# The Bitmap class represents a 24-bit bitmap image. An instance can be constructed
# by calling load or with_size:
#
-# new Bitmap.load(path_to_a_bmp_file)
-# new Bitmap.with_size(400, 300)
+# ~~~nitish
+# var bm1 = new Bitmap.load(path_to_a_bmp_file)
+# var bm2 = new Bitmap.with_size(400, 300)
+# ~~~
#
# The width and height attributes contain the image's width and height,
# respectively.
#
# Individual pixels can be manipulated by calling the set_pixel function:
#
+# ~~~nitish
# set_pixel(x, y, color)
+# ~~~
#
# The no-argument grayscale function converts the bitmap to grayscale and is an
# implementation of this Rossetacode task:
#
# Finally, the bitmap can be saved to a file by calling save:
#
+# ~~~nitish
# save(path_to_a_file)
+# ~~~
#
# For information on the bitmap format, see
# http://en.wikipedia.org/wiki/BMP_file_format
private var image_size: Int is noinit
# 14-byte bitmap header
- private var bitmap_header: Array[Int] = [66, 77, 0, 0, 0, 0, 0, 0, 0, 0, 54, 0, 0, 0]
+ private var bitmap_header = [66, 77, 0, 0, 0, 0, 0, 0, 0, 0, 54, 0, 0, 0]
# 40-byte dib header
- private var dib_header: Array[Int] = [40, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ private var dib_header = [40, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 1, 0, 24, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
# =============== Bitmap header ================
for x in [0..13] do
- bitmap_header[x] = fileReader.read(1)[0].ascii
+ var b = fileReader.read_byte
+ if b < 0 then return
+ bitmap_header[x] = b
end
self.file_size = get_value(bitmap_header.subarray(2, 4))
self.data_offset = get_value(bitmap_header.subarray(10, 4))
# =============== DIB header ================
for x in [0..39] do
- dib_header[x] = fileReader.read(1)[0].ascii
+ var b = fileReader.read_byte
+ if b < 0 then return
+ dib_header[x] = b
end
var dib_size = get_value(dib_header.subarray(0, 4))
# only support BITMAPINFOHEADER
for x in [0..self.height[
do
var row = new Array[Int].with_capacity(self.width)
+ var rgb_str = new CString(3)
for y in [0..self.width[
do
- var red = fileReader.read(1)[0].ascii * 256 * 256
- var green = fileReader.read(1)[0].ascii * 256
- var blue = fileReader.read(1)[0].ascii
- row.add(red + green + blue)
+ var bts = fileReader.read_bytes_to_cstring(rgb_str, 3)
+ if bts < 3 then return
+ var red = rgb_str[0] << 16
+ var green = rgb_str[1] << 8
+ var blue = rgb_str[2]
+ row.add(red.to_i + green.to_i + blue.to_i)
end
self.data.add(row)
end
fileReader.close
end #end of load_from_file method
- # Reads in a series of bytes from the FileReader when loading a Bitmap from a file
- # FileReader.read(1) is used due to https://github.com/privat/nit/issues/1264
- private fun read_chars(fr: FileReader, howMany: Int): String
- do
- var s = ""
- for x in [1..howMany]
- do
- s += fr.read(1)
- end
- return s
- end
-
# Converts the value contained in two or four bytes into an Int. Since Nit
# does not have a byte type, Int is used
private fun get_value(array: Array[Int]): Int
# type, Int is used.
private fun set_value(array: Array[Int], start_index: Int, value: Int)
do
- array[start_index] = value.bin_and(0x000000FF)
- array[start_index + 1] = value.rshift(8).bin_and(0x000000FF)
- array[start_index + 2] = value.rshift(16).bin_and(0x000000FF)
- array[start_index + 3] = value.rshift(24).bin_and(0x000000FF)
+ array[start_index] = value & 0x000000FF
+ array[start_index + 1] = (value >> 8) & 0x000000FF
+ array[start_index + 2] = (value >> 16) & 0x000000FF
+ array[start_index + 3] = (value >> 24) & 0x000000FF
end
# Saves the bitmap into a file
var fw = new FileWriter.open(path)
# Write bitmap header
for x in [0..self.bitmap_header.length[ do
- fw.write(self.bitmap_header[x].ascii.to_s)
+ fw.write(self.bitmap_header[x].code_point.to_s)
end
# Write dib header
for x in [0..self.dib_header.length[ do
- fw.write(self.dib_header[x].ascii.to_s)
+ fw.write(self.dib_header[x].code_point.to_s)
end
# Write color table (if any)
# Write data (no padding for now)
var row = self.data[x]
for y in [0..self.width[ do
var pixel = row[y]
- var red = pixel.rshift(16)
- var green = pixel.bin_and(0x00FF00).rshift(8)
- var blue = pixel.bin_and(0x000000FF)
- fw.write(red.ascii.to_s)
- fw.write(green.ascii.to_s)
- fw.write(blue.ascii.to_s)
+ var red = pixel >> 16
+ var green = (pixel & 0x00FF00) >> 8
+ var blue = pixel & 0x000000FF
+ fw.write(red.code_point.to_s)
+ fw.write(green.code_point.to_s)
+ fw.write(blue.code_point.to_s)
end
end
fw.close
var row = self.data[x]
for y in [0..self.width[ do
var pixel = row[y]
- var red = pixel.rshift(16)
- var green = pixel.bin_and(0x00FF00).rshift(8)
- var blue = pixel.bin_and(0x000000FF)
+ var red = pixel >> 16
+ var green = (pixel & 0x00FF00) >> 8
+ var blue = pixel & 0x000000FF
var lum = (0.2126 * red.to_f + 0.7152 * green.to_f + 0.0722 * blue.to_f).to_i
pixel = lum * 256 * 256 + lum * 256 + lum
self.data[x][y] = pixel
nitlanguage / nit.git / blobdiff