png palette offset example

Author: thirdr

micropython/examples/pico_display/display_png_offset_palette.py

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+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)
+
+# 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