Re: NSBitMapImageRep Woes
Thanks to all. I have my bitmap being drawn but it is upside down. Do isFlipped play any role in this / how do I get it to draw right side up without inverting my raw data? For those interested this is the correct definition of NSBitMapImageRep: m_ptrs[0] = (unsigned char*)m_bitmap.m_array; m_NSBitmapImageRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:m_ptrs pixelsWide:m_bitmap.m_pixelsx pixelsHigh:m_bitmap.m_pixelsy bitsPerSample:8 samplesPerPixel:3 hasAlpha:NO isPlanar:NO colorSpaceName:NSCalibratedRGBColorSpace bitmapFormat:NSAlphaNonpremultipliedBitmapFormat bytesPerRow:(4*m_bitmap.m_pixelsx) bitsPerPixel:32]; On Jan 6, 2010, at 11:32 AM, David Duncan wrote: On Jan 6, 2010, at 10:19 AM, David Blanton wrote: Now, from David Duncan's comment. My bitmap data does have alpha, i.e 4 samples per pixel ARGB. I thought kCGImageAlphaNoneSkipFirst says don't make an alpha plane, skip byte 1 and go to RED. I am not sure how to specify this in the 'bitmapFormat' parameter. AlphaNoneSkipFirst means you have no alpha, and skip any leading bytes per necessary to fill the pixel size. In your particular case since you have 8 bits per component and 3 components, that means skip the first 8 bits of each word then decode 8 bits for each of 3 components. When you create your NSBitmapImageRep however, you specify that there is alpha, which means that you are specifying the equivalent of kCGImageAlphaPremultipliedFirst (since you don't specify the NSAlphaNonpremultipliedBitmapFormat flag). What you really want is to specify no alpha and 3 samples per pixel (if I'm not mistaken, I usually work in Quartz rather than NS for graphics). Specifying 32 bits per pixel as you do should get the same interpretation that you are currently getting via Quartz. Also keep in mind that your Quartz code is more work than you would actually need. Since you aren't drawing to your image data, you should create the CGImage directly via CGImageCreate rather than using CGBitmapContextCreate to then extract a CGImage – the performance difference is in the syscalls necessary to mark the memory for the bitmap context as copy-on-write. -- David Duncan Apple DTS Animation and Printing ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSBitMapImageRep Woes
Answered my own question ... apologize for the noise! On Jan 7, 2010, at 4:05 PM, David Blanton wrote: Thanks to all. I have my bitmap being drawn but it is upside down. Do isFlipped play any role in this / how do I get it to draw right side up without inverting my raw data? For those interested this is the correct definition of NSBitMapImageRep: m_ptrs[0] = (unsigned char*)m_bitmap.m_array; m_NSBitmapImageRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:m_ptrs pixelsWide:m_bitmap.m_pixelsx pixelsHigh:m_bitmap.m_pixelsy bitsPerSample:8 samplesPerPixel:3 hasAlpha:NO isPlanar:NO colorSpaceName:NSCalibratedRGBColorSpace bitmapFormat:NSAlphaNonpremultipliedBitmapFormat bytesPerRow:(4*m_bitmap.m_pixelsx) bitsPerPixel:32]; On Jan 6, 2010, at 11:32 AM, David Duncan wrote: On Jan 6, 2010, at 10:19 AM, David Blanton wrote: Now, from David Duncan's comment. My bitmap data does have alpha, i.e 4 samples per pixel ARGB. I thought kCGImageAlphaNoneSkipFirst says don't make an alpha plane, skip byte 1 and go to RED. I am not sure how to specify this in the 'bitmapFormat' parameter. AlphaNoneSkipFirst means you have no alpha, and skip any leading bytes per necessary to fill the pixel size. In your particular case since you have 8 bits per component and 3 components, that means skip the first 8 bits of each word then decode 8 bits for each of 3 components. When you create your NSBitmapImageRep however, you specify that there is alpha, which means that you are specifying the equivalent of kCGImageAlphaPremultipliedFirst (since you don't specify the NSAlphaNonpremultipliedBitmapFormat flag). What you really want is to specify no alpha and 3 samples per pixel (if I'm not mistaken, I usually work in Quartz rather than NS for graphics). Specifying 32 bits per pixel as you do should get the same interpretation that you are currently getting via Quartz. Also keep in mind that your Quartz code is more work than you would actually need. Since you aren't drawing to your image data, you should create the CGImage directly via CGImageCreate rather than using CGBitmapContextCreate to then extract a CGImage – the performance difference is in the syscalls necessary to mark the memory for the bitmap context as copy-on-write. -- David Duncan Apple DTS Animation and Printing ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/airedale%40tularosa.net This email sent to aired...@tularosa.net ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
NSBitMapImageRep Woes
Here is the code:
@interface MyDocumentView : NSView {
@public
NSBitmapImageRep* m_NSBitmapImageRep;
NSRect m_frameRect;
float m_sz;
BBitmap m_bitmap;
unsigned char* m_ptrs[1];
}
- (void)awakeFromNib {
m_ptrs[0] = (unsigned char*)m_bitmap.m_array;
m_NSBitmapImageRep = [[NSBitmapImageRep alloc]
initWithBitmapDataPlanes:m_ptrs
pixelsWide:m_frameRect.size.width
pixelsHigh:m_frameRect.size.height
bitsPerSample:8
samplesPerPixel:4
hasAlpha:YES
isPlanar:NO
colorSpaceName:NSCalibratedRGBColorSpace
bitmapFormat:NSAlphaFirstBitmapFormat
bytesPerRow:(4 *
m_frameRect.size.width)
bitsPerPixel:32];
}
- (void)drawRect:(NSRect)dirtyRect {
[NSGraphicsContext saveGraphicsState];
[m_NSBitmapImageRep drawInRect:dirtyRect];
[NSGraphicsContext restoreGraphicsState];
}
m_bitmap.m_array is created in readFromData:ofType:fromFile
I know it is correct because if I use this code I get proper results:
(in this case bitmap is a local var but is generated just m_bitmap is.
