From b81a3b76b25b7286419a1e7471252b273c4a575e Mon Sep 17 00:00:00 2001
From: 4am <a2_4am@sent.com>
Date: Sat, 12 Sep 2020 12:58:03 -0400
Subject: [PATCH] add flick transition

---
 res/FX.CONF           |  1 +
 src/fx/fx.hgr.flick.a | 83 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 src/fx/fx.hgr.flick.a

diff --git a/res/FX.CONF b/res/FX.CONF
index a341abaa7..0b9ea31c6 100644
--- a/res/FX.CONF
+++ b/res/FX.CONF
@@ -105,6 +105,7 @@ LITTLE.BOXES
 SPIRAL
 WAVY.CORNER
 REDLINES
+FLICK
 [eof]
 
 #
diff --git a/src/fx/fx.hgr.flick.a b/src/fx/fx.hgr.flick.a
new file mode 100644
index 000000000..68ecd79a3
--- /dev/null
+++ b/src/fx/fx.hgr.flick.a
@@ -0,0 +1,83 @@
+;license:MIT
+;(c) 2018 by 4am
+;
+!cpu 6502
+!to "build/FX/FLICK",plain
+*=$6000
+
+rowcount = $FF                       ; [byte]
+hgrlo = $200                         ; [$C0 bytes]
+startrows_by_column = $2C0           ; [$28 bytes]
+hgrhi = $300                         ; [$C0 bytes]
+rowcounts_by_column = $3C0           ; [$28 bytes]
+
+         !source "src/fx/macros.a"
+
+         +BUILD_HGR_LOOKUP_TABLES hgrlo, hgrhi
+
+         ldy   #$27
+-        lda   #$00
+         sta   startrows_by_column, y
+         lda   initial_rowcounts, y
+         sta   rowcounts_by_column, y
+         dey
+         bpl   -
+frameloop
+         ldy   #$27
+columnloop
+         lda   rowcounts_by_column, y
+         beq   nextcolumn
+         bmi   nextcolumn
+         sta   rowcount
+         ldx   startrows_by_column, y
+         cpx   #$C0
+         bcs   nextcolumn
+rowloop  lda   hgrlo, x
+         sta   $3c
+         sta   $26
+         lda   hgrhi, x
+         sta   $27
+         eor   #$60
+         sta   $3d
+         lda   ($3c), y
+         sta   ($26), y
+         inx
+         dec   rowcount
+         bne   rowloop
+nextcolumn
+         dey
+         bpl   columnloop
+
+         ldy   #$27
+-        lda   rowcounts_by_column, y
+         bmi   +
+         beq   +
+         tax
+         clc
+         adc   startrows_by_column, y
+         sta   startrows_by_column, y
+         lda   next_rowcount, x
+         sta   rowcounts_by_column, y
+         bne   ++                    ; always branches
++        clc
+         adc   #1
+         sta   rowcounts_by_column, y
+++       dey
+         bpl   -
+         lda   #$30
+         jsr   WaitForKeyWithTimeout
+         bmi   exit
+         lda   rowcounts_by_column+$27
+         cmp   #$80
+         bne   frameloop
+exit     rts
+
+         !source "src/wait.a"
+
+initial_rowcounts
+         !byte $01,$01,$00,$00,$FF,$FF,$FE,$FE,$FD,$FD
+         !byte $FC,$FC,$FB,$FB,$FA,$FA,$F9,$F9,$F8,$F8
+         !byte $F7,$F7,$F6,$F6,$F5,$F5,$F4,$F4,$F3,$F3
+         !byte $F2,$F2,$F1,$F1,$F0,$F0,$EF,$EF,$EE,$EE
+next_rowcount
+         !byte $01,$03,$80,$05,$02,$07,$04,$09,$06,$0B,$08,$0D,$0A,$0F,$0C,$11,$0E,$15,$10,$FD,$FD,$12