starting bitmaptools implementation

[hackapet/Adafruit_Blinka_Displayio.git] / bitmaptools / __init__.py

diff --git a/bitmaptools/__init__.py b/bitmaptools/__init__.py
new file mode 100644 (file)
index 0000000..10b1f9f
--- /dev/null
+++ b/bitmaptools/__init__.py
@@ -0,0 +1,122 @@
+from displayio import Bitmap
+import circuitpython_typing
+
+def fill_region(dest_bitmap: Bitmap, x1: int, y1: int, x2: int, y2: int, value: int):
+    for y in range(y1, y2):
+        for x in range(x1, x2):
+            dest_bitmap[x,y] = value
+
+def draw_line(dest_bitmap: Bitmap, x1: int, y1: int, x2: int, y2: int, value: int):
+    dx = abs(x2 - x1)
+    sx = 1 if x1 < x2 else -1
+    dy = -abs(y2 - y1)
+    sy = 1 if y1 < y2 else -1
+    error = dx + dy
+
+    while True:
+        dest_bitmap[x1, y1] = value
+        if x1 == x2 and y1 == y2:
+            break
+        e2 = 2 * error
+        if e2 >= dy:
+            error += dy
+            x1 += sx
+        if e2 <= dx:
+            error += dx
+            y1 += sy
+
+def draw_circle(dest_bitmap: Bitmap, x: int, y: int, radius: int, value: int):
+    x = max(0, min(x, dest_bitmap.width - 1))
+    y = max(0, min(y, dest_bitmap.height - 1))
+
+    xb = 0
+    yb = radius
+    d = 3 - 2 * radius
+
+    # Bresenham's circle algorithm
+    while xb <= yb:
+        dest_bitmap[xb + x, yb + y] = value
+        dest_bitmap[-xb + x, -yb + y] = value
+        dest_bitmap[-xb + x, yb + y] = value
+        dest_bitmap[xb + x, -yb + y] = value
+        dest_bitmap[yb + x, xb + y] = value
+        dest_bitmap[-yb + x, xb + y] = value
+        dest_bitmap[-yb + x, -xb + y] = value
+        dest_bitmap[yb + x, -xb + y] = value
+
+        if d <= 0:
+            d = d + (4 * xb) + 6
+        else:
+            d = d + 4 * (xb - yb) + 10
+            yb = yb - 1
+        xb += 1
+
+
+def draw_polygon(dest_bitmap: Bitmap,
+                 xs: circuitpython_typing.ReadableBuffer,
+                 ys: circuitpython_typing.ReadableBuffer,
+                 value: int, close: bool | None = True):
+
+    if len(xs) != len(ys):
+        raise ValueError("Length of xs and ys must be equal.")
+
+    for i in range(len(xs)-1):
+        cur_point = (xs[i], ys[i])
+        next_point = (xs[i+1], ys[i+1])
+        print(f"cur: {cur_point}, next: {next_point}")
+        draw_line(dest_bitmap=dest_bitmap,
+                  x1=cur_point[0], y1=cur_point[1],
+                  x2=next_point[0], y2=next_point[1],
+                  value=value)
+
+    if close:
+        print(f"close: {(xs[0], ys[0])} - {(xs[-1], ys[-1])}")
+        draw_line(dest_bitmap=dest_bitmap,
+                  x1=xs[0], y1=ys[0],
+                  x2=xs[-1], y2=ys[-1],
+                  value=value)
+
+def blit(dest_bitmap: Bitmap, source_bitmap: Bitmap,
+         x: int, y: int, *,
+         x1: int = 0, y1: int = 0,
+         x2: int | None = None, y2: int | None = None,
+         skip_source_index: int | None = None,
+         skip_dest_index: int | None = None):
+
+    """Inserts the source_bitmap region defined by rectangular boundaries"""
+    # pylint: disable=invalid-name
+    if x2 is None:
+        x2 = source_bitmap.width
+    if y2 is None:
+        y2 = source_bitmap.height
+
+    # Rearrange so that x1 < x2 and y1 < y2
+    if x1 > x2:
+        x1, x2 = x2, x1
+    if y1 > y2:
+        y1, y2 = y2, y1
+
+    # Ensure that x2 and y2 are within source bitmap size
+    x2 = min(x2, source_bitmap.width)
+    y2 = min(y2, source_bitmap.height)
+
+    for y_count in range(y2 - y1):
+        for x_count in range(x2 - x1):
+            x_placement = x + x_count
+            y_placement = y + y_count
+
+            if (dest_bitmap.width > x_placement >= 0) and (
+                    dest_bitmap.height > y_placement >= 0
+            ):  # ensure placement is within target bitmap
+                # get the palette index from the source bitmap
+                this_pixel_color = source_bitmap[
+                    y1 + (y_count * source_bitmap.width) + x1 + x_count
+                ]
+
+                if (skip_source_index is None) or (this_pixel_color != skip_source_index):
+                    if (skip_dest_index is None) or (dest_bitmap[y_placement * dest_bitmap.width + x_placement] != skip_dest_index):
+                        dest_bitmap[  # Direct index into a bitmap array is speedier than [x,y] tuple
+                            y_placement * dest_bitmap.width + x_placement
+                        ] = this_pixel_color
+            elif y_placement > dest_bitmap.height:
+                break
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