context = CGBitmapContextCreate (bitmap.m_array, bitmap.m_pixelsx,
bitmap.m_pixelsy, 8, bitmap.m_pixelsx * 4, colorSpace,
kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Host);
CGImageRelease(_cgImageRef);
_cgImageRef = CGBitmapContextCreateImage (context);
CGImageRetain(_cgImageRef);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
The problem is I just see garbage, no image. Clearly I am doing
something wrong with the NSBitMapImageRep but I have no idea what.
Please comment!
db
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Re: NSBitMapImageRep Woes
On Jan 6, 2010, at 9:21 AM, David Blanton wrote: m_NSBitmapImageRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:m_ptrs pixelsWide:m_frameRect.size.width pixelsHigh:m_frameRect.size.height bitsPerSample:8 samplesPerPixel:4 hasAlpha:YES isPlanar:NO colorSpaceName:NSCalibratedRGBColorSpace bitmapFormat:NSAlphaFirstBitmapFormat bytesPerRow:(4 * m_frameRect.size.width) bitsPerPixel:32]; This code creates a bitmap with alpha. context = CGBitmapContextCreate (bitmap.m_array, bitmap.m_pixelsx, bitmap.m_pixelsy, 8, bitmap.m_pixelsx * 4, colorSpace, kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Host); This code creates a bitmap without alpha. The problem is I just see garbage, no image. Clearly I am doing something wrong with the NSBitMapImageRep but I have no idea what. Hence garbage. -- David Duncan Apple DTS Animation and Printing ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSBitMapImageRep Woes
On Jan 6, 2010, at 11:21 AM, David Blanton wrote:
- (void)drawRect:(NSRect)dirtyRect {
[NSGraphicsContext saveGraphicsState];
[m_NSBitmapImageRep drawInRect:dirtyRect];
[NSGraphicsContext restoreGraphicsState];
}
The docs for -drawInRect: say it does nothing if you haven't set the size of
the image. I know the size is (potentially) different from the
pixel-width/height, although I don't know if NSBitmapImageRep assumes an
initial size based on the pixel dimensions.
Also, you probably don't want to draw to the dirty rect. You want to draw to
the view's bounds, presumably.
Regards,
Ken
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Re: NSBitMapImageRep Woes
On Jan 6, 2010, at 9:21 AM, David Blanton wrote:
Here is the code:
@interface MyDocumentView : NSView {
@public
NSBitmapImageRep* m_NSBitmapImageRep;
NSRect m_frameRect;
float m_sz;
BBitmap m_bitmap;
unsigned char* m_ptrs[1];
}
- (void)awakeFromNib {
m_ptrs[0] = (unsigned char*)m_bitmap.m_array;
m_NSBitmapImageRep = [[NSBitmapImageRep alloc]
initWithBitmapDataPlanes:m_ptrs
pixelsWide:m_frameRect.size.width
pixelsHigh:m_frameRect.size.height
bitsPerSample:8
samplesPerPixel:4
hasAlpha:YES
isPlanar:NO
colorSpaceName:NSCalibratedRGBColorSpace
bitmapFormat:NSAlphaFirstBitmapFormat
bytesPerRow:(4 *
m_frameRect.size.width)
bitsPerPixel:32];
}
Two questions:
1.where ism_frameRectinitialised ?
2.and are the width and height initialised to the precise number of bits
per row and number of rows
of whatever m_ptrs[0] is pointing at ?
3.(I said previously I can't count), are there potential endian issues
involved ?
