Image regress tests.

regress/image-sixel-transparency.sh

@@ -0,0 +1,54 @@
+#!/bin/sh
+
+# Transparent overlap preserves underlying pixels; opaque background modes
+# replace them. Check positions, redraws, resize and erasing stacked images.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export TERM
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+python3 -B - "$TEST_TMUX" <<'PY'
+import sys
+from image_test import image_test, sixel
+from image_terminal import Terminal
+
+w, h = 24, 32
+holes = [None if x // 8 == 1 and y < 16 or (x + y) % 3 == 0 else 0
+    for y in range(h) for x in range(w)]
+base = sixel(w, h, [(100, 0, 0)], [0] * (w * h))
+
+for p2 in (0, 1, 2):
+    with image_test(sys.argv[1]) as test:
+        client = test.attach()
+        test.emit(b'\033[3;3H' + base + b'\033[3;3H' +
+            sixel(w, h, [(0, 0, 100)], holes, p2=p2))
+        background = (255, 0, 0) if p2 == 1 else (0, 0, 0)
+        expected = {(x + 16, y + 32): (0, 0, 255)
+            if holes[y * w + x] == 0 else background
+            for y in range(h) for x in range(w)}
+        for width in (40, 4, 40):
+            test.resize(client, width, 16)
+            test.redraw()
+            terminal = Terminal(sx=width)
+            terminal.feed(client.data)
+            terminal.check({point: c for point, c in expected.items()
+                if point[0] < width * 8})
+        # One erase must remove the same cell from every overlapping placement.
+        test.emit(b'\033[3;3H\033[X')
+        terminal.feed(client.data)
+        expected = {point: c for point, c in expected.items()
+            if not (16 <= point[0] < 24 and 32 <= point[1] < 48)}
+        terminal.check(expected)
+        test.redraw()
+        terminal = Terminal()
+        terminal.feed(client.data)
+        terminal.check(expected)
+
+with image_test(sys.argv[1]) as test:
+    client = test.attach()
+    test.emit(sixel(24, 32, [(100, 0, 0)], [None] * (24 * 32)))
+    assert not client.images(), 'fully transparent image produced output'
+    test.redraw()
+    assert not client.images(), 'fully transparent image survived redraw'
+PY