Merge 3aa4f170a8 into f1ea35fbbf

G/S/C Unicorn: Fix get_brightness to use correct max value.

libraries/cosmic_unicorn/cosmic_unicorn.cpp

@@ -494,11 +494,14 @@ namespace pimoroni {
   void CosmicUnicorn::set_brightness(float value) {
     value = value < 0.0f ? 0.0f : value;
     value = value > 1.0f ? 1.0f : value;
+    // Max brightness is - in fact - 256 since it's applied with:
+    // result = (channel * brightness) >> 8
+    // eg: (255 * 256) >> 8 == 255
     this->brightness = floor(value * 256.0f);
   }
 
   float CosmicUnicorn::get_brightness() {
-    return this->brightness / 255.0f;
+    return this->brightness / 256.0f;
   }
 
   void CosmicUnicorn::adjust_brightness(float delta) {

libraries/galactic_unicorn/galactic_unicorn.cpp

@@ -488,11 +488,14 @@ namespace pimoroni {
   void GalacticUnicorn::set_brightness(float value) {
     value = value < 0.0f ? 0.0f : value;
     value = value > 1.0f ? 1.0f : value;
+    // Max brightness is - in fact - 256 since it's applied with:
+    // result = (channel * brightness) >> 8
+    // eg: (255 * 256) >> 8 == 255
     this->brightness = floor(value * 256.0f);
   }
 
   float GalacticUnicorn::get_brightness() {
-    return this->brightness / 255.0f;
+    return this->brightness / 256.0f;
   }
 
   void GalacticUnicorn::adjust_brightness(float delta) {

libraries/stellar_unicorn/stellar_unicorn.cpp

@@ -485,11 +485,14 @@ namespace pimoroni {
   void StellarUnicorn::set_brightness(float value) {
     value = value < 0.0f ? 0.0f : value;
     value = value > 1.0f ? 1.0f : value;
+    // Max brightness is - in fact - 256 since it's applied with:
+    // result = (channel * brightness) >> 8
+    // eg: (255 * 256) >> 8 == 255
     this->brightness = floor(value * 256.0f);
   }
 
   float StellarUnicorn::get_brightness() {
-    return this->brightness / 255.0f;
+    return this->brightness / 256.0f;
   }
 
   void StellarUnicorn::adjust_brightness(float delta) {

micropython/examples/inky_frame/display_png.py

@@ -0,0 +1,36 @@
+from picographics import PicoGraphics, DISPLAY_INKY_FRAME as DISPLAY      # 5.7"
+# from picographics import PicoGraphics, DISPLAY_INKY_FRAME_4 as DISPLAY  # 4.0"
+# from picographics import PicoGraphics, DISPLAY_INKY_FRAME_7 as DISPLAY  # 7.3"
+import pngdec
+
+# Create a PicoGraphics instance
+graphics = PicoGraphics(DISPLAY)
+WIDTH, HEIGHT = graphics.get_bounds()
+
+# Set the font
+graphics.set_font("bitmap8")
+
+# Create an instance of the PNG Decoder
+png = pngdec.PNG(graphics)
+
+# Clear the screen
+graphics.set_pen(1)
+graphics.clear()
+graphics.set_pen(0)
+
+# Few lines of text.
+graphics.text("PNG Pencil", 70, 100, WIDTH, 3)
+
+# Open our PNG File from flash. In this example we're using a cartoon pencil.
+# You can use Thonny to transfer PNG Images to your Inky Frame.
+try:
+    png.open_file("pencil_256x256.png")
+
+    # Decode our PNG file and set the X and Y
+    png.decode(200, 100)
+
+except OSError:
+    graphics.text("Unable to find PNG file! Copy 'pencil_256x256.png' to your Inky Frame using Thonny :)", 10, 70, WIDTH, 3)
+
+# Start the screen update
+graphics.update()

