我遇到了原本似乎应该是一个非常简单的问题，但是花了很多时间试图找出并且无处可去。
我正在使用Apple的GLImageProcessing示例代码，并将其简化为显示一个带有UISlider的EAGLView，用于调整图像的色调。我已经修改了EAGLView以继承UIImageView，这样我就可以对显示的图像有更多的控制权。这很好用。当我尝试将第二个图像添加到屏幕时出现问题。理想情况下，我想要显示背景图像和其他几个图像，并让色调滑块同时改变所有图像的色调。但是，当我尝试向屏幕添加第二个图像时，第一个图像变成一个普通的黑色视图，当我移动滑块时实际上变成了紫色，但是没有反应。新视图确实按预期运行。如果我要添加第三个，前两个将无效，第三个将正常运行。
我认为我想要做的是拥有一个EAGLView并为新图像添加纹理，但似乎没有任何效果。任何指导我正确方向的帮助将非常感激。谢谢！
来自ViewController.h。用于在viewDidLoad方法中添加新EAGLView子视图的代码。在笔尖中已经加载了另一个视图：
- (void)viewDidLoad
{
UIImage *img = [UIImage imageNamed:@"Image.png"];
EAGLView *newView = [[EAGLView alloc] initWithImage:img texID:0];
self.view2 = newView;
self.view2.frame = CGRectMake(110, 110, 100, 100);
[self.view addSubview:self.view2];
[newView release];
}
一个简单的IBAction就价值变化发起了：
- (void)sliderAction:(id)sender
{
[self.imageView drawViewWithSliderValue:self.slider.value];
[self.view2 drawViewWithSliderValue:self.slider.value];
}
从EAGLView.h，这是EAGLView初始化代码和绘图代码。它与示例代码几乎相同，只是它允许您将图像传递到initGL中：
-(id) initializeEAGLwithTexID:(int)texID{
// Get the layer
CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;
eaglLayer.opaque = YES;
eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:NO], kEAGLDrawablePropertyRetainedBacking,
kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat,
nil];
context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
if (!context || ![EAGLContext setCurrentContext:context])
{
[self release];
return nil;
}
// Create system framebuffer object. The backing will be allocated in -reshapeFramebuffer
glGenFramebuffersOES(1, &viewFramebuffer[texID]);
glGenRenderbuffersOES(1, &viewRenderbuffer[texID]);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer[texID]);
glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer[texID]);
glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer[texID]);
// Perform additional one-time GL initialization
UIImage *myImage = self.image;
NSLog(@"holding image of width: %f height %f", myImage.size.width, myImage.size.height);
CGImageRef imageRef = myImage.CGImage;
initGL(imageRef, texID);
return self;
}
-(id) initWithImage:(UIImage *)image texID:(int)texID{
if((self = [super initWithImage:image])){
self.opaque = YES;
self.contentMode = UIViewContentModeScaleToFill;
[self initializeEAGLwithTexID:texID];
}
return self;
}
- (void)drawViewWithSliderValue:(float)value;
{
drawGL(backingWidth, backingHeight, value, currentID);
[context presentRenderbuffer:GL_RENDERBUFFER_OES];
}
来自Imaging.c，initGL代码和drawGL。我修改了代码来处理用于处理多个纹理的数组。我相对肯定这里创建的一堆数组是不必要的，但是因为它们没有伤害任何东西，所以还没有尝试删除任何数组：
void initGL(CGImageRef myImage, int currID)
{
int i;
// Query renderer capabilities that affect this app's rendering paths
renderer[currID].extension[APPLE_texture_2D_limited_npot] =
(0 != strstr((char *)glGetString(GL_EXTENSIONS), "GL_APPLE_texture_2D_limited_npot"));
renderer[currID].extension[IMG_texture_format_BGRA8888] =
(0 != strstr((char *)glGetString(GL_EXTENSIONS), "GL_IMG_texture_format_BGRA8888"));
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &renderer[currID].maxTextureSize);
// Constant state for the lifetime of the app-- position and unit0 are always used
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnable(GL_TEXTURE_2D);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
// Load image into texture
loadTexture(myImage, &Input[currID], &renderer[currID], currID);
// Modify quad texcoords to match (possibly padded) image
for (i = 0; i < 4; i++)
{
fullquad[i].s *= Input[currID].s;
fullquad[i].t *= Input[currID].t;
flipquad[i].s *= Input[currID].s;
flipquad[i].t *= Input[currID].t;
}
// Create 1x1 for default constant texture
// To enable a texture unit, a valid texture has to be bound even if the combine modes do not access it
GLubyte half[3][4] = {{ 0x80, 0x80, 0x80, 0x80 },{ 0x80, 0x80, 0x80, 0x80 },{ 0x80, 0x80, 0x80, 0x80 }};
glActiveTexture(GL_TEXTURE1);
glGenTextures(1, &Half[currID].texID);
Half[currID].wide = Half[currID].high = 1;
Half[currID].s = Half[currID].t = 1.0;
glBindTexture(GL_TEXTURE_2D, Half[currID].texID);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_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);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, half[currID]);
glActiveTexture(GL_TEXTURE0);
// Remember the FBO being used for the display framebuffer
glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, (GLint *)&SystemFBO[currID]);
// Create scratch textures and FBOs
glGenTextures(1, &Degen[currID].texID);
Degen[currID].wide = Input[currID].wide;
Degen[currID].high = Input[currID].high;
Degen[currID].s = Input[currID].s;
Degen[currID].t = Input[currID].t;
glBindTexture(GL_TEXTURE_2D, Degen[currID].texID);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_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);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Degen[currID].wide, Degen[currID].high, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glGenFramebuffersOES(1, &DegenFBO[currID]);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, DegenFBO[currID]);
glFramebufferTexture2DOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, Degen[currID].texID, 0);
glGenTextures(1, &Scratch[currID].texID);
Scratch[currID].wide = Input[currID].wide;
Scratch[currID].high = Input[currID].high;
Scratch[currID].s = Input[currID].s;
Scratch[currID].t = Input[currID].t;
glBindTexture(GL_TEXTURE_2D, Scratch[currID].texID);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_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);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Scratch[currID].wide, Scratch[currID].high, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glGenFramebuffersOES(1, &ScratchFBO[currID]);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, ScratchFBO[currID]);
glFramebufferTexture2DOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, Scratch[currID].texID, 0);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, SystemFBO[currID]);
}
void drawGL(int wide, int high, float val, int currID)
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrthof(0, wide, 0, high, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glScalef(wide, high, 1);
glBindTexture(GL_TEXTURE_2D, Input[currID].texID);
// Render filtered image to system framebuffer
glViewport(0, 0, wide, high);
hue(flipquad, val);
}
答案 0 :(得分：0)
也许iPhone OS一次只支持一个Open GL视图？