- (void)drawRect:(NSRect)dirtyRect {
[NSGraphicsContext saveGraphicsState];
[m_NSBitmapImageRep drawInRect:dirtyRect];
[NSGraphicsContext restoreGraphicsState];
}
m_bitmap.m_array is created in readFromData:ofType:fromFile
I know it is correct because if I use this code I get proper results:(in this
case bitmap is a local var but is generated just m_bitmap is.
context = CGBitmapContextCreate (bitmap.m_array, bitmap.m_pixelsx,
bitmap.m_pixelsy, 8, bitmap.m_pixelsx * 4, colorSpace,
kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Host);
CGImageRelease(_cgImageRef);
_cgImageRef = CGBitmapContextCreateImage (context);
CGImageRetain(_cgImageRef);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
The problem is I just see garbage, no image. Clearly I am doing something
wrong with the NSBitMapImageRep but I have no idea what.
Please comment!
=
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Visit www.nonatomic-retain.com
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Visit www.trilithon.com
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Re: NSBitMapImageRep Woes
OK.
So, from other comments I made some changes.
1. Correctly set the dimensions by using m_bitmap.m_pixelsx and
m_bitmap.m_pixelsy (these are members of our portable bitmap class).
m_NSBitmapImageRep = [[NSBitmapImageRep alloc]
initWithBitmapDataPlanes:m_ptrs
pixelsWide:m_bitmap.m_pixelsx
pixelsHigh:m_bitmap.m_pixelsy
bitsPerSample:8
samplesPerPixel:4
hasAlpha:YES
isPlanar:NO
colorSpaceName:NSCalibratedRGBColorSpace
bitmapFormat:NSAlphaFirstBitmapFormat
bytesPerRow:(4 *
m_bitmap.m_pixelsx)
bitsPerPixel:32];
And changed the drawInRect to draw in the views bounds
- (void)drawRect:(NSRect)dirtyRect {
NSRect bounds = [self bounds];
[NSGraphicsContext saveGraphicsState];
[m_NSBitmapImageRep drawInRect:bounds];
[NSGraphicsContext restoreGraphicsState];
}
Now, from David Duncan's comment.
My bitmap data does have alpha, i.e 4 samples per pixel ARGB. I
thought kCGImageAlphaNoneSkipFirst says don't make an alpha plane,
skip byte 1 and go to RED.
I am not sure how to specify this in the 'bitmapFormat' parameter.
On Jan 6, 2010, at 10:35 AM, David Duncan wrote:
On Jan 6, 2010, at 9:21 AM, David Blanton wrote:
m_NSBitmapImageRep = [[NSBitmapImageRep alloc]
initWithBitmapDataPlanes:m_ptrs
pixelsWide:m_frameRect.size.width
pixelsHigh:m_frameRect.size.height
bitsPerSample:8
samplesPerPixel:4
hasAlpha:YES
isPlanar:NO
colorSpaceName:NSCalibratedRGBColorSpace
bitmapFormat:NSAlphaFirstBitmapFormat
bytesPerRow:(4 *
m_frameRect.size.width)
bitsPerPixel:32];
This code creates a bitmap with alpha.
context = CGBitmapContextCreate (bitmap.m_array, bitmap.m_pixelsx,
bitmap.m_pixelsy, 8, bitmap.m_pixelsx * 4, colorSpace,
kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Host);
This code creates a bitmap without alpha.
The problem is I just see garbage, no image. Clearly I am doing
something wrong with the NSBitMapImageRep but I have no idea what.
Hence garbage.
--
David Duncan
Apple DTS Animation and Printing
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Re: NSBitMapImageRep Woes
On Jan 6, 2010, at 10:19 AM, David Blanton wrote: Now, from David Duncan's comment. My bitmap data does have alpha, i.e 4 samples per pixel ARGB. I thought kCGImageAlphaNoneSkipFirst says don't make an alpha plane, skip byte 1 and go to RED. I am not sure how to specify this in the 'bitmapFormat' parameter. AlphaNoneSkipFirst means you have no alpha, and skip any leading bytes per necessary to fill the pixel size. In your particular case since you have 8 bits per component and 3 components, that means skip the first 8 bits of each word then decode 8 bits for each of 3 components. When you create your NSBitmapImageRep however, you specify that there is alpha, which means that you are specifying the equivalent of kCGImageAlphaPremultipliedFirst (since you don't specify the NSAlphaNonpremultipliedBitmapFormat flag). What you really want is to specify no alpha and 3 samples per pixel (if I'm not mistaken, I usually work in Quartz rather than NS for graphics). Specifying 32 bits per pixel as you do should get the same interpretation that you are currently getting via Quartz. Also keep in mind that your Quartz code is more work than you would actually need. Since you aren't drawing to your image data, you should create the CGImage directly via CGImageCreate rather than using CGBitmapContextCreate to then extract a CGImage – the performance difference is in the syscalls necessary to mark the memory for the bitmap context as copy-on-write. -- David Duncan Apple DTS Animation and Printing ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: NSBitMapImageRep Woes
On 07/01/2010, at 4:21 AM, David Blanton wrote: bytesPerRow:(4 * m_frameRect.size.width) bitsPerPixel:32]; Apart from what others have said, you can pass 0 for these parameters and they get calculated for you. That's usually safest because any inconsistency among the parameters throws an exception. --Graham ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
