4cade/res/notes/transitions/corner.py

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2019-11-06 01:12:26 +00:00
#!/usr/bin/env python3
from math import sqrt, sin, cos, acos, pi
import util
# 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 flipped (so 0,0 ends up on the bottom left) then
# 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):
return (sqrt(t)*cos(2*pi*sqrt(t)), 0.87*sqrt(t)*sin(2*pi*sqrt(t)))
coords = []
for i in range(2000000):
a, b = f(float(i)/10.0)
x = round(max_x+a)
y = round(b)
if x % 2 != 0 or y % 3 != 0:
continue
if x < 0 or x >= max_x or y < 0 or y >= max_y:
continue
coords.append((x,y))
unique_coords = util.unique(coords)
unique_vals = util.vals_3bit(unique_coords)
ripple_vals = util.ripple(unique_vals)
ripple_vals = util.ripple(ripple_vals)
with open("../../../src/fx/fx.hgr.corner.superripple.data.a", "w") as f:
for aval, bval in ripple_vals:
f.write(" !byte %s,%s\n" % (aval, bval))