******************************************************************************* * * Source Control * -------------- * $Header: ReadPixelArray.asm,v 35.0 88/04/22 11:50:46 bart Exp $ * * by Bart Whitebook * * Copyright (c) 1988 Commodore-Amiga, Inc. * * Executables based on this information may be used in software * for Commodore Amiga computers. All other rights reserved. * * This information is provided "as is"; no warranties are made. * All use is at your own risk, and no liability or responsibility is assumed. * ******************************************************************************* include 'exec/types.i' * Required data type definitions include 'graphics/gfx.i' * BitMap structure definition include 'exec/nodes.i' include 'exec/lists.i' include 'exec/interrupts.i' include 'exec/ports.i' include 'exec/libraries.i' include 'graphics/gfxbase.i' include 'graphics/clip.i' * Layer structure definition include 'graphics/rastport.i' * RastPort structure definition include 'hardware/blit.i' * Minterm definitions xdef _ReadPixelArray * Define public entry points xdef _ReadPixelLine PAGE ******* graphics.library/ReadPixelArray ************************************** * * NAME * ReadPixelArray -- read the pen number value of a rectangular array * of pixels starting at a specified x,y location and continuing * through to another x,y location within a certain RastPort. * * SYNOPSIS * count = ReadPixelArray(rp,xstart,ystart,xstop,ystop,array,defval,temprp) * d0 a0 d0:16 d1:16 d2:16 d3:16 a2 d7:8 a1 * * LONG count; * struct RastPort *rp; * SHORT xstart, ystart; * SHORT xstop, ystop; * UBYTE *array; * UBYTE defval; * struct RastPort *temprp; * * FUNCTION * For each pixel in a rectangular region, combine the bits from each * of the bit-planes used to describe a particular RastPort into the pen * number selector which that bit combination normally forms for the * system hardware selection of pixel color. * * INPUTS * rp - pointer to a RastPort structure * (xstart,ystart) starting point in the RastPort * (xstop,ystop) stopping point in the RastPort * array - pointer to an array of uwords in which to store the pixel data * temprp - temporary rastport (copy of rp with Layer set == NULL, * temporary memory allocated for temp BitMap * temprp->BitMap with Rows set == 1, * and with BytesPerrow set == * ((((xstart-xstop+1)+0xf)>>4)<<1), * and temporary memory allocated for * temprp->BitMap->Planes[]) * * RESULT * For each pixel in the array: * Pen - (0..255) number at that position is returned * (defval) is returned if cannot read that pixel * * NOTE * xstop must be >= xstart * ystop must be >= ystart * * BUGS * * SEE ALSO * WritePixel graphics/rastport.h * ****************************************************************************** xref _LVOLockLayerRom xref _LVOWaitBlit xref _LVOUnlockLayerRom xref _LVOClipBlit xref _GfxBase _ReadPixelArray: movem.l d2/d3/d7/a2/a6,-(sp) move.l _GfxBase,a6 move.l 24(sp),a0 ; rp movem.l 28(sp),d0/d1/d2/d3 ; xstart, ystart, xstop, ystop movea.l 44(sp),a2 ; array move.l 48(sp),d7 ; defval movea.l 52(sp),a1 ; temprp jsr readpixelarray movem.l (sp)+,d2/d3/d7/a2/a6 rts readpixelarray: movem.l d2/d3/d4/d5/d6/d7/a2/a3/a4,-(sp) sub.w d0,d2 ; width of rectangle to read ext.l d2 addq.l #1,d2 ble.s array_error ; width non-positive ? move.w d0,d4 ; temp storage for current x move.w d1,d5 ; temp storage for current y sub.w d1,d3 ; height of rectangle to read ext.l d3 addq.l #1,d3 ble.s array_error ; height non-positive ? movea.l a0,a3 ; protect rastport pointer -- does not modify cc movea.l a1,a4 ; protect temprp pointer -- does not modify cc moveq.l #0,d6 ; clear count of pixels returned bra.s rpxaloop_count rpxaloop_start: movea.l a3,a0 ; rp move.l d4,d0 ; x move.l d5,d1 ; y (current line) ; width in d2 (see above) ; array in a2 (see above) movea.l a4,a1 ; temprp jsr readpixelline addq.l #1,d5 ; next line adda.l d2,a2 ; increment base pointer to array by width words adda.l d2,a2 add.l d2,d6 ; add one line of pixels to pixel count rpxaloop_count: dbra d3,rpxaloop_start rpxaloop_end: move.l d6,d0 ; return pixel count movem.l (sp)+,d2/d3/d4/d5/d6/d7/a2/a3/a4 rts array_error: moveq.l #-1,d0 movem.l (sp)+,d2/d3/d4/d5/d6/d7/a2/a3/a4 rts ******* graphics.library/ReadPixelLine *************************************** * * NAME * ReadPixelLine -- read the pen number value of a horizontal line * of pixels starting at a specified x,y location and continuing * right for count pixels. * * SYNOPSIS * count = ReadPixelLine(rp,xstart,ystart,width,array,defval,temprp) * d0 a0 d0:16 d1:16 d2 a2 d7:8 a1 * * LONG