add maple effects

res/fx.conf

@@ -1 +1 @@
-RIPPLE
+RIPPLE

res/notes/transitions/maple.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+import PIL.Image # https://pillow.readthedocs.io/
+import util
+
+# maple.png is the source image. The source image MUST have a white background,
+# but other colors and pixel depth are irrelevant. This one is black & white.
+# Due to the Apple II pixel aspect ratio, we do a 1-time aspect-ratio-losing resize
+# to squash the image to 87% height.
+#
+# $ gm convert maple.png -resize "100%x87%!" squash.png
+# (Depending on your shell, you may need to escape the exclamation point. Grr.)
+#
+# Now we can create individual images for each "frame" of the animation, by
+# resizing the (squashed) source image and putting it in a 280x192 frame.
+#
+# $ for w in `seq 1 1500`; do \
+#     gm convert -size 280x192 squash.png \
+#                -resize "$w" \
+#                -background white \
+#                -compose Copy \
+#                -gravity center \
+#                -extent 280x192 thumb"$w".png; \
+#   done
+#
+# Depending on the source image, you may need more or fewer than 1500 frames. This
+# number is duplicated below in the |frames| variable. Sorry.
+#
+# Now we have 1500 (or so) PNG images of what the HGR screen should look like at
+# each stage. Despite each frame being 280x192 and in the correct aspect ratio,
+# only coordinates
+#  - on every 3rd row
+#  - on even columns
+# are included in the final data set.
+#
+# X coordinates are converted to byte+bitmask (but see notes below).
+# Y coordinates are flipped (so 0,0 ends up on the bottom left) then
+# divided by 3.
+#
+# 6502 code will be responsible for plotting each of these coordinates
+# in a 2x3 block. The bitmask usually includes 2 adjacent pixels;
+# the code will also plot the same 2 adjacent pixels in the next two rows.
+#
+# Unfortunately, since bytes are 7 pixels across, some of the 2-pixel-wide
+# blocks will cross a byte boundary. To simplify the 6502 code, these are
+# simply listed as separate coordinate pairs, each with a bitmask that
+# includes 1 pixel instead of 2.
+
+frames = 1500 # number of "thumbN.png" files
+
+coords = []
+for i in range(5, frames, 5):
+    p = PIL.Image.open("maple/thumb%s.png" % i)
+    for x in range(0, 280//2, 2):
+        for y in range(0, 192, 2):
+            if p.getpixel((x,191-y))[0] == 0:
+                coords.append((x,y))
+
+unique_coords = util.unique(coords)
+unique_vals = util.vals_2bit(unique_coords)
+with open("../../../src/fx/fx.hgr.maple.data.a", "w") as f:
+    for aval, bval in unique_vals:
+        f.write("         !byte %s,%s\n" % (aval, bval))
+
+ripple_vals = util.ripple(unique_vals)
+with open("../../../src/fx/fx.hgr.maple.ripple.data.a", "w") as f:
+    for aval, bval in ripple_vals:
+        f.write("         !byte %s,%s\n" % (aval, bval))
+
+unique_vals.reverse()
+with open("../../../src/fx/fx.hgr.maple.in.data.a", "w") as f:
+    for aval, bval in unique_vals:
+        f.write("         !byte %s,%s\n" % (aval, bval))

src/fx/fx.hgr.maple.ripple.a

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+;license:MIT
+;(c) 2019 by 4am
+;
+!cpu 6502
+!to "build/FX/MAPLE.RIPPLE",plain
+*=$6000
+
+         !source "src/fx/fx.hgr.precomputed.2bit.a"
+
+         +FX_PRECOMPUTED_2BIT Coordinates
+
+Coordinates
+         !source "src/fx/fx.hgr.maple.ripple.data.a"
+         !byte $00