BytePusher Nyan Cat

.screenshot.png

nyan.bp

nyan.py

"""
Copyright (C) 2014 nucular
This work is free. You can redistribute it and/or modify it under the
terms of the Do What The Fuck You Want To Public License, Version 2,
as published by Sam Hocevar. See http://www.wtfpl.net/ for more details.
"""

import os, sys
import random


# ==== CONSTANTS =====

NOTICE = " by nucular, WTFPL License "

PAGE = 256
BANK = PAGE * PAGE
MEMSIZE = PAGE * BANK
SIZE_ADDR = 3
SIZE_INSTR = 3 * SIZE_ADDR

# Pointers
GFX = 0x02

S_RBOW = 19*19
S_STAR = 7*7

W_CAT = 33
H_CAT = 21
S_CAT = W_CAT * H_CAT
CAT1 = (GFX + 1) << 16
CAT2 = CAT1 + S_CAT
CAT3 = CAT2 + S_CAT
CAT4 = CAT3 + S_CAT

W_RBOW = 19
H_RBOW = 19
S_RBOW = W_RBOW * H_RBOW
RBOW1 = CAT4 + S_CAT
RBOW2 = RBOW1 + S_RBOW

W_STAR = 7
H_STAR = 7
S_STAR = W_STAR * H_STAR
STAR1 = RBOW2 + S_RBOW
STAR2 = STAR1 + S_STAR
STAR3 = STAR2 + S_STAR
STAR4 = STAR3 + S_STAR


# ==== UTILITY FUNCTIONS ====

pos = 0
size = 0

def prev(n=1):
    return pos - SIZE_INSTR * n

def next(n=1):
    return pos + SIZE_INSTR * n

def tell():
    assert pos == fp.tell()
    return pos

def seek(v):
    global fp, pos, size
    if v > size:
        fp.seek(size)
        fp.write("\x00"*(v-size))
        size = v
    else:
        fp.seek(v)

    pos = v
    assert pos == fp.tell()

# Byte writing
def w1(v):
    """Write one byte"""
    global fp, pos, size
    fp.write(chr(v & 255))
    pos += 1
    if pos > size:
        size = pos

def w2(v):
    """Write two bytes"""
    w1(v>>8)
    w1(v)

def w3(v):
    """Write three bytes"""
    w1(v>>16)
    w2(v)

def op(a, b, c):
    """Write an instruction"""
    w3(a)
    w3(b)
    w3(c)

# Basic instructions
def nop():
    """Do nothing but fill 9 bytes"""
    op(0, 0, next())

def jmp(adr):
    """Jump to an adress"""
    op(0, 0, adr)

def mov(a, b):
    """Copy a byte from a to b"""
    op(a, b, next())

# Simple drawing system
def wspr(adr, data):
    """Write a base64-encoded, zlib-ed sprite statically into the program"""
    global size
    data = data.decode("base64").decode("zlib")
    lp = tell()
    seek(adr)
    fp.write(data)
    if size < adr + len(data):
        size = adr + len(data)
    seek(lp)

def ldspr(adr, x, y, w, h):
    """Draw a sprite at x,y"""
    lp = tell()

    i = 0
    for yp in xrange(h):
        for xp in xrange(w):
            if x + xp < 256 and y + yp < 256:
                t = GFX<<16 | y + yp<<8 | x + xp
                mov(adr + i, t)
            i += 1

def wfill(col):
    """Fill the graphics bank statically"""
    global size
    lp = tell()
    seek(GFX << 16)
    fp.write(chr(col) * 0x10000)
    if size < (GFX << 16) + 0x10000:
        size = (GFX << 16) + 0x10000
    seek(lp)

# Other
def ldpc(v):
    """Set the program counter"""
    jmp(next() + 3)
    lp = tell()
    w3(v)
    mov(lp, 2)
    mov(lp + 1, 3)
    mov(lp + 2, 4)

def wait():
    """Wait for the next frame"""
    # Set the program counter behind an infinite loop
    ldpc(next(6) + 3)
    lp = tell()
    nop()
    jmp(lp)


# ==== MAIN FUNCTION ====

def assemble():
    """Write the actual byte code to the program"""
    global pos, size

    # Zeropage
    w2(0) # Keycodes
    w3(8 + len(NOTICE)) # Program counter
    w1(GFX) # Graphics pointer
    w2(0xFEFF) # Sound pointer

    fp.write(NOTICE)
    pos = pos + len(NOTICE)
    size = size + len(NOTICE)

    # Generate star positions
    stars = []
    for i in xrange(10):
        x, y = random.randint(0, 250), random.randint(0, 250)

        # Avoid placing stars on the rainbow
        while y >= 90 and y <= 160:
            y = random.randint(0, 250)

        # The third value is the frame number
        stars.append([x, y, random.randint(0, 3)])

    def frame(cat, rbow, xoff):
        """Draw a frame, xoff is the x-offset of the rainbow"""
        for x in xrange(0, 100, 17):
            ldspr(rbow, x + xoff, 118, W_RBOW, H_RBOW)

        ldspr(cat, 104, 118, W_CAT, H_CAT)

        for i, v in enumerate(stars):
            s = globals()["STAR" + str(v[2] + 1)]

