add soft iris effects

res/fx.conf

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

res/notes/transitions/softiris.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+
+from math import sqrt, sin, cos, acos, pi
+
+# Graph is plotted across the entire HGR screen, but only coordinates
+#  - in the left half of the screen, AND
+#  - on even rows, AND
+#  - on even columns
+# are included. It is assumed that the graph is symmetrical across
+# the left and half sides of the screen (along an axis at X=140).
+#
+# X coordinates are converted to byte+bitmask (but see notes below).
+# Y coordinates are incremented by 1 so that 0 can terminate the loop.
+#
+# 6502 code will be responsible for plotting each of these coordinates
+# in a 2x2 block. The bitmask usually includes 2 adjacent pixels;
+# the code will also plot the same 2 adjacent pixels in the adjacent row,
+# AND mirror both of those plots in the right half of the screen.
+#
+# Unfortunately, since bytes are 7 bits across, some blocks will cross a
+# byte boundary. To simplify the 6502 code, those are simply listed as
+# separate coordinate pairs, each with a bitmask that includes 1 pixel
+# instead of 2.
+
+max_x = 280
+max_y = 192
+
+def f(t, k, a):
+    r = k/cos(0.4*acos(sin(2.5*(t+pi/2))))
+    return r*cos(t+a),r*sin(t+a)
+
+coords = []
+for k_mul in range(1000):
+    a = float(k_mul*pi/1000)
+    for t_mul in range(int(pi*1000+1)):
+        a, b = f(float(t_mul/100), float(k_mul)/10.0, a)
+        x = round(max_x//2+a*1.2)
+        y = round(max_y//2+b)
+        if (x % 2 != 0) or (y % 2 != 0):
+            continue
+        if x < 0 or x >= max_x//2 or y < 0 or y >= max_y:
+            continue
+        coords.append((x,y))
+
+d = {}
+unique_coords = []
+for c in coords:
+    if not d.get(c):
+        unique_coords.append(c)
+        d[c] = 1
+
+unique_vals = []
+even_byte_bitmask = (0, 0, 1, 1, 2, 2, 3)
+odd_byte_bitmask = (5, 5, 6, 6, 7, 7, 4)
+for x, y in unique_coords:
+    y = y + 1
+    aval = "$" + hex(y)[2:].rjust(2, "0").upper()
+    byte = x//7
+    if byte % 2 == 0:
+        # high 3 bits are 0-3, low 5 bits are 0-39
+        bval = "%" + bin(even_byte_bitmask[x % 7])[2:].rjust(3, "0") + bin(byte)[2:].rjust(5, "0")
+        unique_vals.append((aval, bval))
+        if x % 7 == 6:
+            # this 2x2 block will be split across bytes, so add an extra coordinate pair with the adjacent byte and high 3 bits = 4
+            bval = "%100" + bin(byte+1)[2:].rjust(5, "0") + ";"
+            unique_vals.append((aval, bval))
+    else:
+        # high 3 bits are 5-7 or 4, low 5 bits are 0-39
+        bval = "%" + bin(odd_byte_bitmask[x % 7])[2:].rjust(3, "0") + bin(byte)[2:].rjust(5, "0")
+        unique_vals.append((aval, bval))
+        if x % 7 == 6:
+            # this 2x2 block will be split across bytes, so add an extra coordinate pair with the adjacent byte and high 3 bits = 3
+            bval = "%011" + bin(byte+1)[2:].rjust(5, "0") + ";"
+            unique_vals.append((aval, bval))
+
+with open("../../../src/fx/fx.hgr.soft.iris.data.a", "w") as f:
+    for aval, bval in unique_vals:
+        f.write("         !byte %s,%s\n" % (aval, bval))
+
+unique_vals.reverse()
+with open("../../../src/fx/fx.hgr.soft.iris.in.data.a", "w") as f:
+    for aval, bval in unique_vals:
+        f.write("         !byte %s,%s\n" % (aval, bval))

src/fx/fx.hgr.soft.iris.a

@@ -0,0 +1,14 @@
+;license:MIT
+;(c) 2019 by 4am
+;
+!cpu 6502
+!to "build/FX/SOFT.IRIS",plain
+*=$6000
+
+         !source "src/fx/fx.hgr.precomputed.2bit.a"
+
+         +FX_PRECOMPUTED_2BIT Coordinates
+
+Coordinates
+         !source "src/fx/fx.hgr.soft.iris.data.a"
+         !byte $00

src/fx/fx.hgr.soft.iris.in.a

@@ -0,0 +1,14 @@
+;license:MIT
+;(c) 2019 by 4am
+;
+!cpu 6502
+!to "build/FX/SOFT.IRIS.IN",plain
+*=$6000
+
+         !source "src/fx/fx.hgr.precomputed.2bit.a"
+
+         +FX_PRECOMPUTED_2BIT Coordinates
+
+Coordinates
+         !source "src/fx/fx.hgr.soft.iris.in.data.a"
+         !byte $00