这是我想出的将 24 位 BGR 图像传送到 NSView 的最佳方法。
通过确保 NSWindow 主机也具有相同的颜色空间，我确实减少了大量的 CPU 时间。
我认为这里有 4 或 5 个像素的副本：
- 在
vImage转换中（必填） - 打电话
CGDataProviderCreateWithData - 打电话
CGImageCreate - 创建
NSBitmapImageRep位图 - 在最后的 blit 中
drawInRect（必需）
任何人都想参与改进它？
任何帮助将非常感激。
{
// one-time setup code
CGColorSpaceRef useColorSpace = nil;
int w = 1920;
int h = 1080;
[theWindow setColorSpace: [NSColorSpace genericRGBColorSpace]];
// setup vImage buffers (not listed here)
// srcBuffer is my 24-bit BGR image (malloc-ed to be w*h*3)
// dstBuffer is for the resulting 32-bit RGBA image (malloc-ed to be w*h*4)
...
// this is called @ 30-60fps
if (!useColorSpace)
useColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
vImage_Error err = vImageConvert_BGR888toRGBA8888(srcBuffer, NULL, 0xff, dstBuffer, NO, 0);
CGDataProviderRef newProvider = CGDataProviderCreateWithData(NULL,dstBuffer->data,w*h*4,myReleaseProvider);
CGImageRef myImageRGBA = CGImageCreate(w, h, 8, 32, w*4, useColorSpace, kCGBitmapByteOrderDefault | kCGImageAlphaLast, newProvider, NULL, false, kCGRenderingIntentDefault);
CGDataProviderRelease(newProvider);
// store myImageRGBA in an array of frames (using NSObject wrappers) for later access (setNeedsDisplay:)
...
}
- (void)drawRect:(NSRect)dirtyRect
{
// this is called @ 30-60fps
CGImageRef storedImage = ...; // retrieve from array
NSBitmapImageRep *repImg = [[NSBitmapImageRep alloc] initWithCGImage:storedImage];
CGRect myFrame = CGRectMake(0,0,CGImageGetWidth(storedImage),CGImageGetHeight(storedImage));
[repImg drawInRect:myFrame fromRect:myFrame operation:NSCompositeCopy fraction:1.0 respectFlipped:TRUE hints:nil];
// free image from array (not listed here)
}
// this is called when the CGDataProvider is ready to release its data
void myReleaseProvider (void *info, const void *data, size_t size)
{
if (data) {
free((void *)data);
data=nil;
}
}