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elk1984

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Joined: 11/07/2020
Location: United Kingdom
Posts: 228

Posted: 04:47pm 27 Sep 2020

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At risk of someone pointing me straight to the manual (I have looked and checked in Peter's excellent Graphics Programming on the Colour Maximite 2) - is there a way to get the size of a sprite, loaded image or framebuffer.

The use case is I'd like to load a bitmap bounded by a box. Of course I do know the size of the bitmap I'm loading, but if there was a way to get it from the file I'd prefer not to put hardcoded values in my program.

Thanks

elk1984

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10310

Posted: 05:12pm 27 Sep 2020

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You are asking three different things. For sprite use the SPRITE function for framebuffer use MM.INFO. For a BMP file you are going to need to read the file header and decode it.-

elk1984

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Joined: 11/07/2020
Location: United Kingdom
Posts: 228

Posted: 06:13pm 27 Sep 2020

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matherp said You are asking three different things. For sprite use the SPRITE function for framebuffer use MM.INFO. For a BMP file you are going to need to read the file header and decode it.-

Thanks - the mixing up probably reflects my head

. What I'm trying to do is load a graphic into a sprite to put on screen in a bounded box. If I use SPRITE LOADPNG, is there a way once it is loaded to access the height and width?

TassyJim

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Joined: 07/08/2011
Location: Australia
Posts: 6283

Posted: 09:33pm 27 Sep 2020

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These SUbs are from my FileManager program.
They give the vital stats for image files.

sub jpgInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
LOCAL INTEGER block
LOCAL x$
onDisk = MM.INFO(filesize f$)
info$ = ""
OPEN f$ FOR INPUT AS #2
DO
block = ASC(INPUT$(1,#2)) ' flag for start of block
IF block = 255 THEN
block = ASC(INPUT$(1,#2)) ' block type
IF block = &hC0 THEN
x$ = INPUT$(3,#2)
iHt = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
iWdth = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
EXIT DO
elseif block = &hC2 THEN
info$ = "Progressive"
x$ = INPUT$(3,#2)
iHt = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
iWdth = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
exit do
ENDIF
ENDIF
LOOP
CLOSE #2
END SUB

sub bmpInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
LOCAL x$
onDisk = MM.INFO(filesize f$)
OPEN f$ FOR INPUT AS #2
x$ = INPUT$(18,#2) ' skip this
iWdth = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
iWdth = iWdth +ASC(INPUT$(1,#2))*2^16+ASC(INPUT$(1,#2))*2^24
iHt = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
iHt = iHt +ASC(INPUT$(1,#2))*2^16+ASC(INPUT$(1,#2))*2^24
x$ = INPUT$(2,#2) ' colour planes - not used
info$ = str$(ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256)+" bit"
CLOSE #2
END SUB

sub gifInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
LOCAL x$, iBits as integer
onDisk = MM.INFO(filesize f$)
OPEN f$ FOR INPUT AS #2
x$ = INPUT$(6,#2) ' skip this GIF89a
iWdth = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
iHt = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
x$ = INPUT$(1,#2) ' colour table start and bits
iBits = (asc(x$) and &b00000111) + 1
'if (asc(x$) and &b10000000) then iBits = 0 - iBits ' indicate animated image
CLOSE #2
info$ = str$(iBits)+" bit"
END SUB

sub pngInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
' data from https://en.wikipedia.org/wiki/Portable_Network_Graphics
LOCAL x$, iBits as integer
onDisk = MM.INFO(filesize f$)
OPEN f$ FOR INPUT AS #2
x$ = INPUT$(12,#2)
x$ = INPUT$(4,#2) ' should be IHDR
iWdth = ASC(INPUT$(1,#2))*2^24 + ASC(INPUT$(1,#2))*2^16
iWdth = iWdth +ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
iHt = ASC(INPUT$(1,#2))*2^24 + ASC(INPUT$(1,#2))*2^16
iHt = iHt +ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
iBits = ASC(INPUT$(1,#2)) ' colour bits/pixel
select case ASC(INPUT$(1,#2)) ' colour type
case 0
info$ = str$(iBits)+" bit Grayscale"
case 2
info$ = str$(iBits*3)+" bit Truecolour"
case 3
info$ = str$(iBits)+" bit Palettised"
case 4
info$ = str$(iBits*2)+" bit Grayscale+Alpha"
case 6
info$ = str$(iBits*4)+" bit RGBA"
case else
info$ = str$(iBits)+" bit/pixel"
end select

CLOSE #2
END SUB

Given the file name, they return sizes plus other info.

