1package vt
2
3import "github.com/bnema/vev/pkg/renderer"
4
5func (s *Screen) Resize(width, height int) {
6 if width == s.Frame.Width && height == s.Frame.Height {
7 return
8 }
9 if width <= 0 || height <= 0 {
10 // renderer.Frame permits a collapsed geometry. There is no layout to
11 // preserve until a usable viewport is supplied again.
12 width, height = max(width, 0), max(height, 0)
13 s.buffer = newBuffer(width, height)
14 s.Row, s.Col = 0, 0
15 if state := s.alternate; state != nil {
16 state.buffer = newBuffer(width, height)
17 state.frame = state.buffer.frame
18 state.row, state.col = 0, 0
19 state.scrollTop, state.scrollBottom = 0, height-1
20 }
21 } else {
22 resize := func(b *buffer, row, col int, saved *cursorState, evict bool) (int, int) {
23 active := &bufferCursor{row: row, col: col}
24 var savedPoint *bufferCursor
25 if saved != nil && saved.saved {
26 savedPoint = &bufferCursor{row: saved.row, col: saved.col}
27 }
28 evicted, evictedBounds := b.resize(width, height, active, savedPoint)
29 if evict {
30 for i, line := range evicted {
31 s.recordEvicted(line, evictedBounds[i])
32 }
33 }
34 if savedPoint != nil {
35 saved.row, saved.col = savedPoint.row, clamp(savedPoint.col, 0, width-1)
36 }
37 return active.row, clamp(active.col, 0, width-1)
38 }
39
40 if s.alternate != nil {
41 // Both screen states are reflowed independently, but active and saved
42 // cursors for each state are mapped by their single buffer layout pass.
43 s.Row, s.Col = resize(s.buffer, s.Row, s.Col, &s.savedCursor, false)
44 state := s.alternate
45 if state.buffer == nil {
46 state.buffer = bufferFromFrame(state.frame)
47 }
48 state.row, state.col = resize(state.buffer, state.row, state.col, &state.savedCursor, true)
49 state.frame = state.buffer.frame
50 state.scrollTop, state.scrollBottom = 0, height-1
51 } else {
52 s.Row, s.Col = resize(s.buffer, s.Row, s.Col, &s.savedCursor, true)
53 }
54 }
55 s.Frame = s.buffer.frame
56 // A resize can split an in-flight escape sequence from the terminal state it
57 // was meant to mutate; keep the durable child state but discard partial bytes.
58 s.escapeBuf = s.escapeBuf[:0]
59 s.resetScrollRegion()
60 s.fullRedraw()
61}
62
63// cloneFrame produces an independent copy in canonical layout: it copies the
64// source's logical rows (via Row) into a fresh frame whose offsets are already
65// canonical, so a rotated source is normalized in the clone.
66func cloneFrame(frame renderer.Frame) renderer.Frame {
67 out := renderer.NewFrame(frame.Width, frame.Height)
68 for y := range frame.Height {
69 copy(out.Row(y), frame.Row(y))
70 }
71 return out
72}
73
74func clamp(v, lo, hi int) int {
75 if hi < lo {
76 return lo
77 }
78 if v < lo {
79 return lo
80 }
81 if v > hi {
82 return hi
83 }
84 return v
85}