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These are the sources for the final official release of JPEGView for the Mac, back in 1994.
1 line
1.5 KiB
Plaintext
1 line
1.5 KiB
Plaintext
;*********************************************************/
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;* This source code copyright (c) 1991-2001, Aaron Giles */
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;* See the Read Me file for licensing information. */
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;* Contact email: mac@aarongiles.com */
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;*********************************************************/
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movem.l d3/d4/a6,-(sp) ;Save our registers
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move.l 20(sp),a6 ;Get the address of the FillData structure in a6
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;(based off stack: 3 registers + 1 a6 link + 1 return
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; = 5 * 4 = 20 bytes)
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move.l #32767,d3 ;AND mask for this pixel (32767 = $7fff)
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movea.l baseAdr(a6),a0 ;Get the starting address in a0
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movea.l histogram(a6),a1 ;Point a1 to our histogram
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@RLoop16:
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move.l a0,-(sp) ;Push the address on the stack
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move.l width(a6),d4 ;Get the width counter
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subq.l #1,d4 ;Minus one
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@CLoop16:
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move.w (a0)+,d0 ;Get the colors in d0
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and.l d3,d0 ;Clear out the alpha bit
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addq.w #1,(0,a1,d0.l*2) ;Increment the histogram
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beq.s @RZero16 ;Fix this if it's zero
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dbra.w d4,@CLoop16 ;Continue the loop over all columns
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bra.s @Skip16 ;Skip over the RZero part
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@RZero16:
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subq.w #1,(0,a1,d0.l*2) ;Put it back to 0xffff
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dbra.w d4,@CLoop16 ;Loop over the remaining columns
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@Skip16:
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movea.l (sp)+,a0 ;Return to the beginning of the row
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adda.l rowBytes(a6),a0 ;Go to the next row
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subq.l #1,height(a6) ;Decrement the height
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bne.s @RLoop16 ;If non-zero, branch
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movem.l (sp)+,d3/d4/a6 ;Restore our registers |