我正在尝试创建一个 GLKView ,在其中添加立方体并绘制它们。问题是,每个立方体都是 NSObject 类型,并且有自己的顶点和纹理缓冲区,但我想在单个上下文中绘制它们。为了做到这一点,我关注了一些 WWDC 视频并创建了两个上下文,一个用于渲染,一个用于纹理加载,我将两者放入同一个共享组中。代码方面,我在这方面所做的是向我的 GLKView 添加一个名为 renderContext 的属性,我希望在其中绘制所有立方体,并且我还设置了一个 loaderContext 属性,我想在其中加载纹理。但是,根本没有绘制任何东西,我什么也看不到,有时我会遇到崩溃和 GL ERROR 0x0500。它曾经工作过,模型视图矩阵应该正确设置和一切。异步加载和两个共享上下文的引入导致了问题......
这是代码:
这是 GLKView:容器(包含立方体)
- (void)setupGL {
self.renderContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
self.loaderContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2 sharegroup:self.renderContext.sharegroup];
glGenFramebuffers(1, &defaultFrameBuffer);
glBindFramebuffer(GL_FRAMEBUFFER, defaultFrameBuffer);
glGenRenderbuffers(1, &depthBuffer);
glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, self.bounds.size.width, self.bounds.size.height);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer);
glEnable(GL_DEPTH_TEST);
}
- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect {
self.opaque = NO;
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
[EAGLContext setCurrentContext:self.renderContext];
for(Cube *cube in self.cubes){
[cube draw];
}
}
每个单独的立方体设置如下:
-(id)init {
self = [super init];
if(self){
self.effect = [[GLKBaseEffect alloc]init];
self.effect.transform.projectionMatrix = GLKMatrix4MakePerspective(45.0f,0.95f, 0.1f, 2.0f);
self.effect.transform.projectionMatrix = GLKMatrix4Translate(self.effect.transform.projectionMatrix, 0, 0.0, 0.0);
self.effect.transform.modelviewMatrix = GLKMatrix4Translate(self.effect.transform.modelviewMatrix,0,0,-1.3);
glGenBuffers(1, &vertexArray);
glBindBuffer(GL_ARRAY_BUFFER, vertexArray);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW);
glVertexAttribPointer(GLKVertexAttribPosition,3,GL_FLOAT,GL_FALSE,0,0);
glGenBuffers(1, &texArray);
glBindBuffer(GL_ARRAY_BUFFER, texArray);
glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
glBufferData(GL_ARRAY_BUFFER, sizeof(TexCoords), TexCoords, GL_STATIC_DRAW);
glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, 0,0);
}
return self;
}
并且有一个draw方法:
-(void)draw{
[self.effect prepareToDraw];
self.effect.texture2d0.enabled = YES;
for(int i=0;i<6;i++){
if(i==0)glBindTexture(GL_TEXTURE_2D, frontTexture.name);
if(i==1)glBindTexture(GL_TEXTURE_2D, rightTexture.name);
if(i==2)glBindTexture(GL_TEXTURE_2D, backTexture.name);
if(i==3)glBindTexture(GL_TEXTURE_2D, leftTexture.name);
if(i==4)glBindTexture(GL_TEXTURE_2D, bottomTexture.name);
if(i==5)glBindTexture(GL_TEXTURE_2D, topTexture.name);
glDrawArrays(GL_TRIANGLES, i*6, 6);
}
}
这是我尝试异步加载纹理的方法:
注意:GLKView(容器)是每个单独立方体的父级,我检索其 loaderContext,它位于 renderContext 的共享组中,所以应该正确绘制纹理,对吧?
-(void)loadTextureForTexture:(GLKTextureInfo*)texN withView:(CubeView *)cV{
__block GLKTextureInfo *texName = texN;
EAGLContext *loaderContext = self.parent.loaderContext;
self.textureLoader = [[GLKTextureLoader alloc]initWithSharegroup:loaderContext.sharegroup];
[EAGLContext setCurrentContext:loaderContext];
NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:GLKTextureLoaderOriginBottomLeft];
dispatch_queue_t loaderQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_queue_t mainQueue = dispatch_get_main_queue();
[self.textureLoader textureWithCGImage:[self imageWithView:cV].CGImage options:options queue:loaderQueue completionHandler:^(GLKTextureInfo *tex, NSError *err){
texName = tex;
if(err)
NSLog(@"%@", err);
else
NSLog(@"no error");
dispatch_async(mainQueue, ^{
[self display];
});
}];
}