adding touchpaint example

examples/touchpaint_example.py

@@ -0,0 +1,94 @@
+# SPDX-FileCopyrightText: 2023 Liz Clark for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+"""
+Touch paint example for HX83570 + FT5336 TFT Breakout
+"""
+
+import board
+import displayio
+import adafruit_ft5336
+from adafruit_hx8357 import HX8357
+
+displayio.release_displays()
+
+spi = board.SPI()
+tft_cs = board.TX
+tft_dc = board.RX
+
+display_bus = displayio.FourWire(spi, command=tft_dc, chip_select=tft_cs)
+# display is rotated to align x, y with touch screen x, y
+display = HX8357(display_bus, width=320, height=480, rotation=90)
+
+i2c = board.I2C()  # uses board.SCL and board.SDA
+touch = adafruit_ft5336.Adafruit_FT5336(i2c)
+
+pixel_size = 10
+palette_width = 45
+palette_height = 320 // 8
+
+splash = displayio.Group()
+display.root_group = splash
+
+bitmap = displayio.Bitmap(320, 480, 8)
+color_palette = displayio.Palette(8)
+color_palette[0] = 0x000000
+color_palette[1] = 0xFF0000
+color_palette[2] = 0xFFFF00
+color_palette[3] = 0x00FF00
+color_palette[4] = 0x00FFFF
+color_palette[5] = 0x0000FF
+color_palette[6] = 0xFF00FF
+color_palette[7] = 0xFFFFFF
+
+tile_grid = displayio.TileGrid(
+    bitmap,
+    pixel_shader=color_palette
+
+)
+# tilegrid is flipped to align x, y with touch screen x, y
+tile_grid.flip_y = True
+tile_grid.flip_x = True
+
+splash.append(tile_grid)
+
+display.root_group = splash
+
+current_color = 7
+
+for i in range(palette_width):
+    for j in range(palette_height):
+        bitmap[j + palette_height, i] = 1
+        bitmap[j + palette_height * 2, i] = 2
+        bitmap[j + palette_height * 3, i] = 3
+        bitmap[j + palette_height * 4, i] = 4
+        bitmap[j + palette_height * 5, i] = 5
+        bitmap[j + palette_height * 6, i] = 6
+        bitmap[j + palette_height * 7, i] = 0
+
+while True:
+    if touch.touched:
+        try:
+            for t in touch.points:
+                x = t[0]
+                y = t[1]
+                print(x, y)
+                if (
+                    not 0 <= x < display.width
+                    or not 0 <= y < display.height
+                ):
+                    continue  # Skip out of bounds touches
+                if y < palette_width:
+                    current_color = bitmap[x, y]
+                else:
+                    for i in range(pixel_size):
+                        for j in range(pixel_size):
+                            x_pixel = x - (pixel_size // 2) + i
+                            y_pixel = y - (pixel_size // 2) + j
+                            if (
+                                0 <= x_pixel < display.width
+                                and 0 <= y_pixel < display.height
+                            ):
+                                bitmap[x_pixel, y_pixel] = current_color
+        except RuntimeError:
+            pass