL_RGBA,_backingWIDth,_backingHeight,GL_UNSIGNED_BYTE,NulL);  glBindRenderbuffer(GL_RENDERBUFFER,_depthRenderbuffer);  glrenderbufferStorage(GL_RENDERBUFFER,GL_DEPTH_COMPONENT16,_backingHeight);  // glCheckFramebufferStatus ... SUCCESS}

绘制方法：

- (voID)render:(Scene *)scene{  [EAGLContext setCurrentContext:_context];  glBindFramebuffer(GL_FRAMEBUFFER,_drawFramebuffer);  // Draw using GLKit,custom shaders,drawArrays,drawElements  // Now rendered scene is in _drawTexture  glBindFramebuffer(GL_FRAMEBUFFER,_defaultFramebuffer);  glBindRenderbuffer(GL_RENDERBUFFER,_colorRenderbuffer);  // Create CIImage with our render-to-texture texture  _coreImage = [CIImage imageWithTexture:_drawTexture size:CGSizeMake(_backingWIDth,_backingHeight) flipped:NO colorSpace:nil];  // Ignore filtering for Now; Draw CIImage to current render buffer   [_coreContext drawImage:_coreImage inRect:CGRectMake(0,_backingHeight) fromrect:CGRectMake(0,_backingHeight)];  // Present  [_context presentRenderbuffer:GL_RENDERBUFFER];}

注意,绘制场景后,_drawTexture包含渲染场景.我使用Xcode调试工具(Capture OpenGL ES框架)进行检查.

编辑：如果我尝试从一些其他纹理创建CIImage,然后_drawTexture,它正确显示.我的怀疑是,当CIContext尝试通过CIImage呈现时,_drawTexture可能没有准备好或被某种方式锁定.

EDIT2：我也试图用视口清除替换所有绘图代码：

glVIEwport(0,_backingHeight);  glClearcolor(0,0.8,1);  glClear(GL_color_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

结果仍然是黑色的.这表明问题可能是绘制纹理或帧缓冲区的东西.

解决方法 我终于找到了什么问题. iOS上的2个纹理的非强制功能必须具有线性滤波和夹紧到边缘包装：

glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_liNEAR); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_liNEAR);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);

我的纹理与屏幕大小相同,但是我没有设置这四个参数.

对于后代：上面的代码是OpenGL ES和CoreImage的互连的完美有效的例子.只需确保你正确地初始化你的纹理！

总结

以上是内存溢出为你收集整理的ios – 将CIFilter应用于OpenGL渲染到纹理全部内容，希望文章能够帮你解决ios – 将CIFilter应用于OpenGL渲染到纹理所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。