micropython/examples/pico_display/display_png.py

@@ -0,0 +1,40 @@
+from picographics import PicoGraphics, DISPLAY_PICO_DISPLAY, PEN_RGB332
+import pngdec
+
+# Create a PicoGraphics instance
+display = PicoGraphics(display=DISPLAY_PICO_DISPLAY, pen_type=PEN_RGB332)
+
+# Set the backlight so we can see it!
+display.set_backlight(1.0)
+
+# Create an instance of the PNG Decoder
+png = pngdec.PNG(display)
+
+# Create some pens for use later.
+BG = display.create_pen(200, 200, 200)
+TEXT = display.create_pen(0, 0, 0)
+
+# Clear the screen
+display.set_pen(BG)
+display.clear()
+
+display.set_pen(TEXT)
+display.text("PNG Pencil", 15, 80)
+
+try:
+    # Open our PNG File from flash. In this example we're using an image of a cartoon pencil.
+    # You can use Thonny to transfer PNG Images to your Pico.
+    png.open_file("pencil.png")
+
+    # Decode our PNG file and set the X and Y
+    png.decode(20, 100, scale=3)
+
+# Handle the error if the image doesn't exist on the flash.
+except OSError:
+    print("Error: PNG File missing. Copy the PNG file from the example folder to your Pico using Thonny and run the example again.")
+
+display.update()
+
+# We're not doing anything else with the display now but we want to keep the program running!
+while True:
+    pass

micropython/examples/pico_display/display_png_offset_palette.py

@@ -0,0 +1,54 @@
+from picographics import PicoGraphics, DISPLAY_PICO_DISPLAY, PEN_P8
+import pngdec
+
+# Create a PicoGraphics instance
+display = PicoGraphics(display=DISPLAY_PICO_DISPLAY, pen_type=PEN_P8, rotate=270)
+
+# Set the backlight so we can see it!
+display.set_backlight(1.0)
+
+# Create an instance of the PNG Decoder
+png = pngdec.PNG(display)
+
+# Create some pens for use later.
+BG = display.create_pen(200, 200, 200)
+
+# 16 Reds
+for i in range(16):
+    display.create_pen(i * 16, 0, 0)
+
+# 16 Greens
+for i in range(16):
+    display.create_pen(0, i * 16, 0)
+
+# 16 Blues
+for i in range(16):
+    display.create_pen(0, 0, i * 16)
+
+# Adding in an white background colour at the beginning of each offset.
+for i in range(3):
+    display.update_pen(i * 16, 200, 200, 200)
+
+# Clear the screen
+display.set_pen(BG)
+display.clear()
+
+try:
+    # Open our PNG File from flash. In this example we're using an image of a cartoon pencil.
+    # You can use Thonny to transfer PNG Images to your Pico.
+    png.open_file("pencil_gray.png")
+
+    # Decode our PNG file and set the X and Y
+    png.decode(35, 10, scale=2, mode=pngdec.PNG_COPY, palette_offset=0)
+    png.decode(35, 90, scale=2, mode=pngdec.PNG_COPY, palette_offset=16)
+    png.decode(35, 170, scale=2, mode=pngdec.PNG_COPY, palette_offset=32)
+
+# Handle the error if the image doesn't exist on the flash.
+except OSError:
+    print("Error: PNG File missing. Copy the PNG file from the example folder to your Pico using Thonny and run the example again.")
+
+display.update()
+
+# We're not doing anything else with the display now but we want to keep the program running!
+while True:
+    pass

micropython/examples/tufty2040/display_png.py

@@ -0,0 +1,36 @@
+from picographics import PicoGraphics, DISPLAY_TUFTY_2040
+import pngdec
+
+display = PicoGraphics(display=DISPLAY_TUFTY_2040)
+
+# Create an instance of the PNG Decoder
+png = pngdec.PNG(display)
+
+# Create some pens for use later.
+BG = display.create_pen(200, 200, 200)
+TEXT = display.create_pen(0, 0, 0)
+
+# Clear the screen
+display.set_pen(BG)
+display.clear()
+
+display.set_pen(TEXT)
+display.text("PNG Pencil", 105, 80)
+
+try:
+    # Open our PNG File from flash. In this example we're using an image of a cartoon pencil.
+    # You can use Thonny to transfer PNG Images to your Pico.
+    png.open_file("pencil.png")
+
+    # Decode our PNG file and set the X and Y
+    png.decode(140, 100)
+
+# Handle the error if the image doesn't exist on the flash.
+except OSError:
+    print("Error: PNG File missing. Copy the PNG file from the example folder to your Pico using Thonny and run the example again.")
+
+display.update()
+
+# We're not doing anything else with the display now but we want to keep the program running!
+while True:
+    pass

