Question

我正在尝试渲染两个对象- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect方法，在那里我试图为两个对象绑定单独的纹理。

对于第一个对象，下面是纹理绑定代码

/************* texture binding for object 1 ****************/
glActiveTexture(GL_TEXTURE0);
err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault, 
                                                   _videoTextureCache,
                                                   pixelBuffer,
                                                   NULL,
                                                   GL_TEXTURE_2D,
                                                   GL_RED_EXT,
                                                   _textureWidth,
                                                   _textureHeight,
                                                   GL_RED_EXT,
                                                   GL_UNSIGNED_BYTE,
                                                   0,
                                                   &_lumaTexture);
if (err) 
{
    NSLog(@"Error at CVOpenGLESTextureCacheCreateTextureFromImage %d", err);
}   

glBindTexture(CVOpenGLESTextureGetTarget(_lumaTexture), CVOpenGLESTextureGetName(_lumaTexture));
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); 

glActiveTexture(GL_TEXTURE1);
err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault, 
                                                   _videoTextureCache,
                                                   pixelBuffer,
                                                   NULL,
                                                   GL_TEXTURE_2D,
                                                   GL_RG_EXT,
                                                   _textureWidth/2,
                                                   _textureHeight/2,
                                                   GL_RG_EXT,
                                                   GL_UNSIGNED_BYTE,
                                                   1,
                                                   &_chromaTexture);
if (err) 
{
    NSLog(@"Error at CVOpenGLESTextureCacheCreateTextureFromImage %d", err);
}

glBindTexture(CVOpenGLESTextureGetTarget(_chromaTexture), CVOpenGLESTextureGetName(_chromaTexture));
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

/************* rendering first object ****************/
[self renderFirstObject]; 

/************* texture binding for object 2 ****************/
glEnable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, _texture1);

/************* rendering second object ****************/
[self renderSecondObject];

现在，第一个对象的纹理都受到干扰，而第二个对象得到正确的纹理绑定。

加载_texture1的代码（在视图控制器的启动时执行一次）在

之下

NSDictionary* options = @{[NSNumber numberWithBool:YES] : GLKTextureLoaderOriginBottomLeft};

NSError* error;
NSString* path = [[NSBundle mainBundle] pathForResource:fileName ofType:nil];
GLKTextureInfo* texture = [GLKTextureLoader textureWithContentsOfFile:path options:options error:&error];
if(texture == nil)
    NSLog(@"Error loading file: %@", [error localizedDescription]);
_texture1 = texture.name;
glUseProgram(_program1);
glBindTexture(GL_TEXTURE_2D, _texture1);

Answer 1

＆＃39; ave通过在渲染第二个对象后再次设置第一个对象的纹理来解决此问题。请查看下面的更新代码。

/************* texture binding for object 1 ****************/
    glActiveTexture(GL_TEXTURE0);
    err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault,
                                                       _videoTextureCache,
                                                       pixelBuffer,
                                                       NULL,
                                                       GL_TEXTURE_2D,
                                                       GL_RED_EXT,
                                                       _textureWidth,
                                                       _textureHeight,
                                                       GL_RED_EXT,
                                                       GL_UNSIGNED_BYTE,
                                                       0,
                                                       &_lumaTexture);
    if (err)
    {
        NSLog(@"Error at CVOpenGLESTextureCacheCreateTextureFromImage %d", err);
    }

    glBindTexture(CVOpenGLESTextureGetTarget(_lumaTexture), CVOpenGLESTextureGetName(_lumaTexture));
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glActiveTexture(GL_TEXTURE1);
    err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault,
                                                       _videoTextureCache,
                                                       pixelBuffer,
                                                       NULL,
                                                       GL_TEXTURE_2D,
                                                       GL_RG_EXT,
                                                       _textureWidth/2,
                                                       _textureHeight/2,
                                                       GL_RG_EXT,
                                                       GL_UNSIGNED_BYTE,
                                                       1,
                                                       &_chromaTexture);
    if (err)
    {
        NSLog(@"Error at CVOpenGLESTextureCacheCreateTextureFromImage %d", err);
    }

    glBindTexture(CVOpenGLESTextureGetTarget(_chromaTexture), CVOpenGLESTextureGetName(_chromaTexture));
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    /************* rendering first object ****************/
    [self renderFirstObject];

    /************* texture binding for object 2 ****************/
    glEnable(GL_TEXTURE_2D);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, _texture1);

    /************* rendering second object ****************/
    [self renderSecondObject];


    /************* re-binding texture for object 1 ****************/
    glBindTexture(CVOpenGLESTextureGetTarget(_lumaTexture), CVOpenGLESTextureGetName(_lumaTexture));
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

在多个对象上渲染多个纹理时出现问题

1 个答案: