tests/extmod/framebuf4: Add tests for GS4_HMSB framebuf format.

tests/extmod/framebuf4.py

@@ -0,0 +1,54 @@
+try:
+    import framebuf
+except ImportError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+def printbuf():
+    print("--8<--")
+    for y in range(h):
+        print(buf[y * w // 2:(y + 1) * w // 2])
+    print("-->8--")
+
+w = 16
+h = 8
+buf = bytearray(w * h // 2)
+fbuf = framebuf.FrameBuffer(buf, w, h, framebuf.GS4_HMSB)
+
+# fill
+fbuf.fill(0x0f)
+printbuf()
+fbuf.fill(0xa0)
+printbuf()
+
+# put pixel
+fbuf.pixel(0, 0, 0x01)
+printbuf()
+fbuf.pixel(w-1, 0, 0x02)
+printbuf()
+fbuf.pixel(w-1, h-1, 0x03)
+printbuf()
+fbuf.pixel(0, h-1, 0x04)
+printbuf()
+
+# get pixel
+print(fbuf.pixel(0, 0), fbuf.pixel(w-1, 0), fbuf.pixel(w-1, h-1), fbuf.pixel(0, h-1))
+print(fbuf.pixel(1, 0), fbuf.pixel(w-2, 0), fbuf.pixel(w-2, h-1), fbuf.pixel(1, h-1))
+
+# fill rect
+fbuf.fill_rect(0, 0, w, h, 0x0f)
+printbuf()
+fbuf.fill_rect(0, 0, w, h, 0xf0)
+fbuf.fill_rect(1, 0, w//2+1, 1, 0xf1)
+printbuf()
+fbuf.fill_rect(1, 0, w//2+1, 1, 0x10)
+fbuf.fill_rect(1, 0, w//2, 1, 0xf1)
+printbuf()
+fbuf.fill_rect(1, 0, w//2, 1, 0x10)
+fbuf.fill_rect(0, h-4, w//2+1, 4, 0xaf)
+printbuf()
+fbuf.fill_rect(0, h-4, w//2+1, 4, 0xb0)
+fbuf.fill_rect(0, h-4, w//2, 4, 0xaf)
+printbuf()
+fbuf.fill_rect(0, h-4, w//2, 4, 0xb0)