            # Repeat the star animation
            v[2] = (v[2] + 1) % 4
            ldspr(s, v[0], v[1], W_STAR, H_STAR)

        # Wait four frames
        for i in xrange(4):
            wait()

    # Fill the graphics bank with the blue background color
    wfill(8)

    # Main loop
    lp = tell()
    frame(CAT1, RBOW1, 0)
    frame(CAT2, RBOW1, -1)
    frame(CAT3, RBOW2, 0)
    frame(CAT4, RBOW2, -1)
    jmp(lp)

    # Statically write the sprite data at the end of the program
    wspr(CAT1, SPR_CAT1)
    wspr(CAT2, SPR_CAT2)
    wspr(CAT3, SPR_CAT3)
    wspr(CAT4, SPR_CAT4)
    wspr(RBOW1, SPR_RBOW1)
    wspr(RBOW2, SPR_RBOW2)
    wspr(STAR1, SPR_STAR1)
    wspr(STAR2, SPR_STAR2)
    wspr(STAR3, SPR_STAR3)
    wspr(STAR4, SPR_STAR4)


# ==== SPRITE DATA ====

SPR_CAT1 =\
"eJyFkkEOhCAMRf+yN+A+XsETeSbdujUhLkg40fBbasGZZH4IUvpaW+A4mkQEb0nXYUJ5CxNA/z0q\
iIsiYI5ThxIjcKG4I3J8AS5A4QZopZUaAWwbLANX1l6tiBLathJFFw1oM+qcgVuwLzOoWW6vUh2u\
BixGeIZz8pNYjCjeJYHdqF2rTCkBkcFq1GmDA0RKNJHz84OcO5B41F5jAxjKQWCl0nBZ6F2iH5QC\
LCLueepSgSHo96PRk1gtYzflsaQ/N53DFon4P/oA1McQ/w=="
SPR_CAT2 =\
"eJx9kssNxCAMROdIB+knLaSi1LRcc42E9mCJitYe8zHZ1Y4QH83D2EDOOScVnkpN2QV5Cgtg/jtq\
EreKgBsXG4kA3DekGzPGFzAEGGyApVpVK4DzhEewGYFaMVMwwAgBJ6kCAWgR1AB8ZJgGXAHockDV\
I1yrr+bukWRUaeuXUzZg2+ywkANTY8dBAUMa4EWUMg4ohYAiIjNHBWyrNQUOFQFZz4AXinRQiM8d\
6tCrdn/s+f1rCLDzNfoF9V+VnJ07OAvf7q8+gSke8g=="
SPR_CAT3 =\
"eJxtkssNwyAQROdIB+nHLbgiakquXC2hHJBcUZhZPgvxCJnF89jlF0LVpyk8qHvYtQEou+CBi/7X\
axKXhO4nNREb0I2ZwwM3fAGAMAEu9ZY8gBhhGRhtQDKARIECA44tQzUA68MhCUgO6GoARoa0+pWg\
CwLJVXgbxa6XKssSbH3qLOwlbBM5jwI548UCJ496rLECnMpWgVPyl9Vy2kYRGuCv2+2jHrX8gPj3\
YJZXY6euz9OQfwTPKYps+AOAwicg"
SPR_CAT4 =\
"eJx1klEOhCAMROezN9j7eAVO5Jl2f/k1Ifth4om2MxWsxJ2gBeZRKGpm9jllT+omZk0A9llIwLbR\
/2ZdxCah+1VNxAR048qRgONA3gAgTIBHPaQMYF0RGdibgBoAiR3qCFiWKYMbQERbJAE1AV0BON0z\
1LvvBG0P+6iSwDsoBrxiq/12hDifQjx9iyiitbFBawJK4VWPMzrAWTYHCtwv+WPhrFKFwoqE/LlT\
HX7VtA1jzZ+/Rrn0ehpyRuy1Qr1z+AP+EyfK"
SPR_RBOW1 = "eJzbsgUCOKBgC7HgGBSg8wmCS1CAzicInKAAnU8QiEMBOp8gCIYCdD5BAAtNJD4AovGp0Q=="
SPR_RBOW2 = "eJzj4ICALVCAxCQOHIMCJCZx4BIUIDGJA05QgMQkDohDARKTOBAMBUhM4gA0cDmATADHO6nR"
SPR_STAR1 = "eJzj4OC4zoEOriOR6OIAd1UExQ=="
SPR_STAR2 = "eJzj4OC4zsEBIcAMDjgDhQtXBADIMQgB"
SPR_STAR3 = "eJzj4ICB60jU9esghCYIAQDIMQgB"
SPR_STAR4 = "eJzj4MAOruMQ5wAAOrACWA=="


# ==== ENTRY POINT ====

if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: {0} PATH".format(os.path.relpath(sys.argv[0])))
    else:
        fp = open(sys.argv[1], "wb")
        assemble()