我需要使用在运行时以编程方式制作的图像作为纹理,但不确定如何从一点转到另一点。制作的图像是使用 UIGraphicsBeginImageContextwithOptions() 制作的,下面是我当前从项目中的图像加载纹理的代码:
-(void)loadTextures:(NSString*) filename textureIdentifier:(int) textureNumber {
//enable textures.
glEnable(GL_TEXTURE_2D);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_FASTEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// Bind the number of textures we need.
glGenTextures(1, &texture[textureNumber]);
glBindTexture(GL_TEXTURE_2D, texture[textureNumber]);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D,GL_GENERATE_MIPMAP,GL_TRUE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
NSString *path = [[NSBundle mainBundle] pathForResource:filename ofType:@"png"];
NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
UIImage *image = [[UIImage alloc] initWithData:texData];
if (image == nil)
NSLog(@"Do real error checking here");
GLuint width = CGImageGetWidth(image.CGImage);
GLuint height = CGImageGetHeight(image.CGImage);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
void *imageData = malloc( height * width * 4 );
CGContextRef context = CGBitmapContextCreate( imageData, width, height, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big );
// Flip the Y-axis
CGContextTranslateCTM (context, 0, height);
CGContextScaleCTM (context, 1.0, -1.0);
CGColorSpaceRelease( colorSpace );
CGContextClearRect( context, CGRectMake( 0, 0, width, height ) );
CGContextDrawImage( context, CGRectMake( 0, 0, width, height ), image.CGImage );
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData);
CGContextRelease(context);
free(imageData);
}
最佳答案
简单。从纹理加载器代码中删除这些行,并将它们替换为您的核心图形绘制代码:
NSString *path = [[NSBundle mainBundle] pathForResource:filename ofType:@"png"];
NSData *texData = [[NSData alloc] initWithContentsOfFile:path];
现在替换这一行:
UIImage *image = [[UIImage alloc] initWithData:texData];
与:
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
关于ios - 如何在 opengl es 中使用由 UIGraphicsBeginImageContextWithOptions() 制作的图像,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8859411/