Create framebuf.md

content/firmwareapi/micropython/framebuf.md

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+---
+title: "Framebuf"
+---
+
+Frame buffer manipulation
+
+Quick example:
+```python
+import framebuf
+fbuf = framebuf.FrameBuffer(bytearray(10*100*2), 10, 100, framebuf.RGB565)
+
+fbuf.fill(0)
+fbuf.text('Pycom!', 10,10, 0xffff)
+fbuf.hline(0, 20, 96, 0xffff)
+
+```
+
+## Constructor
+
+### framebuf.FrameBuffer(buffer, width, height, format [, stride=width])
+
+Constructs a FrameBuffer object with parameters
+* `framebuffer`: A bytearray object large enough to contain every pixel
+* `width`: The width of the FrameBuffer in pixels
+* `height`: The height of the FrameBuffer in pixels
+* `format`: The type of pixel used in the Framebuffer and can be one of the following constants:
+    * `framebuf.GS2_HMSB`: 2-bt grayscale
+    * `framebuf.GS4_HMSB`: 4-bit grayscale
+    * `framebuf.GS8`: 8-bit grayscale
+    * `framebuf.MONO_HLSB`: monochrome, horizontally mapped, LSB
+    * `framebuf.MONO_HMSB`: monochrome, horizontally mapped, MSB
+    * `framebuf.MONO_VLSB`: monochrhome, vertically mapped, LSB
+    * `framebuf.MVLSB`: Same as `MONO_VLSB`
+    * `framebuf.RGB565`: 16-bit RGB color (5 bits red, 6 bits blue, 5 buts green)
+* `stride`: The number of pixels between each horizontal line of pixels in the FrameBuffer.
+
+
+The coordinates in the following methods are defined with `(0, 0)` in the upper left-hand corner, with `x` on the horizontal axis, and `y` on the vertical axis.
+The color arguments is a small int that depends the `format` color order. 
+
+### framebuf.FrameBuffer1(buffer, width, height, format)
+
+Provides compatibility with the legacy FrameBuffer class. 
+
+## Methods
+
+### fbuf.fill(c)
+
+Fills the entire FrameBuffer with the specified color
+
+### fbuf.pixel(x, y [, c])
+
+Gets or sets the color at the specified pixel. 
+
+### fbuf.hline(x, y, w, c)
+
+Draws a 1-pixel wide horizontal line starting at `x, y` with width `w` and color `c`
+
+### fbuf.vline(x, y, h, c)
+
+Draws a 1-pixel wide vertical line starting at `x, y` with height `h` and color `c`
+
+### fbuf.line(x1, y1, x2, y2, c)
+
+Draws a 1-pixel wide line starting at `x1, y1` to `x2, y2` with color `c`
+
+### fbuf.rect(x, y, w, y, c)
+
+Draws a 1-pixel rectangle outline with starting corner `x, y`, width `w`, height `h` and color `c`
+
+### fbuf.fill_rect(x, y, w, h, c)
+
+Draws a colored rectangle with starting corner `x, y`, width `w`, height `h` and color `c`
+
+### fbuf.text(s, x, y, [, c = 1])
+
+Write text to the FrameBuffer with characters of 8 by 8 pixels, with `x, y` in the top left hand corner and `c` as the color.
+At the moment, it is not possible to change either the font, or its size.
+
+### fbuf.scroll(xstep, ystep)
+
+Shifts the contents of the FrameBuffer by the given step size in x and y. The pixels will **not** roll around to the other side.
+
+### fbuf.blit(fbuf, x, y [, key])
+
+Draw another FrameBuffer on top of the current one at the given coordinates. If a `key` is specified, the passed FrameBuffer will be considered transparent for that color. All pixels of that color will not be drawn. 
+
+## Constants
+format: `GS2_HMSB`, `GS4_HMSB`, `GS8`, `MONO_HLSB`, `MONO_HMSB`, `MONO_VLSB`, `MVLSB`, `RGB565`