Jim

VK7JH
MMedit

elk1984

Senior Member

Joined: 11/07/2020
Location: United Kingdom
Posts: 228

Posted: 07:18am 28 Sep 2020

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TassyJim said These SUbs are from my FileManager program.
They give the vital stats for image files.

sub jpgInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
�LOCAL INTEGER block
�LOCAL x$
�onDisk = MM.INFO(filesize f$)
�info$ = ""
�OPEN f$ FOR INPUT AS #2
�DO
� �block = ASC(INPUT$(1,#2)) ' flag for start of block
� �IF block = 255 THEN
� � �block = ASC(INPUT$(1,#2)) ' block type
� � �IF block = &hC0 THEN
� � � �x$ = INPUT$(3,#2)
� � � �iHt = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
� � � �iWdth = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
� � � �EXIT DO
� � �elseif block = &hC2 THEN
� � � �info$ = "Progressive"
� � � �x$ = INPUT$(3,#2)
� � � �iHt = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
� � � �iWdth = ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
� � � �exit do
� � �ENDIF
� �ENDIF
�LOOP
�CLOSE #2
END SUB
�
sub bmpInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
�LOCAL x$
�onDisk = MM.INFO(filesize f$)
�OPEN f$ FOR INPUT AS #2
�x$ = INPUT$(18,#2) ' skip this
�iWdth = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
�iWdth = iWdth +ASC(INPUT$(1,#2))*2^16+ASC(INPUT$(1,#2))*2^24
�iHt = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
�iHt = iHt +ASC(INPUT$(1,#2))*2^16+ASC(INPUT$(1,#2))*2^24
�x$ = INPUT$(2,#2) ' colour planes - not used
�info$ = str$(ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256)+" bit"
�CLOSE #2
END SUB
�
sub gifInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
�LOCAL x$, iBits as integer
�onDisk = MM.INFO(filesize f$)
�OPEN f$ FOR INPUT AS #2
�x$ = INPUT$(6,#2) ' skip this GIF89a
�iWdth = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
�iHt = ASC(INPUT$(1,#2))+ASC(INPUT$(1,#2))*256
�x$ = INPUT$(1,#2) ' colour table start and bits
�iBits = (asc(x$) and &b00000111) + 1
�'if (asc(x$) and &b10000000) then iBits = 0 - iBits ' indicate animated image
�CLOSE #2
�info$ = str$(iBits)+" bit"
END SUB
�
sub pngInfo f$, onDisk AS INTEGER, iWdth AS INTEGER, iHt AS INTEGER, info$
�' data from https://en.wikipedia.org/wiki/Portable_Network_Graphics
�LOCAL x$, iBits as integer
�onDisk = MM.INFO(filesize f$)
�OPEN f$ FOR INPUT AS #2
�x$ = INPUT$(12,#2)
�x$ = INPUT$(4,#2) ' should be IHDR
�iWdth = ASC(INPUT$(1,#2))*2^24 + ASC(INPUT$(1,#2))*2^16
�iWdth = iWdth +ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
�iHt = ASC(INPUT$(1,#2))*2^24 + ASC(INPUT$(1,#2))*2^16
�iHt = iHt +ASC(INPUT$(1,#2))*256 + ASC(INPUT$(1,#2))
�iBits = ASC(INPUT$(1,#2)) ' colour bits/pixel
�select case ASC(INPUT$(1,#2)) ' colour type
� �case 0
� � �info$ = str$(iBits)+" bit Grayscale"
� �case 2
� � �info$ = str$(iBits*3)+" bit Truecolour"
� �case 3
� � �info$ = str$(iBits)+" bit Palettised"
� �case 4
� � �info$ = str$(iBits*2)+" bit Grayscale+Alpha"
� �case 6
� � �info$ = str$(iBits*4)+" bit RGBA"
� �case else
� � �info$ = str$(iBits)+" bit/pixel"
�end select
�
�CLOSE #2
END SUB

Given the file name, they return sizes plus other info.

Jim

That's fantastic - thanks TassyJim

elk1984

Senior Member

Joined: 11/07/2020
Location: United Kingdom
Posts: 228

Posted: 06:07pm 28 Sep 2020

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Thanks for the inspiration Jim. �Using your code as a basis, I've reworked as an exercise in improving my knowledge of file handling, arrays etc.

The program needs 4 images (test.bmp, test.gif, test.jpg and test.png) in the same directory as the basic file.

image-info.zip

Any review comments welcome, especially that would help make this standalone and reusable for others.
Edited 2020-09-29 04:15 by elk1984

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