micropython/examples/tufty2040/display_png_offset_palette.py

@@ -0,0 +1,54 @@
+from picographics import PicoGraphics, DISPLAY_TUFTY_2040, PEN_P8
+import pngdec
+
+display = PicoGraphics(display=DISPLAY_TUFTY_2040, pen_type=PEN_P8)
+
+# Create an instance of the PNG Decoder
+png = pngdec.PNG(display)
+
+# Create some pens for use later.
+BG = display.create_pen(200, 200, 200)
+TEXT = display.create_pen(0, 0, 0)
+
+# 16 Reds
+for i in range(15):
+    display.create_pen(i * 16, 0, 0)
+
+# 16 Greens
+for i in range(16):
+    display.create_pen(0, i * 16, 0)
+
+# 16 Blues
+for i in range(15):
+    display.create_pen(0, 0, i * 16)
+
+# Adding in an white background colour at the beginning of each offset.
+for i in range(3):
+    display.update_pen(i * 16, 200, 200, 200)
+
+# Clear the screen
+display.set_pen(BG)
+display.clear()
+
+display.set_pen(TEXT)
+display.text("PNG Pencil \n& Offset Palette", 125, 115)
+
+try:
+    # Open our PNG File from flash. In this example we're using an image of a cartoon pencil.
+    # You can use Thonny to transfer PNG Images to your Pico.
+    png.open_file("pencil_gray.png")
+
+    # Decode our PNG file and set the X and Y
+    png.decode(35, 10, scale=2, mode=pngdec.PNG_COPY, palette_offset=0)
+    png.decode(35, 90, scale=2, mode=pngdec.PNG_COPY, palette_offset=16)
+    png.decode(35, 170, scale=2, mode=pngdec.PNG_COPY, palette_offset=32)
+
+# Handle the error if the image doesn't exist on the flash.
+except OSError:
+    print("Error: PNG File missing. Copy the PNG file from the example folder to your Pico using Thonny and run the example again.")
+
+display.update()
+
+# We're not doing anything else with the display now but we want to keep the program running!
+while True:
+    pass

micropython/modules/picographics/README.md

@@ -583,3 +583,42 @@ The arguments for `decode` are as follows:
 2. Decode Y
 3. Flags - one of `JPEG_SCALE_FULL`, `JPEG_SCALE_HALF`, `JPEG_SCALE_QUARTER` or `JPEG_SCALE_EIGHTH`
 4. If you want to turn off dither altogether, try `dither=False`. This is useful if you want to [pre-dither your images](https://ditherit.com/) or for artsy posterization effects.
+
+### PNG Files
+
+We've included BitBank's PNGDEC - https://github.com/bitbank2/PNGDEC - so you can display PNG files on your LCDs.
+
+Eg:
+
+```python
+import picographics
+import pngdec
+
+display = PicoGraphics(display=DISPLAY_PICO_DISPLAY, pen_type=PEN_RGB332)
+
+# Create a new PNG decoder for our PicoGraphics
+png = pngdec.PNG(display)
+
+# Open the PNG file
+png.open_file("filename.jpeg")
+
+# Decode the PNG
+png.decode(0, 0)
+
+# Display the result
+display.update()
+```
+
+PNG files must be small enough to load into RAM for decoding.
+
+PNGDEC Supports the following PNG types:
+
+1. True Colour
+2. True Colour (with Alpha)
+3. Indexed
+4. Grayscale
+
+The arguments for `decode` are as follows:
+
+1. Decode X - where to place the decoded JPEG on screen
+2. Decode Y