4cade/src/fx/fx.hgr.radial3.a

;license:MIT
;(c) 2019 by 4am
;
!cpu 6502
!to "build/FX/RADIAL3",plain
*=$6000

         !source "src/fx/fx.hgr.precomputed.1bit.a"

         +BUILD_HGR_LOOKUP_TABLES hgrlo, hgr1hi
         +BUILD_HGR_MIRROR_LOOKUP_TABLES hgrlomirror, hgr1himirror
         +BUILD_MIRROR_COLS mirror_cols
         +BUILD_SPARSE_BITMASKS copymasks, mirror_copymasks
         +LDADDR Coordinates
         +STAY input
         +LDADDR EndCoordinates-2
         +STAY reverse_input
         jmp   Loop
Exit     rts
Loop     ldy   #0
         lda   (input),y
         bmi   Exit
         tax
         +ROW_X_TO_BASE_ADDRESSES
         +ROW_X_TO_MIRROR_ADDRESSES
         inc   input
         lda   (input),y
         +HIGH_3_LOW_5 input

         ; top-left quadrant (original row, original column, original input order)
         +COPY_BIT src1, dest1, copymasks
         +COPY_BIT src2, dest2, copymasks

         ; bottom-right quadrant (opposite row, opposite column, original input order)
         lda   mirror_cols,y
         tay
         +COPY_BIT mirror_src1, mirror_dest1, mirror_copymasks
         +COPY_BIT mirror_src2, mirror_dest2, mirror_copymasks

         ldy   #0
         lda   (reverse_input),y
         tax
         +ROW_X_TO_BASE_ADDRESSES
         +ROW_X_TO_MIRROR_ADDRESSES
         iny
         lda   (reverse_input),y
         +HIGH_3_LOW_5 reverse_input

         ; bottom-left quadrant (opposite row, original column, reverse input order)
         +COPY_BIT mirror_src1, mirror_dest1, copymasks
         +COPY_BIT mirror_src2, mirror_dest2, copymasks

         ; top-right quadrant (same row, opposite column, reverse input order)
         lda   mirror_cols,y
         tay
         +COPY_BIT src1, dest1, mirror_copymasks
         +COPY_BIT src2, dest2, mirror_copymasks

         inc   input
         bne   +
         inc   input+1
+        lda   reverse_input
         beq   +
         dec   reverse_input
         dec   reverse_input
         jmp   Loop
+        dec   reverse_input
         dec   reverse_input
         dec   reverse_input+1
         bit   $c000
         bmi   +
         jmp   Loop
+        rts

!if * and 1 {
         !byte 0
}
Coordinates
         !source "src/fx/fx.hgr.radial.data.a"
EndCoordinates
         !byte $80