我遇到了 Texture2D 的问题，我想了解如何更好地使用它。
我从这里获取了 Crashlander Texture2D 类和 XCode 4 中的默认 OpenGL 项目，强制它加载 OpenGL ES1.1
首先，一个概念问题。Texture2D init 方法上的 size 明明就是一个 OpenGL 的大小，但是 fontSize 参数和 OpenGL 世界有什么关系呢？
二、调试。我从下面的代码中得到的结果是一个黑色（或者我在 glColor 中设置的任何颜色）方块，文本应该在哪里。
这是我在代码中所做的更改：
- (void)awakeFromNib
{
EAGLContext *aContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
if (!aContext) {
aContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
}
self.labelAtTheTop = [[[Texture2D alloc] initWithString:@"Some Text" dimensions:CGSizeMake(1, 1) alignment:UITextAlignmentLeft fontName:@"Helvetica" fontSize:14.0f] autorelease];
if (!aContext)
NSLog(@"Failed to create ES context");
else if (![EAGLContext setCurrentContext:aContext])
NSLog(@"Failed to set ES context current");
self.context = aContext;
[aContext release];
[(EAGLView *)self.view setContext:context];
[(EAGLView *)self.view setFramebuffer];
animating = FALSE;
animationFrameInterval = 1;
self.displayLink = nil;
}
- (void)drawFrame
{
[(EAGLView *)self.view setFramebuffer];
// Replace the implementation of this method to do your own custom drawing.
glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glColor4f(0.0f, 0.0f, 0.0f, 1.0f);
glPushMatrix();
glLoadIdentity();
[self.labelAtTheTop drawAtPoint:CGPointMake(0, 0)];
glPopMatrix();
glDisable(GL_COLOR_MATERIAL);
// Disable modes so they don't interfere with other parts of the program
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
glDisable(GL_TEXTURE_2D);
glDisable(GL_BLEND);
[(EAGLView *)self.view presentFramebuffer];
}