count; * struct RastPort *rp; * SHORT xstart, ystart; * LONG width; * UBYTE *array; * UBYTE defval; * struct RastPort *temprp; * * FUNCTION * For each pixel in a rectangular region, combine the bits from each * of the bit-planes used to describe a particular RastPort into the pen * number selector which that bit combination normally forms for the * system hardware selection of pixel color. * * INPUTS * rp - pointer to a RastPort structure * (x,y) a point in the RastPort * width - count of horizontal pixels to read * array - pointer to an array of uwords in which to store the pixel data * temprp - temporary rastport (copy of rp with Layer set == NULL, * temporary memory allocated for * temprp->BitMap with Rows set == 1, * and temporary memory allocated for * temprp->BitMap->Planes[]) * * RESULT * For each pixel in the array: * Pen - (0..255) number at that position is returned * (defval) is returned if cannot read that pixel * * NOTE * width must be non negative * * BUGS * * SEE ALSO * WritePixel graphics/rastport.h * ****************************************************************************** _ReadPixelLine: movem.l d2/d7/a2/a6,-(sp) move.l _GfxBase,a6 move.l 20(sp),a0 ; rp movem.l 24(sp),d0/d1/d2 ; xstart, ystart, width movea.l 36(sp),a2 ; array move.l 40(sp),d7 ; defval movea.l 44(sp),a1 ; temprp jsr readpixelline movem.l (sp)+,d2/d7/a2/a6 rts readpixelline: movem.l d2/d3/d4/d5/d6/d7/a2,-(sp) move.l d2,d4 ; copy "width" pixels moveq.l #1,d5 ; copy one row of pixels move.l #(ABC+ABNC),d6 ; vanilla copy moveq.l #0,d2 ; copy to temprp(0,0) moveq.l #0,d3 ****************************************************************************** jsr tmploop_init ; initialize tmpras to default value ****************************************************************************** move.l a1,-(sp) ; save temprp jsr _LVOClipBlit(a6) ; do it the easy way move.l (sp)+,a1 ; restore temprp ; width now in d5 movea.l rp_BitMap(a1),a1 ; get BitMap pointer move.b bm_Depth(a1),d2 ; Depth in d2 lea.l bm_Planes(a1),a1 ; address of first plane pointer in a1 moveq.l #0,d0 ; source word offset rplloop_init: moveq.l #$10,d3 ; set counter - 16 bits in a word bra.s rplloop_count rplloop_start: subq.l #1,d3 ; advance to next bit bge.s same_word ; not time to move onto next word just yet moveq.l #$0f,d3 ; reset counter - account for 'subq.l #1' above ; addq.l #4,d0 ; increment source LONGWORD offset addq.l #2,d0 ; increment source WORD offset same_word: move.l d2,d1 ; number of planes in d1 moveq.l #0,d5 ; storage to build pixel desription lsl.l #2,d1 ;convert to long index bra.s shift_count *----------------------------------------------------------------------------- shift_start: ; move.l d1,d6 ; plane number in d6 ; lsl.l #2,d6 ; build plane pointer offset in d6 ; movea.l 0(a1,d6),a0 ; get plane pointer movea.l 0(a1,d1),a0 ; get plane pointer roxl.l 0(a0,d0) ; rol high bit left into extend roxl.l #1,d5 ; rol extend bit left into pixel description shift_count: subq.l #4,d1 ; decrement long offset bge.s shift_start ; dbra d1,shift_start shift_end: move.w d5,(a2)+ ; store pixel description in destination array *----------------------------------------------------------------------------- rplloop_count: dbra d4,rplloop_start ; loop back if not done entire width rplloop_end: movem.l (sp)+,d2/d3/d4/d5/d6/d7/a2 rts ****************************************************************************** tmploop_init: movem.l d0/d1/d2/d3/d4/d5/d7/a0/a1,-(sp) movea.l rp_BitMap(a1),a1 ; get BitMap pointer move.b bm_Depth(a1),d2 ; Depth in d2 moveq.l #0,d3 move.w bm_BytesPerRow(a1),d3 ; numbytes in d3 lea.l bm_Planes(a1),a1 ; address of first plane pointer in a1 move.l d2,d1 ; number of planes in d1 subq.l #1,d2 ; adjust # of planes for low to high count bra.s tmpshift_count tmpshift_start: ; fill temprp with defval moveq.l #0,d0 roxr.l #1,d7 ; ror low bit of d7 into extend bit roxr.l #1,d0 ; ror extend bit into high bit of d0 beq.s stuff0 ; stuff null stuff1: moveq.l #-1,d0 ; stuff ~null stuff0: move.l d2,d5 ; build plane number in d5 sub.l d1,d5 ; plane number in d5 (low to high) lsl.l #2,d5 ; build plane pointer offset in d5 movea.l 0(a1,d5),a0 ; get plane pointer move.l d3,d4 ; init numbytes lsr.l #1,d4 ; convert to numwords bra.s tmploop_count tmploop_start: move.w d0,(a0)+ ; stuff proper word into this plane of the tmpras tmploop_count: dbra d4,tmploop_start ; d4 words tmploop_end: tmpshift_count: dbra d1,tmpshift_start tmpshift_end: movem.l (sp)+,d0/d1/d2/d3/d4/d5/d7/a0/a1 rts ****************************************************************************** end