Remove GIF support

Author: deshipu

stage.py

@@ -1,6 +1,5 @@
 import time
 import array
-import digitalio
 import struct
 try:
     import zlib
@@ -155,8 +154,6 @@ def __init__(self, filename):
         self.colors = 0
 
     def read_header(self):
-        """Read the file's header information."""
-
         if self.colors:
             return
         with open(self.filename, 'rb') as f:
@@ -168,10 +165,9 @@ def read_header(self):
             f.seek(46)
             self.colors = int.from_bytes(f.read(4), 'little')
 
-    def read_palette(self):
-        """Read the color palette information."""
-
-        palette = array.array('H', (0 for i in range(16)))
+    def read_palette(self, palette=None):
+        if palette is None:
+            palette = array.array('H', (0 for i in range(16)))
         with open(self.filename, 'rb') as f:
             f.seek(self.data - self.colors * 4)
             for color in range(self.colors):
@@ -181,7 +177,6 @@ def read_palette(self):
         return palette
 
     def read_data(self, buffer=None):
-        """Read the image data."""
         line_size = self.width >> 1
         if buffer is None:
             buffer = bytearray(line_size * self.height)
@@ -196,143 +191,6 @@ def read_data(self, buffer=None):
         return buffer
 
 
-def read_blockstream(f):
-    while True:
-        size = f.read(1)[0]
-        if size == 0:
-            break
-        for i in range(size):
-            yield f.read(1)[0]
-
-
-class EndOfData(Exception):
-    pass
-
-
-class LZWDict:
-    def __init__(self, code_size):
-        self.code_size = code_size
-        self.clear_code = 1 << code_size
-        self.end_code = self.clear_code + 1
-        self.codes = []
-        self.clear()
-
-    def clear(self):
-        self.last = b''
-        self.code_len = self.code_size + 1
-        self.codes[:] = []
-
-    def decode(self, code):
-        if code == self.clear_code:
-            self.clear()
-            return b''
-        elif code == self.end_code:
-            raise EndOfData()
-        elif code < self.clear_code:
-            value = bytes([code])
-        elif code <= len(self.codes) + self.end_code:
-            value = self.codes[code - self.end_code - 1]
-        else:
-            value = self.last + self.last[0:1]
-        if self.last:
-            self.codes.append(self.last + value[0:1])
-        if (len(self.codes) + self.end_code + 1 >= 1 << self.code_len and
-            self.code_len < 12):
-                self.code_len += 1
-        self.last = value
-        return value
-
-
-def lzw_decode(data, code_size):
-    dictionary = LZWDict(code_size)
-    bit = 0
-    try:
-        byte = next(data)
-        try:
-            while True:
-                code = 0
-                for i in range(dictionary.code_len):
-                    code |= ((byte >> bit) & 0x01) << i
-                    bit += 1
-                    if bit >= 8:
-                        bit = 0
-                        byte = next(data)
-                yield dictionary.decode(code)
-        except EndOfData:
-            while True:
-                next(data)
-    except StopIteration:
-        return
-
-
-class GIF16:
-    """Read 16-color GIF files."""
-
-    def __init__(self, filename):
-        self.filename = filename
-
-    def read_header(self):
-        with open(self.filename, 'rb') as f:
-            header = f.read(6)
-            if header not in {b'GIF87a', b'GIF89a'}:
-                raise ValueError("Not GIF file")
-            self.width, self.height, flags, self.background, self.aspect = (
-                struct.unpack('<HHBBB', f.read(7)))
-            self.palette_size = 1 << ((flags & 0x07) + 1)
-        if not flags & 0x80:
-            raise NotImplementedError()
-        if self.palette_size > 16:
-            raise ValueError("Too many colors (%d/16)." % self.palette_size)
-
-    def read_palette(self):
-        palette = array.array('H', (0 for i in range(16)))
-        with open(self.filename, 'rb') as f:
-            f.seek(13)
-            for color in range(self.palette_size):
-                buffer = f.read(3)
-                c = color565(buffer[0], buffer[1], buffer[2])
-                palette[color] = ((c << 8) | (c >> 8)) & 0xffff
-        return palette
-
-    def read_data(self, buffer=None):
-        line_size = (self.width + 1) >> 1
-        if buffer is None:
-            buffer = bytearray(line_size * self.height)
-        with open(self.filename, 'rb') as f:
-            f.seek(13 + self.palette_size * 3)
-            while True: # skip to first frame
-                block_type = f.read(1)[0]
-                if block_type == 0x2c:
-                    break
-                elif block_type == 0x21: # skip extension
-                    extension_type = f.read(1)[0]
-                    while True:
-                        size = f.read(1)[0]
-                        if size == 0:
-                            break
-                        f.seek(1, size)
-                elif block_type == 0x3b:
-                    raise NotImplementedError()
-            x, y, w, h, flags = struct.unpack('<HHHHB', f.read(9))
-            if (flags & 0x80 or flags & 0x40 or
-                    w != self.width or h != self.height or x != 0 or y != 0):
-                raise NotImplementedError()
-            min_code_size = f.read(1)[0]
-            x = 0
-            y = 0
-            for decoded in lzw_decode(read_blockstream(f), min_code_size):
-                for pixel in decoded:
-                    if x & 0x01:
-                        buffer[(x >> 1) + y * line_size] |= pixel
-                    else:
-                        buffer[(x >> 1) + y * line_size] = pixel << 4
-                    x += 1
-                    if (x >= self.width):
-                        x = 0
-                        y += 1
-        return buffer
-
-
 class PNG16:
     """Read 16-color PNG files."""
 
@@ -564,6 +422,7 @@ def __init__(self, width, height, font=None, palette=None, buffer=None):
 
     def char(self, x, y, c=None, hightlight=False):
         """Get or set the character at the given location."""
+
         if not 0 <= x < self.width or not 0 <= y < self.height:
             return
         if c is None:
@@ -575,6 +434,7 @@ def char(self, x, y, c=None, hightlight=False):
 
     def move(self, x, y, z=None):
         """Shift the whole layer respective to the screen."""
+
         self.x = x
         self.y = y
         if z is not None:
@@ -583,6 +443,7 @@ def move(self, x, y, z=None):
 
     def cursor(self, x=None, y=None):
         """Move the text cursor to the specified row and column."""
+
         if y is not None:
             self.row = min(max(0, y), self.width - 1)
         if x is not None:
@@ -593,6 +454,7 @@ def text(self, text, hightlight=False):
         Display text starting at the current cursor location.
         Return the dimensions of the rendered text.
         """
+
         longest = 0
         tallest = 0
         for c in text:
@@ -612,6 +474,7 @@ def text(self, text, hightlight=False):
 
     def clear(self):
         """Clear all text from the layer."""
+
         for i in range(self.width * self.height):
             self.buffer[i] = 0
 
@@ -647,6 +510,7 @@ def __init__(self, display, fps=6, scale=None):
 
     def tick(self):
         """Wait for the start of the next frame."""
+
         self.last_tick += self.tick_delay
         wait = max(0, self.last_tick - time.monotonic())
         if wait:
@@ -656,6 +520,7 @@ def tick(self):
 
     def render_block(self, x0=None, y0=None, x1=None, y1=None):
         """Update a rectangle of the screen."""
+
         if x0 is None:
             x0 = self.vx
         if y0 is None:
@@ -676,6 +541,7 @@ def render_block(self, x0=None, y0=None, x1=None, y1=None):
 
     def render_sprites(self, sprites):
         """Update the spots taken by all the sprites in the list."""
+
         layers = [l.layer for l in self.layers]
         for sprite in sprites:
             x = int(sprite.x) - self.vx